Influence of herring (Clupea harengus) and herring fractions on metabolic status in rats fed a high energy diet

AIM

Few dietary studies have looked beyond fish oil to explain the beneficial metabolic effects of a fish-containing diet. Our aim was to study whether addition of herring, or sub-fractions of herring, could counteract negative metabolic effects known to be induced by a high-fat, high-sugar diet.

METHODS

Rats were given six different diets: standard pellets; high energy diet with chicken mince (HiE control); high energy diet with herring mince (HiE herring); and high energy diet with chicken mince and either herring oil (HiE herring oil), herring press juice, PJ (HiE PJ) or herring low molecular weight PJ (HiE LMW-PJ). Factors associated with the metabolic syndrome were measured.

RESULTS

There were no differences in energy intake or body weight between the groups, but animals fed high energy diets had a higher body fat content compared with the pellet group, although not statistically significant in all groups. Mesenteric adipocyte size was smaller in the HiE herring oil group compared with the HiE control. Glucose clamp studies showed that, compared with the pellet group, the HiE control and HiE herring diets, but not the HiE herring oil diet, induced insulin resistance. Addition of herring or herring oil to the high energy diet decreased total cholesterol levels, triacylglycerols and the atherogenic index compared with the HiE control group.

CONCLUSIONS

The results suggest that addition of herring or herring oil counteracts negative effects on blood lipids induced by a high energy diet. The lipid component of herring thus seems to be responsible for these beneficial effects.

The development of emotional distress in 158 patients with recently diagnosed rheumatoid arthritis: a prospective 5-year follow-up study

OBJECTIVES

To describe the development of emotional distress among patients with newly diagnosed rheumatoid arthritis (RA), and to explore for early predictors of elevated distress over time.

METHODS

The study group consisted of 158 early RA patients (64% females) with mean age of 51.4 (SD = 12.7) years at disease onset. The patients were evaluated once a year for up to at least 4 years after baseline. Emotional distress was measured with the Symptom Checklist (SCL-90), disability with the Health Assessment Questionnaire (HAQ), pain with a visual analogue scale (VAS), and disease activity by an active joint count and erythrocyte sedimentation rate (ESR). Questions concerning social support were also included.

RESULTS

Emotional distress decreased slowly for a majority of the patients. The change reached statistical significance in the third year from study start. A minority (12%) showed continuously high and increasing levels of distress. Measures of disease activity were poor predictors of distress. The best predictor of distress over time was distress at baseline. Other predictors were gender, age, civil status, and social support.

CONCLUSIONS

Emotional distress tended to decrease for most patients in this cohort, but a minority showed continuously high levels. Patients at higher risk of developing emotional distress over time had higher levels of distress at baseline, were younger, more often female, and cohabiting, and experienced less social support.

Exhaled nitric oxide and bronchial responsiveness in healthy subjects exposed to organic dust

Inhalation of organic dust from swine houses causes an intense inflammatory reaction in the respiratory tract, and increased bronchial responsiveness to methacholine in healthy subjects. The aims of the present study were to investigate whether exhaled nitric oxide (NO) is a marker of the inflammation caused by exposure to organic dust (swine dust), whether there is a relationship between an increase in exhaled NO and bronchial responsiveness, and also whether wearing a half-mask influences the airway reaction (assessed by exhaled NO) and the increased bronchial responsiveness. Thirty-three healthy nonatopic, nonsmoking subjects were exposed during 3 h of light work in a swine confinement building. Eleven of the subjects were wearing a half-mask and 22 were unprotected. Lung function, bronchial responsiveness and exhaled NO were measured before and after exposure. The provocative concentration causing a 20% fall in forced expiratory volume in one second fell by 2.7 (2.1-4.1) (median (25th-75th percentiles)) doubling concentration steps in subjects without a half-mask and by 1.5 (0.9-2.9) doubling concentration steps in subject wearing a mask. Exhaled NO increased from 7.5 (5.7-13.7) parts per billion (ppb) before to 13.4 (10.5-17.5) ppb after exposure in the unprotected group and was unaltered (8.3 (6.1-14.1) to 8.6 (6.6-14.6) ppb) in the group wearing a half-mask. There was no correlation between NO increase and provocative dose causing a 20% fall in the forced expiratory volume in one second decrease. In conclusion, bronchial responsiveness and exhaled nitric oxide increased after exposure to a swine confinement facility. Half-mask abolished the increase in exhaled nitric oxide levels, but influenced the increase in bronchial responsiveness to a minor extent. These results indicate that these two outcome measures reflect different aspects of airway inflammation induced by exposure to a farming environment.

