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Biomedical subjects

G Fitzgerald

Publications and source records attributed to G Fitzgerald.

At least 19 recordsLinked to original sources
PubMed2003

Conjugated linoleic acid biosynthesis by human-derived Bifidobacterium species.

AIMS: To assess strains of Lactobacillus, Lactococcus, Pediococcus and Bifidobacterium for their ability to produce the health-promoting fatty acid conjugated linoleic acid (CLA) from free linoleic acid. METHODS AND RESULTS: In this study, strains of Lactobacillus, Lactococcus, Pediococcus and Bifidobacterium were grown in medium containing free linoleic acid. Growth of the bacteria in linoleic acid and conversion of the linoleic acid to CLA was assessed. Of the bacteria assessed, nine strains of Bifidobacterium produced the c9, t11 CLA isomer from free linoleic acid. The t9, t11 CLA isomer was also produced by some strains, but at much lower concentrations. CONCLUSIONS: The production of CLA by bifidobacteria exhibited considerable interspecies variation. Bifidobacterium breve and B. dentium were the most efficient CLA producers among the range of strains tested, with B. breve converting up to 65% linoleic acid to c9, t11 CLA when grown in 0.55 mg ml(-1) linoleic acid. Strains also varied considerably with respect to their sensitivity to linoleic acid. SIGNIFICANCE AND IMPACT OF THE STUDY: The production of CLA by probiotic bifidobacteria offers a possible mechanism for some health-enhancing properties of bifidobacteria and provides novel opportunities for the development of functional foods.

Adult↗
PubMed2002

Identification of a phosphofructokinase-encoding gene from Streptococcus thermophilus CNRZ1205--a novel link between carbon metabolism and gene regulation?

In order to isolate genes encoding so-called Two-Component Regulatory Systems from the lactic acid bacterium Streptococcus thermophilus, a cloning strategy was employed based on suppression of the alkaline phosphatase-negative phenotype displayed by the Escherichia coli strain ANCC22. Several suppressing clones were obtained which were shown to produce alkaline phosphatase activity. Sequence analysis of four of these clones revealed the presence of overlapping DNA inserts representing two ORFs, designated pfkT and pykT, whose deduced protein products exhibit significant similarity to phosphofructokinases and pyruvate kinases, respectively, from a variety of bacteria. A plasmid bearing pfkT was shown to complement a phosphofructokinase-negative mutant of E. coli, showing that this gene indeed specifies phosphofructokinase activity. It was shown that suppression of the alkaline phosphatase-negative phenotype of E. coli ANCC22 due to the presence of pfkT is caused by modulation of the intracellular level of acetyl phosphate.

Alkaline Phosphatase↗
PubMed2002

Improved survival of Lactobacillus paracasei NFBC 338 in spray-dried powders containing gum acacia.

AIMS: To assess the protective effect of gum acacia (GA) on the performance of Lactobacillus paracasei NFBC 338 during spray-drying, subsequent storage and exposure of the culture to porcine gastric juice. METHODS AND RESULTS: For these studies, Lact. paracasei NFBC 338 was grown in a mixture of reconstituted skim milk (10% w/v) and GA (10% w/v) to mid log phase and spray-dried at outlet temperatures between 95 and 105 degrees C. On spray drying at the higher air outlet temperature of 100-105 degrees C, the GA-treated culture displayed 10-fold greater survival than control cells. Probiotic lactobacilli in GA-containing powders also survived dramatically better than untreated cultures during storage at 4-30 degrees C for 4 weeks. A 20-fold better survival of the probiotic culture in GA-containing powders was obtained during storage at 4 degrees C while, at 15 and 30 degrees C, greater than 1000-fold higher survival was obtained. Furthermore, the viability of probiotic lactobacilli in GA-containing powders was 100-fold higher when exposed to porcine gastric juice over 120 min compared with the control spray-dried culture. CONCLUSIONS: The data indicate that GA has applications in the protection of probiotic cultures during drying, storage and gastric transit. SIGNIFICANCE AND IMPACT OF THE STUDY: Gum acacia treatment for the manufacture of probiotic-containing powders should result in more efficient probiotic delivery to the host gastrointestinal tract.

