Very- and ultra-long-period seismic signals prior to and during caldera formation on La Réunion Island.

Early detection of the onset of a caldera collapse can provide crucial information to understand their formation and thus to minimize risks for the nearby population and visitors. Here, we analyse the 2007 caldera collapse of Piton de la Fournaise on La Réunion Island recorded by a broadband seismic station. We show that this instrument recorded ultra-long period (ULP) signals with frequencies in the range (0.003-0.01 Hz) accompanied by very-long period (VLP) signals (between 0.02 and 0.50 Hz) prior to and during the caldera formation suggesting it is possible to detect the beginning of the collapse at depth and anticipate its surface formation. Interestingly, VLP wave packets with a similar duration of 20 s are identified prior to and during the caldera formation. We propose that these events could result from repeating piston-like successive collapses occurring through a ring-fault structure surrounding a magma reservoir from the following arguments: the source mechanism from the main collapse, the observations of slow source processes as well as observations from the field and the characteristic ring-fault seismicity.

An outbreak of cyclosporiasis in 1996 associated with consumption of fresh berries- Ontario.

BACKGROUND: A large foodborne outbreak of cyclosporiasis occurred in North America in 1996. An index cluster of cases associated with a catered event on May 11, 1996, in Ontario sparked the recognition of this outbreak in Canada. OBJECTIVES: To describe the Ontario experience with the North American outbreak of cyclosporiasis in 1996. PATIENTS AND METHODS: Public health units investigated the index and subsequent event-associated clusters. Investigations included retrospective cohort studies of clusters, traceback of suspect foods and a case-control study of sporadic cases. These activities, coordinated with those in the United States, were part of an international investigation. RESULTS: In Ontario, 232 cases of cyclosporiasis (20 laboratory-confirmed and 72 clinically defined cases associated with seven events plus 140 additional laboratory-confirmed sporadic cases) were identified between May 1 and July 30, 1996. For the index cluster, a strawberry flan with raspberries and blueberries was the only significant exposure (relative risk 2.16, P=0.02). Fresh berries were served at all seven events associated with clusters of cases. Raspberries were definitely served at three events, possibly served at three events, and not served at one event. Only imported berries were available in Ontario in May 1996, when initial clusters and sporadic cases were identified. The raspberries served at the two events with well documented traceback data came from Guatemala. Univariate analyses of the matched case-control study demonstrated that illness was associated with consumption of raspberries (matched odds ratio 21.0, 95% CI 3.48 to 448) and strawberries (matched odds ratio 28.5, 95% CI 4.02 to 478). Further evidence amassed by the international investigation compellingly implicated Guatemalan raspberries as the vehicle of the outbreak. CONCLUSION: Cyclosporiasis may be acquired domestically from the consumption of contaminated produce. The scope and vehicle of this international foodborne outbreak were recognized through a coordinated public health response.

[How is hemolytic-uremic syndrome in childhood acquired in Switzerland?]. / Wie wird das hämolytisch-urämische Syndrom des Kindesalters in der Schweiz erworben?

Intestinal infections with shigatoxin-producing Escherichia coli or Shigella dysenteriae type I play a major role in the pathogenesis of the hemolytic-uremic syndrome in childhood. Escherichia coli has been repeatedly detected in the intestines of healthy cattle. Twenty-seven children with hemolytic-uremic syndrome were treated at our hospital between June 1990 and March 1997. Factors indicating a possible previous contact with bovine intestinal content were found in 18 out of the 27 patients: parents stockbreeders (n = 7), recent visit to a cowshed or contact with cowdung or manure (n = 5), residence in a rural cattle-breeding area (n = 5), or consumption of raw milk (n = 1). The factors mentioned were found in 5 out of 27 control patients (p < 0.01). Two children experienced hemolytic-uremic syndrome after a stay respectively in Egypt and Tunisia. Our results indicate an important source for acquisition of hemolytic-uremic syndrome in childhood. Observing simple hygienic rules such as washing of hands and pasteurization of milk is likely to have a positive influence on the incidence of this illness. There are also grounds to consider adding the hemolytic-uremic syndrome to the list of travel-related diseases.

Comparison of the western blot assay with the neutralizing-antibody and enzyme-linked immunosorbent assays for measuring antibody to verocytotoxin 1.