Sodium cromoglycate attenuates pulmonary inflammation without influencing bronchial responsiveness in healthy subjects exposed to organic dust

BACKGROUND

Inhalation of organic dust from a pig house induces airway inflammation and increases bronchial responsiveness to methacholine in healthy subjects.

OBJECTIVE

To study whether sodium cromoglycate influences the airway inflammatory reaction and the increase in airway responsiveness induced by inhalation of organic dust.

METHODS

Bronchoalveolar and nasal lavages, and bronchial methacholine challanges were performed and blood samples were drawn in 32 healthy subjects before and after exposure to dust in a pig farm. Sodium cromoglycate was inhaled (20 mg, twice a day) and administered intranasally (5.2 mg, twice a day) by 16 and a corresponding placebo was given to the other 16 healthy controls for two weeks prior to exposure.

RESULTS

Exposure induced a significant increase in inflammatory cells and soluble components (pro-inflammatory cytokines, inflammatory mediators) in bronchoalveolar and nasal lavage fluid in both groups. The increase in neutrophils, interleukin (IL)-6 and tumour necrosis factor (TNF)-alpha as well as myeloperoxidase and soluble intracellular adhesion molecule (ICAM)-1 in bronchoalveolar lavage (BAL) fluid was significantly reduced by treatment with sodium cromoglycate. Although sodium cromoglycate inhalation largely influenced a variety of inflammatory indices in bronchoalveolar lavage fluid it had no effect on the increase in bronchial responsiveness to methacholine.

CONCLUSION

Sodium cromoglycate alters the airway inflammatory response to inhaled organic dust without influencing the dust-induced increase in bronchial responsiveness to methacholine.

Maternal endotoxemia results in obesity and insulin resistance in adult male offspring

Events in utero appear to be important factors contributing to the development of somatic disorders at adult age. The aim of this study was to examine whether maternal immune challenge would be followed at adult age by metabolic and endocrine abnormalities in the offspring. Pregnant rats were given injections of either endotoxin (Escherichia coli lipopolysaccharide; 0.79 mg/kg, ip) or vehicle on days 8, 10, and 12 of gestation. Adult male offspring to lipopolysaccharide-exposed dams were heavier than controls (P < 0.05) and showed increased adipose tissue weights (P < 0.05), elevated food intake (P < 0.05), and increased circulating leptin (P < 0.01). The effect of insulin on glucose uptake was reduced, as measured by an euglycemic hyperinsulinemic clamp technique (P < 0.05). Serum levels of 17beta-estradiol and progesterone were elevated (P < 0.01 and P < 0.05, respectively). Baseline levels of corticosterone were normal, but the corticosterone response to stress was attenuated (P < 0.05), and hippocampal glucocorticoid receptor protein was up-regulated (P < 0.05). Female offspring were uninfluenced, except for increased testosterone levels (P < 0.05), increased baseline corticosterone levels (P < 0.05), and enlargement of heart and adrenals (P < 0.05). The results indicate that maternal endotoxemia leads to obesity, insulin resistance, and high serum levels of leptin in the adult male offspring. This study reports a novel animal model of obesity with features of the metabolic syndrome.

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.

House dust induces IL-6 and IL-8 response in A549 epithelial cells

The in vitro potency of house dust to induce cytokine response in A549 lung epithelial cells was studied. Dusts collected from carpet, bed, shelf and floor of a villa and an apartment by vacuuming were found to trigger the production of interleukin-8 (IL-8) and interleukin-6 (IL-6) in a dose-dependent manner, and the interleukin production was several-fold higher than of swine dust (used as a positive control). The IL-8 and IL-6 production of pure Escherichia coli lipopolysaccharide was significantly lower than of the dusts and a peptidoglycan-polysaccharide complex did not show any stimulatory effect at all. The lipopolysaccharide and peptidoglycan contents of the samples were determined by gas chromatography-tandem mass spectrometry analysis of, respectively, 3-hydroxy fatty acids and muramic acid; in addition, ergosterol was monitored for fungal biomass. The inflammatory properties of house dust upon inhalation may be reflected in its high potency to induce cytokine response in lung epithelial cells.