Animals↗
PubMed2001

Level of maternal antibody required to protect neonates against early-onset disease caused by group B Streptococcus type Ia: a multicenter, seroepidemiology study.

Because of the difficulty of conducting efficacy trials of vaccines against group B streptococcus (GBS), the licensure of these vaccines may have to rely on studies that measure vaccine-induced antibody levels that correlate with protection. This study estimates the level of maternal antibody required to protect neonates against early-onset disease (EOD) caused by GBS type Ia. Levels of maternal serum IgG GBS Ia antibodies, measured by ELISAs in 45 case patients (neonates with EOD caused by GBS Ia) and in 319 control subjects (neonates colonized by GBS Ia but without EOD) born at > or =34 weeks gestation were compared. The probability of developing EOD declined with increasing maternal levels of IgG GBS Ia antibody (P = .03). Neonates whose mothers had levels of IgG GBS Ia antibody > or =5 microg/mL had an 88% lower risk (95% confidence interval, 7%-98%) of developing type-specific EOD, compared with those whose mothers had levels < 0.5 microg/mL. A vaccine that induces IgG GBS Ia antibody levels > or =5 microg/mL in mothers can be predicted to confer a high degree of type-specific immunity to EOD to their infants.

Age of Onset↗
PubMed2001

In vitro selection criteria for probiotic bacteria of human origin: correlation with in vivo findings.

The enteric flora comprises approximately 95% of the total number of cells in the human body and can elicit immune responses while protecting against microbial pathogens. However, the resident bacterial flora of the gastrointestinal tract may also be implicated in the pathogenesis of diseases such as inflammatory bowel disease (ulcerative colitis and Crohn disease). The objectives of the Probiotic Research Group based at University College Cork were to isolate and identify lactic acid bacteria exhibiting beneficial probiotic traits, such as bile tolerance in the absence of deconjugation activity, acid resistance, adherence to host epithelial tissue, and in vitro antagonism of pathogenic microorganisms or those suspected of promoting inflammation. To isolate potentially effective probiotic bacteria, we screened the microbial population adhering to surgically resected segments of the gastrointestinal tract (the environment in which they may subsequently be reintroduced and required to function). In total, 1500 bacterial strains from resected human terminal ilea were assessed. From among these organisms, Lactobacillus salivarius subsp. salivarius strain UCC118 was selected for further study. In mouse feeding trials, milk-borne L. salivarius strain UCC118 could successfully colonize the murine gastrointestinal tract. A human feeding study conducted in 80 healthy volunteers showed that yogurt can be used as a vehicle for delivery of strain UCC118 to the human gastrointestinal tract with considerable efficacy in influencing gut flora and colonization. In summary, we developed criteria for in vitro selection of probiotic bacteria that may reflect certain in vivo effects on the host such as modulation of gastrointestinal tract microflora.

Animals↗
PubMed2001

Market potential for probiotics.

"Functional foods" as a marketing term was initiated in Japan in the late 1980s and is used to describe foods fortified with ingredients capable of producing health benefits. This concept is becoming increasingly popular with consumers because of a heightened awareness of the link between health, nutrition, and diet. Food manufacturers are enthusiastic about developing such products because the added ingredients give increased value to food. The global market for functional foods in the coming years is predicted to grow rapidly. Although Japan currently accounts for about one-half of this market, the fastest rate of growth is expected to be in the United States. Probiotic products represent a strong growth area within the functional foods group and intense research efforts are under way to develop dairy products into which probiotic organisms such as Lactobacillus and Bifidobacterium species are incorporated. Such probiotic foods may modulate gut microbial composition, thereby leading to improved gut health, for example, through improved tolerance to lactose in lactose-intolerant individuals or improved resistance to pathogenic bacteria. Large numbers of viable microorganisms are likely to be required in the food product, which should be consumed regularly to experience the health effect. The probiotic market, especially dairy products such as yogurts and fermented milks, has experienced rapid growth in Europe. The long-term exploitation of probiotics as health promoters is dependent on several factors, including sound, scientifically proven clinical evidence of health-promoting activity; accurate consumer information; effective marketing strategies; and, above all, a quality product that fulfills consumer expectations.

