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M Glennon

Publications and source records attributed to M Glennon.

At least 19 recordsLinked to original sources
PubMed2005

CAG repeat length in an infertile male population of Irish origin.

The androgen receptor (AR) gene, located on the X chromosome, is an important regulator of human spermatogenesis. In the past decade, the link between the CAG polyglutamine tract, situated on exon one of the AR gene, and reduced spermatogenesis has become a controversial one. Alterations in the length of the CAG polyglutamine tract have been associated with prostate cancer at a reduced intrinsic length and neuromuscular diseases at a CAG repeat length of > or = 40. Minimal intermediate increases have been linked with depressed spermatogenesis in infertile males. Asian and Australian groups have published an association between increased CAG repeat length and reduced spermatogenesis while many European studies have found no such association. The aim of this study was to document the association between increased CAG repeat length and reduced spermatogenesis in a group of Irish infertile males and controls known to have fathered at least one child. The study employed the ABI 377 DNA sequencer to size the CAG repeat region of exon one of the AR gene in each group. Statistical analysis revealed no actual link between the length of the CAG tract and a reduction of spermatogenesis in a cohort of infertile patients (n = 66) of Irish ethnic origin when compared to a fertile control group (n = 77) (p = 0.599).

Electrophoresis, Polyacrylamide Gel↗
PubMed2004

Application of real-time PCR and RT-PCR assays for the detection and quantitation of VT 1 and VT 2 toxin genes in E. coli O157:H7.

Real-time PCR assays, based on hybridisation probes and LightCycler technology, were developed for VT 1 and VT 2 genes and applied to the detection and quantitation of DNA and mRNA of Escherichia coli O157:H7. The qualitative consensus PCR assay for the detection of VT 1 and/or VT 2 genes had a detection limit of 100 fg of E. coli O157:H7 genomic DNA and did not detect DNA from 13 non-VTEC isolates. When E. coli O157:H7 was inoculated into minced beef, enriched and recovered by immunomagnetic separation, the real-time consensus PCR assay had a detection limit of log(10)3.5 ml(-1) E. coli O157:H7 cells. Nineteen E. coli O157:H7 isolates, derived from food, bovine samples and human faeces, were analysed and compared for mRNA expression of three genes, VT 1, VT 2 and gapA (housekeeping gene), using quantitative real-time PCR assays. While there was no statistically significant difference for the expression of the VT 1 (p=0.134) or VT 2 (p=0.52) mRNA in the E. coli O157:H7 isolates from food, bovine and human sources, three clinical isolates did show lower expression of VT 2 compared to other isolates in the study. The study indicates that the consensus qualitative real-time PCR assay for VT 1 and VT 2 is rapid and sensitive and that the quantitative assays reported here have the potential to be used as an alternative method to more conventional methods for studying VT 1 and VT 2 virulence gene expression in E. coli O157:H7 with potential application in other pathogenic E. coli species.

DNA Fingerprinting↗
PubMed2003

Cystic fibrosis mutation frequencies in an Irish population.

The incidence of cystic fibrosis (CF) at birth in Ireland is 1/1461. Neonate CF genetic testing is not routinely performed in Ireland. Currently, screening is only carried out where there is clinical evidence or a family history to suggest disease. Here we report the frequencies of common CF mutations occurring in an Irish population composed of samples collected from western, mid-western and southern regions of Ireland. Rarer CF mutations were also identified in a selected number of CF patients. In addition, a number of polymorphisms were identified, some of which are reported to be functionally and phenotypically important.

Cystic Fibrosis↗
PubMed2003

HFE alleles in an Irish cystic fibrosis population.

The variable clinical manifestations of cystic fibrosis (CF) suggest the influence of modifier genes. Genetic and environmental factors that determine whether an individual will develop associated complications are still being determined. It has been proposed that the gene for hemochromatosis, HFE, may be a modifier locus for CF disease phenotype. Recent research has suggested a relationship between mutations to the HFE gene and the development of meconium ileus (MI) and liver disease in CF. This study aims to expand our knowledge of the HFE mutations C282Y and H63D carrier rate in an Irish population of CF allele carriers. PCR restriction enzyme analysis was performed on blood samples from CF patients to identify the C282Y and H63D mutations. HFE status of CF allele carriers and CF patients (Delta F508) homozygotes with and without meconium ileus was determined. The carrier frequency for C282Y was 30.8% for the Delta F508 homozygote MI positive group, as compared to 12.5% for the non-Delta F508 MI positive group but did not reach statistical significance (p = 0.27). Interestingly, no Delta F508 homozygote patients were homozygous for the C282Y mutation.

