Publications by authors named "O'Halloran F"

Lactoferrin is an antimicrobial glycoprotein that demonstrates a broad-spectrum of activity against a wide variety of clinical pathogens. This study investigated the potential of bovine lactoferrin (bLf) against multidrug resistant Staphylococcus capitis (S. capitis) strains.

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Background: Multiple Myeloma (MM) is a haematological malignancy with increasing global incidence. Diagnosis of MM should be initiated at the primary care level to achieve the best patient outcome. However, this can be delayed due to nonspecific presenting symptoms, such as back pain and fatigue.

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Neonatal infection is a significant cause of mortality and morbidity in infants. The global incidence of multi-drug resistance continues to rise among neonatal pathogens, indicating a need for alternative treatment strategies. Nisin is an antimicrobial peptide that exhibits broad-spectrum activity against a wide variety of clinical pathogens and can be used in combination with antibiotics to improve their effectiveness.

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In recent years, the life expectancy of Multiple Myeloma (MM) patients has substantially improved, but this cancer remains incurable with increasing incidence in the developed world. Most MM patients will eventually relapse due to residual drug-resistant cancerous cells that survive treatment, commonly referred to as minimal residual disease (MRD). Methods to improve MRD detection in MM patients are generating considerable interest as a means of monitoring patients' response to treatment.

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Age-related changes to the gastrointestinal tract (GIT) can impact how food is digested. Studying the effects of these changes can help identify functional foods for older adults. Cheese was digested using two simulated gastrointestinal digestion (SGID) models representing adult and elderly gastro-intestinal conditions.

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Amino acid bioavailability is critical for muscle protein synthesis (MPS) and preservation of skeletal muscle mass (SMM). Ageing is associated with reduced responsiveness of MPS to essential amino acids (EAA). Further, the older adult population experiences anabolic resistance, leading to increased frailty, functional decline and depleted muscle mass preservation, which facilitates the need for increased protein intake to increase their SMM.

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Group B Streptococcus (GBS) is the leading cause of neonatal disease worldwide, and invasive disease in adults is becoming more prevalent. Currently, some countries adopt an intrapartum antibiotic prophylaxis regime to help prevent the transmission of GBS from mother to neonate during delivery. This precaution has reduced the incidence of GBS-associated early-onset disease; however, rates of late-onset disease and stillbirths associated with GBS infections remain unchanged.

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Aims: This study investigated the potential synergy between erythromycin and nisin against clinical Group B Streptococcus (GBS) strains.

Methods And Results: The combination of erythromycin and nisin was examined for synergistic activity using checkerboard and time-kill assays against invasive and colonizing GBS strains. Additionally, the immunological effect of the antibiotic combination was investigated in vitro using human U937 cells and ELISA analysis.

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Objectives: Streptococcus agalactiae is the leading cause of neonatal disease worldwide, and infections caused by this opportunistic pathogen are becoming increasingly more prevalent in adults. With the global incidence of antimicrobial resistance continuing to rise, there is a recognised need for new therapeutic agents. Nisin is a potent antimicrobial peptide with demonstrated broad-spectrum activity against a range of clinically significant pathogens.

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In an effort to control weight gain, much attention has focused on the identification of bioactive peptides from food sources that induce satiety hormone secretion and increase the feeling of fullness. In this study, a screening platform identified a sodium caseinate hydrolysate, LFC25, that significantly increased calcium signalling in the enteroendocrine cell line, STC-1, and as a result increased secretion of the satiety hormone, GLP-1, in a dose-dependent manner. Administration of this hydrolysate to mice reduced the cumulative food intake over an eight hour period.

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Group B Streptococcal isolates (n = 235) from the South of Ireland were characterised by serotyping, antimicrobial susceptibility and determination of the phenotypic and genotypic mechanisms of resistance. Resistance to erythromycin and clindamycin was observed in 21·3% and 20·4% of the total population, respectively. The c-MLSB phenotype was the most common phenotype detected (62%), with ermB being the predominant genetic determinant, present in 84% of resistant isolates.

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Diacetyl is a volatile flavour compound that has a characteristic buttery aroma and is widely used in the flavour industry. The aroma of a food plays an important role in food palatability and thus intake. This study investigates the effect of diacetyl on the satiety hormone, glucagon-like peptide (GLP-1), using the enteroendocrine cell line, STC-1.

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Background: The crater lakes of Barombi Mbo and Barombi Kotto are well-known transmission foci of schistosomiasis and soil-transmitted helminthiasis having had several important control initiatives previously. To collect contemporary epidemiological information, a cross-sectional survey was undertaken inclusive of: signs and symptoms of disease, individual treatment histories, local water, sanitation and hygiene (WASH)-related factors and malacological surveillance, with molecular characterisation of specimens.

Methods: At each lake, a community cross-sectional survey was undertaken using a combination of stool and urine parasitological sampling, and interview with pro-forma questionnaires.

