Active Precipitation of Radiation Belt Electrons Using Rocket Exhaust Driven Amplification (REDA) of Man-Made Whistlers.

Ground-based very low frequency (VLF) transmitters located around the world generate signals that leak through the bottom side of the ionosphere in the form of whistler mode waves. Wave and particle measurements on satellites have observed that these man-made VLF waves can be strong enough to scatter trapped energetic electrons into low pitch angle orbits, causing loss by absorption in the lower atmosphere. This precipitation loss process is greatly enhanced by intentional amplification of the whistler waves using a newly discovered process called rocket exhaust driven amplification (REDA). Satellite measurements of REDA have shown between 30 and 50 dB intensification of VLF waves in space using a 60 s burn of the 150 g/s thruster on the Cygnus satellite that services the International Space Station. This controlled amplification process is adequate to deplete the energetic particle population on the affected field lines in a few minutes rather than the multi-day period it would take naturally. Numerical simulations of the pitch angle diffusion for radiation belt particles use the UCLA quasi-linear Fokker Planck model to assess the impact of REDA on radiation belt remediation of newly injected energetic electrons. The simulated precipitation fluxes of energetic electrons are applied to models of D-region electron density and bremsstrahlung X-rays for predictions of the modified environment that can be observed with satellite and ground-based sensors.

Penetration of MeV electrons into the mesosphere accompanying pulsating aurorae.

Pulsating aurorae (PsA) are caused by the intermittent precipitations of magnetospheric electrons (energies of a few keV to a few tens of keV) through wave-particle interactions, thereby depositing most of their energy at altitudes ~ 100 km. However, the maximum energy of precipitated electrons and its impacts on the atmosphere are unknown. Herein, we report unique observations by the European Incoherent Scatter (EISCAT) radar showing electron precipitations ranging from a few hundred keV to a few MeV during a PsA associated with a weak geomagnetic storm. Simultaneously, the Arase spacecraft has observed intense whistler-mode chorus waves at the conjugate location along magnetic field lines. A computer simulation based on the EISCAT observations shows immediate catalytic ozone depletion at the mesospheric altitudes. Since PsA occurs frequently, often in daily basis, and extends its impact over large MLT areas, we anticipate that the PsA possesses a significant forcing to the mesospheric ozone chemistry in high latitudes through high energy electron precipitations. Therefore, the generation of PsA results in the depletion of mesospheric ozone through high-energy electron precipitations caused by whistler-mode chorus waves, which are similar to the well-known effect due to solar energetic protons triggered by solar flares.

Missing driver in the Sun-Earth connection from energetic electron precipitation impacts mesospheric ozone.

Energetic electron precipitation (EEP) from the Earth's outer radiation belt continuously affects the chemical composition of the polar mesosphere. EEP can contribute to catalytic ozone loss in the mesosphere through ionization and enhanced production of odd hydrogen. However, the long-term mesospheric ozone variability caused by EEP has not been quantified or confirmed to date. Here we show, using observations from three different satellite instruments, that EEP events strongly affect ozone at 60-80 km, leading to extremely large (up to 90%) short-term ozone depletion. This impact is comparable to that of large, but much less frequent, solar proton events. On solar cycle timescales, we find that EEP causes ozone variations of up to 34% at 70-80 km. With such a magnitude, it is reasonable to suspect that EEP could be an important part of solar influence on the atmosphere and climate system.

Upper endoscopic findings in children with active juvenile chronic arthritis.

