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1.
Foods ; 13(11)2024 May 24.
Article in English | MEDLINE | ID: mdl-38890860

ABSTRACT

The milk fat globule membrane (MFGM) contains bioactive proteins, carbohydrates, and lipids. Polar lipids found in the MFGM play a critical role in maintaining cell membrane integrity and neuronal signalling capacity, thereby supporting brain health. This review summarises the literature on the MFGM and its phospholipid constituents for improvement of mental health across three key stages of the human lifespan, i.e., infancy, adulthood, and older age. MFGM supplementation may improve mental health by reducing neuroinflammation and supporting neurotransmitter synthesis through the gut-brain axis. Fortification of infant formula with MFGMs is designed to mimic the composition of breastmilk and optimise early gut and central nervous system development. Early behavioural and emotional development sets the stage for future mental health. In adults, promising results suggest that MFGMs can reduce the negative consequences of situational stress. Preclinical models of age-related cognitive decline suggest a role for the MFGM in supporting brain health in older age and reducing depressive symptoms. While there is preclinical and clinical evidence to support the use of MFGM supplementation for improved mental health, human studies with mental health as the primary target outcome are sparce. Further high-quality clinical trials examining the potential of the MFGM for psychological health improvement are important.

2.
J Hum Nutr Diet ; 2024 May 27.
Article in English | MEDLINE | ID: mdl-38798237

ABSTRACT

BACKGROUND: Milk fat globule membranes (MFGM) present a nutritional intervention with the potential to improve psychological well-being and mitigate the negative effects of stress on health. The present study aimed to investigate participant's experience of different aspects of health during a trial of MFGM supplementation and determine the effect of MFGM on qualitative measures of psychological and physical well-being. METHODS: Seventy-three adults in New Zealand who were enrolled in a clinical trial to test MFGM supplementation for improvement of psychological well-being took part in a post-intervention interview. Participants and researchers remained blinded to intervention group allocation. Interviews were conducted over the video conferencing platform Zoom and transcribed. A mixed methods analytical approach included thematic analysis to identify emerging themes and χ2 regression models to examine frequency of improvements in different aspects of well-being between the MFGM and placebo groups. RESULTS: There were no significant demographic or psychological differences between interviewees and non-interviewed study participants. Four central themes emerged from the data for all participants: improved well-being, increased ability to cope with stress and improvements in mood, improvement in physical energy or activity, and improved sleep. The frequency of improved ability to cope with stress and improved sleep quality was significantly higher in participants who received MFGM supplementation compared to those receiving the placebo. CONCLUSIONS: Qualitative data may capture aspects of improved sleep or psychological well-being not measured by rating scales. The results suggest that MFGM supplementation may improve the ability to cope with stress and improve sleep quality in healthy adults.

3.
Br J Nutr ; 131(8): 1289-1297, 2024 Apr 28.
Article in English | MEDLINE | ID: mdl-38053344

ABSTRACT

This study investigated the effects of Lacticaseibacillus rhamnosus HN001 supplementation on the architecture and gene expression in small intestinal tissues of piglets used as an animal model for infant humans. Twenty-four 10-d-old entire male piglets (4·3 (sd 0·59) kg body weight) were fed an infant formula (IF) (control) or IF supplemented with 1·3 × 105 (low dose) or 7·9 × 106 (high dose) colony-forming units HN001 per ml of reconstituted formula (n 8 piglets/treatment). After 24 d, piglets were euthanised. Samples were collected to analyse the histology and gene expression (RNAseq and qPCR) in the jejunal and ileal tissues, blood cytokine concentrations, and blood and faecal calprotectin concentrations. HN001 consumption altered (false discovery rate < 0·05) gene expression (RNAseq) in jejunal tissues but not in ileal tissues. The number of ileal goblet cells and crypt surface area increased quadratically (P < 0·05) as dietary HN001 levels increased, but no increase was observed in the jejunal tissues. Similarly, blood plasma concentrations of IL-10 and calprotectin increased linearly (P < 0·05) as dietary HN001 levels increased. In conclusion, supplementation of IF with HN001 affected the architecture and gene expression of small intestine tissue, blood cytokine concentration and frequencies, and blood calprotectin concentrations, indicating that HN001 modulated small intestinal tissue maturation and immunity in the piglet model.