Alleles↗
PubMed2002

A preliminary report on the implication of RT-PCR detection of DAZ, RBMY1, USP9Y and Protamine-2 mRNA in testicular biopsy samples from azoospermic men.

In this study, reverse transcription-polymerase chain reaction (RT-PCR) was optimized to analyse the presence of DAZ, RBMY1, USP9Y, protamine-2, SRY and actin messenger RNA (mRNA) in testicular cells of men suffering from idiopathic azoospermia. All samples (n=28), including five controls, showed normal expression of actin, SRY and USP9Y. Sperm was not recovered from eight patients after testicular biopsy. Of these, four patients showed altered mRNA levels for the fertility genes, DAZ, RBMY1 and protamine-2. One patient, who was previously shown to be azoospermia factor region (AZF)b deleted, lacked RBM mRNA and presented with reduced amplification of protamine-2 mRNA. This correlated with previous studies, which proposed that RBM expression is exclusive to AZFb and that the lack of testicular RBMY1 mRNA results in suppressed spermatogenesis. Two patients were each lacking DAZ mRNA but did show expression of RBMY1 mRNA at a reduced level, suggesting that there might be residual spermatogenesis in the absence of DAZ expression. Protamine-2 mRNA was detected in one patient and was absent in the second patient. Finally, one patient lacked DAZ, RBMY1 and protamine-2 mRNA. The 19 remaining azoospermic patients presented with normal expression patterns for each of the fertility genes studied. This study demonstrates that the expression of spermatogenesis-specific genes varies in azoospermia. The study of the expression of such genes in a larger number of patients might be useful in characterizing and identifying subpopulations of azoospermic men.

Biopsy↗
PubMed2002

Real-time polymerase chain reaction detection of bovine DNA in meat and bone meal samples.

We describe a real-time polymerase chain reaction (PCR) assay for the detection of bovine DNA extracted from meat and bone meal (MBM) samples. PCR primers were used to amplify a 271-bp region of the mitochondrial ATPase 8-ATPase 6 gene, and a fluorogenic probe (BOV1) labeled with a 5' FAM reporter and a 3' TAMRA quencher was designed to specifically detect bovine PCR product. The specificity of the BOV1 probe for the detection of the bovine PCR product was confirmed by Southern blot hybridization analysis of the probe with PCR products generated from ovine, porcine, and bovine genomic DNA extracted from blood and with PCR products generated from genomic DNA extracted from single-species laboratory scale rendered MBM samples. The specificity of the BOV1 probe was also evaluated in real-time PCR reactions including these genomic targets. Both methods demonstrated that the BOV1 probe was specific for the detection of bovine PCR product. The BOV1 probe had a detection limit of 0.0001% bovine material by Southern blot DNA probe hybridization analysis and a detection limit of 0.001% bovine material in the real-time PCR assay. Application of the real-time PCR assay to six industrial samples that had previously tested positive for the presence of bovine material with a conventional PCR assay yielded positive results with the real-time PCR assay for four samples.

Animal Feed↗
PubMed2001

Species-specific PCR for the identification of ovine, porcine and chicken species in meta and bone meal (MBM).

BSE, first identified in the UK in 1986 is thought to have arisen from feeding scrapie infected Meat and Bone Meal (MBM), produced under sub-optimal conditions, to cattle. For quality and safety reasons there is a requirement for a good analytical test for the surveillance of processed MBM. This study describes species-specific PCR assays for the identification of ovine, porcine and poultry species in MBM. A comparison between two distinct DNA extraction methods, i.e. the silicaguanidiumthiocyanate DNA isolation procedure and a commercial DNA extraction kit, is also presented. Application of this technology to species identification in industrial MBM was investigates as part of this study.

Animal Feed↗
PubMed2001

Molecular detection of Y chromosome microdeletions: an Irish study.

The region of the Y chromosome most critical for male fertility is called the azoospermia factor (AZF) region and it is located within subintervals five and six on the long arm of the Y chromosome. Several genes, all residing here, contribute to spermatogenesis and deletions in these genes are thought to be pathogenetically involved in some cases of male infertility associated with azoospermia or oligozoospermia. The aim of this study was to establish the prevalence of microdeletions in the AZF region of the Y chromosome in an Irish male population undergoing fertility treatment. To do this, we applied and compared two independent polymerase chain reaction (PCR) based screening methods, namely, a PCR protocol using several sequence-tagged site (STS) primer sets and a recently published multiplex PCR Y chromosome screening protocol. A total of 78 patients, attending the IVF unit at University College Hospital, Galway, were included in this study. Of them, 56 suffered from idiopathic azoospermic/oligozoospermic infertility. The remaining 22 patients had various conditions, which may have contributed to their infertility. A total of 50 age-matched normospermic men were included as controls. Two microdeletions were found; one in the AZFa region and one in AZFb region. These deletions were observed among the truly idiopathic cases. Further analysis was performed to study the extent of the deletions and it was confirmed that each deletion encompassed the respective AZF region including the AZF candidate gene.

