Differential cognitive effects of Ginkgo biloba after acute and chronic treatment in healthy young volunteers

Acute doses of Ginkgo biloba have been shown to improve attention and memory in young, healthy participants, but there has been a lack of investigation into possible effects on executive function. In addition, only one study has investigated the effects of chronic treatment in young volunteers. This study was conducted to compare the effects of ginkgo after acute and chronic treatment on tests of attention, memory and executive function in healthy university students. Using a placebo-controlled double-blind design, in experiment 1, 52 students were randomly allocated to receive a single dose of ginkgo (120 mg, n=26) or placebo (n=26), and were tested 4h later. In experiment 2, 40 students were randomly allocated to receive ginkgo (120 mg/day; n=20) or placebo (n=20) for a 6-week period and were tested at baseline and after 6 weeks of treatment. In both experiments, participants underwent tests of sustained attention, episodic and working memory, mental flexibility and planning, and completed mood rating scales. The acute dose of ginkgo significantly improved performance on the sustained-attention task and pattern-recognition memory task; however, there were no effects on working memory, planning, mental flexibility or mood. After 6 weeks of treatment, there were no significant effects of ginkgo on mood or any of the cognitive tests. In line with the literature, after acute administration ginkgo improved performance in tests of attention and memory. However, there were no effects after 6 weeks, suggesting that tolerance develops to the effects in young, healthy participants.

Is influenza vaccination cost effective for healthy people between ages 65 and 74 years? A randomised controlled trial

The aim of this study was to determine the cost effectiveness of influenza vaccination for healthy people aged 65-74 years living in the UK. People without risk factors for influenza (chronic heart, lung or renal disease, diabetic, immuno-suppressed or those living in an institution) were identified from 20 general practitioner (GP) practices in Liverpool in September 1999. 729/5875 (12.4%) eligible individuals were recruited and randomised to receive either influenza vaccine or placebo (ratio 3: 1)! with all participants receiving 23-valent-pneumococcal polysaccharide vaccine unless already administered. The primary analysis was the frequency of influenza as recorded by a GP diagnosis of pneumonia or influenza like illness. In 2000, the UK vaccination policy was changed with influenza vaccine becoming available. for all people aged 65 years and over irrespective of risk. As a consequence of this policy change. the study had to be fundamentally restructured and only results obtained over a one rather than the originally planned two-year randomised controlled trial framework were used. Results from 1999/2000 demonstrated no significant difference between groups for the primary outcome (relative risk 0.8, 95%, CI 0.16-4.1). In addition. there were no deaths or hospitalisations for influenza associated respiratory illness in either group. The subsequent analysis. using both national and local sources of evidence, estimated the following cost effectiveness indicators: (1) incremental NHS cost per GP consultation avoided = pound2000; (2) incremental NHS cost per hospital admission avoided = pound61,000: (3) incremental NHS cost per death avoided = pound1.900.000 and (4) incremental NHS cost per QALY gained = pound304,000. The analysis suggested that influenza vaccination in this Population would not be cost effective. (C) 2004 Elsevier Ltd. All rights reserved.

Relationship between 24-hour urinary-free cortisol excretion and salivary cortisol levels sampled from awakening to bedtime in healthy subjects

The utility of repeated salivary cortisol sampling as a substitute for 24-hour urinary-free cortisol (UFC) assessment was examined. Forty-four participants completed both 24-hour collections and 6 salivary collections at wake-up, 08:00, 12:00, 16:00, 20:00 and bedtime, during the same 24-hour period. The results demonstrated that mean, maximum, and amplitude (maximum minus minimum) for salivary cortisol all correlated positively with urinary cortisol, but the associations of these variables with urinary-free cortisol excretion were relatively small. Furthermore, a single salivary sample taken at wake-up was as good an indicator of overall cortisol production as the measures derived from multiple salivary samples. An examination of subject compliance indicated that many subjects failed to collect the timed salivary collections as instructed. The authors conclude that diurnal salivary cortisol sampling versus 24-hour urinary cortisol collections are likely to provide different information about ambient hypothalamic-pituitary-adrenal productivity, and therefore these measures should not be used interchangeably. In addition, subject compliance is a serious consideration in designing studies that employ home salivary collections. Published by Elsevier Science Inc.