Subject(s)
Lacticaseibacillus rhamnosus , Probiotics , Humans , Infant , Animals , Male , Swine , Probiotics/therapeutic use , Dietary Supplements , Ileum , Cytokines/genetics , Leukocyte L1 Antigen Complex , Gene Expression
4.
Int J Mol Sci ; 24(13)2023 Jun 21.
Article in English | MEDLINE | ID: mdl-37445611

ABSTRACT

Brain signalling pathways involved in subclinical anxiety and depressed mood can be modulated via the gut brain axis (GBA), providing the potential for diet and dietary components to affect mood. We investigated behavioural, physiological and gut microbiome responses to the Lacticaseibacillus rhamnosus strain HN001 (LactoB HN001™), which has been shown to reduce postpartum anxiety and depression, and a milk fat globule membrane-enriched product, Lipid 70 (SurestartTM MFGM Lipid 70), which has been implicated in memory in stress-susceptible Wistar Kyoto rats. We examined behaviour in the open field, elevated plus maze and novel object recognition tests in conjunction with the expression of host genes in neuro-signalling pathways, and we also assessed brain lipidomics. Treatment-induced alterations in the caecal microbiome and short-chain fatty acid (SCFA) profiles were also assessed. Neither ingredient induced behavioural changes or altered the brain lipidome (separately or when combined). However, with regard to brain gene expression, the L. rhamnosus HN001 + Lipid 70 combination produced a synergistic effect, reducing GABAA subunit expression in the amygdala (Gabre, Gat3, Gabrg1) and hippocampus (Gabrd). Treatment with L. rhamnosus HN001 alone altered expression of the metabotropic glutamate receptor (Grm4) in the amygdala but produced only minor changes in gut microbiota composition. In contrast, Lipid 70 alone did not alter brain gene expression but produced a significant shift in the gut microbiota profile. Under the conditions used, there was no observed effect on rat behaviour for the ingredient combination. However, the enhancement of brain gene expression by L. rhamnosus HN001 + Lipid 70 implicates synergistic actions on region-specific neural pathways associated with fear, anxiety, depression and memory. A significant shift in the gut microbiota profile also occurred that was mainly attributable to Lipid 70.


Subject(s)
Gastrointestinal Microbiome , Lacticaseibacillus rhamnosus , Probiotics , Female , Rats , Animals , Receptors, GABA-A , Lacticaseibacillus , Probiotics/pharmacology , Glycolipids/pharmacology , Diet
5.
Front Microbiol ; 14: 1272754, 2023.
Article in English | MEDLINE | ID: mdl-38188575

ABSTRACT

Application of beneficial microorganisms as probiotics targets a broad range of intended uses, from maintaining health and supporting normal bodily functions to curing and preventing diseases. Currently, three main regulatory fields of probiotic products can be defined depending on their intended use: the more similar probiotic foods and probiotic dietary supplements, and live biotherapeutic products. However, it is not always straightforward to classify a probiotic product into one of these categories. The regulatory nuances of developing, manufacturing, investigating and applying each category of probiotic products are not universal, and not always apparent to those unfamiliar with the various global probiotic regulatory guidelines. Various global markets can be significantly different regarding legislation, possible claims, market value and quality requirements for the development and commercialization of probiotic products. Furthermore, different probiotic product categories are also linked with variable costs at different stages of product development. This review outlines the current landscape comparing probiotic foods, probiotic dietary supplements, and live biotherapeutics as probiotic products from a regulatory lens, focusing on product development, manufacturing and production, and clinical research agenda. The aim is to inform and promote a better understanding among stakeholders by outlining the expectations and performance for each probiotic product category, depending on their intended use and targeted geographical region.

