Caseinoglycomacropeptide inhibits adhesion of pathogenic Escherichia coli strains to human cells in culture

Caseinoglycomacropeptide (CGMP) derived from kappa-casein was investigated for its ability to inhibit the adhesion of 3 strains of verotoxigenic Escherichia coli (VTEC) and 3 strains of enteropathogenic Escherichia coli (EPEC) to human HT29 tissue cell cultures. Effects on adhesion of Desulfovibrio desulfuricans, Lactobacillus pentosus, Lactobacillus casei, Lactobacillus acidophilus, and Lactobacillus gasseri were also investigated. Generally, CGMP exerted effective anti-adhesive properties at a dose of 2.5 mg/mL, albeit with a high degree of strain specificity. The CGMP reduced adhesion of VTEC strains to < 50% of the control and reduced adhesion of EPEC strains to between 80 and 10% of the control. The CGMP also reduced the adhesion of L. pentosus and L. casei to 44 and 42%, respectively. A slight but significant reduction of L. acidophilus, to 81%, was observed, but no significant effects were detected with either Dsv. desulfuricans or L. gasseri. Further investigation of the dose response relationships with the E. coli strains gave IC50 values ranging between 0.12 and 1.06 mg/mL.

Inhibition of the adhesion of enteropathogenic Escherichia coli strains to HT-29 cells in culture by chito-oligosaccharides

The ability of chito-oligosaccharides (COS) to inhibit selected intestinal bacteria was investigated. COS at 2.5 mg ml(-1) had no significant effect on the adhesion of three strains of verotoxigenic Escherichia coli (VTEC), Lactobacillus pentosus, L. casei or L. gasseri to human HT29 cells in tissue culture. However, COS significantly inhibited adhesion of three strains of enteropathogenic E. coli (EPEC) to below 30% of the level of adhesion seen in the controls. Dose-response curves were constructed to further characterise the inhibition of EPEC strains to HT29 cells. (c) 2005 Elsevier Ltd. All rights reserved.

Molecular identification and anti-pathogenic activities of putative probiotic bacteria isolated from faeces of healthy elderly individuals

One hundred and nine lactic acid bacterial strains (56 bifidobacteria-like and 53 lactobacilli-like) were isolated from faecal samples donated by healthy elderly individuals (>65 years old). Isolates were identified to species level by phenotypic analysis (by API) and by 16S rDNA sequencing. Eleven species of Lactobacillus and six species of Bifidobacterium were identified. The most frequently isolated lactobacillus was L. fermentum and the most frequently isolated bifidobacterium was closely related to B. infantis by 16S rDNA sequence alignment. The isolates were characterized for their antimicrobial activity against Clostridium difficile, enteropathogenic Escherichia coli (EPEC), verocytotoxigenic E. coli (VTEC) and Campylobacter jejuni. The lactobacilli displayed variations in their antimicrobial activity with few strains showing inhibitory activity against all pathogens. The bifidobacteria displayed higher levels of inhibitory activity against C. jejuni and Cl. difficile than against the E. coli strains. Keywords: Lactobacillus, Bifidobacterium, elderly, gastrointestinal microbiota, inhibition, Clostridium difficile, enteropathogenic Escherichia coli (EPEC), verocytotoxigenic E. coli (VTEC), Campylobacter jejuni.

rRNA probes used to quantify the effects of glycomacropeptide and alpha-lactalbumin supplementation on the predominant groups of intestinal bacteria of infant rhesus monkeys challenged with enteropathogenic Escherichia coli

Objectives: Certain milk factors may help to promote the growth of a host-friendly colonic microflora (e.g. bifidobacteria, lactobacilli) and explain why breast-fed infants experience fewer and milder intestinal infections than those who are formula-fed. The effects of supplementation of formula with two such milk factors was investigated in this study. Materials and Methods: Infant rhesus macaques were breastfed, fed control formula, or formula supplemented with glycomacropeptide (GMP) or alpha-lactalburnin (alpha-LA) from birth to 5 months of age. Blood was drawn monthly and rectal swabs were collected weekly. At 4.5 months of age, 10(8) colonyforming units of enteropathogenic E.coli O127, strain 2349/68 (EPEC) was given orally and the response to infection assessed. The bacteriology of rectal swabs pre- and post-infection was determined by culture independent fluorescence in situ hybridization. Results: Post-challenge, breast-fed infants and infants fed alpha-LA-supplemented formula had no diarrhea, whilst those infants fed GMP-supplemented formula had intermittent diarrhea. In infants fed control formula the diarrhea was acute. Conclusions: Supplementation of infant formula with appropriate milk proteins may be useful for improving the infant's ability to resist acute infection caused by E.coli.

