[Efficacy of freeze-dried Lactobacilli in functional diarrhoe: a pilot study]. / Wirksamkeit eines Lactobazillen-Lyophilisats bei funktioneller Diarrhoe: eine Pilotstudie.

BACKGROUND AND OBJECTIVE: The pathogenic role of the intestinal milieu for symptoms in functional bowel disorders such as functional diarrhea (FD) or associated pain and bloating in the irritable bowel syndrome (IBS) is the rationale for probiotic treatment approaches. It was the aim of this pilot study to test the effects of a lyophilisate from devitalized lactobacilli and their culture medium in patients with chronic FD. METHODS: Following a one-week basal period, 22 patients mit FD (12 with IBS) were treated with Lacteol (2 capsules/day) for 4 weeks. Stool frequency, consistency (assessed by BSFS), urge, pain and bloating were recorded daily using a standardized symptom diary, and global relief was recorded weekly. RESULTS: Daily stool frequency and number of days with urge were significantly decreased starting in week 1 (-0.6 ± 0.2/day; p = 0.005; and -1.3 ± 0.3 days, respectively; p = 0.001). This effect persisted throughout week 4 (-0.6 ± 0.2/day; p< 0.02; and -1.4 ± 0.5 days, respectively; p = 0.025). After 4 weeks, 50% of patients reported satisfactory symptom relief, including improvement in maximal stool consistency (BSFS: -0.3 ± 0.2; p = 0.04), and 43% of patients recorded a decrease in stool frequency of ≥ 25%. CONCLUSION: These findings suggest a clinically relevant efficacy of Lacteol in a subgroup of patients with FD, particularly with regard to stool frequency, urge and stool consistency. As the study design does not allow to exclude that a placebo component might have contributed to these effects, the results should be corroborated in an larger, placebo-controlled trial.

Quantitative trait loci for resistance to Heligmosomoides bakeri and associated immunological and pathological traits in mice: comparison of loci on chromosomes 5, 8 and 11 in F2 and F6/7 inter-cross lines of mice.

A comparison of F2 and F6/7 inter-cross lines of mice, derived from CBA and SWR parental strains, has provided strong evidence for several previously undetected quantitative trait loci (QTL) for resistance to Heligmosomoides bakeri. Five QTL affecting average faecal egg counts and/or worm burdens in week 6 were detected on mouse chromosomes 5 (Hbnr9 and Hbnr10), 8 (Hbnr11) and 11 (Hbnr13 and Hbnr14). Three QTL for faecal egg counts in weeks 4 and 6 were found on both chromosomes 5 (Hbnr9) and 11 (Hbnr13 and Hbnr14). Two QTL for the mucosal mast cell protease 1 (MCPT1) response were located on chromosomes 8 (Hbnr11) and 11 (Hbnr13), two for the IgG1 antibody response to adult worms on chromosomes 5 (Hbnr10) and 8 (Hbnr11), two for PCV in week 6 on chromosomes 5 (Hbnr9) and 11 (Hbnr13), and two for the granulomatous response on chromosome 8 (Hbnr12) and 11 (Hbnr15). Our data emphasize that the control of resistance to H. bakeri is multigenic, and regulated by genes within QTL regions that have a complex range of hierarchical relationships.

Heligmosomoides bakeri: a model for exploring the biology and genetics of resistance to chronic gastrointestinal nematode infections.

The intestinal nematode Heligmosomoides bakeri has undergone 2 name changes during the last 4 decades. Originally, the name conferred on the organism in the early 20th century was Nematospiroides dubius, but this was dropped in favour of Heligmosomoides polygyrus, and then more recently H. bakeri, to distinguish it from a closely related parasite commonly found in wood mice in Europe. H. bakeri typically causes long-lasting infections in mice and in this respect it has been an invaluable laboratory model of chronic intestinal nematode infections. Resistance to H. bakeri is a dominant trait and is controlled by genes both within and outside the MHC. More recently, a significant QTL has been identified on chromosome 1, although the identity of the underlying genes is not yet known. Other QTL for resistance traits and for the accompanying immune responses were also defined, indicating that resistance to H. bakeri is a highly polygenic phenomenon. Hence marker-assisted breeding programmes aiming to improve resistance to GI nematodes in breeds of domestic livestock will need to be highly selective, focussing on genes that confer the greatest proportion of overall genetic resistance, whilst leaving livestock well-equipped genetically to cope with other types of pathogens and preserving important production traits.

Coastal oceanography sets the pace of rocky intertidal community dynamics.

The structure of ecological communities reflects a tension among forces that alter populations. Marine ecologists previously emphasized control by locally operating forces (predation, competition, and disturbance), but newer studies suggest that inputs from large-scale oceanographically modulated subsidies (nutrients, particulates, and propagules) can strongly influence community structure and dynamics. On New Zealand rocky shores, the magnitude of such subsidies differs profoundly between contrasting oceanographic regimes. Community structure, and particularly the pace of community dynamics, differ dramatically between intermittent upwelling regimes compared with relatively persistent down-welling regimes. We suggest that subsidy rates are a key determinant of the intensity of species interactions, and thus of structure in marine systems, and perhaps also nonmarine communities.

Chasing the genes that control resistance to gastrointestinal nematodes.

The host-protective immune response to infection with gastrointestinal (GI) nematodes involves a range of interacting processes that begin with recognition of the parasite's antigens and culminate in an inflammatory reaction in the intestinal mucosa. Precisely which immune effectors are responsible for the loss of specific worms is still not known although many candidate effectors have been proposed. However, it is now clear that many different genes regulate the response and that differences between hosts (fast or strong versus slow or weak responses) can be explained by allelic variation in crucial genes associated with the gene cascade that accompanies the immune response and/or genes encoding constitutively expressed receptor/signalling molecules. Major histocompatibility complex (MHC) genes have been recognized for some time as decisive in controlling immunity, and evidence that non-MHC genes are equally, if not more important in this respect has also been available for two decades. Nevertheless, whilst the former have been mapped in mice, only two candidate loci have been proposed for non-MHC genes and relatively little is known about their roles. Now, with the availability of microsatellite markers, it is possible to exploit linkage mapping techniques to identify quantitative trait loci (QTL) responsible for resistance to GI nematodes. Four QTL for resistance to Heligmosomoides polygyrus, and additional QTL affecting faecal egg production by the worms and the accompanying immune responses, have been identified. Fine mapping and eventually the identification of the genes (and their alleles) underlying QTL for resistance/susceptibility will permit informed searches for homologues in domestic animals, and human beings, through comparative genomic maps. This information in turn will facilitate targeted breeding to improve resistance in domestic animals and, in human beings, focused application of treatment and control strategies for GI nematodes.

Effect of excessive dietary vitamin E on the chick.

Day-old male broiler chicks were fed a broiler ration for five weeks to which was added one of the following levels of dl-alpha tocopheryl acetate; 0; 2,000; 4,000; 8,000; 16,000; 32,000, and 64,000 I.U./kg. The chicks fed diets containing 4,000 I.U./kg. or more of vitamin E showed decreased pigmentation in their beaks, feet and shanks, and liver as a percent of body weight was significantly increased. Feeding at least 8,000 I.U./kg of the vitamin significantly reduced chick body weight and resulted in waxy appearing feathers. Dietary inclusion of 16,000 I.U./kg. or more of vitamin E significantly increased feather, spleen, liver, and plasma vitamin E content.