Gram positive bacteria induce IL-6 and IL-8 production in human alveolar macrophages and epithelial cells

BACKGROUND AND OBJECTIVE

Inhalation of dust from swine confinement buildings results in an acute inflammatory reaction in the respiratory tract. The dust has a high microbial content, dominated by Gram positive bacteria. The aim of the present study was to evaluate the significance of bacteria in the induction of IL-6 and IL-8 release from respiratory epithelial cells and alveolar macrophages. The results would give an indication to what extent the bacteria contribute to the toxic inflammation following exposure to swine dust.

METHODS

Epithelial cells from a human lung carcinoma cell line (A549) and human alveolar macrophages obtained from healthy subjects by bronchoalveolar lavage, were stimulated with swine dust, LPS, one Gram negative and four Gram positive bacteria strains. The dose-response release of IL-6 and IL-8 were studied. In addition, a bacteria-free supernatant was prepared from each strain and used for stimulation.

RESULTS

With a few exceptions, a dose-dependent IL-6 and IL-8 release was demonstrated from both cell types after stimulation with bacteria. In epithelial cells, Escherichia coli was the most potent bacteria at the highest concentration of 400 bacteria/cell regarding secretion of both IL-6 and IL-8 (P < 0.001), followed by Staphylococcus hominis and Staphylococcus lentus. In alveolar macrophages, S. lentus was the most potent strain (P < 0.001) in inducing cytokine release (P < 0.001), followed by S. hominis and E. coli concerning IL-6 secretion or Micrococcus luteus and E. coli with respect to IL-8 secretion (P < 0.001). Differences in potency between the various bacteria could be demonstrated, both within the two cell types as well as between the epithelial cells and macrophages. Bacteria-free supernatants were also able to induce cytokine release in both cell types. In macrophages the supernatants were even more potent stimuli than whole bacteria.

CONCLUSIONS

The results indicate that bacteria or bacterial products could be an important contributing factor to the inflammatory reaction following exposure to swine dust.

Increase in interleukin-6 and fibrinogen in peripheral blood after swine dust inhalation

OBJECTIVES

The inhalation of dust from swine confinement buildings causes inflammatory responses in the airways with a rise of interleukin-6 (IL-6). The purpose of this study was to confirm the increase in serum IL-6 after inhalation of swine dust and investigate a possible increase in plasma fibrinogen.

METHODS

Eight healthy nonsmoking volunteers inhaled dust for 4 hours inside a swine confinement building. Inhalable dust and endotoxin were sampled. The concentrations of IL-6 and fibrinogen were determined in serum and plasma.

RESULTS

The study showed a clear increase in the concentrations of IL-6 and fibrinogen after exposure.

CONCLUSIONS

As fibrinogen is an important risk factor for ischemic heart disease, the increased concentration of fibrinogen among persons exposed to swine dust may increase the risk for this disease.

Airway responses in naive subjects to exposure in poultry houses: comparison between cage rearing system and alternative rearing system for laying hens

BACKGROUND

Workers in the poultry industry have increased frequencies of respiratory health problems. The aim of the present study was to investigate acute health effects from exposure in poultry houses and to compare the health effects observed in a cage rearing system and the alternative "cage-less" rearing system for laying hens.

METHODS

Thirty-four subjects were exposed for 3 hr in confined poultry houses. The subjects were randomized into three groups: one was exposed in a building with a cage rearing system and the two other groups were exposed in buildings with a cage-less system, with either young hens and fresh bedding material or with older hens and old bedding material.

RESULTS

Inhalable dust levels were approximately 4 mg/m3 in the buildings with the cage-less system and 2 mg/m3 in the building with cage rearing system; the endotoxin concentration was approximately 100 ng/m3 in both systems. Bronchial responsiveness to methacholine increased approximately fivefold in all groups following exposure. The concentration of the proinflammatory cytokine interleukin-6 (IL-6) increased in nasal lavage fluid and in peripheral blood as a result of the exposure. The number of leukocytes in peripheral blood increased only in the groups exposed among loose laying hens.