The effects of alpha-lactalbumin and glycomacropeptide on the association of CaCo-2 cells by enteropathogenic Escherichia coli, Salmonella typhimurium and Shigella flexneri

Two milk components, alpha-lactalbumin (alpha-La) and glycomacropeptide (GMP) may inhibit intestinal infection/intoxification. (3)[H] thymidine-labeled enteropathogenic Escherichia coli (EPEC), Salmonella typhimurium (ATCC 6994) or Shigella flexneri (ATCC 9199) were introduced to CaCo-2 cultures and their association with CaCo-2 cells was assessed. Undigested, pepsin-digested and pepsin- and pancreatin-digested alpha-lactalbumin and glycomacropeptide inhibited association. Thus, milk supplemented with alpha-lactalbumin and glycomacropeptide might be effective in inhibiting associations of the pathogens EPEC, Salmonella typhimurium, and Shigella flexneri to intestinal cells.

Differential induction of apoptosis in human colonic carcinoma cells (Caco-2) by Atopobium, and commensal, probiotic and enteropathogenic bacteria: mediation by the mitochondrial pathway

The induction of apoptosis in mammalian cells by bacteria is well reported. This process may assist infection by pathogens whereas for non-pathogens apoptosis induction within carcinoma cells protects against colon cancer. Here, apoptosis induction by a major new gut bacterium, Atopobium minutum, was compared with induction by commensal (Escherichia coli K-12 strains), probiotic (Lactobacillus rhamnosus, Bifidobacterium latis) and pathogenic (E. coli: EPEC and VTEC) gut bacteria within the colon cancer cell line, Caco-2. The results show a major apoptotic effect for the pathogens, mild effects for the probiotic strains and A. minutum, but no effect for commensal E. coli. The mild apoptotic effects observed are consistent with the beneficial roles of probotics in protection against colon cancer and suggest, for the first time, that A. minutum possesses similar advantageous, anti-cancerous activity. Although bacterial infection increased Caco-2 membrane FAS levels, caspase-8 was not activated indicating that apoptosis is FAS independent. Instead, in all cases, apoptosis was induced through the mitochondrial pathway as indicated by BAX translocation, cytorchrome c release, and caspase-9 and -3 cleavage. This suggests that an intracellular stimulus initiates the observed apoptosis responses.

Social interaction deficits and conversational inadequacy in Williams syndrome

Research on social communication skills in individuals with Williams syndrome has been inconclusive, with some arguing that these skills are a relative strength and others that they are a weakness. The aim of the present study was to investigate social interaction abilities in a group of children with WS, and to compare them to a group of children with specific language impairment and a group of typically developing children. Semi-structured conversations were conducted and 100-150 utterances were selected for analysis in terms of exchange structure, turn taking, information transfer and conversational inadequacy. The statistical analyses showed that the children with WS had difficulties with exchange structure and responding appropriately to the interlocutor's requests for information and clarification. They also had significant difficulties with interpreting meaning and providing enough information for the conversational partner. Despite similar language abilities with a group of children with specific language impairment, the children with WS had different social interaction skills, which suggests that they follow an atypical trajectory of development and their neurolinguistic profile does not directly support innate modularity. (c) 2005 Elsevier Ltd. All rights reserved.

Texture segmentation in Williams syndrome

Williams syndrome (WS) is a developmental disorder in which visuo-spatial cognition is poor relative to verbal ability. At the level of visuo-spatial perception, individuals with WS can perceive both the local and global aspects of an image. However, the manner in which local elements are integrated into a global whole is atypical, with relative strengths in integration by luminance, closure, and alignment compared to shape, orientation and proximity. The present study investigated the manner in which global images are segmented into local parts. Segmentation by seven gestalt principles was investigated: proximity, shape, luminance, orientation, closure, size (and alignment: Experiment I only). Participants were presented with uniform texture squares and asked to detect the presence of a discrepant patch (Experiment 1) or to identify the form of a discrepant patch as a capital E or H (Experiment 2). In Experiment 1, the pattern and level of performance of the WS group did not differ from that of typically developing controls, and was commensurate with the general level of non-verbal ability observed in WS. These results were replicated in Experiment 2, with the exception of segmentation by proximity, where individuals with WS demonstrated superior performance relative to the remaining segmentation types. Overall, the results suggest that, despite some atypical aspects of visuo-spatial perception in WS, the ability to segment a global form into parts is broadly typical in this population. In turn, this informs predictions of brain function in WS, particularly areas V1 and V4. (c) 2006 Elsevier Ltd. All rights reserved.

