Magnesium in drinking water in relation to morbidity and mortality from acute myocardial infarction

We investigated the importance of magnesium and calcium in drinking water in relation to morbidity and mortality from acute myocardial infarction. Cases were men and women 50-74 years of age living in 18 Swedish municipalities who had suffered an acute myocardial infarction some time between October 1, 1994, and June 30, 1996. Controls were randomly selected from the same study base. We interviewed the surviving cases (N = 823) and controls (N = 853), focusing on risk factors for acute myocardial infarction. We collected individual data on drinking water levels of magnesium and calcium. We classified subjects by quartile of water magnesium or calcium levels. The total number of cases was similar in the four quartiles. The risk of death was 7.6% (95% confidence interval = 2.1-13.1) lower in the quartile with high magnesium levels (> or = 8.3 mg/liter). The odds ratio for death from acute myocardial infarction in relation to water magnesium was 0.64 (95% confidence interval = 0.42-0.97) for the highest quartile relative to the three lower ones. Multivariate analyses showed that other risk factors were not important confounders. For calcium, this study was inconclusive. The data suggest that magnesium in drinking water is associated with lower mortality from acute myocardial infarction, but not with the total incidence.

Influence of vegetables on the expression of GSTP1 in humans--a pilot intervention study (Sweden)

BACKGROUND

There are indications that a diet rich in vegetables and/or fruit has a protective effect against several types of diseases, including cancer. Data from experimental and epidemiological studies suggest that antioxidant constituents may provide protection against environmental carcinogens.

AIMS

This study investigated the effect of additional vegetables in the diet on the expression of the endogenous antioxidant enzyme GSTP1 in human lymphocytes.

METHODS

Six subjects were given an addition of mixed vegetables to their normal diet for a period of three weeks. The expression of GSTP1 protein and mRNA in lymphocytes was measured by Western blot and RT competitive PCR.

RESULTS

After the intervention all six subjects had lower levels of GSTP1 mRNA, and five of the six subjects had lower GSTP1 protein levels. This suggests that increased vegetable intake decreases GSTP1 expression, possibly through the supply of additional antioxidants.

Preliminary report on the results of the second phase of a round- robin endotoxin assay study using cotton dust

In an on-going endotoxin assay study, a two-part interlaboratory endotoxin assay study has been completed. The purpose of the study was to compare the variation in assay results between different laboratories, and, if the variation was high, to see if a common protocol would reduce the variation. In both parts of the study, membrane filters laden with the same approximate amount and type of cotton dust were sent for analysis to laboratories that "routinely" perform endotoxin analyses. First, each of these laboratories performed the analysis using the methodology common to its laboratory. In the second part of the study, membrane filters with cotton dust were again sent to the same laboratories where the analyses were performed as before but with a common extraction protocol. The preliminary results from the first phase of the study have been collected and showed that intra-laboratory variations were small, but large and significant interlaboratory variation was observed. The results were reported elsewhere. The preliminary results from the second part of the study consisting of the data currently collected are presented here. Again, intra-laboratory variations were small, but, also again, large and significant inter-laboratory variation was observed. However, in this part of the study, the range between the highest and lowest average results was narrower than in the first part of the study. Influence of the assay kit type was examined. The variation within assay kit type was small but significant differences in results were observed between assay kit types. The findings suggest that endotoxin concentration in samples can be ranked within laboratories, but not necessarily between laboratories. However, some of the variation between laboratories has been reduced by a common extraction protocol which suggests the possibility of further standardization that may lead to better comparability between laboratories.

Labeling of the glucocorticoid receptor and Na,K-ATPase in a rat otitis media model

HYPOTHESIS

Glucocorticoid hormones exert an influence on the inflammatory response of the middle ear during acute otitis media. Rats with experimentally induced purulent otitis media were given either glucocorticoid hormones in excess or a glucocorticoid hormone blocker that deprived the animals of the hormone.

BACKGROUND

Acute otitis media is a common inflammatory disease among children. Streptococcus pneumoniae is the most usual causative agent. The standard treatment today is phenoxymethylpenicillin. The role of glucocorticoid hormones in inflammatory reactions in the middle ear has been widely debated.

METHODS

In an otitis media model, a suspension of pneumococci was inoculated into the bulla of the rat, after the animals were pretreated with either a dose of corticosteroid hormones or the glucocorticoid receptor blocking agent RU 486. Rats with induction of otitis media only, but no pretreatment, were used as control subjects, as were the left control-operated ears of all rats. The inflammatory response in the inner ear and in the middle ear was evaluated. The presence of glucocorticoid receptors and the enzyme Na,K-ATPase was investigated with immunohistochemistry.

