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The prevalence of adult-type hypolactasia varies ethnically and geographically among populations. A [C/T.sub.-13910] single nucleotide polymorphism (SNP), upstream of the lactase gene, is known to be associated with lactase non-persistence. The aim of this study was to determine the prevalence of lactase-persistent and non-persistent genotypes in the Hungarian population, the age at onset and the applicability of the lactose HZ breath test in comparison with genetic screening. The prevalence of the [C/C.sub.13910] genotype among adults was 37%. Hypolactasia starts to appear at around 5 years of age. Over the age of 12 years, almost all of those with a [C/C.sub.-13910] genotype have lactase non-persistence. The [C/C.sub.13910] genotype was closely associated with a positive lactose [H.sub.2] breath test in symptomatic children, whereas the lactase-persistent genotypes correlated better with a negative [H.sub.2] test in a control group. In conclusion, supplementary non-invasive breath and genotyping tests furnish a perfect clinical diagnosis. doi:10.1038/ejcn.2008.74; published online 21 January 2009 Keywords: lactose intolerance; single nucleotide polymorphism [C/T.sub.-13910] [H.sub.2] breath test; specificity; sensitivity; positive and negative predictive value, Introduction Adult-type hypolactasia (ATH, lactase non-persistence) is an autosomal recessive trait with ethnic and geographical variations in its prevalence and age at onset (Swallow, 2003; Rasinpera et al., 2004). A [...]

Breath analysis can be a valuable, noninvasive tool for the clinical diagnosis of a number of pathological conditions. The detection of ammonia in exhaled breath is of particular interest for it has been linked to kidney malfunction and peptic ulcers. Pulsed cavity ringdown spectroscopy in the mid-IR region has developed into a sensitive analytical technique for trace gas analysis. A gas analyzer based on a pulsed mid-IR quantum cascade laser operating near 970 [cm.sup.-1] has been developed for the detection of ammonia levels in breath. We report a sensitivity of ~50 parts per billion with a 20 s time resolution for ammonia detection in breath with this system. The challenges and possible solutions for the quantification of ammonia in human breath by the described technique are discussed. OCIS codes: 300.6340, 170.4580, 280.3420, 140.5960, 300.1030.

Byline: L. I. Irzhak (1), P. V. Polyakov (1) Abstract: Stange's and Genci's functional tests performed at rest and during exercise and blood tests have shown that the duration of voluntary breath holding depends on appearance in the blood of hypoxia, hypercapnia, and acidosis signs only after the influence of fatigue of respiratory muscles and respiratory center has become insufficient. Author Affiliation: (1) Syktyvkar State University, Syktyvkar, Komi Republic, Russia Article History: Registration Date: 12/10/2004

Byline: D. Teculescu (1), A. B. Bohadana (1), S. E. Megherbi (1), E. Costantino (2), Q. T. Pham (1) Keywords: Key words: Single breath N2 test--Acceptability--Field survey. Abstract: Because some authors have reported high rates of failure in performing the single breath N.sub.2 (SBN.sub.2) test in rural areas, the present study aimed at evaluating its acceptability in a female population, unfamiliar with lung function testing, in a rural area of northeastern France. Two hundred ninety-eight women from a rural area volunteered for a preventive medicine examination (91.6% of those invited) four of them were excluded for clinical reasons, and six (2%) were unable to perform spirometry. The protocol included completion of a questionnaire, spirometry with a bronchial reactivity test, skin prick test, and the SBN.sub.2 test utilizing a computerized assembly. Although failures caused by the apparatus were few (n= 7, 2.4%) 96 of 281 women (34.1%) were unable to produce two valid SBN.sub.2 tests in a series of six attempts. Compared with the group who succeeded in the test (n= 185), women who failed were older and had a higher prevalence of bronchial hyperresponsiveness. Logistic regression confirmed the independent association of these two variables with an inability to perform. We conclude that in a female population completely unfamiliar with lung function testing the SBN.sub.2 test has a high rate of failure associated with higher age and the presence of bronchial hyperresponsiveness. Author Affiliation: (1) Institut National de la Sante et de la Recherche Medicale (I.N.S.E.R.M.), Unite 420, B.P. 184, 54505 VandAuvre-Les-Nancy Cedex, France, FR (2) II Divisione Pneumologia, Policlinica Bari, Bari, Italy, IT Article note: Accepted for publication: 17 November 1998

Background: Exhaled breath condensate (EBC) is a rapidly expanding area of research to study airway inflammation through the detection of volatile and non-volatile substances in the airways. Aims: To determine [...]

One-hundred-and-fifty-nine patients, aged 18 and above, from a country hospital were subjected to breath-analysis to determine the correlation between the results of the breath-analyzer and the statements of the patients about their intake of alcohol before injury. Discrepancies were noted when the patient was interviewed before the analysis. The fraction of people contradicting their reports of alcohol intake was low. The timing of the breath analysis test did not influence the results, despite the discrepancies observed through a prior testing recommended to facilitate statistical and medical studies.