CONCLUSION

In the present study, we have demonstrated among previously non-exposed subjects, that 3-hr exposure in confined buildings for egg production induces an acute inflammatory reaction in the upper airways and increased bronchial responsiveness. There is a tendency towards stronger reactions in the groups exposed in the buildings with loose housing for laying hens.

Induction of insulin resistance by glucosamine reduces blood flow but not interstitial levels of either glucose or insulin

To study the effects of a glucosamine infusion on skeletal muscle metabolism, microdialysis was performed in the medial femoral muscle in Sprague-Dawley rats during a euglycemic-hyperinsulinemic clamp (insulin infusion 18 mU x kg(-1) x min(-1)). During steady-state clamping conditions (70 min), an infusion of glucosamine (30 micromol x kg(-1) x min(-1)) or saline was given for 240 min. Blood flow was measured by the microsphere technique at the end of the clamp. An approximately 36% (P < 0.001) reduction in the glucose infusion rate was seen after 170 min in the glucosamine-treated rats compared with control rats. There were no significant differences in interstitial or plasma levels of either insulin or glucose between the two groups. Both interstitial (2.31 +/- 0.18 vs. 1.71 +/- 0.24 mmol/l, P < 0.05) and arterial plasma lactate concentrations (1.29 +/- 0.09 vs. 0.79 +/- 0.09 mmol/l, P < 0.01) were significantly higher in control rats compared with glucosamine-treated rats. Blood flow was significantly reduced in hind limb femoral muscles in the glucosamine-treated rats compared with control rats. The most pronounced reduction in blood flow was seen in the Soleus muscle (27.6 +/- 3.4 vs. 14.7 +/- 2.0 ml x 100 g(-1) x min(-1), P < 0.01). These results demonstrate that induction of insulin resistance by glucosamine results in a reduction of the blood flow rate as well as the uptake of glucose and the production of lactate in skeletal muscle. As a result of the inhibited glucose metabolism, the interstitial glucose concentration was unchanged despite the reduced blood flow after glucosamine administration. The data suggest the importance of regulation of blood flow by nonoxidative metabolism of glucose in resting muscle.

Exposure of healthy volunteers to swine house dust increases formation of leukotrienes, prostaglandin D2, and bronchial responsiveness to methacholine

BACKGROUND

Acute exposure of healthy subjects to swine house dust causes increased bronchial responsiveness to methacholine but no acute bronchoconstriction. The role of cysteinyl leukotrienes and mast cells in increased bronchial responsiveness is unclear.

METHODS

Ten non-asthmatic subjects were exposed to swine dust for three hours while weighing pigs in a piggery. Urine was collected prior to and for up to 12 hours after entering the piggery and at the same times five days before and the day after exposure. As indices of whole body leukotriene production and mast cell activation, urinary levels of leukotriene E4 (LTE4) and 9 alpha, 11 beta-PGF2, the earliest appearing urinary metabolite of prostaglandin D2 (PGD2), were measured. Bronchial responsiveness to methacholine was determined five days before and the day after the exposure.

RESULTS

Methacholine PD20FEV1 decreased from 1.32 mg (95% CI 0.22 to 10.25) before exposure to 0.38 mg (95% CI 0.11 to 1.3) after exposure (p < 0.01). Associated with the increase in bronchial responsiveness there was a significant mean difference between post- and prechallenge levels of LTE4 (difference 38.5 ng/mmol creatinine (95% CI 17.2 to 59.8); p < 0.01) and 9 alpha, 11 beta-PGF2 (difference 69 ng/mmol creatinine (95% CI 3.7 to 134.3); p < 0.05) on the day of exposure to swine dust. Swine dust exposure induced a 24-fold increase in the total cell number and a 12-fold increase in IL-8 levels in the nasal lavage fluid. The levels of LTB4 and LTE4 in nasal lavage fluid following exposure also increased 5.5-fold and 2-fold, respectively.

CONCLUSIONS

The findings of this study indicate that cysteinyl leukotrienes and other mast cell mediators contribute to the development of increased bronchial responsiveness following inhalation of organic swine dust.

Induction of IL-8 production in human alveolar macrophages and human bronchial epithelial cells in vitro by swine dust

BACKGROUND

Exposure to swine dust causes an intense airway inflammation with increased levels of interleukin 8 (IL-8) and predominantly neutrophils in the nasal and bronchoalveolar lavage fluids of healthy human subjects. It is not clear which components in the swine house environment are responsible for the airway reaction. The aim of the present study was to evaluate and compare the effect in vitro of swine dust components on human alveolar macrophages and bronchial epithelial cells.