RESULTS

The inflammatory response in the animals with untreated otitis media and in the group with otitis media in rats pretreated with the receptor blocker was much more extensive than in the group of animals pretreated with corticosteroids. In the corticosteroid-treated group, the tympanic membrane and the mucous membrane of the middle ear were less edematous, but the middle ear cavity contained more pus. Only a few lymphocytes were found in the inner ears of these rats. When the inner ear was labeled with antibodies against glucocorticoid receptors, there seemed to be no difference between the labeling patterns in the three groups. This was also the case for antibody labeling against Na,K-ATPase.

CONCLUSION

The present results indicate that the reaction in the middle ear mucous membrane is more pronounced in rats that had been pretreated with the hormone receptor blocking drug. An increase of corticosteroid hormone levels during the inflammatory process seem to diminish the reaction in the tympanic membrane and the middle ear mucosa. Neither the hormone receptor blocking drug nor the steroid hormones change the content of glucocorticoid receptors and Na,K-ATPase in the inner ear in the otitis media rat model.

An airbone mold-derived product, beta-1,3-D-glucan, potentiates airway allergic responses

Repeated inhalation of allergen leads to the down-regulation of allergen-specific IgE responses in non-atopic individuals as well as in mice. This phenomenon is named inhalation-induced IgE tolerance. In contrast, inhaled allergen causes significant IgE and allergic responses in atopic persons. The mechanisms involved in this differential regulation of airway allergen-specific immune responses remain unclear. Besides the allergen exposure of genetically susceptible individuals, environmental contamination is considered to play a role as an initiating factor for airway allergic responses. Using a murine model, we demonstrate here that airborne beta-1, 3-D-glucan, which exists frequently in our environment, particularly in highly humid areas, can abrogate inhalation-induced IgE isotype-specific down-regulation and promote airway eosinophil infiltration to inhaled antigen.

Introduction and summary: workshop on children's health and indoor mold exposure

To evaluate the health consequences for children of indoor exposure to molds, an international workshop was organized with 15 scientists from eight countries. The participants agreed that exposure to molds may constitute a health threat to children resulting in respiratory symptoms in both the upper and lower airways, an increased incidence of infections, and skin symptoms. Allergy, either to molds or to other indoor agents, also presents a health risk. At very high exposure levels to specific molds, nose bleeding, hemoptysis, and pulmonary hemorrhage have been documented. Pediatricians and allergists need to obtain information about mold and dampness in the home environment when examining children with chronic respiratory symptoms, recurrent infections, or persistent fatigue and headache. Measurement techniques are available to determine exposure. Most important, the source of dampness must be eliminated and the indoor environment must be thoroughly cleaned of molds.

Indoor air-related effects and airborne (1 --> 3)-beta-D-glucan

In studies on the relation between indoor mold exposure and symptoms/disease, the exposure should be described in terms of biomass and not viability. This paper reviews field studies in which (1--> 3)-ss-d-glucan was measured as a marker of biomass and was related to the extent of symptoms and measures of inflammation among exposed subjects. Increased levels of (1-->3)-ss-d-glucan were related to an increased extent of symptoms and markers of inflammation. The data suggest that (1-->3)-ss-d-glucan can be used as a risk marker in indoor environments.

Indoor air-related effects and airborne (1 --> 3)-beta-D-glucan

In studies on the relation between indoor mold exposure and symptoms/disease, the exposure should be described in terms of biomass and not viability. This paper reviews field studies in which (1--> 3)-ss-d-glucan was measured as a marker of biomass and was related to the extent of symptoms and measures of inflammation among exposed subjects. Increased levels of (1-->3)-ss-d-glucan were related to an increased extent of symptoms and markers of inflammation. The data suggest that (1-->3)-ss-d-glucan can be used as a risk marker in indoor environments.