Visuospatial cognition in Williams syndrome: reviewing and accounting for the strengths and weaknesses in performance

Individuals with Williams syndrome typically show relatively poor visuospatial abilities in comparison to stronger verbal skills. However, individuals' level of performance is not consistent across all visuospatial tasks. The studies assessing visuospatial functioning in Williams syndrome are critically reviewed, to provide a clear pattern of the relative difficulty of these tasks. This prompts a possible explanation of the variability in performance seen, which focuses on the processing demands of some of these tasks. Individuals with Williams syndrome show an atypical processing style on tests of construction, which does not affect tests of perception.

Strategies and biases in location memory in Williams syndrome

Individuals with Williams syndrome (WS) demonstrate impaired visuo-spatial abilities in comparison to their level of verbal ability. In particular, visuo-spatial construction is an area of relative weakness. It has been hypothesised that poor or atypical location coding abilities contribute strongly to the impaired abilities observed on construction and drawing tasks [Farran, E. K., & Jarrold, C. (2005). Evidence for unusual spatial location coding in Williams syndrome: An explanation for the local bias in visuo-spatial construction tasks? Brain and Cognition, 59, 159-172; Hoffman, J. E., Landau, B., & Pagani, B. (2003). Spatial breakdown in spatial construction: Evidence from eye fixations in children with Williams syndrome. Cognitive Psychology, 46, 260-301]. The current experiment investigated location memory in WS. Specifically, the precision of remembered locations was measured as well as the biases and strategies that were involved in remembering those locations. A developmental trajectory approach was employed; WS performance was assessed relative to the performance of typically developing (TD) children ranging from 4- to 8-year-old. Results showed differential strategy use in the WS and TD groups. WS performance was most similar to the level of a TD 4-year-old and was additionally impaired by the addition of physical category boundaries. Despite their low level of ability, the WS group produced a pattern of biases in performance which pointed towards evidence of a subdivision effect, as observed in TD older children and adults. In contrast, the TD children showed a different pattern of biases, which appears to be explained by a normalisation strategy. In summary, individuals with WS do not process locations in a typical manner. This may have a negative impact on their visuo-spatial construction and drawing abilities. (c) 2007 Elsevier Ltd. All rights reserved.

Methods of producing haploid and doubled haploid oil palms

The present invention relates to haploid oil palm plants and homozygous doubled haploid oil palm plants. The invention also relates to methods for producing and selecting haploid and doubled haploid plants. More particularly, but not exclusively, the method may be used for selecting haploid and doubled haploid oil palm plants. Haploid and doubled haploid plants are selected by a large-scale screening based on a combination of the phenotype with the use of molecular methods combined with flow cytometry techniques to identify haploid and doubled haploid plants. More particularly, a method for selecting haploid and doubled haploid plants is described comprising: (a) germinating seeds; (b) selecting seedlings with atypical phenotype; (c) assessing heterozygosity using markers; (d) isolating cells from the seedlings and determining the DNA content of the cells; and (e) isolating and purifying the DNA and using defined molecular markers to characterise the genotype of the plant. The haploid oil palm plants may be used for producing homozygous doubled haploid oil palms: doubled haploids may be intercrossed to produce uniform F.sub.1 hybrids of superior properties.