A Western blot (immunoblot) assay (WBA) was developed to detect immunoglobulin G (IgG) antibodies against Escherichia coli Verocytotoxin 1 (VT1) by using a chemiluminescence detection system. The assay was compared with a VT1-neutralizing-antibody (VT1-NAb) assay and an anti-VT1 IgG enzyme-linked immunosorbent assay (ELISA). When four human serum samples that were known to be positive by VT1-NAb assay and ELISA were titrated to the endpoint by the three assays, the WBA gave endpoint titers that were up to 8-fold higher than those by ELISA and up to 256-fold higher than those by the VT1-NAb assay. Of 32 serum samples that were known to be positive by VT1-NAb assay and ELISA, 31 (97%) were positive by WBA; the one sample with a discrepant result gave borderline results by the VT1-NAb assay and ELISA. Of 52 serum samples that were known to be negative by the VT1-NAb assay and ELISA, 50 (96%) were negative and 2 (4%) were positive by WBA. Of 44 serum samples that gave discrepant results by the VT1-NAb assay and ELISA, neither of the latter correlated with the results of WBA. In an investigation of 19 pairs of acute- and convalescent-phase serum samples from patients with hemolytic-uremic syndrome, 10 pairs that were positive by the VT1-NAb assay were also WBA positive, while 9 pairs that were NAb negative were also WBA negative. The WBA is inherently more specific and sensitive than either the NAb assay or the ELISA and may be used as a "gold standard" to detect IgG antibodies to VT1. Like the NAb assay and the ELISA for detecting antibodies to VT1, the WBA has little to offer in the diagnostic setting but is expected to play an important role in seroepidemiological studies.

Antipyretic effect of parenteral paracetamol (propacetamol) in pediatric oncologic patients: a randomized trial.

The antipyretic efficacy of propacetamol, an intravenous prodrug of paracetamol, was evaluated in two pediatric prospective randomized studies. In the first, we-compared one standard intravenous dose of propacetamol (30 mg/kg) to one standard intravenous dose of acetylsalicylic acid (ASA, 15 mg/kg) in 10 nononcologic patients with bacterial illnesses. In the second study, we compared two intravenous doses of propacetamol (30 mg/kg versus 15 mg/kg) in 24 oncologic patients with fever and neutropenia. No statistically significant differences in antipyretic efficacy were found between standard doses of propacetamol and ASA; even when half-doses of propacetamol (15 mg/kg) were used, good antipyretic efficacy was observed, which was not statistically different from that observed with the full dose. The use of propacetamol seems promising for patients (such as oncologic patients) who cannot receive enteral paracetamol formulas.

Neutralizing antibodies to Escherichia coli Vero cytotoxin 1 and antibodies to O157 lipopolysaccharide in healthy farm family members and urban residents.

An enzyme-linked immunosorbent assay (ELISA) to detect antibodies to Escherichia coli O157 lipopolysaccharide (LPS) was developed with sera from 63 children with confirmed recent E. coli O157 infection and from 256 age-stratified urban controls. The median ELISA values for control and case sera were 0.05 (interquartile range, 0 to 0.20; mean +/- standard deviation [SD], 0.15 +/- 0.22) and 1.41 (interquartile range, 1.11 to 1.59; mean +/- SD, 1.41 +/- 0.53), respectively (P < 0.001). With a breakpoint of 0.59 (mean ELISA value of the control sera + 2 SDs), the assay had a sensitivity, specificity, and positive and negative predictive values of 95, 94, 80, and 98%, respectively, for recent E. coli O157 infection. The O157 LPS assay and Vero cytotoxin (VT) 1-neutralizing-antibody (NAb) assay were used to compare the relative frequencies of O157 LPS antibodies and VT1-NAbs in an age-stratified urban population from Toronto, Ontario, Canada, and in 216 healthy family members from dairy farm in southern Ontario. The frequency of O157 LPS antibodies was about threefold higher in dairy farm residents (12.5%) than in urban residents (4.7%) (P < 0.01). Similarly, the frequency of VT1-NAbs was about sixfold higher in dairy farm residents (42.0%) than in urban residents (7.7%) (P < 0.001). These findings are consistent with a greater level of exposure of dairy farm residents to VT-producing E. coli (VTEC) strains. The high rate of seropositivity to VT1 in farm residents probably reflects the booster effect of repeated VTEC exposures and argues against a sustained generalized immunosuppressive effect of VT1. Seroepidemiological studies may help in assessing the level of exposure of different populations to VTEC strains.