METHODS

Normal human bronchial epithelial cells (NHBE), human pulmonary epithelial carcinoma cell line (A549), and human alveolar macrophages were stimulated with swine dust, lipopolysaccharides (LPS; present in Gram negative bacteria), grain dust (swine feed components), and glucans (a structural component of fungi) in a dose response manner (1-100 micrograms/ml).

RESULTS

Swine dust at a concentration of 100 micrograms/ml increased IL-8 production 20 fold in NHBE cells, 28 fold in A549 cells, and 15 fold in macrophages. LPS (100 micrograms/ml) stimulated all three cell types significantly, in macrophages to the same extent as swine dust, but in NHBE and A549 cells swine dust was 5-8 times as potent. Grain dust (100 micrograms/ml) had no effect in A549 cells and macrophages but not NHBE cells. Both glucans and grain dust were weaker stimuli than swine dust and LPS. The LPS content of swine dust solution was 2.16 (0.2) ng/100 micrograms and of grain dust was 0.53 (0.04) ng/100 micrograms.

CONCLUSIONS

Swine dust is a strong stimulus for IL-8 production in both bronchial epithelial cells and human alveolar macrophages, whereas LPS has different potency in these cells.

Effect of rheumatoid arthritis on work status and social and leisure time activities in patients followed 8 years from onset

OBJECTIVE

To evaluate the development of handicap in patients with rheumatoid arthritis (RA) followed 8 years from onset.

METHODS

The study group consisted of 106 patients participating in a prospective early RA study. The mean duration of joint symptoms at inclusion was one year. The patients were assessed at least once annually. Disability was measured with the Health Assessment Questionnaire (HAQ) and emotional distress with a self-administered test (Symptom Checklist). Work status and different social measures were registered. A structured interview regarding work capacity, leisure time, and social activities was performed about 8 years after disease onset.

RESULTS

Compared to study start, disease activity had decreased, emotional distress was unchanged, disability had increased somewhat, and radiographic changes had increased markedly. The prevalence of work disability at the end of the study was 37%. The majority of patients that eventually got disability pension had stopped working the first year after onset. Seventy-eight percent of the patients who continued to work had to adjust their work conditions to stay employed. The 3 most important predictors for work disability were higher HAQ at study start, lower educational level, and older age. Three-quarters of the patients had to alter leisure time activities and half of them were not satisfied with their recreation. Many patients experienced difficulties in their roles as spouse and parent. Higher levels of emotional distress were associated with these handicaps.

CONCLUSION

In this cohort of patients with RA we found a high frequency of different types of handicaps at an early stage. Slightly more than 1/3 were work disabled. The majority had stopped working during the first year. Patients perceived handicaps in terms of changed leisure time activities, and difficulties performing different social roles were frequent. Patients with these handicaps felt more emotional distress.

Effect of exposure to swine dust on levels of IL-8 in airway lavage fluid

BACKGROUND

Inhalation of swine dust causes airway inflammation with influx of inflammatory cells, predominantly neutrophils, into the lungs. A study was undertaken to determine whether or not exposure to swine dust induces release of interleukin 8 (IL-8) into upper and lower airways and how this possible release is related to cellular influx. A further aim was to study the relationship between the inflammatory response and swine dust exposure.

METHODS

Thirty one healthy, non-smoking, previously unexposed subjects were exposed to swine dust during three hours work in a swine house. Bronchoalveolar lavage (BAL) was performed two weeks before and 24 hours after the exposure (n = 16). Nasal lavage and acoustic rhinometry were carried out 1-2 hours before and seven hours after the start of the exposure (n = 31). Exposure measurements were performed with personal sampling equipment.