Variation in the human Cannabinoid Receptor (CNR1) gene modulates gaze duration for happy faces

BACKGROUND: Humans from an early age look longer at preferred stimuli, and also typically look longer at facial expressions of emotion, particularly happy faces. Atypical gaze patterns towards social stimuli are common in Autism Spectrum Conditions (ASC). However, it is unknown if gaze fixation patterns have any genetic basis. In this study, we tested if variations in the cannabinoid receptor 1 (CNR1) gene are associated with gaze duration towards happy faces. This gene was selected because CNR1 is a key component of the endocannabinoid system, involved in processing reward, and in our previous fMRI study we found variations in CNR1 modulates the striatal response to happy (but not disgust) faces. The striatum is involved in guiding gaze to rewarding aspects of a visual scene. We aimed to validate and extend this result in another sample using a different technique (gaze tracking). METHODS: 30 volunteers (13 males, 17 females) from the general population observed dynamic emotion expressions on a screen while their eye movements were recorded. They were genotyped for the identical four SNPs in the CNR1 gene tested in our earlier fMRI study. RESULTS: Two SNPs (rs806377 and rs806380) were associated with differential gaze duration for happy (but not disgust) faces. Importantly, the allelic groups associated with greater striatal response to happy faces in the fMRI study were associated with longer gaze duration for happy faces. CONCLUSIONS: These results suggest CNR1 variations modulate striatal function that underlies the perception of signals of social reward such as happy faces. This suggests CNR1 is a key element in the molecular architecture of perception of certain basic emotions. This may have implications for understanding neurodevelopmental conditions marked by atypical eye contact and facial emotion processing, such as ASC.

Evidence that convergence rather than accommodation controls intermittent distance exotropia

Purpose. This study considered whether vergence drives accommodation or accommodation drives vergence during the control of distance exotropia for near fixation. High accommodative convergence to accommodation (AC/A) ratios are often used to explain this control, but the role of convergence to drive accommodation (the CA/C relationship) is rarely considered. Atypical CA/C characteristics could equally, or better, explain common clinical findings. Methods. 19 distance exotropes, aged 4-11 years, were compared while controlling their deviation with 27 non-exotropic controls aged 5-9 years. Simultaneous vergence and accommodation responses were measured to a range of targets incorporating different combinations of blur, disparity and looming cues at four fixation distances between 2m and 33cm. Stimulus and response AC/A and CA/C ratios were calculated. Results. Accommodation responses for near targets (p=0.017) response gains (p=0.026) were greater in the exotropes than the controls. Despite higher clinical stimulus AC/A ratios, the distance exotropes showed lower laboratory response AC/A ratios (p=0.02), but significantly higher CA/C ratios (p=0.02). All the exotropes, whether the angle changed most with lenses (“controlled by accommodation”) or on occlusion (“controlled by fusion”), used binocular disparity not blur as their main cue to target distance. Conclusions. Increased vergence demand to control intermittent distance exotropia for near also drives significantly more accommodation. Minus lens therapy is more likely to act by correcting over-accommodation driven by controlling convergence, rather than by inducing blur-driven vergence. The use of convergence as a major drive to accommodation explains many clinical characteristics of distance exotropia, including apparently high near stimulus AC/A ratios.

Cortisol levels in response to starting school in children at increased risk for social phobia

Background: Research on depression has identified hyperactivity of the HPA axis as a potential contributory factor to the intergenerational transmission of affective symptoms. However, this has not yet been examined in the context of social phobia. The current study compared HPA axis activity in response to a universal social stressor (starting school) in children of 2 groups of women: one with social phobia and one with no history of anxiety (comparison group). To determine specificity of effects of maternal social phobia, a third group of children were also examined whose mothers had generalised anxiety disorder (GAD). Method: Children provided salivary cortisol samples in the morning, afternoon and at bedtime across 3 time-blocks surrounding the school start: a month before starting school (baseline), the first week at school (stress response), and the end of the first school term (stress recovery). Child behavioural inhibition at 14 months was also assessed to explore the influence of early temperament on later stress responses. Results: All children displayed an elevation in morning and afternoon cortisol from baseline during the first week at school, which remained elevated until the end of the first term. Children in the social phobia group, however, also displayed an equivalent elevation in bedtime cortisol, which was not observed for comparison children or for children of mothers with GAD. Children in the social phobia group who were classified as 'inhibited' at 14 months displayed significantly higher afternoon cortisol levels overall. Summary: A persistent stress response to school in the morning and afternoon is typical for all children, but children of mothers with social phobia also display atypical elevations in evening cortisol levels when at school - signalling long-term disruption of the circadian rhythm in HPA axis activity. This is the first study to report HPA axis disruption in children at risk of developing social phobia, and future research should aim to determine whether this represents a pathway for symptom development, taking early temperament into account.