6.
Front Nutr ; 9: 1002369, 2022.
Article in English | MEDLINE | ID: mdl-36386940

ABSTRACT

The probiotic Lacticaseibacillus rhamnosus strain HN001 has been shown to have several beneficial health effects for both pediatric and maternal groups, including reduced risk of eczema in infants and gestational diabetes and postnatal depression in mothers. While L. rhamnosus HN001 appears to modify immune and gut barrier biomarkers, its mode of action remains to be fully elucidated. To gain insights into the role of HN001 on the infant microbiome, the impacts of L. rhamnosus HN001 supplementation was studied in 10-day old male piglets that were fed either infant formula, or infant formula with L. rhamnosus HN001 at a low (1.3 × 105 CFU/ml) or high dose (7.9 × 106 CFU/ml) daily for 24 days. The cecal and fecal microbial communities were assessed by shotgun metagenome sequencing and host gene expression in the cecum and colon tissue was assessed by RNA-seq. Piglet fecal samples showed only modest differences between controls and those receiving dietary L. rhamnosus HN001. However, striking differences between the three groups were observed for cecal samples. While total lactobacilli were significantly increased only in the high dose L. rhamnosus HN001 group, both high and low dose groups showed an up to twofold reduction across the Firmicutes phylum and up to fourfold increase in Prevotella compared to controls. Methanobrevibacter was also decreased in HN001 fed piglets. Microbial genes involved in carbohydrate and vitamin metabolism were among those that differed in relative abundance between those with and without L. rhamnosus HN001. Changes in the cecal microbiome were accompanied by increased expression of tight junction pathway genes and decreased autophagy pathway genes in the cecal tissue of piglets fed the higher dose of L. rhamnosus HN001. Our findings showed supplementation with L. rhamnosus HN001 caused substantial changes in the cecal microbiome with likely consequences for key microbial metabolic pathways. Host gene expression changes in the cecum support previous research showing L. rhamnosus HN001 beneficially impacts intestinal barrier function. We show that fecal samples may not adequately reflect microbiome composition higher in the gastrointestinal tract, with the implication that effects of probiotic consumption may be missed by examining only the fecal microbiome.

7.
Metabolites ; 12(8)2022 Jul 26.
Article in English | MEDLINE | ID: mdl-35893256

ABSTRACT

The milk fat globule membrane (MFGM) appears to play an important role in infant neurocognitive development; however, its mechanism(s) of action remains unclear. This study aimed to investigate the role of a dietary MFGM supplement on the lipid profiles of different neonatal brain regions. Ten-day-old male piglets (4−5 kg) were fed unsupplemented infant formula (control, n = 7) or an infant formula supplemented with low (4%) or high (8%) levels of MFGM (n = 8 each) daily for 21 days. Piglets were then euthanized, and brain tissues were sectioned. Untargeted liquid chromatography-mass spectrometry lipidomics was performed on the cerebellum, hippocampus, prefrontal cortex, and the rest of the brain. The analyses identified 271 and 171 lipids using positive and negative ionization modes, respectively, spanning 16 different lipid classes. MFGM consumption did not significantly alter the lipidome in most brain regions, regardless of dose, compared to the control infant formula. However, 16 triacylglyceride species were increased in the hippocampus (t-test, p-value < 0.05) of the high-supplemented piglets. Most lipids (262 (96.7%) and 160 (93.6%), respectively) differed significantly between different brain regions (ANOVA, false discovery rate corrected p-value < 0.05) independent of diet. Thus, this study highlighted that dietary MFGM altered lipid abundance in the hippocampus and detected large differences in lipid profiles between neonatal piglet brain regions.

8.
Biosens Bioelectron ; 153: 112035, 2020 Apr 01.
Article in English | MEDLINE | ID: mdl-31989941

ABSTRACT

Biosensing through White Light Reflectance Spectroscopy (WLRS) is based on monitoring the shift of interference spectrum due to the binding reactions occurring on top of a thin SiO2 layer deposited on a silicon chip. Multi-analyte determinations were possible through scanning of a single sensor chip on which multiple bioreactive areas have been created. Nonetheless, the implementation of moving parts increased the instrumentation size and complexity and limited the potential for on-site determinations. Thus, in this work, a new approach, which is based on patterning the sensor surface to create areas with different SiO2 thickness, is developed and evaluated for multi-analyte determinations with the WLRS set-up. The areas of different thickness can be interrogated by a single reflection probe placed on a fixed position over the chip and the reflection spectrum recorded is de-convoluted to the spectra corresponding to each area allowing the simultaneous monitoring of the bioreactions taking place at each one of them. The combination of different areas thickness was optimized using chips with two areas for single analyte assays. The optimum chips were then used for the simultaneous determination of two mycotoxins, aflatoxin B1 and fumonisin B1. A competitive immunoassay format was followed employing immobilization of mycotoxin-protein conjugates onto the SiO2 of different thickness. It was found that the dual-analyte assays had identical analytical characteristics with the respective single-analyte ones. The detection limits achieved were 0.05 ng/mL for aflatoxin B1 and 1.0 ng/mL for fumonisin B1, with dynamic ranges extending up to 5.0 and 50 ng/mL, respectively. The sensor was also evaluated for the determination of the two mycotoxins in whole grain samples (wheat and maize). The extraction protocol was optimized and recoveries ranging from 85 to 115% have been determined. Due to lack of moving parts, the novel multi-analyte format is expected to considerably facilitate the built-up of a portable device for determination of analytes at the point-of-need.