Indoor mold and Children's health

Reactive airways disease in children is increasing in many countries around the world. The clinical diagnosis of asthma or reactive airways disease includes a variable airflow and an increased sensitivity in the airways. This condition can develop after an augmented reaction to a specific agent (allergen) and may cause a life-threatening situation within a very short period of exposure. It can also develop after a long-term exposure to irritating agents that cause an inflammation in the airways in the absence of an allergen. (paragraph) Several environmental agents have been shown to be associated with the increased incidence of childhood asthma. They include allergens, cat dander, outdoor as well as indoor air pollution, cooking fumes, and infections. There is, however, increasing evidence that mold growth indoors in damp buildings is an important risk factor. About 30 investigations from various countries around the world have demonstrated a close relationship between living in damp homes or homes with mold growth, and the extent of adverse respiratory symptoms in children. Some studies show a relation between dampness/mold and objective measures of lung function. Apart from airways symptoms, some studies demonstrate the presence of general symptoms that include fatigue and headache and symptoms from the central nervous system. At excessive exposures, an increased risk for hemorraghic pneumonia and death among infants has been reported. (paragraph) The described effects may have important consequences for children in the early years of life. A child's immune system is developing from birth to adolescence and requires a natural, physiologic stimulation with antigens as well as inflammatory agents. Any disturbances of this normal maturing process will increase the risk for abnormal reactions to inhaled antigens and inflammagenic agents in the environment. (paragraph) The knowledge about health risks due to mold exposure is not widespread and health authorities in some countries may not be aware of the serious reactions mold exposure can provoke in some children. Individual physicians may have difficulty handling the patients because of the lack of recognition of the relationship between the often complex symptoms and the indoor environment (paragraph) The workshop was organized to develop a basis for risk assessment and formulation of recommendations, particularly for diagnostic purposes and prevention, and to formulate priorities for future research. The participants were all active researchers with current experience in child health, molds, and respiratory disease. They were engaged in free and intensive discussions on a scientific basis throughout the duration of the 3-day workshop (paragraph) This monograph contains peer-reviewed papers based on individual presentations at the workshop as well as the workshop conclusions. They are offered to the public health community, administrators, research agencies, physicians, particularly pediatricians, nurses and health workers as information and encouragement to engage themselves in this health problem of importance for the next generation in our population. (paragraph) Acknowledgments: The workshop received financial support from the U.S. Environmental Protection Agency, the National Center for Environmental Assessment at the U.S. EPA, the Vardal Foundation (Sweden), Astra Corp (Sweden), the Committee on Organic Dusts, International Commission on Occupational Health. The printing of this document was made possible by a grant from the Center for Indoor Air Research (U.S.). Yvonne Peterson, research secretary, provided excellent and invaluable assistance in the organization and publication efforts.

Health effects among workers in sewage treatment plants

OBJECTIVES

To further assess the presence of fatigue, symptoms of diarrhoea, and inflammation of airways among people working in sewage plants and the relation to airborne bacterial endotoxin at the workplace.

METHODS

34 Employees in sewage treatment plants and 35 controls were selected. They underwent a questionnaire investigation, and spirometry and airway responsiveness were measured. Measurements were made of airborne endotoxin at different workplaces.

RESULTS

The amount of airborne endotoxin varied between 3.8 and 32,170 ng/m3. Workers reported significantly higher nose irritation, tiredness, and diarrhoea. Airway responsiveness was increased among sewage workers, but no differences between the groups were found for spirometry.

CONCLUSIONS

The results confirm previous studies on the presence of airways and intestinal inflammation among workers in sewage treatment plants. The most likely causative agent is endotoxin, and at 14 of 23 workplaces, concentrations exceeded recommended guidelines.

Airways inflammation among workers in a paper industry

Exposure to organic dusts may cause airways inflammation in a large proportion of exposed persons. Most studies have relied on questionnaires and spirometry for diagnosis. To assess the possibility of determining the presence of inflammation using clinical diagnostic procedures, a study was undertaken among workers in a paper industry. Participants were 83 workers and 44 controls. Airborne endotoxin and (1-->3)-beta-D-glucan levels at the worksites were determined. The effects of this exposure were evaluated using a questionnaire, spirometry and measurements of airway responsiveness (methacholine) and levels of eosinophil cationic protein (ECP), myeloperoxidase (MPO), and C-reactive protein (CRP) in serum. The workers had a decreased baseline forced expiratory volume in one second (FEV1) and an increased airway responsiveness compared with controls. The concentrations of ECP and MPO were elevated compared with controls. There was a relation between exposure to endotoxin and (1-->3)-beta-D-glucan and airway responsiveness as well as ECP levels, when controlling for age, sex, smoking habits, atopy and asthma. The results suggest an increased prevalence of subjective respiratory symptoms, and an increased airway responsiveness among exposed workers. There was also a relationship between the serum concentration of eosinophil cationic protein and airway responsiveness. Taken together, the results suggest the presence of airways inflammation in the workers.

