Household dampness and microbial exposure related to allergy and respiratory health in Danish adults

Background: Indoor dampness has consistently been associated with respiratory symptoms and exacerbations. The causal mechanisms may involve increased microbial exposures. However, the evidence regarding the influence of indoor microbial exposures under damp- and non-damp conditions on the risk of asthma and allergy has been inconclusive. Objective: The aim of this study was to investigate the association between dampness and microbial exposure with allergy and respiratory health in Danish adults using a cross-sectional design. Methods: From 1,866 participants of the Health2006 cohort, we selected three non-overlapping groups: 196 at random, 107 with confirmed atopy, and 99 without atopy. Bedroom dust was sampled using electrostatic dust fall collectors and analysed for endotoxin, β-(1,3)-D-glucan, 19 microbial species or groups, and total fungal load. Household moisture-related problems and asthma were self-reported by questionnaire. Atopy was determined by skin-prick-testing and lung function was measured by spirometry. Results: Household moisture damage was positively associated with asthma outcomes, although this was statistically significant only in atopics for self-reported asthma (odds ratio (OR) 3.52; 95%CI 1.01-12.7). Mould odor was positively associated with wheezing (OR 6.05; 95%CI 1.19-30.7) in atopics. Inconsistent associations were found for individual microbial exposures and health outcomes. Inverse associations were observed between microbial diversity and rhinitis in the random sample and both doctor-diagnosed and self-reported asthma in non-atopics. Conclusions: In conclusion, our findings suggest that household moisture damage may increase the risk of asthma and wheeze with mould odor in atopics. In addition, asthma and allergy may be affected by the indoor microbial composition in urban domestic environments. Further studies are needed to identify and understand the causal agents and underlying mechanisms behind the potential effects of environmental microbial exposure on human health.

Determinants of vitamin D status in a general population of Danish adults

BACKGROUND AND AIMS

Danish legislation regarding food fortification has been very restrictive and vitamin D deficiency is thought to be common in Denmark due to inadequate dietary intakes and the fact that in Denmark (latitude 56°N) vitamin D is only synthesized in the skin after exposure to solar radiation during summertime (April-September). The purpose of this study was to evaluate the vitamin D status of a general adult population in Denmark and, in addition, associations between vitamin D status and distinct lifestyle factors were studied.

METHODS

A random sample of 6784 persons from a general population aged 30-60 years participated in a health examination in 1999-2001. Serum samples from all participants were stored and levels of 25-hydroxyvitamin D (25(OH)D) were measured by HPLC in 2009. The method was compared to another HPLC method. Information on dietary intake of vitamin D and other lifestyle factors were obtained by questionnaires. A total of 6146 persons defined as ethnic Danes and with successful measurements of 25(OH)D were included in the analyses.

RESULTS

The overall prevalence of vitamin D deficiency (25(OH)D<25 nmol/l) and insufficiency (25(OH)D<50 nmol/l) were 13.8% and 52.2%, respectively. A marked seasonal fluctuation was seen in serum levels of 25(OH)D - median values of 25(OH)D were lowest in February and highest in August. In multiple logistic regression models (n=5506), low vitamin D status was significantly associated with obesity (BMI≥30), daily smoking and a sedentary lifestyle. However, measurements of 25(OH)D were not associated with the estimated dietary intake of vitamin D. Comparison of two HPLC methods demonstrated considerable differences in accuracy.

DISCUSSION AND CONCLUSIONS

Our results suggest that poor vitamin D status is common among adults in a Northern European country without food fortification with vitamin D. Methodological issues are, however, of great importance when using cut-off values to define poor vitamin D status. In addition, we demonstrated that low serum levels of 25(OH)D were associated with several lifestyle factors.