RESULTS

The exposure led to 19-fold and 70-fold increases in the neutrophil concentrations in nasal lavage and BAL fluid, respectively (p < 0.001). In BAL, fluid macrophages, lymphocytes and eosinophils increased significantly. The IL-8 levels in BAL fluid increased from < 31.3 ng/l to 63 (43-109) ng/l (median (25-75th percentile), p < 0.001), and in nasal lavage fluid the concentrations increased from 144 (97-227) ng/l to 1064 (864-1437) ng/l (p < 0.001). IL-8 levels showed a significant correlation with the increase in neutrophils in the nasal lavage fluid but not in the BAL fluid. Acoustic rhinometry demonstrated significant swelling of the nasal mucosa. The air concentration of inhalable dust was 23.3 (20.0-29.3) mg/m3, endotoxin 1.3 (1.1-1.4) micrograms/m3, and muramic acid 0.99 (0.78-2.1) microgram/m3.

CONCLUSIONS

The concentration of IL-8 increases in BAL fluid and nasal lavage fluid following exposure to swine dust and may be one of the chemoattractants contributing to the recruitment of neutrophils to the nasal cavity and the alveolar space.

CD8+ T cells from HIV type 1-seronegative individuals suppress virus replication in acutely infected cells

CD8+ lymphocytes (CD8 cells) have been shown to inhibit replication of the human immunodeficiency virus (HIV) in vitro when cocultured with HIV-infected CD4+ lymphocytes (CD4 cells). This suppressive effect on HIV replication in experimentally infected CD4 cells has so far been demonstrated only for CD8 cells from HIV-seropositive individuals. In the present study we have investigated if CD8 cells from HIV-negative individuals can also suppress HIV replication in experimentally infected CD4 cells. Positively selected CD4 cells were infected with phenotypically different primary isolates of HIV type 1 and 2 (HIV-1 and HIV-2). Graded numbers of CD8 cells were added to the infected cultures. The T cells were activated by antibodies directed against the CD3 molecule or the T cell receptor. Culture supernatants were harvested for HIV p24 quantitation and the CD8 suppression of HIV replication was calculated by comparing p24 levels from parallel cultures in the presence or absence of CD8 cells from different donors. We show that CD8 cells from unexposed HIV-seronegative blood donors are able to control HIV-1 and HIV-2 replication in experimentally infected autologous CD4 cells. The antiviral activity of CD8 cells from and HIV-naive individual was reproducible over time and the suppressive effect was comparable to that seen with CD8 cells from HIV-positive individuals. The infected cells were not eliminated from the cultures. The suppressive effect of CD8 cells varied depending on the dose and biological phenotype of the virus used for infection. Thus, exposure to HIV in vivo is not a prerequisite for CD8 cells to exert a suppressive effect on HIV replication in acutely infected cells.

Exposure to bacteria in swine-house dust and acute inflammatory reactions in humans

Inhalation of swine-house dust may cause an acute airway inflammatory condition (organic dust toxic syndrome). Thirty-eight healthy subjects were exposed to swine dust while weighing swine for 3 h. We studied the correlation between acute health effects and the inhaled bacterial exposure markers peptidoglycan (the main constituent of the cell walls of gram-positive bacteria, but also present in lesser amounts in gram-negative bacteria) and lipopolysaccharides (LPS; present only in gram-negative bacteria). LPS activity in airborne dust was measured with the Limulus amebocyte lysate assay (LPS(LAL)), and the total LPS was estimated from 3-hydroxy fatty acids, which were measured with gas chromatography-mass spectrometry (GC-MS) (LPS(GC-MS)). Peptidoglycan was estimated from muramic acid measured with GC-MS. The median (25th to 75th percentile) concentration of inhalable dust was 21 (16 to 25) mg/m3. LPS(LAL) was 1.2 (0.9 to 1.4) microg/m3; LPS(GC-MS) was 3.9 (2.5 to 4.9) microg/m3; and the peptidoglycan concentration in airborne dust was 6.5 (2.7 to 13) microg/m3. All exposure markers correlated significantly with an increase in serum interleukin-6. LPS(LAL) showed the highest correlation (r2 = 0.29) and total inhaled dust the lowest (r2 = 0.09). LPS(LAL) also correlated with symptoms and with an increase in bronchial responsiveness and decrease in vital capacity (VC). Peptidoglycan, but not LPS(LAL), correlated with an increase in the blood granulocyte concentration and in body temperature. The results suggest that several microbial agents in inhaled swine-house dust may contribute to acute systemic health effects.