Subject(s)
Food Contamination/analysis , Mycotoxins/analysis , Silicon Dioxide/chemistry , Silicon/chemistry , Aflatoxin B1/analysis , Animals , Antibodies, Monoclonal/chemistry , Biosensing Techniques , Equipment Design , Fumonisins/analysis , Immunoassay , Light , Limit of Detection , Mice , Spectrophotometry , Surface Properties , Triticum/chemistry , Zea mays/chemistry
9.
Front Neurosci ; 11: 20, 2017.
Article in English | MEDLINE | ID: mdl-28184185

ABSTRACT

Attention is increasingly being focussed on probiotics as potential agents to restore or improve gastrointestinal (GI) transit. Determining mechanism of action would support robust health claims. The probiotic bacterium Bifidobacterium lactis HN019 reduces transit time, but its mechanisms of action and effects on motility patterns are poorly understood. The aim of this study was to investigate changes in GI motility induced by an extract of HN019 on distinct patterns of colonic motility in isolated rat large intestine, compared with a known promotility modulator, prucalopride. The large intestines from male Sprague Dawley rats (3-6 months) were perfused with Kreb's buffer at 37°C in an oxygenated tissue bath. Isometric force transducers recorded changes in circular muscle activity at four independent locations assessing contractile propagation between the proximal colon and the rectum. HN019 extract was perfused through the tissue bath and differences in tension and frequency quantified relative to pre-treatment controls. Prucalopride (1 µM) increased the frequency of propagating contractions (by 75 ± 26%) in the majority of preparations studied (10/12), concurrently decreasing the frequency of non-propagating contractions (by 50 ± 11%). HN019 extract had no effect on contractile activity during exposure (n = 8). However, following wash out, contraction amplitude of propagating contractions increased (by 55 ± 18%) in the distal colon, while the frequency of non-propagating proximal contractions decreased by 57 ± 7%. The prokinetic action of prucalopride increased the frequency of synchronous contractions along the length of colon, likely explaining increased colonic rate of transit in vivo. HN019 extract modified motility patterns in a different manner by promoting propagating contractile amplitude and inhibiting non-propagations, also demonstrating prokinetic activity consistent with the reduction of constipation by B. lactis HN019 in humans.

10.
mSystems ; 1(6)2016.
Article in English | MEDLINE | ID: mdl-27921083

ABSTRACT

To investigate the impact of probiotic supplementation of infant formula on immune parameters, intestinal microbiota, and metabolism, five individually housed infant rhesus monkeys exclusively fed standard infant formula supplemented with probiotics (Bifidobacterium animalis subsp. lactis HN019) from birth until 3 months of age were compared with five standard formula-fed and five breast-fed monkeys. Anthropometric measurements, serum insulin, immune parameters, fecal microbiota, and metabolic profiles of serum, urine, and feces were evaluated. Consumption of B. lactis-supplemented formula reduced microbial diversity, restructured the fecal microbial community, and altered the fecal metabolome at the last two time points, in addition to increasing short-chain fatty acids in serum and urine. Circulating CCL22 was lower and threonine, branched-chain amino acids, urea, and allantoin, as well as dimethylglycine in serum and urine, were increased in the group supplemented with B. lactis compared with the standard formula-fed group. These results support a role of probiotics as effectors of gut microbial activity regulating amino acid utilization and nitrogen cycling. Future risk-benefit analyses are still needed to consolidate the existing knowledge on the long-term consequences of probiotic administration during infancy. IMPORTANCE Probiotics are becoming increasingly popular due to their perceived effects on health, despite a lack of mechanistic information on how they impart these benefits. Infant formula and complementary foods are common targets for supplementation with probiotics. However, different probiotic strains have different properties, and there is a lack of data on long-term health effects on the consumer. Given the increasing interest in supplementation with probiotics and the fact that the gastrointestinal tracts of infants are still immature, we sought to determine whether consumption of infant formula containing the probiotic Bifidobacterium animalis subsp. lactis HN019 for 3 months starting at birth would impact gut microbial colonization, as well as infant immunity and metabolism, when compared with consumption of formula alone.