Scalds in children caused by water from electrical kettles: effect of prevention through information

Electrical kettles (el-kettles) were virtually unknown in Danish households in the mid-1980s, but have since become more common. In 1996, (65 per cent of all Danish households had an el-kettle. As the number of el-kettles have increased, so have the number of scalds caused by water from toppled el-kettles. The first patient with an el-kettle scald was admitted to the Burns Centre at Hvidovre hospital in 1988. From 1988 to 1993 29 patients were admitted with this type of scald; 15 patients in 1993 alone. All the patients were toddlers 5-30 months of age. When el-kettle scalds were compared to scalds caused by other mechanisms in children under 5 years of age, it was found that the former occurred to younger children than the latter (60 per cent of el-kettle scalded children were less than 1 year of age compared to 28 per cent scalded by other means), the scalds were more extensive (median of TBSA were 13 per cent and 6 per cent, respectively), and the scalds were deeper (53 per cent and 24 per cent, respectively, needed skin-grafting). In 1993 campaigns were started to inform parents that the cord of the el-kettle should be short and not hang over the edge of the table. In the following years a considerable decrease in the number of el-kettle scalds was found. When the number of expected el-kettle scalds was estimated from the number of Danish households having an el-kettle, it was found that more than half the expected number of el-kettle scalds were avoided.

[Scalds in children caused by water from toppled electrical kettles. Mechanisms, costs and preventive measures]

Since 1988 a new type of burns in children has been recorded at the Burns Centre at Hvidovre Hospital in Copenhagen, being scalds caused by water from toppled electrical kettles (el-kettles). The children with el-kettle scalds were younger and their injuries more severe than those of children whose scalds had other causes. During the six year period 1988 to 1993, a total of 29 children (0-3 years) have been admitted with scalds caused by el-kettles, 15 children alone in 1993. The costs for treatment have been more than 3 million Danish kroner, 1.8 million DKK alone in 1993. From 1993 preventive measures were taken to reduce the number of this type of scalds. Since the number of households with el-kettles in Denmark is on the increase, an increasing number of toddlers with severe scalds could be anticipated. However, a fall in the number of children admitted was registered in 1994 (four children) and 1995 (six children).

Capsular contracture after breast reconstruction with the tissue expansion technique. A comparison of smooth and textured silicone breast prostheses

Twenty consecutive breast reconstructions were done by the expansion technique. Either textured or smooth expander prostheses were used followed by silicone implants. Histological samples were taken from the capsule when the expander was removed and the implant inserted. The results show no difference in capsular formation between the groups, although the microscopic evaluations from the group with textured prostheses showed considerable numbers of silicone droplets. The patients were generally pleased with the results even though some reconstructed breasts were slightly firm when evaluated postoperatively.

Outbreak of infection in a burns unit due to Pseudomonas aeruginosa originating from contaminated tubing used for irrigation of patients

Five patients with extensive deep burns developed septicaemia due to Pseudomonas aeruginosa serogroup O-7.8 and phage type 21 or 21/188 shortly after they had been admitted to hospital. Four other burned patients became colonized with the same strain. The source of infection was contaminated tap water used for irrigation of the burns, as part of the first-aid treatment which the patients received when entering the hospital. Contamination was restricted to showers and tubing that were permanently connected to the taps, and the outbreak stopped after they had been disinfected. Tubing and showers used for irrigation of burns should be dismantled and heat-disinfected after each patient and not reconnected to the taps until immediately before the next treatment. Taps used for irrigation of burns should be monitored regularly for the presence of P. aeruginosa and other potentially pathogenic bacteria. Routine typing of P. aeruginosa isolates from burned patients is indicated in order to detect and eliminate hidden sources of infection.

[Epidemiological studies on scalded children admitted to the burns unit at the Hvidovre hospital during 1981-1990]

During the ten year period 1981 to 1990, a total of 436 children aged 0-5 years were admitted for scalds at the Burns Unit of Hvidovre Hospital. We did not find any reduction in the number of admissions during this period nor was any change in the patterns of scalds found. Water, tea and coffee were the main causal agents of scalds and the dominant group of scalded children was between the ages one to two years. In 37% of cases, the scalds required grafting and the average stay in hospital was 16 days. The background for this unchanged pattern could be that the prophylactive campaigns have been insufficient.