(1-->3)-beta-D-glucan may contribute to pollen sensitivity

The amount of (1-->3)-beta-D-glucan in pollen from different plants was evaluated using the Limulus assay with a specific lysate. The amount ranged from 79 to 1800 ng/10(6) pollen. A calculation of the inhaled dose suggests that the amount of (1-->3)-beta-D-glucan present during periods with a high pollen content in the air exceeds levels that cause airways inflammation.

Magnesium and calcium in drinking water and death from acute myocardial infarction in women

A relation between water hardness and cardiovascular death has been shown in previous studies. In this case-control study, we investigated the levels of magnesium and calcium in drinking water and death from acute myocardial infarction among women. The study population encompassed 16 municipalities in southern Sweden. Cases were women who had died from acute myocardial infarction between the ages of 50 and 69 years during 1982-1993 (N = 378), and controls were women who had died from cancer (N = 1,368). We obtained magnesium and calcium concentrations of the individual water sources. We divided the subjects into quartiles and found that odds ratios (ORs) were lower at higher levels of both magnesium and calcium. For the quartile with the highest magnesium levels (> or =9.9 mg/liter), the OR adjusted for age and calcium was 0.70 (95% confidence interval = 0.50-0.99). For calcium, the adjusted OR for the quartile with the highest level (> or =70 mg/liter) was 0.66 (95% confidence interval = 0.47-0.94). The results suggest that magnesium and calcium in drinking water are important protective factors for death from acute myocardial infarction among women.

Inflammatory response after inhalation of bacterial endotoxin assessed by the induced sputum technique

BACKGROUND

Organic dusts may cause inflammation in the airways. This study was performed to assess the usefulness of the induced sputum technique for evaluating the presence of airways inflammation using inhaled endotoxin (lipopolysaccharide) as the inducer of inflammation.

METHODS

To characterise the inflammatory response after inhalation of endotoxin, 21 healthy subjects inhaled 40 micrograms lipopolysaccharide and were examined before and 24 hours after exposure. Examinations consisted of a questionnaire for symptoms, spirometric testing, blood sampling, and collection of induced sputum using hypertonic saline. Eleven of the subjects inhaled hypertonic saline without endotoxin exposure as controls. Cell counts, eosinophilic cationic protein (ECP), and myeloperoxidase (MPO) were determined in blood and sputum.

RESULTS

A significantly higher proportion of subjects reported respiratory and general symptoms after endotoxin inhalation. MPO and the number of neutrophils in the blood were higher and spirometric values were decreased after the lipopolysaccharide challenge. In the sputum MPO, ECP, and the numbers of neutrophils and lymphocytes were higher after the lipopolysaccharide challenge. No significant differences were found after the inhalation of hypertonic saline compared with before, except for a significantly lower number of lymphocytes in the sputum.

CONCLUSIONS

The results support previous studies that inhaled endotoxin causes an inflammation at the exposure site itself, as well as general effects. Sampling of sputum seems to be a useful tool for assessing the presence of airways inflammation, and the inhalation of hypertonic saline used to induce sputum did not significantly interfere with the results found after inhalation of lipopolysaccharide.

Airways inflammation, atopy, and (1--> 3)-beta-D-glucan exposures in two schools

This study investigated two schools, one of which had previous mold problems. Pupils aged 6 to 13 yr were investigated using a questionnaire on symptoms and a skin prick test. The amount of airborne (1--> 3)-beta-D-glucan was measured in the classrooms. The levels were significantly higher in the problem school than in the control school (15.3 versus 2.9 ng/m3). The extent of respiratory as well as general symptoms was higher among the pupils in the problem school. Among the atopics, the extent of symptoms of dry cough, cough with phlegm, and hoarseness was similar to the nonatopics in the control school, but significantly higher in the problem school. The results suggest that (1--> 3)-beta-D-glucan, either by itself or as an indicator of molds, is a risk indicator of airways inflammation.