AIM: To investigate the association between gastroduodenal mucosal damage and symptoms of the digestive tract in children with juvenile chronic arthritis (JCA). METHODS: This was a prospective, open, non-randomized study. Gastroscopy was performed on 45 children with active JCA in 1996-2000. Gastrointestinal symptoms before and during the treatment were noted, as was the length of antirheumatic medication, for which the data were retrospectively assessed. Plasma haemoglobin (Hb) and mean corpuscular volume (MCV) levels and erythrocyte sedimentation rate (ESR) were analysed. Mucosal biopsies were obtained for histology and Helicobacter pylori culture. All patients were taking non-steroidal anti-inflammatory drugs (NSAIDs) and 11 (24.4%) were on peroral steroids; 16 (35.6%) were receiving hydorxychloroquine, 9 salazopyrine, 5 myocrisine and 14 methotrexate. RESULTS: Seven children (15.6%) were found to have active inflammation in their gastric and/or duodenal mucosa, two having ulcers and two being infected with H. pylori. Abnormal endoscopic findings were more common in symptomatic children (n = 24) than in children without symptoms (n = 21) (75% vs 38%, p = 0.017). There was no clear association between the Hb or MCV level and the degree of gastroduodenal inflammation (p = 0.98 and 0.7, respectively). Significantly more children (66.6% vs 33.3%) experienced abdominal pain after beginning medical therapy than before therapy (p = 0.02). CONCLUSION: Endoscopic evaluation of patients with JCA and receiving NSAIDs should be considered at least in symptomatic cases.

Development of progressive pulmonary interstitial and intra-alveolar cholesterol granulomas (PICG) associated with therapy-resistant chronic systemic juvenile arthritis (CJA).

A girl aged 5 years with therapy-resistant chronic systemic juvenile arthritis (CJA) developed progressive fibrosing lung disease. Histology of an open lung biopsy revealed pulmonary interstitial and intra-alveolar cholesterol granulomas (PICG). Since treatment with steroids and immunosuppressive drugs did not prevent progression of lung fibrosis, an experimental treatment with a tumor necrosis factor alpha (TNF alpha) antagonist etanercept was started. Although development of chronic changes in the lung parenchyma could not be prevented, this treatment brought considerable relief and markedly improved the child's physical capacity. By ruling out other causes for development of PICG, we concluded that the primary disease had caused the development of cholesterol granulomata by macrophage activation. We suggest, therefore, that a trial with etanercept in children with otherwise therapy-resistant CJA should be considered, especially if pulmonary complications have developed.

Elevated serum transferrin receptor concentration in children with juvenile chronic arthritis as evidence of iron deficiency.

OBJECTIVES: Active juvenile chronic arthritis (JCA) is accompanied by anaemia of chronic disease, which may be indistinguishable from anaemia due to iron deficiency. We speculate that elevation of the serum transferrin receptor (sTfR) concentration, which should not be influenced by inflammation, would be useful for detecting the role of iron status in anaemic children with JCA. METHODS: sTfR concentrations were measured in 30 children with JCA. RESULTS: The median sTfR was elevated, 6.1 (range 3.4-13.0) mg/l. In 13 patients (43%) the concentrations exceeded the upper limit for healthy subjects. Haemoglobin (r = - 0.48, P = 0.008), mean corpuscular volume (r = - 0.47, P = 0.009) and mean corpuscular haemoglobin (r = - 0.65, P = 0.0001) correlated inversely with sTfR concentration. CONCLUSIONS: In 13 of the 30 patients with JCA, the sTfR concentration, which is an indicator of iron status and erythropoiesis, was elevated. The results raise the possibility that sTfR is able to distinguish iron-deficiency anaemia from anaemia of chronic disease. It should be further explored as a candidate.

Growth of prepubertal children with juvenile chronic arthritis.

The height and height velocity standard deviation scores (HSDS and HVSDS) of 64 prepubertal children with mild to moderate chronic arthritis were calculated at the time of diagnosis and then annually during treatment and follow-up of 4 y. Preceding the diagnosis, children with chronic arthritis were as a group slightly taller than their healthy peers. During the year before the diagnosis they had grown faster than their peers. During the first year of treatment their growth velocity decreased (change in the mean HVSDS from +0.63 to -0.52), but during further follow-up it returned to the pretreatment level (the mean HVSDS being +0.53 four years after the diagnosis). The growth was influenced more by polyarticular than by pauciarticular disease. The cumulative total dose of glucocorticosteroids did not have statistically significant influence on growth. In conclusion, growth retardation in prepubertal children with chronic arthritis was seen following the diagnosis and initiation of treatment, more so in polyarticular disease. During further follow-up, growth velocity increased. This reflected the growth promoting effect of inflammatory process control.