Age and flexible thinking: an experimental demonstration of the beneficial effects of increased cognitively stimulating activity on fluid intelligence in healthy older adults

The disuse hypothesis of cognitive aging attributes decrements in fluid intelligence in older adults to reduced cognitively stimulating activity. This study experimentally tested the hypothesis that a period of increased mentally stimulating activities thus would enhance older adults' fluid intelligence performance. Participants (N = 44, mean age 67.82) were administered pre- and post-test measures, including the fluid intelligence measure, Cattell's Culture Fair (CCF) test. Experimental participants engaged in diverse, novel, mentally stimulating activities for 10-12 weeks and were compared to a control condition. Results supported the hypothesis; the experimental group showed greater pre- to post-CCF gain than did controls (effect size d = 0.56), with a similar gain on a spatial-perceptual task (WAIS-R Blocks). Even brief periods of increased cognitive stimulation can improve older adults' problem solving and flexible thinking.

A double-blind, placebo controlled human study investigating the effects of coffee derived manno-oligosaccharides on the faecal microbiota of a healthy adult population.

The aims of this study were to assess the impact of coffee derived mannooligosaccharides on the faecal microbiota of a healthy UK based population. Methods and Results: A double-blind, placebo-controlled, crossover human intervention study was conducted. Volunteers were assigned, 3g MOS, 5g MOS and placebo coffee preparations, to consume daily over a 3 wks, followed by a 2 wk washout period. Faecal samples were collected, and microbial population characterised using fluorescence in situ hybridization. Short-chain and branched-chain fatty acid profiles were obtained by gas chromatography. All treatments led to significant lactobacilli increases (placebo, p < 0.001; 3g, p = 0.04; 5g, p=0.04). The 3g treatment led to a significant bifidobacteria increase (p=0.001). Significantly less iso-valerate was found in faeces following 3g MOS daily (p=0.05). Conclusions: The 3g dose of MOS led to a potentially beneficial shift in the faecal microbiota. MOS was therefore confirmed to be a prebiotic at 3g dose. Significance and Impact of Study: This study provides confirmation of a new novel prebiotic, that can be considered for incorporation into a wider variety of food products, to provide different selective and nutritional properties.

The demand for a healthy diet: estimating the almost ideal demand system with infrequency of purchase

A Bayesian method of estimating multivariate sample selection models is introduced and applied to the estimation of a demand system for food in the UK to account for censoring arising from infrequency of purchase. We show how it is possible to impose identifying restrictions on the sample selection equations and that, unlike a maximum likelihood framework, the imposition of adding up at both latent and observed levels is straightforward. Our results emphasise the role played by low incomes and socio-economic circumstances in leading to poor diets and also indicate that the presence of children in a household has a negative impact on dietary quality.

Phenotypic and phylogenetic characterization of a new Corynebacterium species from dogs: description of Corynebacterium auriscanis sp. nov.

Six strains of a previously undescribed catalase-positive coryneform bacterium isolated from clinical specimens from dogs were characterized by phenotypic and molecular genetic methods. Biochemical and chemotaxonomic studies revealed that the unknown bacterium belonged to the genus Corynebacterium sensu stricto. Comparative 16S rRNA gene sequencing showed that the six strains were genealogically highly related and constitute a new subline within the genus Corynebacterium; this subline is close to but distinct from C. falsenii, C. jeikeium, and C. urealyticum. The unknown bacterium from dogs was distinguished from all currently validated Corynebacterium species by phenotypic tests including electrophoretic analysis of whole-cell proteins. On the basis of phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as a new species, Corynebacterium auriscanis. The type strain of C. auriscanis is CCUG 39938T.

Actinomyces catuli sp. nov., from dogs

An Actinomyces-like bacterium was recovered from two dogs. Based on cellular morphology and biochemical criteria, the unknown bacterium resembled the genus Actinomyces but it did not appear to correspond to any of the currently recognized species of this genus. PAGE analysis of whole-cell proteins confirmed that the strain was phenotypically distinct from all other Actinomyces species and comparative 16S rRNA gene sequencing showed that the bacterium represents an unknown sub-line within the genus. Based on phenotypic and phylogenetic evidence, it is proposed that the bacterium from dogs be classified as a new species of the genus Actinomyces, Actinomyces catuli. The type strain of Actinomyces catuli is CCUG 41709T (= CIP 106507T).

Actinomyces canis sp. nov., isolated from dogs

Three strains of a previously undescribed catalase-positive Actinomyces-like bacterium were isolated from dogs. Biochemical testing and PAGE analysis of whole-cell proteins indicated that the strains were phenotypically highly related to each other but different from previously described Actinomyces and Arcanobacterium species. Sequencing of 16S rRNA showed that the unknown bacterium represents a new subline within a cluster of species which includes Actinomyces hyovaginalis, Actinomyces georgiae, Actinomyces meyeri, Actinomyces odontolyticus, Actinomyces radingae and Actinomyces turicensis. On the basis of phenotypic evidence and 16S rRNA sequence divergence levels (greater than 5% with recognized Actinomyces species) it is proposed that the unknown strains from canine sources be classified as a new species with the name Actinomyces canis sp. nov. The type strain of Actinomyces canis is CCUG 41706T (= CIP 106351T).