Bifidobacterium↗
PubMed2000

Characterisation of whiskeys using solid-phase microextraction with gas chromatography-mass spectrometry.

The application of solid-phase microextraction and gas chromatography-mass spectrometry to the detection of flavour volatiles present in Irish and Scottish whiskeys was investigated. A method was developed to characterise these volatiles which included the extraction, identification and quantification of 17 congeners which included fusel alcohols, acetates and esters. The method validation produced the optimum fibre [85 microm poly(acrylate)], extraction time (35 min), sample volume size (3 ml) and desorption time (5 min). The impact of salt on the absorption process was also studied. Characteristic profiles were determined for each whiskey and the flavour congeners were quantified using 4-methyl-2-pentanol as the internal standard. Calibration ranges were determined for each of the congeners with coefficients of linearity ranging from 0.993 (butan-1-ol) to 0.999 (ethyl laurate) and relative standard deviations ranging from 2.5% (2-methylbutan-1-ol) to 21% (furfural) at a concentration of 18.2 mg/l. Detection limits ranged from 0.1 mg/l (ethyl caprate) to 21 mg/l (butan-2-ol).

Alcoholic Beverages↗
PubMed2000

Measurement of trihalomethanes in potable and recreational waters using solid phase micro extraction with gas chromatography-mass spectrometry.

Solid phase micro extraction (SPME) was applied to the determination of selected trihalomethanes (THMs), chloroform, bromodichloromethane, dibromochloromethane, bromoform, in potable and recreational waters. The selected samples were environmentally significant due to mandatory limits imposed by regulatory agencies. Extraction of the analytes was performed using headspace SPME (fused silica fibre with a 100 microm poly(dimethylsiloxane coating) followed by thermal desorption at 220 degrees C and GC-MS analysis. A linear working range of 10-160 microg/l was established with relative standard deviations (%RSD) within the range, 0.9-19%. Limits of detection (LOD) were 1.0-2.8 microg/l. The highest THM concentration was 61.8 microg/l which was well within the proposed European Union directive of 100 microg/l. The total THMs determined in swimming pool waters ranged from 105-134 microg/l, with chloroform accounting for 84-86% of total THM.

Bromine↗
PubMed2000

Intraosseous infusion devices: a comparison for potential use in special operations.

OBJECTIVE: To determine which intraosseous (IO) devices were easy to learn to use, easy to use once the skill was obtained, and appropriate for the Special Operations environment. METHODS: Thirty-one Navy SEAL corpsmen, Air Force pararescuemen, Army Special Forces, and Ranger medics, in a prospective, randomly assigned, cross-over study, tested four commercially available, Food and Drug Administration-cleared IO devices. The systems included the injection models First Access for Shock and Trauma (FAST, Pyng Medical) and Bone Injection Gun (Wais Medical, Kress USA Corporation) and the hand-driven threaded-needle SurFast (Cook Critical Care) and straight-needle Jamshidi needle (Baxter) models. The Special Operations medical care providers received a lecture regarding IO use, viewed videotapes of the injection models, and practiced with demonstration units in the classroom. Each participant then entered the cadaver lab where all four of the IO devices were placed in randomly assigned order. A poststudy questionnaire was then completed. The FAST was placed in the sternum, whereas the other units were placed in either medial proximal or distal medial tibia. Each participant was assessed for time, number of attempts, and success. The presence of marrow, extravasation, quality of flow, and security of needle were evaluated in combination to help determine success. RESULTS: All four devices were believed to be easy to learn as well as easy to place. FAST was successful in 29 of 30 insertions (94%) with a placement time of 114 +/- 36 (mean +/- SD) seconds. The Bone Injection Gun was similarly successful (29 of 31 insertions, 94%) with a mean placement time of 70 +/- 33 seconds. This time was statistically significantly faster (p < 0.05) than that with FAST, but not with the other devices. Thirty of 31 SurFast placements (97%) were successful, on average taking 88 +/- 33 seconds to place. The Jamshidi needle also had 30 of 31 successful placements (97%) at an average 90 +/- 59 seconds. No one device was rated by the participants as significantly better than the others; however, the Bone Injection Gun did have 65% of participants rate it as first or second (closest was Jamshidi needle at 52%). CONCLUSION: These IO devices were easy to teach and learn as well as easy to use. Insertion times compared favorably with peripheral intravenous catheter placement in the face of hemorrhage. All four devices can be appropriately used in the Special Operations environment and are reasonable alternatives when intravenous access cannot be gained. Although no device was rated higher than the others, particular features are desirable (low weight/size, simplicity, reusability, secure, clean, well protected).