Dietary therapy with Lactobacillus GG, bovine colostrum or bovine immune colostrum in patients with juvenile chronic arthritis: evaluation of effect on gut defence mechanisms.

The effect of dietary therapy with a human Lactobacillus strain GG (ATCC 53103), bovine colostrum, or bovine immune colostrum with specific antibodies against anaerobic intestinal bacteria on gut defence mechanisms were studied in juvenile chronic arthritis. Thirty patients with juvenile chronic arthritis were randomly allocated to receive a freeze-dried powder of Lactobacillus GG, or bovine colostrum, or bovine immune colostrum, for a two-week period. Immunologic and non-immunologic gut defence mechanisms were indirectly investigated in blood and faecal samples. In patients receiving Lactobacillus GG, the median (interquartile range) frequency of immunoglobulin-secreting cells, determined by enzyme-linked immunospot assay, increased in the IgA class from 1840 (690-2530) to 3480 (1030-13 170)/10(6) cells; p=0.02. Likewise the median (interquartile range) frequency of specific antibody-secreting cells against dietary antigens increased during the Lactobacillus GG therapy in the IgM class from 3.8 (1.4-5.0) to 11.2 (5.0-30.0)/10(6) cells; p=0.02. In addition, Lactobacillus GG therapy decreased the median (interquartile range) activity of faecal urease, which has been associated with mucosal tissue damage, from 40.3 (21.7-54.3) to 28.6 (24.5-49.4) nmol. min(-1) (mg protein)(-1); p=0.10, while, in patients receiving bovine colostrum, faecal urease activity increased (from 42.2 to 80.6; p=0.04). All findings were transient. We suggest that gut defence mechanisms are disturbed in juvenile chronic arthritis and we further suggest that orally administered Lactobacillus GG has a potential to reinforce the mucosal barrier mechanisms in juvenile chronic arthritis.

Azathioprine in patients with juvenile chronic arthritis: a longterm followup study.

OBJECTIVE: To evaluate drug survival, efficacy, side effects, and longterm toxicity of azathioprine treatment in patients with juvenile chronic arthritis (JCA). METHODS: In an uncontrolled, prospective study we evaluated 129 consecutive patients with JCA refractory to therapy in whom azathioprine treatment was begun during 1980-1989. In the first 29 patients, a 2 year trial was planned, while for the remaining 100 patients the protocol was to continue until remission or dropout. The median treatment period was 13 months (range 3 days-8.5 yrs). Patients were assessed every 2 months for 2 years for efficacy, side effects, growth and need for glucocorticoids, and outcome evaluated in late 1996. RESULTS: Remission without drugs was attained in 19 patients (15%); in addition, temporary remission in patients continuing treatment was attained in 18 cases (14%). Treatment was discontinued due to side effects in 18 cases (14%); in two-thirds of these cases side effects occurred during the first 2 months. Of the total number of patients, 49 (38%) completed 2 years of treatment, with significant improvement in both clinical and laboratory indices of disease activity. Treatment had no noticeable effect on iridocyclitis. One patient died of cytomegalovirus infection during azathioprine treatment. CONCLUSION: Azathioprine is a useful drug in severe JCA, with a sustained effect and acceptable side effects. Even in cases of incomplete remission, its glucocorticoid sparing effect was noteworthy.

Increased bacterial urease activity in faeces in juvenile chronic arthritis: evidence of altered intestinal microflora?

