Effect of cagA status on the sensitivity of enzyme immunoassay in diagnosing Helicobacter pylori-infected children.

BACKGROUND: The aims of our study were twofold. First, we sought to evaluate in symptomatic children the influence of the Helicobacter pylori genotype on gastritis, abdominal pain, and circulating anti-H. pylori IgG antibodies (anti-H. pylori IgG) or pepsinogen A (PGA) and C (PGC). Additionally, we sought to assess anti-H. pylori IgG, PGA, and PGC patterns in a large cohort (N = 921) of asymptomatic children. MATERIALS AND METHODS: In 183 symptomatic children, H. pylori infection and the presence of gastritis were evaluated by histology. In a subgroup of 20 H. pylori-positive children, the H. pylori genotype was evaluated also by polymerase chain reaction. Nine hundred and twenty-one asymptomatic children, aged 11 to 14 years, were studied by anti-H. pylori IgG, PGA, and PGC serum determination. RESULTS: The infection was found in 33 of 183 symptomatic children; among the 20 H. pylori-positive children for which the H. pylori genotype was available, cagA was present or absent in equal percentages. H. pylori infection was associated with more severe gastritis and higher serum levels of anti-H. pylori IgG and PGC but not with abdominal pain. In infected children, higher levels of anti-H. pylori IgG and the presence of abdominal pain were associated with infections caused by cagA-positive strains. In the cohort of 921 asymptomatic children, raised levels of anti-H. pylori IgG, PGA, and PGC were found in approximately 5% of the cases. CONCLUSIONS: Infection with cagA-positive H. pylori strains can be associated with increased frequency of reported abdominal pain and higher circulating levels of anti-H. pylori IgG. The serological assessment of H. pylori IgG using H. pylori antigens containing significant amounts of cagA protein may, therefore, underestimate the true prevalence of infection.

[Silent celiac disease: results of a study in secondary schools of Padua]. / La celiachia silente: risultati di uno studio nelle scuole medie di Padova.

Aim of this study was the assessment of the prevalence of coeliac disease (CD) in children attending the secondary school in the city of Padua. 939 students, aged 10-15 years (mean age: 12 years, 7 months), 35% eligible population, were accepted to undergo a study process which included three stages: a) in all students venous sample was taken for measurement of the IgG and IgA anti-gliadin antibodies (AGA); b) measurement of serum immunoglobulins and anti-endomysium antibodies (AEA) if AGA IgA was resulted positive; c) intestinal biopsy was performed in 3 students; two of them had pathologic levels of AGA IgG and IgA and AEA. These patients were females and had decreased rates of statural growth, anemia with iron deficiency, anorexia, abdominal pain, asthenia. The third girl had positive AGA IgG and IgA but absence of AEA and normal biopsy. She also had symptoms of abdominal pain, reduced height. Follow-up studies have been planned to establish a latent phase of CD. In conclusion, the prevalence of CD was 2.13/1000 (0.37-8.55, 95% CI), if we consider the patients with established diagnosis of CD in the same urban area and of the same age, the overall incidence increases to 2.6/1000. This prevalence, therefore, is higher, than that of 0.5/1000 previously reported in the general population, with a ratio of 1/4 between patients already known and the cases detected in this study.

European multicentre evaluation of the ABBOTT Spectrum clinical chemistry analyzer.

The analytical performance of the selective multitest ABBOTT Spectrum analyser was studied according to the ECCLS guidelines and partly the CERMAB protocol in a multicentre evaluation involving laboratories from six European countries. Fifteen analytes, including the electrolytes sodium, potassium and chloride, were measured each in at least 3 laboratories, all at 37 degrees C, except the electrolytes, which are measured at room temperature. The trial lasted approximately three months and involved the collection of over 60,000 data points. It yielded the following results: 1. The precision was at least as good as the precision obtained with the comparison instruments. The majority of the coefficients of variation were between 1 and 4%. 2. The recovery for method assigned control sera values was, with few exceptions, within 10%. 3. Good agreement with respect to the method assigned values of control materials and method comparison with patient specimens to different instruments (e.g. SMAC, Hitachi 737, RA 1000) was found. 4. No drift was observed. 5. Reagent-related carry-over was not found. Specimen-related carry-over was detected in some cases, the deviation being of little or no clinical significance. 6. The manufacturer's claims regarding method linearity were as stated or exceeded. 7. The open system capability was tested and rated as very convenient. 8. The practicability of the instrument was very good.

A new synthetic peptide with elastase inhibiting effect.

A new peptide, obtained by chemical synthesis, inhibits porcine pancreatic elastase activity "in vitro" with an IC50 of 24 mmol/l. The effect of the peptide was also tested on human plasma elastase by using plasmas with different levels of alpha-1-antitrypsin. The synthetic peptide apparently decreased the amount of normal plasma elastase, assayed by an immunoenzymatic method, with a dose-dependent effect and an IC50 of 13 mmol/l. In plasma with higher amounts of alpha-1-antitrypsin the IC50 value was 18 mmol/l.

[Comparative evaluation of a new method for the determination of alpha-amylase]. / Valutazione comparativa di un nuovo metodo per il dosaggio dell'alfa-amilasi.

A new method for alpha-amilase determination has been compared with other two methods already tested. All these methods have been evaluated by linearity, precision, accuracy and correlation tests. Affinity of the three different substrates for pancreatic and salivary isoenzymes has been valued too. The new method is based on the use of a mixture of p-nitrophenimaltopentaoside and p-nitrophenilhexaoside and it has given excellent results in the different tests and it has shown to be easily adaptable to automatized and centrifugal analysis. Moreover the hydrolysis of well defined substrates gives products which absorb in the visible part of the spectrum and it is an evident advantage. Therefore, this method is one of the most satisfactory for alpha-amilase determination too.