Allied Health Personnel↗
PubMed2000

Factors associated with decisions about clinical BRCA1/2 testing.

Testing for mutations in BRCA1 and BRCA2 can provide important information about breast and ovarian cancer risk to a small but identifiable subgroup of women. Women who test positive for a BRCA1/2 mutation can pursue more aggressive cancer surveillance and prevention regimens. Among families with known mutations, women who test negative may avoid unnecessary interventions. Currently, little is known about the factors associated with the use of clinical BRCA1/2 testing. The objective of this study was to determine the factors associated with decisions about clinical BRCA1/2 testing among women undergoing clinical BRCA1/2 counseling through a retrospective cohort study of women who participated in a university-based clinic offering breast cancer risk assessment, genetic counseling, and BRCA1/2 testing between January 1996 and April 1998. From the 251 eligible women who responded to a follow-up survey, 125 (50%) had undergone or were undergoing BRCA1/2 testing, 86 (34%) had decided not to undergo testing, and 40 (16%) were undecided about testing. After multivariate adjustment, we found that women who chose to undergo BRCA1/2 testing were more likely to have a known familial mutation [odds ratio (OR), 7.46; 95% confidence interval (CI), 0.97-62.16], more likely to be Ashkenazi Jewish (OR, 6.37; 95% CI, 2.68-15.12), more likely to want cancer risk information for family members (OR, 1.93; 95% CI, 0.99-4.14), more likely to want information about ovarian cancer risk (OR, 1.69; 95% CI, 1.18-3.69), and less likely to be concerned about insurance or job discrimination (OR, 0.45; 95% CI, 0.21-0.94). These associations were also found in the subgroup of women with a predicted probability of a BRCA1 mutation of 25%. Our study suggests that approximately half of eligible women choose to undergo clinical BRCA1/2 testing after participating in counseling. Women who have the highest risk of carrying a mutation, and thus the greatest probability of gaining some useful information from the test results, are most likely to undergo testing. Women who undergo testing are also more interested in ovarian cancer risk information and less concerned about job and insurance discrimination.

Adult↗
PubMed1999

Smoky bars and restaurants: who avoids them and why?

The objective of this study was to provide new insight into who avoids smoky places, the types of places they avoid, and the reasons they give. A representative sample of Massachusetts adults (N = 4,929) was surveyed by telephone during 1995 and 1996. Forty-six percent of non-smokers reported having avoided a smoky place. Reasons were aversion to the lingering smell (34.8%) and health issues (31.9%). Many adults avoid restaurants and bars because of the expectation of excessive environmental tobacco smoke (ETS). Patronage may increase after smoke-free policies are implemented and nonsmokers become aware of the opportunity to dine in establishments free of ETS.

Adult↗
PubMed1999

Evaluation of cheddar cheese as a food carrier for delivery of a probiotic strain to the gastrointestinal tract.

