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Biomedical subjects

M Higgins

Publications and source records attributed to M Higgins.

At least 19 recordsLinked to original sources
PubMed2006

How useful is external cephalic version in clinical practice?

We reviewed retrospectively all women with a singleton breech presentation after 36 weeks' gestation who were referred for an external cephalic version (ECV) in the 3 years from 2001 - 2003. The number (n = 107) referred was low and the overall success rate of 24.5% was also low. Over the 3 years, our practice of ECV prevented only 15 caesarean sections and thus made little contribution to reducing the hospital's overall caesarean section rate. This audit highlights the need for a review of current practices in our hospital. ECV is recommended by the guidelines of the RCOG and it is a concern that the results achieved by enthusiasts of ECV may not be achieved in everyday obstetric practice.

Breech Presentation↗
PubMed2006

Changes to the phenotypic profile of Vibrio harveyi when infected with the Vibrio harveyi myovirus-like (VHML) bacteriophage.

AIMS: To determine if infection of Vibrio harveyi with the V. harveyi myovirus-like (VHML) bacteriophage causes a change to the phenotypic profile of this species. METHODS AND RESULTS: Using 46 biochemical and metabolic tests, phenotypic profiles for noninfected V. harveyi and VHML infected V. harveyi were developed. Comparison of the infected and bacteriophage-infected strains of V. harveyi 645, 20 and 45 were found to have different test results for d-gluconate utilization, gamma-glutamyl transpeptidase and sulfatase activity, respectively. Using probabilistic identification, VHML infected and noninfected strains were identified as V. harveyi and had similar Willcox probability scores though the modal likelihood scores were reduced for VHML infected strains. One VHML infected strain, 642b, was misidentified as V. campbellii by phenotyping but not by PCR. It would appear that the phenotype of V. harveyi strains infected with VHML, are sufficiently altered that they occur at the margins of the known range of strain variation for V. harveyi. CONCLUSION: Infection of V. harveyi with VHML causes the phenotypic profile of the bacterium to change. This change reduces the modal likelihood score resulting in a poorer level of assurance for an identification of V. harveyi, especially in the natural host, strain 642. The bacteriophage VHML integrates into different sites in different strains of V. harveyi. SIGNIFICANCE AND IMPACT OF THE STUDY: The identification of V. harveyi as the causative agent of mortality in aquatic organisms is predominantly achieved through phenotyping. Since bacteriophages alter virulence in V. harveyi, understanding the effect they have on phenotype is important.

Culture Media↗
PubMed2006

High-solids centrifuge is a boon and a curse for managing anaerobically digested biosolids.

High-solids centrifugation can reduce the cost of managing or disposing of anaerobically digested biosolids. High-solids centrifuges can increase relative cake solids by as much as 5% DS compared with other dewatering devices, such as belt filter presses, with a resulting 15-20% reduction in overall mass of hauled biosolids. Cost reductions can be similar (15-20%) or more, depending on the type of disposal or management involved. For example, the additional removal of water from the cake increases the energy content in the biosolids, thereby facilitating incineration or heat drying processes. For land application, the benefits are more mixed. As explained in this paper, increases in biosolids odours associated with high-solids centrifuges may increase digestion requirements and may compel producers to transport biosolids to more remote, distant sites, potentially increasing transportation costs. High-solids centrifuges shear anaerobically digested biosolids. The shear results in a net increase in labile protein, an odour precursor. Additionally, high-solids centrifugation also results in the inhibition of methanogenesis, a major mechanism for degradation of organosulphur odours. Therefore, the risks and benefits should both be weighed when considering high-solids centrifuges for land application of anaerobically digested biosolids.

Centrifugation↗
PubMed2004

High-throughput genotyping of human platelet antigens using the 5'-nuclease assay and minor groove binder probe technology.