Effects of a novel galactooligosaccharide on the faecal microbiota of healthy and inflammatory bowel disease cats during a randomized, double-blind, cross-over feeding study

Inflammatory bowel disease (IBD) is a common gastrointestinal disorder of cats with no known aetiological agent. Previous work has suggested that the faecal microbiota of IBD cats is significantly different from that of healthy cats, including significantly lower bifidobacteria, bacteroides and total counts in IBD cats and significantly lower levels of sulfate-reducing bacteria in healthy cats. Prebiotics, including galactooligosaccharides (GOS), have been shown to elicit a bifidogenic effect in humans and other animals. The purpose of the current study was to examine the impact of a novel GOS supplementation on the faecal microbiota of healthy and IBD cats during a randomized, double-blind, cross-over feeding study. Eight oligonucleotide probes targeting specific bacterial populations and DAPI stain (total bacteria) were used to monitor the feline faecal microbiota. Overall, inter-animal variation was high; while a trend of increased bifidobacterial levels was seen with GOS supplementation it was not statistically significant in either healthy or IBD cats. No significant differences were observed in the faecal microbiota of IBD cats and healthy cats fed the same diet. Members of the family Coriobacteriaceae (Atopobium cluster) were found to be the most abundant bacteria in the feline microbiota.

Longitudinal investigation of the faecal microbiota of healthy full-term infants using fluorescence in situ hybridization and denaturing gradient gel electrophoresis.

From birth onwards, the gastrointestinal (GI) tract of infants progressively acquires a complex range of micro-organisms. It is thought that by 2 years of age the GI microbial population has stabilized. Within the developmental period of the infant GI microbiota, weaning is considered to be most critical, as the infant switches from a milk-based diet (breast and/or formula) to a variety of food components. Longitudinal analysis of the biological succession of the infant GI/faecal microbiota is lacking. In this study, faecal samples were obtained regularly from 14 infants from 1 month to 18 months of age. Seven of the infants (including a set of twins) were exclusively breast-fed and seven were exclusively formula-fed prior to weaning, with 175 and 154 faecal samples, respectively, obtained from each group. Diversity and dynamics of the infant faecal microbiota were analysed by using fluorescence in situ hybridization and denaturing gradient gel electrophoresis. Overall, the data demonstrated large inter- and intra-individual differences in the faecal microbiological profiles during the study period. However, the infant faecal microbiota merged with time towards a climax community within and between feeding groups. Data from the twins showed the highest degree of similarity both quantitatively and qualitatively. Inter-individual variation was evident within the infant faecal microbiota and its development, even within exclusively formula-fed infants receiving the same diet. These data can be of help to future clinical trials (e.g. targeted weaning products) to organize protocols and obtain a more accurate outline of the changes and dynamics of the infant GI microbiota.

A double-blind, placebo-controlled, cross-over study to establish the bifidogenic effect of a very-long-chain inulin extracted from globe artichoke (Cynara scolymus) in healthy human subjects

There is growing interest in the use of inulins as substrates for the selective growth of beneficial gut bacteria such as bifidobacteria and lactobacilli because recent studies have established that their prebiotic effect is linked to several health benefits. In the present study, the impact of a very-long-chain inulin (VLCI), derived from globe artichoke (Cynara scolymus), on the human intestinal microbiota compared with maltodextrin was determined. A double-blind, cross-over study was carried out in thirty-two healthy adults who were randomised into two groups and consumed 10 g/d of either VLCI or maltodextrin, for two 3-week study periods, separated by a 3-week washout period. Numbers of faecal bifidobacteria and lactobacilli were significantly higher upon VLCI ingestion compared with the placebo. Additionally, levels of Atopobium group significantly increased, while Bacteroides–Prevotella numbers were significantly reduced. No significant changes in faecal SCFA concentrations were observed. There were no adverse gastrointestinal symptoms apart from a significant increase in mild and moderate bloating upon VLCI ingestion. These observations were also confirmed by in vitro gas production measurements. In conclusion, daily consumption of VLCI extracted from globe artichoke exerted a pronounced prebiotic effect on the human faecal microbiota composition and was well tolerated by all volunteers.