11.
Pediatr Allergy Immunol ; 26(3): 262-271, 2015 May.
Article in English | MEDLINE | ID: mdl-25779902

ABSTRACT

BACKGROUND: There is strong evidence to support a genetic predisposition to eczema and more recently studies have suggested that probiotics might be used to prevent eczema by modifying the expression of putative allergy-associated genes. The aim of this present study was to investigate whether two probiotics, Lactobacillus rhamnosus HN001 (HN001) and Bifidobacterium animalis subsp. lactis HN019 (HN019), can modify the known genetic predisposition to eczema conferred by genetic variation in the Toll-like receptor (TLR) genes in a high-risk infant population. METHODS: We selected 54 SNPs in the Toll-like receptor genes. These SNPs were analysed in 331 children of sole European ancestry as part of a double-blind, randomized, placebo-controlled trial examining the effects of HN001 and HN019 supplementation on eczema development and atopic sensitization. RESULTS: The data showed that 26 TLR SNPs interacted with HN001 resulting in a significantly reduced risk of eczema, 18 for eczema severity as defined by SCORAD ≥ 10 and 20 for atopic sensitization compared to placebo. There were only two SNPs that interacted with HN019 resulting in a reduced risk of eczema, eczema severity or atopy. CONCLUSIONS: This is the first study to show that the negative impact of specific TLR genotypes may be positively affected by probiotic supplementation. HN001 exhibits a much stronger effect than HN019 in this respect.


Subject(s)
Bifidobacterium/immunology , Dermatitis, Atopic/drug therapy , Eczema/diet therapy , Lacticaseibacillus rhamnosus/immunology , Probiotics/administration & dosage , Toll-Like Receptors/genetics , White People , Child, Preschool , Dermatitis, Atopic/genetics , Dermatitis, Atopic/immunology , Dietary Supplements , Double-Blind Method , Eczema/genetics , Eczema/immunology , Female , Follow-Up Studies , Genetic Predisposition to Disease , Humans , Infant , Infant, Newborn , Placebo Effect , Polymorphism, Single Nucleotide , Pregnancy , Risk
12.
PLoS One ; 9(10): e109239, 2014.
Article in English | MEDLINE | ID: mdl-25299190

ABSTRACT

In 2006, a new haemorrhagic syndrome affecting newborn calves, Bovine Neonatal Pancytopenia (BNP), was reported in southern Germany. It is characterized by severe bleeding, destruction of the red bone marrow, and a high case fatality rate. The syndrome is caused by alloreactive, maternal antibodies that are ingested by the calf with colostrum and result from a dam vaccination with one particular vaccine against Bovine-Viral-Diarrhoea-Virus. Because bovine colostrum is increasingly gaining interest as a dietary supplement for human consumption, the current study was initiated to elucidate whether BNP alloantibodies from BNP dams (i.e. animals that gave birth to a BNP-affected calf) cross-react with human cells, which could pose a health hazard for human consumers of colostral products. The present study clearly demonstrates that BNP alloantibodies cross-react with human lymphocytes in vitro. In agreement with previous reports on BNP, the cross-reactive antibodies are specific for MHC-I molecules, and sensitize opsonised human cells for in vitro complement lysis. Cross-reactive antibodies are present in serum and colostrum of individual BNP dams. They can be traced in commercial colostrum powder manufactured from cows immunized with the vaccine associated with BNP, but are absent from commercial powder manufactured from colostrum excluding such vaccinated cows. In humans alloreactive, MHC-I specific antibodies are generally not believed to cause severe symptoms. However, to minimize any theoretical risk for human consumers, manufacturers of bovine colostrum for human consumption should consider using only colostrum from animals that have not been exposed to the vaccine associated with BNP.