BACKGROUND AND OBJECTIVES: Human platelet antigen (HPA) genotyping is a valuable tool for typing platelets to assist in the management of alloimmunized thrombocytopenic patients. We describe, for the first time, 5' nuclease assays (NA) to genotype HPA-5 and -15, and improved 5'-NA to genotype HPA-1, -2 and -3, by utilizing minor groove binder (MGB) and non-fluorescent quencher (NFQ) technology. Superior probe specificity and fluorescent performance is attained through MGB-NFQ probe modifications compared with previous 5'-NA designs. MATERIALS AND METHODS: Primers and dye-labelled MGB-NFQ probes were designed and synthesized to detect the single nucleotide polymorphism responsible for each HPA-1, -2, -3, -5 and -15. One-hundred blood samples were tested for the combinations of HPA genotypes 1, 2, 3 and 5 by our traditional sequence-specific primer-polymerase chain reaction (SSP-PCR) method, and 41 blood samples were tested for HPA-15 by SSP-PCR at an external laboratory. These results were then compared with those obtained by using the new 5'-NA. RESULTS: There was complete concordance of results for all samples tested by SSP-PCR and 5'-NA. The 5'-NA offers distinct advantages over non-fluorescent genotyping methods. DNA amplification and allele discrimination occurs in a single closed tube for each antigen with no post-PCR manipulation required. This minimizes the risk of cross-contamination and mislabelling of samples, as well as making the assay less time-consuming to perform. In comparison with other fluorescent assays, the 5'-NA has the highest sample throughput, resulting from the use of a 96-well platform, identical cycling conditions for all assays and the potential for automation. CONCLUSIONS: Genotyping for HPA-1, -2, -3, -5, and -15 by the 5'-NA is suitable for routine analysis. The latest 5'-NA design, using MGB probe technology, ensures superior detection of all alleles and is the most versatile fluorescent assay, ideal for both urgent clinical samples and large-scale screening programs.

Antigens, Human Platelet↗
PubMed2004

Water Environment Research Foundation (WERF) anaerobic digestion and related processes, odour and health effects study.

Biosolids odour emissions can affect the ability of wastewater utilities to implement beneficial biosolids processing and reuse programs. Communities often become more sensitised and vocal about biosolids issues, once they experience odours emanating from a nearby site. Odour impacts from biosolids, including potential human health effects, have been targeted recently by many national and local newspapers, citizens' groups, and regulatory agencies, who have raised significant concerns, ranging from viable disposal methods/sites to outright bans. Many national and local regulatory agencies in the United States are considering biosolids disposal bans in their communities because of misinformation, poor science, and citizen pressure, but primarily because of odour impact concerns. The wastewater industry has a relatively poor understanding of the operations and treatment parameters that influence biosolids odour emissions. Thus, wastewater treatment plants are often unable to control the odour quality of the biosolids that are delivered into communities. A research study to demonstrate the influence of anaerobic digestion, mechanical dewatering, and storage design and operating parameters on the odour quality of the final product was performed and is the subject of this paper. Established and new sampling and analytical methods were used to measure biosolids odour emissions from 11 test sites in North America. By determining the impacts of these control variables on biosolids odour quality, design and operations of anaerobic digestion systems might be enhanced. This paper also summarises a corollary study performed as part of the WERF research study that addresses the health effects of biosolids odours.

Community Participation↗
PubMed2003

Nuclear export inhibitor leptomycin B induces the appearance of novel forms of human Mdm2 protein.

The nuclear export inhibitor leptomycin B (LMB) prevents the export of proteins from the nucleus to the cytoplasm, protects p53 from Mdm2-mediated degradation and is a very potent inducer of the p53 transcriptional activity. Here we suggest that LMB can also interfere with the degradation of human Mdm2. In the presence of this drug, we observed two novel forms of this protein: a slow mobility form and an amino-terminal fragment with an apparent molecular mass of 32 kDa. The presence of this 32 kDa band is abolished with proteasome inhibitors, indicating that its appearance could be because of limited processing by the proteasome. These results may be useful in understanding the mechanism of degradation of Mdm2 by the proteasome.

Active Transport, Cell Nucleus↗
PubMed2002

Effects of repetitive hypoglycemia on neuroendocrine response and brain tyrosine hydroxylase activity in the rat.