Adult↗
PubMed2001

Evaluation of a PCR/DNA probe colorimetric membrane assay for identification of Campylobacter spp. in human stool specimens.

DNA was extracted from 50 human stool specimens using the QIAamp DNA stool minikit. PCR amplification was followed by post-PCR hybridization to DNA probes specific for the Campylobacter genus, Campylobacter jejuni, and Campylobacter coli in a colorimetric membrane assay. Thirty-two of 38 culture-positive specimens were PCR/DNA probe positive for C. jejuni. The assay is rapid and simple and can be applied to stool specimens for the detection of Campylobacter.

Campylobacter↗
PubMed2001

Evaluation of clarithromycin resistance and cagA and vacA genotyping of Helicobacter pylori strains from the west of Ireland using line probe assays.

The prevalence of clarithromycin resistance-associated mutations, the cytotoxin-associated gene (cagA), and the various vacuolating cytotoxin (vacA) genotypes was determined in 50 gastric biopsy specimens from Helicobacter pylori-infected patients, using line probe assays. The clarithromycin resistance-associated mutation A2143G was detected in H. pylori strains from 26% of the specimens, which suggested that the high rate of H. pylori treatment failure in Ireland may be partly attributable to the presence of these mutations. All strains examined carried the vacA s1 genotype, and 76% were cagA positive. Of these 50 specimens, 13 (26%) carried H. pylori strains with vacA midregion genotype m1, 29 (58%) carried strains that were m2, 1 (2%) was infected by a strain that was positive for both m1 and m2, and 7 (14%) carried strains that could not be typed.

Anti-Bacterial Agents↗
PubMed2001

Detection and diagnosis of mycobacterial pathogens using PCR.

In the year 2001, it is estimated that 3 million people will die from tuberculosis, caused by the infectious agent, Mycobacterium tuberculosis. After decades of decline in the disease, the resurgence of tuberculosis seen worldwide in the 1990s sparked a renewed interest and commitment of funds for research into M. tuberculosis and other pathogenic mycobacterial species. The discovery of the PCR in the 1980s has had a major influence on the progress made possible in the study of these fastidious, tough-walled and slow-growing mycobacterial species. In the last 10 years, PCR has allowed us to amplify parts of the genome, decipher the nucleotide sequence, discover new mycobacterial species, determine epidemiological relationships between strains and identify genetic changes involved in drug resistance.

DNA Restriction Enzymes↗
PubMed2001

PCR-ELISAs for the detection of Campylobacter jejuni and Campylobacter coli in poultry samples.

Campylobacter species, primarily Campylobacter jejuni and Campylobacter coli, are regarded as a major cause of human gastrointestinal disease, commonly acquired by eating undercooked chicken. We describe a PCR-ELISA for the detection of Campylobacter species and the discrimination of C. jejuni and C. coli in poultry samples. The PCR assay targets the 16S/23S ribosomal RNA intergenic spacer region of Campylobacter species with DNA oligonucleotide probes designed for the specific detection of C. jejuni, C. coli, and Campylobacter species immobilized on Nucleo-Link wells and hybridized to PCR products modified with a 5' biotin moiety. The limit of detection of the PCR-ELISA was 100-300 fg (40-120 bacterial cells) for C. jejuni and C. coli with their respective species-specific oligonucleotide probes and 10 fg (4 bacterial cells) with the Campylobacter genus-specific probe. Testing of poultry samples, which were presumptive positive for Campylobacter following culture on the Malthus V analyzer, with the PCR-ELISA determined Campylobacter to be present in 100% of samples (n = 40) with mixed cultures of C. jejuni/C. coli in 55%. The PCR-ELISA when combined with culture pre-enrichment is able to detect the presence of Campylobacter and definitively identify C. jejuni and C. coli in culture-enriched poultry meat samples.

Animals↗
PubMed1997

PCR-based fingerprinting of Mycobacterium bovis isolates.

We investigated a number of PCR-based strategies for sub-typing isolates of Mycobacterium bovis. A panel of 15 PCR primers, designed from random sequences, insertion sequences and repetitive elements, were analyzed for their ability to allow differentiation between eight M. bovis isolates. PCR products were analyzed using agarose gel electrophoresis and polyacrylamide gel electrophoresis. Random primer based PCR, conducted with a variety of primers did not differentiate between isolates of M. bovis. Successful differentiation between isolates was achieved by the amplification of fragments located between DNA repetitive elements and insertion sequences of the M. bovis genome. PCR primers designed from the major polymorphic tandem repeat (MPTR) region and from insertion sequences IS6110 and IS986 allowed differentiation between isolates of M. bovis. This study is presented as a first step towards the development of PCR-based methods to differentiate between isolates.