The intestinal microflora was indirectly evaluated in juvenile chronic arthritis (JCA) by analysing enzyme activities--urease, beta-glucosidase and beta-glucuronidase--in faeces. In 18 out of 26 JCA patients, the illness had been diagnosed during the past year. The control group was composed of eight age-matched control patients and 18 family members of JCA patients (3-36 yr). The mean [95% confidence interval (CI)] urease activity, but not the activities of beta-glucosidase and beta-glucuronidase, in faeces from the JCA group differed from that in the control group: 32.3 (26.6-38.1) nmol/min/mg protein vs 24.0 (16.8-31.6), P = 0.07. The difference was more marked in a comparison of JCA patients with family members (P = 0.03). In a subgroup of subjects, the effect of 10 days oral bacteriotherapy with Lactobacillus GG on faecal enzyme activities was then investigated (n = 8 JCA patients, n = 8 control patients). This short-term oral bacteriotherapy reduced the increased urease activity in faeces of JCA patients. Keeping in mind the small number of subjects, it may be inferred from the present results that the increased urease activity in JCA is specific for the disease, suggesting altered intestinal microflora in JCA.

Incidence of systemic connective tissue diseases in children: a nationwide prospective study in Finland.

OBJECTIVE: To study the incidence of systemic connective tissue diseases (CTD) and of systemic onset juvenile arthritis (S-JA) in children aged 0 to 15 years. METHODS: A nationwide, prospective, hospital based series of new patients from Finland collected during a 4-year period and supplemented with data from the National Hospital Discharge Register. The population at risk was 1.02 million. Classification criteria developed for adult CTD and the American Rheumatism Association criteria for JA were used. RESULTS: The annual incidence rates found were as follows: systemic lupus erythematosus 0.37, polymyositis/dermatomyositis (PM/DM) 0.30, mixed connective tissue disease 0.10, scleroderma 0.05, and S-JA 0.47/100,000. Girls outnumbered boys in the whole series of CTD (24:9) and also in S-JA (11:8), but in PM/DM the sex distribution was even. CONCLUSION: CTD and S-JA are rare before the age of 16 years. From the present incidence figures and those recently published for JA the incidence of CTD is estimated to be between 4 and 7% of that of JA, and S-JA accounts for only 2 to 4% of all JA.

Breast feeding of low birthweight infants.

The incidence and length of breast feeding of LBW (less than or equal to 2500 grams) infants were investigated. A marked increase from 1979 to 1982 was noted: the incidence rose from 78% to 91% and the proportion of infants breast fed for 3 months rose from 54% to 67%. A breast feeding promotion programme did not influence the length of breast feeding of LBW infants within one year of the intervention. Smaller infants, those with RDS and those from lower social classes were breast fed less than others.

The influence of perinatal factors on breast feeding.

The effect on breast feeding of various factors connected with delivery and the immediate post partum period were investigated in a group of 1701 parturients. Children born by caesarean section or assisted delivery, those of low birth weight or asphyxiated at birth started breast feeding significantly less often than healthy children delivered normally. The length of breast feeding was not affected by these factors once it was started, 49% breast feeding for six months or more. Exceptionally young and old mothers breast fed less well than mothers in general. Mothers whose husbands attended the delivery breast fed more often and longer than others. Failure to start breast feeding occurred in only 2.4% of the material. In this material with high breast feeding rates it can be concluded that obstetric and perinatal abnormalities have a small but nevertheless significant effect on the incidence of breast feeding.

Breast feeding: reasons for giving up and transient lactational crises.

A prospective study of the course of breast feeding was carried out in a group of 150 mothers. The reasons for terminating breast feeding before six months and the occurrence of transient lactational crises were recorded. 23% of the mothers gave up breast feeding because of lactational difficulties. 12% stopped for external reasons and 65% carried on beyond six months. 36% of mothers experienced one or more transient lactational crises, which were successfully overcome by proper breast feeding techniques in a few days.