[Invasive Pseudomonas aeruginosa and Ecthyma gangrenosum infection in a child without risk factors]. / Infection invasive à Pseudomonas aeruginosa et Ecthyma gangrenosum chez un enfant sans facteurs de risques.

BACKGROUND: Pseudomonas aeruginosa sepsis, well known in immunocompromised patients, is rare in previously healthy children. CASE REPORT: A previously healthy 4 month-old boy was admitted with the suspicion of meningococcal septicemia. Three days prior to admission, he had developed high fever and two 4 cm-diameter skin lesions on his right leg, with dark red colour and a central haemorrhagic blister. He subsequently developed generalized seizures; meningitis and urinary tract infection were excluded. Despite topical therapy with an antistaphylococcal drug skin lesions extended, particularly at the level of the head. The patient was given oral amoxicillin-clavulanate, but his condition worsened; he was transferred to our intensive care unit with septic shock and a diagnosis of meningococcemia. Blood cultures grew Pseudomonas aeruginosa. Despite intensive therapy and appropriate antibiotic therapy, the patient died. CONCLUSION: To allow early diagnosis and adequate treatment, it is mandatory to diagnose Ecthyma gangrenosum as the most frequent manifestation of invasive infection with Pseudomonas aeruginosa.

Focal nodular hyperplasia of the liver in children: review of follow-up and outcome.

The authors used a conservative approach to treat focal nodular hyperplasia of the liver (FNH) and were interested in the long-term results of different therapeutic approaches in order to establish the most appropriate treatment. A review of the literature was conducted, and 31 pediatric case reports were identified in which follow-up and outcome data were noted. Tumor resection was performed in 18 cases (58%), operative biopsy alone in nine (29%), vascular ligation in two, and embolization of hepatic arteries in two. The outcome appears to be good for both groups of patients, ie, those with observation alone and those with resection. More information is to be collected regarding the new procedures (embolization and ligation). This is a retrospective analysis, and data from future international prospective studies are needed.

Mycobacterium genavense invasive infection in two children with AIDS: long-term followup.

Mycobacterium genavense is a rare cause of opportunistic infection in immunocompromised hosts. Follow up of two cases of M. genavense invasive infection in children with haemophilia A and AIDS are presented. One patient died 18 months after diagnosis of M. genavense infection of an indirectly related cause, probably of Pneumocystis carinii pneumonia. The second patient still attends our outpatient clinic and the infection is under control. Both presented with abdominal lymphomas and pain and a wasting syndrome. A combination of several drugs against atypical mycobacteria is used for treatment.

[Levamisole in children with frequently recurring idiopathic nephrotic syndrome]. / Levamisol bei Kindern mit häufig rezidivierendem idiopathischem nephrotischem Syndrom.

10 children (8 boys and 2 girls) with frequently relapsing idiopathic nephrotic syndrome were treated with levamisole (5 mg/kg weekly). In 6 children with steroid dependent nephrotic syndrome a marked reduction in steroids by 62% to 75% was possible. Severe, transient neutropenia was observed in one patient. Levamisole failed to influence the disease course positively in 3 patients with relapses associated with intercurrent illness. It is concluded that levamisole may favourably influence steroid dependence in children with frequently relapsing idiopathic nephrotic syndrome.

Method for assessment of experimental allergy in guinea pigs adapted to cosmetic ingredients.

2 protocols are presented to predict and assess allergic reactions after application of chemicals or cosmetic products, either raw materials or finished products. The first is an open epidermal induction and challenge, the intensity of the reaction being maximized by injecting Freund's complete adjuvant into the foot pad. The second allows detection of weaker allergens and is a quasi-intradermal induction: both the adjuvant and test substance are injected into the foot pad. In both protocols, the challenge consisted of a single topical application in the lumbar region of 10 microliter of test substance and components, allowing study of cross-sensitization, the large surface available permitting 6 different contacts.