Animals↗
PubMed1996

A Mycobacterium malmoense-specific DNA probe from the 16S/23S rRNA intergenic spacer region.

Mycobacterium malmoense was first described in 1977. It is now recognized as an opportunistic human pathogen which can be difficult to identify using standard methods. M. malmoense may be underestimated as the causative agent of clinical disease because of the recognized difficulties in its primary cultivation and identification. In this study, the nucleotide sequence of the 16S/23S rRNA intergenic spacer region from five clinical isolates of M. malmoense has been determined, in order to develop a PCR-based DNA probe assay to facilitate the early identification of this organism. The DNA sequence generated was utilized to design an oligunucleotide probe that specifically hybridizes with M. malmoense. The ability of this DNA probe to detect geographically distinct M. malmoense isolates was investigated. The value of this DNA probe was realized by its ability to differentiate three isolates of the Mycobacterium avium complex, which had been misidentified as M. malmoense using conventional biochemical methods.

Base Sequence↗
PubMed1996

Evaluation of a novel PCR-based diagnostic assay for detection of Mycobacterium tuberculosis in sputum samples.

We report on a PCR-based assay we have developed for the detection of Mycobacterium tuberculosis in sputum samples. One hundred sputum specimens, which included 34 culture-positive and 66 culture-negative specimens, were evaluated with this system. Of the 34 culture-positive specimens, 31 were PCR positive, and 60 of the culture-negative specimens were PCR negative. An internal standard has been included in the assay system to monitor PCR inhibition and to confirm the reliability of the PCR assay.

Biological Assay↗
PubMed1995

Evaluation of a PCR based method for identification of mycobacterial isolates.

In recent years an increasing number of mycobacterial species have been described as causing disease in humans. Identification of isolates to the species level is essential for evaluation of the significance of an isolate. Conventional methods for identification based on selective inhibitors of growth and biochemical reactions are slow. We have evaluated a novel method, PCR restriction enzyme pattern analysis (PRA), for identification of mycobacterial isolates. Fifty three cultures including a mixed culture of M. tuberculosis and M. avium and four mycobacterial cultures contaminated with rapidly growing organisms of other genera were studied. The method permits identification of most isolates within 1 to 2 days, including some contaminated cultures, and results were generally in accordance with those obtained by conventional methods.

Bacteriological Techniques↗
PubMed1995

Effects of JO 1784, a selective sigma ligand, on the autoradiographic localization of M1 and M2 muscarinic receptor subtypes in trimethyltin treated rats.

The distribution patterns of M1 and M2 muscarinic receptor subtypes following TMT and JO 1784 administration in the male Sprague-Dawley rat were investigated. In the present study, JO 1784 was injected in doses of 1, 4 and 16 mg/kg i.p. for one week prior to the single injection of TMT (8 mg/kg i.p.) and subsequently for 33 days. The effects of JO 1784 on the density of muscarinic receptor sub-types (M1 and M2) in the control and trimethyltin (TMT) treated rats were then evaluated. The topographic distribution and changes in muscarinic (M1 and M2) receptor densities were determined by means of autoradiography using [3H]quinuclidinylbenzilate (QNB). Both sub-types of muscarinic receptors contributed to the observed decrease in total muscarinic receptor binding in TMT-treated rats. In control rats, JO 1784 alone decreased M1 receptor density in the amygdaloid nuclei, basal ganglia, cortex and hippocampus and decreased M2 receptor density in the amygdaloid nuclei, basal ganglia, cortex, hippocampus, hypothalamus and septal regions. In TMT treated rats, chronic JO 1784 administration has a "neuroprotective effect" on both M1 and M2 receptors subtypes. Thus, following chronic administration of JO 1784 to TMT treated rats, both increases and decreases in M1 receptor density were observed relative to TMT animals. A significant increase in M1 receptor density was found in the cortex, olfactory regions, septum, thalamus and basal forebrain nuclei. In the hippocampus (CA2 and CA3), a significant decrease in M1 receptor density was observed. In TMT-treated rats, JO 1784 produced a significant increase in M2, receptor density in several brain regions with the most marked effects occurring in the amygdaloid nuclei, basal ganglia, cortex, hippocampus and hypothalamus. The ability of the selective sigma ligand, JO 1784, to attenuate the loss of muscarinic receptors in TMT treated rats could be of importance in the development of novel neuroprotective drugs.

Animals↗