Time course of interleukin-6 and tumor necrosis factor-alpha increase in serum following inhalation of swine dust

Inhalation of swine dust induces airway inflammation and general symptoms, such as fever and malaise. In the present investigation, the presence and time course of changes in tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in serum were studied to evaluate possible mechanisms by which inhalation of swine dust induces general symptoms. A group of 14 previously nonexposed subjects weighed swine for 3 h. The average +/- SD inhalable dust concentration was 22.4 +/- 4.7 mg/m3 and endotoxin, 1.2 +/- 0.4 microgram/m3. TNF-alpha in serum increased from 2.5 (1.8 to 3.1) ng/L (median, interquartile range) before exposure to maximum values 10.0 (4.6 to 15.7) ng/L between 3 and 5 h after the start of exposure. IL-6 increased from less than 1.5 to 21.4 (18.6 to 33.6) ng/L 4 to 11 h after the start of exposure. Maximum IL-6 occurred 1 to 5 h after the maximum TNF-alpha. In many subjects, however, an early rise in IL-6 parallel to the change in TNF-alpha was seen. The results that some of the peripheral reactions to swine dust might be mediated by TNF-alpha and IL-6. The early rise in IL-6 implies multiple origins of the IL-6.

Psychological reactions in patients with early rheumatoid arthritis

We report the interaction of RA and psychological factors over 2 years in a group of 89 patients with newly established disease. Short-time outcome regarding physical features was fairly good. Disease activity decreased, and disability evaluated by HAQ remained at a low level. Psychological distress as measured by the depression and anxiety subscales of SCL 90 (Symptom Check List) was not very pronounced and not related to disease state factors. A slight decrease of anxiety was recorded after 2 years. A new adjustment test was applied. It contained 13 items focused mainly on negative illness effects such as loss of independence, feelings of guilt, and change of social and leisure time activities. Three factors (regret of lost life values, dysphoric mood, and acceptance) explained 48% of the variance of the 13 items. The validity of the test was acceptable. The patients' degree of adjustment changed slowly or not at all during the 2 years.

Early rheumatoid arthritis--some social, economical, and psychological aspects

Physical, psychological, and social features were assessed with standardized methods in 84 early RA patients followed prospectively for 2 years. During this time disease activity decreased, and disability evaluated by HAQ remained small. Psychological distress measured by SCL-90 (Symptom Check List) was in general not very pronounced and fairly stable over time. A high pain level at baseline provided a 4 times higher risk for a high level of psychological distress after 2 years. The prevalence of early retirement was 37% at the end of the study. Physical demanding work and a high initial HAQ score were the best predictors of work disability, increasing the risk of not working 10.7 and 5.5 times, respectively. At least 28% of patients had lower annual income compared to the year before disease onset. The ability to do shopping, home work, leisure time activities and social activities were negatively influenced by the disease in more than half of the patients. The social and economical consequences were thus considerable in the early stages of RA.

Effects of short-term testosterone exposure on insulin sensitivity of muscles in female rats

The effects of testosterone on insulin sensitivity were studied in oophorectomized female rats. Euglycemic, hyperinsulinemic clamp measurement showed a marked decrease of insulin sensitivity after 48 but not 24 h of testosterone exposure, which was overcome at high insulin concentrations. Insulin stimulation of 2-deoxyglucose uptake as well as glycogen synthesis was measured in the white and red parts of the gastrocnemius, the extensor digitorum longus, and soleus muscles as well as in the liver (only glycogen synthesis). After 24 h of treatment, inhibition of both 2-deoxyglucose uptake and glycogen synthesis was found in the most insulin-sensitive muscles. After 48 h of insulin stimulation, glycogen synthesis was inhibited in all examined individual muscles (white and red parts of gastrocnemius, extensor digitorum longus, and soleus) as was the activity of the insulin-sensitive part of glycogen synthase in muscle. Inhibition of insulin-stimulated 2-deoxyglucose uptake again affected the most insulin-sensitive muscles. There was a slight but significant change of muscle fiber composition toward less long-chain myosin and more short-chain myosin-containing fibers. Serum cortisol, plasma free fatty acids, and blood glycerol did not change. It is concluded that testosterone administration in moderate doses to oophorectomized female rats is followed by a rapid deterioration of insulin sensitivity in muscle, mediated mainly by perturbations of the insulin receptor-glycogen synthesis systems apparently coinciding with changes in muscle morphology.