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Streptococcus dysgalactiae ssp. dysgalactiae is an important causative agent of bovine mastitis worldwide. Lactoferrin is an innate immune protein that is associated with many functions including immunomodulatory, antiproliferative, and antimicrobial properties.

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Purpose: Peptide YY (PYY) is a gastrointestinal hormone with physiological actions regulating appetite and energy homoeostasis. The cellular mechanisms by which nutrients stimulate PYY secretion from intestinal enteroendocrine cells are still being elucidated.

Methods: This study comprehensively evaluated the suitability of intestinal STC-1 cells as an in vitro model of PYY secretion.

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The incidence of obesity and obesity-associated diseases, such as type-2 diabetes, has reached epidemic proportions in recent years. It is predicted that by 2015 over 1.5 billion consumers will be overweight or obese.

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Background: Starch is a main source of glucose and energy in the human diet. The extent to which it is digested in the gastrointestinal tract plays a major role in variations in postprandial blood glucose levels. Interactions with other biopolymers, such as dairy proteins, during processing can influence both the duration and extent of this postprandial surge.

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Foods that have a low glycaemic index or foods that contain slowly digestible starch are beneficial in controlling fluctuations in blood glucose and insulin levels. The study hypothesis is that gelatinisation of starch in structured casein networks provides a method for decreasing the digestion rate of the starch and, hence, minimising postprandial glucose fluctuations. This study examined the effect of starch gelatinisation with or without casein on (1) gene expression and peptide secretion levels of the incretin hormones glucagon-like peptide 1 and glucose-independent insulinotropic polypeptide and (2) gene expression of the sodium-glucose cotransporter and GLUT-2 in intestinal cell culture systems.

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Genetic polymorphisms present in the bovine lactoferrin (LTF) gene promoter have the potential to affect milk lactoferrin concentrations. The objectives were: (1) to identify, in silico, SNPs in the promoter region of the LTF gene that could affect transcription factor binding activity, (2) to investigate the effects of these SNPs in vitro by measuring promoter transcriptional activities of different bovine LTF promoter haplotypes and (3) to investigate the genetic association between LTF promoter SNPs and milk lactoferrin concentration. Haplotypes were deduced from sequencing of the 2.

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Cholecystokinin (CCK) is a peptide hormone secreted from the I-cells of the intestine and it has important physiological actions related to appetite regulation and satiety. In this study we used STC-1 cells to investigate the effects of common dietary-derived fatty acids (FAs) on I-cell secretory function and metabolism. We extend earlier studies by measuring the acute and chronic effects of 11 FAs on CCK secretion, cellular CCK content, CCK mRNA levels, cellular DNA synthesis, cellular viability and cytotoxicity.

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Lactoferrin plays an important role in the innate immune system, with well-characterized antibacterial, antiviral, and immune modulatory properties. The objective of this study was to determine the allele and haplotype frequency of polymorphisms at positions -586, -190, and -28 of the bovine lactoferrin promoter in Holstein-Friesians and to quantify their association with performance using phenotypic data on progeny from 848 sires. Associations between genotypes and performance were quantified using weighted mixed models with genotyped individuals included as a random effect, and average expected relationships among individuals accounted for through a numerator relationship matrix.

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The lactoferrin gene sequences of 70 unrelated dairy cows representing six different dairy breeds were investigated for single nucleotide polymorphisms to establish a baseline of polymorphisms that exist within the Irish bovine population. Twenty-nine polymorphisms were identified within a 2.2kb regulatory region.

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Anti-microbial resistance is an emerging public health issue. Farmed animals may act as reservoirs and potential sources of anti-microbial resistant Campylobacters. The aim of this study was to investigate the anti-microbial resistance profile of cattle and environmental Campylobacter isolates from normal untreated feedlot cattle, the role of the gyrA Thr-86-Ile mutation in ciprofloxacin-resistant Campylobacter jejuni isolates and the involvement of the tripartite CmeABC efflux system for multi-resistant C.

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In this study, a tripartite-operon-encoding efflux system together with its regulatory gene was characterized in an Irish Campylobacter coli isolate CIT-382 showing high-level resistance to nalidixic acid and ciprofloxacin. Sequence comparisons revealed significant homology between C. coli and the cmeABC operon of Campylobacter jejuni.

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Two hundred and thirty fecal specimens were collected from children (up to 5 years of age) admitted with suspected rotaviral gastroenteritis at four Irish hospitals (Cork University Hospital, Mercy Hospital, Cork, Waterford Regional Hospital, and Kerry General Hospital) in the southern region of Ireland, between 2001 and 2004. Following laboratory confirmation of the aetiological agent, the rotavirus G-type was determined in all positive samples by reverse transcriptase-polymerase chain reaction (RT-PCR). The distribution of the G-types (n=230) over the 3 year period was G1 (31%), G9 (21.

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