Sexual function and somatopsychic reactions after local excision of vulvar intra-epithelial neoplasia

Eighteen patients, under the age of 60 years, who have been treated with local excision of the vulva, participated in the study in which sexual function and somatopsychic reactions were evaluated by personal interviews. Furthermore both objective and subjective cosmetic results were registered. After this type of operation, fewer than one-third of the patients had postoperative sexual and somatopsychic problems, whereas more than half of the patients undergoing vulvectomy did report such problems. Fourteen out of 18 patients were satisfied with the cosmetic result and in 12 of the patients no disfiguration was found. This study shows that local excision of intra-epithelial neoplasia of the vulva is far less sexually traumatic than is vulvectomy.

[Scalding among children caused by electric kettles. An increasing problem]

The object of this work is briefly to draw attention to a new type of accident as the cause of scalding in children. The increasing use of electric kettles has resulted in an increased number of scalding accidents caused by these kettles. Within a period of six months, eight children under the age of five years were treated in the Department for Burns, Hvidovre Hospital on account of overturned electric kettles, a form of accident which had not previously been observed in this department. All of the children had pulled the cable. Seven out of eight children were admitted to hospital and transplantations proved necessary in three children.

Histamine-induced paradoxical GH response to TRH/GnRH in men and women: dependence on gonadal steroid hormones

A stimulatory GH response to TRH and GnRH occurs frequently in patients with various pathological conditions, but is absent in normal subjects. We have previously shown that histamine induced a paradoxical GH response to TRH in normal men. Since gonadal steroids influence GH secretion, we investigated whether infusion of histamine might induce a GH response to combined administration of TRH (200 micrograms) and GnRH (100 micrograms) in 6 normal women during the early follicular and luteal phase of the same menstrual cycle and in 7 normal men. Histamine had no effect on basal GH secretion in men or in women during the two phases of the menstrual cycle. However, compared with saline, histamine induced a GH response to TRH/GnRH in men (GH peak: 5.5 +/- 1.0 vs 1.4 +/- 0.3 micrograms/l; p less than 0.01) and in women during the luteal phase (GH peak: 5.2 +/- 1.6 vs 1.5 +/- 0.4 micrograms/l; p less than 0.025), but not during the early follicular phase of the cycle (GH peak: 1.7 +/- 0.5 vs 1.6 +/- 0.3 micrograms/l). In luteal-phase women the GH response to TRH/GnRH correlated with the serum estradiol-17 beta level (GH area/E2: r = 0.98; p less than 0.005) and the serum estrone level (GH area/E1: r = 0.81; p less than 0.05). In men the GH response to TRH/GnRH did not correlate with estrogen or androgen levels. We conclude that high physiological levels of estrogens are pertinent to the activation of a histamine-induced GH response to TRH/GnRH in women, whereas the role of androgens and estrogens for the induction of the response in men seems more complex.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma concentrations of pituitary and peripheral hormones during ranitidine treatment for two years in men with duodenal ulcer

The effects of treatment for 2 years with the histamine H2-receptor antagonist ranitidine (100 or 200 mg b.d. for 6 weeks followed by 100 or 200 mg daily) on plasma concentrations of pituitary and peripheral hormones in ten men with duodenal ulcer have been investigated. Stimulation tests with TRH 200 micrograms i.v. and LHRH 100 micrograms i.v. were performed before, during (6 and 24 months), and at least 6 months after treatment. Basal and TRH-stimulated prolactin (PRL) secretion was marginally reduced after treatment for 6 months, but not for 24 months. The LH response to LHRH was slightly increased after treatment for 6 months and 24 months and after the end of treatment. The plasma concentrations of TSH, FSH, cortisol, androgenic hormones, and thyroid hormones did not change significantly during treatment. No adverse effects were reported during the observation period. The few, minor changes in pituitary hormone concentrations were all within the reference range. They may be related to ranitidine treatment, but are more likely to be due to age-dependent alterations in hormone secretion. It is concluded that long-term treatment with ranitidine does not cause major changes in circulating hormone concentrations.