Subject(s)
Cattle Diseases/immunology , Colostrum/immunology , Cross Reactions/immunology , Genes, MHC Class I/immunology , Isoantibodies/immunology , Pancytopenia/immunology , Vaccines/immunology , Animals , Animals, Newborn/immunology , Body Fluids/immunology , Bone Marrow/immunology , Cattle , Cells, Cultured , Diarrhea Viruses, Bovine Viral/immunology , Female , Germany , Humans , Immunization/methods , Leukocytes/immunology , Pancytopenia/veterinary , Pregnancy , Vaccination/methods
13.
Article in English | MEDLINE | ID: mdl-24960697

ABSTRACT

Elastic constants c11, c12, and c44 of degenerately doped silicon are studied experimentally as a function of the doping level and temperature. First-and second-order temperature coefficients of the elastic constants are extracted from measured resonance frequencies of a set of MEMS resonators fabricated on seven different wafers doped with phosphorus (carrier concentrations 4.1, 4.7, and 7.5 x 10(19) cm(-3)), arsenic (1.7 and 2.5 x 10(19) cm(-3)), or boron (0.6 and 3 × 10(19) cm(-3)). Measurements cover a temperature range from -40°C to +85°C. It is found that the linear temperature coefficient of the shear elastic parameter c11 - c12 is zero at n-type doping level of n ~ 2 x 10(19) cm(-3), and that it increases to more than 40 ppm/K with increasing doping. This observation implies that the frequency of many types of resonance modes, including extensional bulk modes and flexural modes, can be temperature compensated to first order. The second-order temperature coefficient of c11 - c12 is found to decrease by 40% in magnitude when n-type doping is increased from 4.1 to 7.5 × 10(19) cm(-3). Results of this study enable calculation of the frequency drift of an arbitrary silicon resonator design with an accuracy of ±25 ppm between the calculated and real(ized) values over T = -40°C to +85°C at the doping levels covered in this work. Absolute frequency can be estimated with an accuracy of ±1000 ppm.

14.
Appl Environ Microbiol ; 80(9): 2851-9, 2014 May.
Article in English | MEDLINE | ID: mdl-24584241

ABSTRACT

Lactobacillus rhamnosus HN001 is a probiotic strain reported to increase resistance to epithelium-adherent and -invasive intestinal pathogens in experimental animals. To increase understanding of the relationship between strain HN001 and the bowel, transcription of selected genes in the mucosa of the murine small bowel was measured. Mice previously naive to lactobacilli (Lactobacillus-free mice) were examined after daily exposure to HN001 in drinking water. Comparisons were made to results from matched Lactobacillus-free mice. Infant and adult mice were investigated to provide a temporal view of gene expression in response to exposure to HN001. Genes sgk1, angptl4, and hspa1b, associated with the apoptosis pathway, were selected for investigation by reverse transcription-quantitative PCR on the basis of a preliminary duodenal DNA microarray screen. Normalized to gapdh gene transcription, these three genes were upregulated after 6 to 10 days exposure of adult mice to HN001. Angptl4 was shown by immunofluorescence to be upregulated in duodenal epithelial cells of mucosal samples. Epithelial cell migration was faster in HN001-exposed mice than in the Lactobacillus-free controls. Transcriptional responses in infant mice differed according to bowel region and age. For example, sgk1 was upregulated in duodenal, jejunal, and ileal mucosa of mice less than 25 days old, whereas angptl4 and hspa1b were upregulated at 10 days in the duodenum but downregulated in the jejunal mucosa until mice were 25 days old. Overall, the results provide links between a probiotic strain, mucosal gene expression, and host phenotype, which may be useful in delineating mechanisms of probiotic action.


Subject(s)
Intestines/microbiology , Lacticaseibacillus rhamnosus/physiology , Mice/genetics , Probiotics/administration & dosage , Transcription, Genetic , Animals , Intestinal Mucosa/metabolism , Mice/metabolism , Mice/microbiology , Mice, Inbred BALB C
15.
Article in English | MEDLINE | ID: mdl-19942540

ABSTRACT

After optimizing for electromechanical coupling coefficient K(2), the main performance improvement in the thin film bulk acoustic wave resonators and filters can be achieved by improving the Q value, i.e., minimizing the losses. In Bragg-reflector-based solidly mounted resonator technology, a significant improvement of Q has been achieved by optimizing the reflector not only for longitudinal wave, the intended operation mode, but also for shear waves. We have investigated the remaining acoustic radiation losses to the substrate in so-optimized 1850-MHz AlN resonators by removing the substrate underneath the resonators and comparing the devices with and without substrate by electrical characterization before and after the substrate removal. Several methods to extract Q-values of the resonators are compared. Changes caused by substrate removal are observed in resonator behavior, but no significant improvement in Q-values can be confirmed. Loss mechanisms other than substrate leakage are concluded to dominate the resonator Q-value. Difficulties of detecting small changes in the Q-values of the resonators are also discussed.