Magnesium in drinking water and body magnesium status measured using an oral loading test

Epidemiological studies have shown an inverse relationship between magnesium in drinking water and death from ischaemic heart disease. The question is whether magnesium in drinking water can be critical for the body magnesium status. The aim of this study was to investigate, using an oral loading test, whether a change in body magnesium status could be found among people who change from drinking water with a low magnesium concentration to water with higher concentrations. The subjects participating in the study were 9 men and 3 women 65-70 years old, living in the city of Göteborg, Sweden, where the magnesium concentration in the tap water is low (1.6 mg/l). Drinking water was prepared with 200 mg MgCl2 x 6H2O added per litre to a level of 25 mg/l, and was distributed to the subjects twice a week for 6 weeks. Excretion of magnesium, potassium and creatinine, basal and after oral magnesium loading (tablets containing 575 mg), was measured in 24 h urine before and after the supplementation period. Calculations were made for the total excretion (mmol/24 h), and in relation to creatinine. The subjects' intake of magnesium via food and water was estimated using a questionnaire. There was a difference between the post load excretion of magnesium, expressed as the magnesium/creatinine ratio, before and after the supplementation period. The mean percentage change was a 14.6% (p=0.047) increase. No changes were found for potassium. In summary, the results indicate that magnesium in drinking water can affect body magnesium status.

Airways inflammation and glucan in a rowhouse area

A study was undertaken in a number of rowhouses, some of which had had previous problems related to dampness and water leakage. The aim of the study was to assess the relation between exposure to airborne (1--> 3)-beta-D-glucan, a cell-wall substance in molds, and airways inflammation. The study involved 75 houses with indoor (1--> 3)-beta-D-glucan levels ranging from 0 to 19 ng/m3. Of 170 invited tenants, 129 (76%) participated in the study. A questionnaire relating to symptoms was used, and measurements were made of lung function and airway responsiveness. Myeloperoxidase (MPO), eosinophilic cationic protein (ECP), and C-reactive protein (CRP) were measured in serum. Atopy was determined with the Phadiatop test. The major findings were a relation between exposure to (1--> 3)- beta-D-glucan and an increased prevalence of atopy, a slightly increased amount of MPO, and a decrease in FEV1 over the number of years lived in the house. The results suggests the hypothesis that exposure to (1--> 3)-beta-D-glucan or molds indoors could be associated with signs of a non-specific inflammation.

Airways inflammation and glucan exposure among household waste collectors

A field study was made on 17 workers collecting unsorted household waste, eight workers collecting organic/nonorganic separated waste, and 24 controls. Measurements of airborne endotoxin and (1-->3)-beta-D-glucan were made in their working environments. Examinations consisted of a questionnaire for symptoms, spirometry, airway responsiveness, and blood and sputum sampling for determination of cell counts, eosinophilic cationic protein (ECP), and myeoloperoxidase (MPO). A higher proportion of waste collectors reported diarrhea, congested nose, and unusual tiredness as compared to controls. The number of blood lymphocytes was higher among waste collectors and were dose-related to the amount of airborne (1-->3)-beta-D-glucan at the workplaces. The amount of ECP and the number of macrophages were lower in sputum among waste collectors as compared with controls. The results suggest that certain dusts from household waste may cause airway inflammation as well as general symptoms, and the effects were associated with higher (1-->3)-beta-D-glucan levels.

[Did glucan in indoor environment cause respiratory tract inflammation?]

Three children living in a house affected by mould manifested severe airways and general symptoms indicative of non-specific airways inflammation. Measurement of airborne (1-->3)-beta-D-glucan, a cell wall constituent in moulds, yielded values ranging from 22 to 115 ng/m3, as compared to normal values of some few ng/m3. On moving to relatives, all three children improved and could terminate medication after 2-3 weeks. The findings are consistent with previous reports of symptoms induced by exposure to mould, and suggest that quantification of viable organisms may not adequately reflect the exposure risk.

(1-->3)-beta-D-glucan and endotoxin modulate immune response to inhaled allergen

Exposure to dust may involve co-exposure to agents which are allergens, together with those which are pro-inflammatory. To study the effects of such a co-exposure, the humoral and inflammatory responses were studied in guinea pigs inhaling the T-cell-dependent antigen ovalbumin (OVA) and the inflammatory agents (1 --> 3)-beta-D-glucan and lipopolysaccharide (LPS). The effects were evaluated as inflammatory cells in the lung and serum antibodies to OVA. LPS caused a stimulation of the OVA-induced antibody production which was abolished by simultaneous exposure to (1 --> 3)-beta-D-glucan. An increase of eosinophils after OVA exposure was decreased by co-exposure to (1 --> 3)-beta-D-glucan. The results demonstrate a complex interaction between adaptive and innate immune mechanisms in the lung, determined by exposure to common contaminants in airborne dust.