Temporal responses of cutaneous blood flow and plasma catecholamine concentrations to histamine H1- or H2-receptor stimulation in man

We have studied the effect of histamine and H1- or H2-receptor antagonists on cutaneous blood flow and catecholamine release in man. Histamine was infused alone or in combination with mepyramine, an H1-antagonist or cimetidine, an H2-antagonist for 2 h. Cutaneous blood flow was measured continuously with a laser Doppler flowmeter, and noradrenaline and adrenaline concentrations were determined in blood samples drawn every 15 min. The infusion of histamine caused an immediate and sustained vasodilatation. The Concomitant infusion of mepyramine prevented the immediate vasodilatation, but had no effect on the sustained response. The Concomitant infusion of cimetidine was without effect on the immediate vasodilatation, but abolished the sustained response. Infusion of the antagonists alone had no effect on cutaneous blood flow. Histamine caused a rapid and sustained increase in plasma noradrenaline, while the increase during concomitant H1-receptor blockade was delayed but achieved the level observed during the histamine infusion. The response to histamine during H2-receptor blockade was small and transient. The rise in plasma adrenaline was not significant. These findings suggest that histamine causes an immediate cutaneous vasodilatation through H1-receptors and a more sustained response through H2-receptors. The vasodilatation is accompanied by an increase in plasma catecholamine concentrations. Despite the continuous infusion of histamine, blood flow decreased during the last hour of histamine infusion, while the plasma noradrenaline concentration was still elevated.

The relationship of secretin and somatostatin levels in plasma to glucose administration and acid secretion during fasting

The concentrations of secretin and somatostatin in plasma were measured in 10 healthy subjects during a 4-day fast. The fast induced increased concentrations of plasma secretin (from 1.2 +/- 0.5 to 9.5 +/- 2.3 pmol/l) and somatostatin (from 5.2 +/- 1.5 to 8.6 +/- 1.7 pmol/l). Gastric aspiration for 1 h suppressed the high concentrations of secretin by 46% and somatostatin by 27%. The intravenous infusion of glucose reduced the plasma secretin even further by 88%; the decrease in somatostatin was not statistically significant. The study shows that gastric aspiration and/or glucose infusion suppressed the high plasma concentration of secretin and that factors other than hyperchlorhydria must be involved in the hypersecretinemia seen during starvation. The elevated plasma somatostatin concentration seen during starvation may be a consequence of increased acid secretion.

Histaminergic regulation of prolactin secretion: dose-response relationship and possible involvement of the dopaminergic system