Hypoglycemia-associated autonomic failure (HAAF) is a syndrome of acute adaptation to a metabolic stressor, in which neuroendocrine responses to repetitive hypoglycemic bouts are blunted. The CNS mechanisms that contribute to HAAF are unknown. In the present study, we modeled HAAF in the rat and measured the activity of tyrosine hydroxylase (TH) as an index of acute noradrenergic activation, to test the hypothesis that noradrenergic activation of the hypothalamus might be impaired. In association with a significant counter-regulatory response to a single bout of hypoglycemia (elevated corticosterone, catecholamines, and glucagon), TH activity was elevated overall in brainstem NE cell body areas and hypothalamus. With multiple hypoglycemic episodes in a 24 h period, the counter-regulatory response was blunted, and hypothalamic TH activity was comparable to that of saline-infused controls. In a similar paradigm, multiple bouts of CNS neuroglucopenia did not blunt the hyperglycemic or corticosterone responses, and were required for elevation of TH activity. This alternate response pattern suggests that insulin-induced hypoglycemia and cerebral neuroglucopenia represent somewhat different metabolic stressors at the CNS.

Animals↗
PubMed2001

Fenvalerate treatment affects development of olfactory glomeruli in Manduca sexta.

Low doses of fenvalerate, a widely used type-II pyrethroid insecticide, have been shown previously to produce abnormal olfactory centers in the brain and abnormal olfactory-mediated behavior in beetles (Wegerhoff et al. [1998] Neuroreport 9:3241-3245). Here, we use the experimental advantages of the moth Manduca sexta to explore the cellular changes that lead to these abnormalities. Our results indicate that treatment with fenvalerate may affect multiple aspects of the development of the primary olfactory centers, the antennal lobes, in Manduca, including ingrowth of olfactory receptor axons, axon fasciculation, and targeting within the antennal lobe, and intercellular signaling between the receptor axons and the glial cells that ordinarily surround and stabilize the developing olfactory glomeruli.

Animals↗
PubMed2001

Usefulness of cardiovascular family history data for population-based preventive medicine and medical research (the Health Family Tree Study and the NHLBI Family Heart Study).

Detailed medical family history data have been proposed to be effective in identifying high-risk families for targeted intervention. With use of a validated and standardized quantitative family risk score (FRS), the degree of familial aggregation of coronary heart disease (CHD), stroke, hypertension, and diabetes was obtained from 122,155 Utah families and 6,578 Texas families in the large, population-based Health Family Tree Study, and 1,442 families in the NHLBI Family Heart Study in Massachusetts, Minnesota, North Carolina, and Utah. Utah families with a positive family history of CHD (FRS > or =0.5) represented only 14% of the general population but accounted for 72% of persons with early CHD (men before age 55 years, women before age 65 years) and 48% of CHD at all ages. For strokes, 11% of families with FRS > or =0.5 accounted for 86% of early strokes (<75 years) and 68% of all strokes. Analyses of >5,000 families sampled each year in Utah for 14 years demonstrated a gradual decrease in the frequency of a strong positive family history of CHD (-26%/decade) and stroke (-15%/decade) that paralleled a decrease in incidence rates (r = 0.86, p <0.001 for CHD; r = 0.66, p <0.01 for stroke). Because of the collaboration of schools, health departments, and medical schools, the Health Family Tree Study proved to be a highly cost-efficient method for identifying 17,064 CHD-prone families and 13,106 stroke-prone families (at a cost of about $27 per high-risk family) in whom well-established preventive measures can be encouraged. We conclude that most early cardiovascular events in a population occur in families with a positive family history of cardiovascular disease. Family history collection is a validated and relatively inexpensive tool for family-based preventive medicine and medical research.

Adult↗
PubMed2001

Preparing for coronary angioplasty: the patients' experiences.

Coronary angioplasty and stent placement procedures now represent one of the fastest growing specialties in cardiac care; patients undergo a short stay admission with limited care time with nurses. The purpose of this study was to describe participants' experiences of preparing for angioplasty in such an environment. Eight men and three women were interviewed 1 month after discharge from hospital. Verbatim transcripts were analysed for major themes using the qualitative techniques of grounded theory. Participants described working through a problem solving process in response to the perceived health threat associated with undergoing angioplasty. In step one, the problem was identified. In step two, coping responses were taken to try and solve the problem. In step three, the results of the coping responses were appraised or evaluated. The two problems identified were ongoing chest pain and anxiety related to fear of the unknown. The coping responses initiated included acquiring knowledge of the angioplasty, confidence in the skill of the doctor, support from family and gearing up psychologically. In the final appraisal of the coping responses, the participants decided to either go ahead with, or delay the angioplasty procedure. The results of this study indicate that the preparation for angioplasty represents a period of adjustment that may be anxiety provoking. Participants' experiences provide new knowledge of the concerns and challenges faced when undergoing such an invasive procedure in a short stay environment. The results clearly highlight that psychosocial aspects of nursing care are an essential component of nursing practice for angioplasty patients.