Subject(s)
Acoustics/instrumentation , Energy Transfer , Membranes, Artificial , Transducers , Computer-Aided Design , Equipment Design , Equipment Failure Analysis , Reproducibility of Results , Sensitivity and Specificity
16.
Forum Nutr ; 60: 196-208, 2007.
Article in English | MEDLINE | ID: mdl-17684416

ABSTRACT

It is becoming increasingly accepted by consumers that live lactic acid bacteria do exert health benefits when eaten. In addition, it is also becoming recognised that not all probiotic bacteria are equal. It is now no longer just a question of providing sufficient numbers of viable bacteria in a product; industry must also provide proof of efficacy for each strain. In the early 1990s, Fonterra embarked on a programme to develop proprietary probiotic strains, and as a result, commercialised two strains, Bifidobacterium lactis HN019 and Lactobacillus rhamnosus HN001. Over the past decade, Fonterra has developed a significant body of peerreviewed published reports around these strains, including studies showing safety in animal and human trials, protection against pathogens such as Salmonella typhimurium and Escherichia coli O157:H7, modulation of human and animal immune markers at realistic dose rates, and efficacy in human clinical trials. Based on this work, HN019 and HN001 have been applied to several functional foods both by Fonterra (under the DR10 and DR20 brands, respectively) and by third parties (e.g. under the HOWARU brand by Danisco). While the 'gold standard' of proof of efficacy is a phase III clinical trial, ethical considerations as well as expense preclude the use of clinical trials as screening tools for probiotics. Therefore, biomarkers have to be employed to identify strains with probiotic utility, and to define the different positive health benefits of existing probiotic strains. However, as the mechanisms by which most probiotic bacteria exert their health benefits remain unclear, the question of which biomarkers accurately reflect efficacy in vivo remains unresolved. With recent technological advances, and the shift toward probiotics targeted to specific conditions, researchers are beginning to tease out how probiotic bacteria work, and it is this knowledge that will inform biomarker development and improve the ability to offer the market safe and effective probiotic functional foods.


Subject(s)
Antibiosis , Consumer Product Safety , Food Microbiology , Food, Organic , Probiotics , Animals , Bifidobacterium/physiology , Biomarkers/analysis , Colony Count, Microbial , Escherichia coli O157/growth & development , Humans , Lactobacillus/physiology
17.
Immunogenetics ; 53(12): 993-1001, 2002 Mar.
Article in English | MEDLINE | ID: mdl-11904675

ABSTRACT

Dendritic cells (DC) are the professional antigen-presenting cells that initiate immune responses. While DC take up antigen, migrate to lymph nodes and present processed antigen to T lymphocytes, little is known of the intracellular biochemical pathways controlling these events. Using the differential display technique, employing the activated blood DC-like cell line L428, we isolated a cDNA induced during DC differentiation likely to have a regulatory function. This cDNA encoded a putative 530-amino-acid (aa) protein consisting of a unique hydrophilic domain (106 aa) and a domain (424 aa) similar to the methylation pathway enzyme S-adenosylhomocysteine hydrolase (AHCY). Therefore, this molecule was termed DC-expressed AHCY-like molecule (DCAL). DCAL mRNA was expressed moderately in fresh blood DC, but was not detectable in other peripheral blood mononuclear cells. DCAL mRNA increased markedly during activation of blood and skin DC (Langerhans cells), but was diminished in terminally differentiated tonsil DC. Cultured monocytes expressed little DCAL mRNA, but levels increased markedly when differentiated into DC by cytokines GM-CSF and IL-4. The DCAL gene [Chromosome (Chr) 1] and another previously identified DCAL-like molecule KIAA0828 (Chr 7) differed from the AHCY gene (Chr 20) in gene organization. Thus, DCAL may have a role in controlling critical events in DC differentiation and belong to a novel family of AHCY-like molecules.


Subject(s)
Dendritic Cells/cytology , Dendritic Cells/enzymology , Hydrolases/genetics , Adenosylhomocysteinase , Amino Acid Sequence , Base Sequence , Cell Differentiation , Cell Line , Chromosome Mapping , Chromosomes, Artificial, Bacterial , DNA, Complementary/genetics , Gene Expression Profiling , Humans , Molecular Sequence Data , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sequence Homology, Amino Acid
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