Histamine (HA) may participate in the neuroendocrine regulation of pituitary hormone secretion. HA diphosphate infused iv for 120 min in a dose of 9, 18, 30, or 50 micrograms/kg BW.h to six normal men stimulated PRL secretion in a dose-dependent manner [absolute change in PRL (delta PRL) area = 52 X (HA dose) - 618; r = 0.9926; P less than 0.001]. The stimulatory effect of HA was modest and occurred during the second hour of infusion. This increase might be due to the opposing effects of HA on PRL secretion, specifically stimulation via H1 receptors and inhibition via H2 receptors. The PRL-releasing effect of 11 micrograms HA dihydrochloride was not significantly different from that of an equimolar dose of HA diphosphate (18 micrograms). Selective activation of H2 receptors by combined infusion of HA and the H1 receptor antagonist mepyramine inhibited PRL secretion compared to the effect of NaCl [delta PRL, -55 +/- 23 (+/- SEM) vs. -20 +/- 17 microIU/ml; P less than 0.01; n = 6). Mepyramine infused alone had no effect (delta PRL, -43 +/- 22 vs. -33 +/- 30 microIU/ml; n = 6). Selective activation of H1 receptors by combined infusion of HA and the H2 receptor antagonist cimetidine stimulated PRL secretion (delta PRL, 193 +/- 40 vs. -20 +/- 17 microIU/ml; P less than 0.0005; n = 6). When infused alone, cimetidine had only a modest and late stimulatory effect (delta PRL, 35 +/- 22 vs. -27 +/- 15; P less than 0.025; n = 6). Dopamine receptor blockade with metoclopramide (MET; 10 mg, three times daily, orally) did not prevent the PRL-inhibiting action of H2 receptor activation (delta PRL, -374 +/- 70 vs. -184 +/- 107 microIU/ml; P less than 0.01; n = 6), whereas the PRL-stimulating effect of H1 receptor activation was abolished by the drug (delta PRL, -249 +/- 64 vs. -174 +/- 54 microIU/ml; n = 6). The latter effect of MET was not due to exhaustion of the lactotrophs, since 200 micrograms TRH stimulated PRL secretion during MET treatment. These findings suggest that the H1 receptor-mediated PRL-stimulating effect of HA occurs through an inhibition of the dopaminergic system, whereas the H2 receptor-mediated PRL-inhibiting effect of HA does not involve dopaminergic neurons.

Effect of histamine on basal and TRH/LH-RH-stimulated PRL and LH secretion during different phases of the menstrual cycle in normal women

The neurotransmitter histamine (HA) may participate in the regulation of some pituitary hormones. We, therefore, investigated the effect of HA (50 micrograms/kg body weight/h, infusion 0-240 min) on basal and thyrotropin-releasing hormone (TRH) and luteinizing hormone releasing hormone (LH-RH) stimulated prolactin (PRL) and LH secretion in 5 normal women during the early follicular and the luteal phases of the same menstrual cycle. HA had no effect on the basal secretion of the two hormones. However, the PRL response to 200 micrograms TRH during the HA infusion was significantly increased compared to the response to a saline control infusion during the early follicular phase (peak responses were 1,902 +/- 398 vs. 1,228 +/- 230 microIU/ml, p less than 0.025) and during the luteal phase (peak responses were 2,261 +/- 335 vs. 1,647 +/- 245 microIU/ml, p less than 0.05). HA potentiated the LH response to 100 micrograms LH-RH during the early follicular phase (peak responses were 37.1 +/- 4.9 vs. 26.9 +/- 4.5 mIU/ml, p less than 0.05) and during the luteal phase (peak responses were 79.3 +/- 22.5 vs. 50.7 +/- 11.4 mIU/ml, p less than 0.025). We, therefore, found HA to have a potentiating effect on TRH/LH-RH-stimulated PRL and LH secretion in women. The results are similar to our previous findings in men, although the potentiating effects of HA were higher in women.

Histamine-induced paradoxical growth hormone response to thyrotropin-releasing hormone in normal men