Cheddar cheese was evaluated as a food carrier for the delivery of viable microorganisms of Enterococcus faecium (Fargo 688; Quest Int., Naarden, The Netherlands) to the gastrointestinal tract. This strain had previously been shown to possess properties required of a probiotic microorganism including the ability to relieve irritable bowel syndrome. The strain was found to survive to high numbers in Cheddar cheese during ripening at 8 degrees C for 15 mo (4 x 10(8) cfu/g) and in yogurt during storage at 4 degrees C for 21 d (4 x 10(7) cfu/g). In an in vitro model system, Cheddar cheese was found to have a greater protective effect than yogurt upon exposure of the probiotic culture to porcine gastric juice at pH 2. Subsequently, a feeding trial involving 8 pigs per group was performed in which a rifampicin-resistant variant of the probiotic strain was fed for 21 d at a mean daily intake of 1.3 x 10(10) cfu/d from Cheddar cheese or 3.7 x 10(9) cfu/d from yogurt. During the feeding period, Cheddar cheese yielded a significantly higher mean fecal probiotic count (2 x 10(6) cfu/g of feces) than did yogurt (5.2 x 10(5) cfu/g of feces). These data indicate that mature Cheddar cheese compares very favorably with fresh yogurt as a delivery system for viable probiotic microorganisms to the gastrointestinal tract.

Animal Feed↗
PubMed1999

Respiratory nematodiases in raptors in Quebec.

This is a retrospective study on wild raptors submitted to the Université de Montréal (Quebec, Canada) from 1989 to 1996. Cyathostoma spp. (Nematoda: Syngamidae) adults and/or eggs were found in air sacs, lungs, bronchi, and trachea of 12 raptors (Falconiformes and Strigiformes) from Quebec, Canada, belonging to eight different species, five of which are first host records for this parasite: barred owl (Strix varia), snowy owl (Nyctea scandiaca), northern harrier (Circus cyaneus), northern goshawk (Accipiter gentilis), and broad-winged hawk (Buteo platypterus). The infection was considered fatal in four birds, while no significant clinical signs were observed in the other cases. Major pathologic changes included diffuse pyogranulomatous air sacculitis, pneumonia, and bronchitis. A few unidentified larval nematodes embedded in a granuloma were found in the lungs of an additional Coopers' hawk (Accipiter cooperii); they were not considered clinically significant. A dead nematode, surrounded by necrotic inflammatory cells, was found in the air sac of a northern goshawk. The presence of nematodes in air sacs or lungs should be considered in wild raptors demonstrating respiratory problems.

Air Sacs↗
PubMed1999

Pansteatitis in a free-ranging red-tailed hawk (Buteo jamaicensis).

A free-ranging juvenile female red-tailed hawk (Buteo jamaicensis) that was unable to fly was admitted to a rehabilitation center and died 1 day later. Hematology and serum chemistry abnormalities included moderate regenerative anemia, elevated creatine kinase, and hyperphosphatemia. Necropsy revealed a generalized steatitis, and histology showed a necrotizing and granulomatous pansteatitis with intralesional pigment compatible with ceroid. There was also moderate diffuse myodegeneration, mild multifocal cardiomyopathy, and mild multifocal hepatic necrosis. These changes and lesions resemble those caused by vitamin E deficiency in mammals and fish-eating birds.

Adipose Tissue↗
PubMed1998

Development of a probiotic cheddar cheese containing human-derived Lactobacillus paracasei strains.