GH responses to TRH occur in patients with certain diseases, such as acromegaly, severe liver disease, uremia, and mental disorders, and presumably reflect disruption of normal hypothalamic control of GH secretion. Since histamine (HA) inhibits hypothalamic stimulation of GH secretion, we investigated the combined effect of HA receptor activation and TRH administration on GH secretion in normal men. Eight men were given 4-h infusions of the following: saline, HA, HA plus mepyramine (Me; and H1-antagonist), HA plus cimetidine (C; an H2-antagonist), and C alone. TRH (200 micrograms) was injected iv 2 h after the start of each infusion. HA alone or in combination with either antagonist had no effect on basal or TRH-stimulated TSH secretion and no effect on basal GH secretion. However, when TRH was injected during H1 stimulation by HA plus C, GH secretion increased significantly [from 0.7 +/- 0.1 to 7.1 +/- 1.8 (+/- SEM) ng/ml; P less than 0.01] in seven of eight subjects. This GH response was reproducible and did not occur when saline was administered instead of TRH. A smaller and delayed GH response to TRH occurred during infusions of HA alone (from 0.8 +/- 0.1 to 4.9 +/- 1.0 ng/ml; P less than 0.05). No effect of TRH on GH secretion occurred during the infusion of saline (1.2 +/- 0.3 ng/ml), HA plus Me (0.9 +/- 0.1 ng/ml), or C (2.2 +/- 1.0 ng/ml). There was a significant increase in GH secretion after cessation of the infusions of HA (from 3.4 +/- 1.1 to 7.5 +/- 2.2 ng/ml) and HA plus Me (from 0.8 +/- 0.1 to 5.1 +/- 1.8 ng/ml). This rebound in GH secretion might indicate an inhibitory effect of TRH during H2-receptor stimulation. This concept is supported by the significantly smaller GH response to TRH during HA infusion than during HA plus C infusion (P less than 0.01). The study indicates that H1-receptor stimulation induces a stimulatory effect of TRH on GH secretion in normal men and that H2-receptor stimulation possibly induces an inhibitory effect of TRH on GH secretion.

Histamine regulation of prolactin secretion through H1- and H2-receptors

Histamine (HA) regulates PRL secretion in the rat by a stimulatory effect through H1-receptors and an inhibitory effect through H2-receptors. The effect of HA antagonists on basal and TRH-stimulated PRL secretion was investigated in five normal men. During saline infusion, serum PRL declined, as seen normally after sleep. HA infusion caused a significantly higher PRL secretion than that observed during the saline infusion [maximum change in PRL (delta PRL), 28 +/- 20 vs. -71 +/- 30 microIU/ml; P less than 0.05]. This effect of HA on PRL secretion was inhibited during the combined infusion of HA and the H1-antagonist mepyramine (delta PRL, 28 +/- 20 vs. -77 +/- 13 microIU/ml; P less than 0.025). The PRL-stimulating effect of HA was strongly enhanced during the combined infusion of HA and the H2-antagonist cimetidine (delta PRL, -28 +/- 20 vs. 132 +/- 57 microIU/ml; P less than 0.0125). This effect of HA and cimetidine on PRL secretion was higher than the effect of cimetidine alone (delta PRL, 132 +/- 57 vs. 17 +/- 22 microIU/ml; P less than 0.05). This shows that the H2-antagonist is not the only stimulator of PRL secretion. During the different infusions, serum PRL concentrations were in the following rank order: mepyramine less than saline less than HA less than cimetidine less than HA plus cimetidine. The same rank order was found for the PRL responses to TRH during the different infusions. These data indicate a HA stimulatory effect through H1-receptors and an inhibitory effect through H2-receptors on PRL secretion in human males.

Comparison between dose-responses of prolactin, thyroid stimulating hormone and growth hormone to two different histamine H-2 receptor antagonists in normal men

The effects of the histamine H2-receptor antagonists, ranitidine and cimetidine on prolactin (PRL), thyroid stimulating hormone (TSH), and growth hormone (GH) were studied in six normal males. Intravenous bolus injections of saline and of 50, 100, and 200 mg ranitidine and 300 mg cimetidine were tested. Ranitidine (100 and 200 mg) and cimetidine (300 mg) caused a significant increase in PRL secretion, whereas saline and ranitidine (50 mg) did not. TSH and GH secretion were unaffected by all doses. A dose-response relationship between ranitidine and PRL was established, and a dose of 65 mg ranitidine was found to be the minimal effective PRL-releasing dose. Plasma ranitidine concentration was measured by specific RIA. The results indicate an effect of H2-receptor antagonists on physiological functions in the control of PRL secretion. Histamine, therefore, may play a role in the regulation of PRL secretion.