Cheddar cheese was manufactured with either Lactobacillus salivarius NFBC 310, NFBC 321, or NFBC 348 or L. paracasei NFBC 338 or NFBC 364 as the dairy starter adjunct. These five strains had previously been isolated from the human small intestine and have been characterized extensively with respect to their probiotic potential. Enumeration of these strains in mature Cheddar cheese, however, was complicated by the presence of high numbers (>10(7) CFU/g of cheese) of nonstarter lactic acid bacteria, principally composed of lactobacilli which proliferate as the cheese ripens. Attempts to differentiate the adjunct lactobacilli from the nonstarter lactobacilli based on bile tolerance and growth temperature were unsuccessful. In contrast, the randomly amplified polymorphic DNA method allowed the generation of discrete DNA fingerprints for each strain which were clearly distinguishable from those generated from the natural flora of the cheeses. Using this approach, it was found that both L. paracasei strains grew and sustained high viability in cheese during ripening, while each of the L. salivarius species declined over the ripening period. These data demonstrate that Cheddar cheese can be an effective vehicle for delivery of some probiotic organisms to the consumer.

Amino Acids↗
PubMed1997

Potent alpha 4 beta 1 peptide antagonists as potential anti-inflammatory agents.

The migration, adhesion, and subsequent extravasation of leukocytes into inflamed tissues contribute to the pathogenesis of a variety of inflammatory diseases including asthma, rheumatoid arthritis, inflammatory bowel disease, and multiple sclerosis. The integrin adhesion receptor alpha 4 beta 1 expressed on leukocytes binds to the extracellular matrix protein fibronectin and to the cytokine inducible vascular cell adhesion molecule-1 (VCAM-1) at inflamed sites. Binding of alpha 4 beta 1 to VCAM-1 initiates firm adhesion of the leukocyte to the vascular endothelium followed by extravasation into the tissue. Monoclonal antibodies generated against either alpha 4 beta 1 or VCAM-1 can moderate this inflammatory response in a variety of animal models. Recently peptides containing a consensus LDV sequence based on the connecting segment-1 (CS-1) of fibronectin and cyclic peptides containing an RCD motif have shown promise in modulating leukocyte migration and inflammation presumably by blocking the interaction of alpha 4 beta 1 with VCAM-1. Here we describe novel, highly potent, cyclic peptides that competitively inhibit alpha 4 beta 1 binding to VCAM-1 and fibronectin at sub nanomolar concentrations. The structure of a representative analog was determined via NMR spectroscopy and used to facilitate optimization of peptide leads. The peptides discussed here utilize similar functional groups as the binding epitope of VCAM-1, inhibit lymphocyte migration in vivo, and are highly selective for alpha 4 beta 1. Furthermore the structure--activity relationships described here have provided a template for the structure-based design of small molecule antagonists of alpha 4 beta 1-mediated cell adhesion processes.

Animals↗
PubMed1997

Application and evaluation of the phage resistance- and bacteriocin-encoding plasmid pMRC01 for the improvement of dairy starter cultures.

The conjugative 63-kb lactococcal plasmid pMRC01 encodes bacteriophage resistance and production of and immunity to a novel broad-spectrum bacteriocin, designated lacticin 3147 (M.P. Ryan, M.C. Rea, C. Hill, and R.P. Ross, Appl. Environ. Microbiol. 62:612-619, 1996). The phage resistance is an abortive infection mechanism which targets the phage-lytic cycle at a point after phage DNA replication. By using the genetic determinants for bacteriocin immunity encoded on the plasmid as a selectable marker, pMRC01 was transferred into a variety of lactococcal starter cultures to improve their phage resistance properties. Selection of resulting transconjugants was performed directly on solid media containing the bacteriocin. Since the starters exhibited no spontaneous resistance to the bacteriocin as a selective agent, this allowed the assessment of the transfer of the naturally occurring plasmid into a range of dairy starter cultures. Results demonstrate that efficient transfer of the plasmid was dependent on the particular recipient strain chosen, and while high-frequency transfer (10(-3) per donor) of the entire plasmid to some strains was observed, the plasmid could not be conjugated into a number of starters. In this study, transconjugants for a number of lactococcal starter cultures which are phage resistant and bacteriocin producing have been generated. This bacteriocin-producing phenotype allows for control of nonstarter flora in food fermentations, and the phage resistance property protects the starter cultures in industry. The 63-kb plasmid was also successfully transferred into Lactococcus lactis MG1614 cells via electroporation.

Bacteriocins↗