Adaptation, Psychological↗
PubMed2001

Comparison of the FemoStop device and manual pressure in reducing groin puncture site complications following coronary angioplasty and coronary stent placement.

This study compared two techniques, the FemoStop device (RADI Medical Systems, Uppsala, Sweden) and manual pressure, currently used by nurses to achieve haemostasis at the groin puncture site following removal of femoral arterial sheaths in patients following coronary angioplasty and coronary stent placement. Participants were randomly allocated the FemoStop device or manual pressure. Participants' groins were observed for evidence of complications including haemorrhage, haematoma formation and pseudoaneurysm following removal of the femoral arterial sheath and the following day. Of the 274 participants recruited into the study, 5.5% (n = 15) were unable to be included as a result of the absence of data on the Angioplasty Record of Care Form (n = 5) or excessive bleeding at the groin puncture site (n = 10). This left 259 eligible participants. Of these, 18.1% (n = 47) did not have their groin puncture site inspected by a post-procedural observer, thereby reducing the number of participants eligible to complete all stages of the study to 212. The results showed that the presence of a haematoma on removal of the femoral arterial sheath had a significant relationship with the type of treatment used, with those participants in the FemoStop device group showing a greater incidence of haematoma development at the time of sheath removal than those in the manual pressure group. No significant difference was detected in haematoma formation or bleeding between the two groups as a result of the risk factors identified in the literature, including participant anxiety, weight or anticoagulant therapy. There was not any significant difference between the two groups in reported pain during removal of the femoral arterial sheath; however, there was a significant distinction in the amount of time taken to achieve haemostasis. The results showed that haemostasis was achieved more quickly in those participants in the manual pressure group than those in the FemoStop group. The results of this research study indicate that although manual pressure achieved haemostasis more quickly than the FemoStop device, both methods are as effective in reducing groin complications in patients following removal of the femoral arterial sheath following coronary angioplasty and stent placement.

Coronary Angiography↗
PubMed2001

Antimycobacterial agent based on mRNA encoding human beta-defensin 2 enables primary macrophages to restrict growth of Mycobacterium tuberculosis.

Human macrophages are hosts for Mycobacterium tuberculosis, the causative agent of tuberculosis, which killed approximately 1.87 million people in 1997. Human alveolar macrophages do not express alpha- or beta-defensins, broad-spectrum antimicrobial peptides which are expressed in macrophages from other species more resistant to infection with M. tuberculosis. It has been previously reported that M. tuberculosis is susceptible to killing by defensins, which may explain the difference in resistance. Defensin peptides have been suggested as a possible therapeutic strategy for a variety of infectious diseases, but development has been hampered by difficulties in their large-scale production. Here we report the cellular synthesis of human beta-defensin 2 via highly efficient mRNA transfection of human macrophages. This enabled mycobactericidal and mycobacteristatic activity by the macrophages. Although human macrophages are difficult to transfect with plasmid vectors, these studies illustrate that primary macrophages are permissive for mRNA transfection, which enabled expression of a potentially therapeutic protein.

Anti-Bacterial Agents↗
PubMed2000

Mtr1, a novel biallelically expressed gene in the center of the mouse distal chromosome 7 imprinting cluster, is a member of the Trp gene family.

We recently described a novel putative Ca(2+) channel gene, MTR1, which shows a high level of homology to the human TRPC7 gene and the melastatin 1 (MLSN1) gene, another Trp (transient receptor potential protein)-related gene whose transcript was found to be downregulated in metastatic melanomas. It maps to human chromosome band 11p15.5, which is associated with the Beckwith-Wiedemann syndrome and predisposition to a variety of neoplasias. Here we report the isolation and characterization of the murine orthologue Mtr1. The chromosomal localization on distal chromosome 7 places it in a cluster of imprinted genes, flanked by the previously described Tapa1 and Kcnq1 genes. The Mtr1 gene encodes a 4.4-kb transcript, present in a variety of fetal and adult tissues. The putative open reading frame consists of 24 exons, encoding 1158 amino acids. Transmembrane prediction algorithms indicate the presence of six membrane-spanning domains in the proposed protein. Imprinting analysis, using RT-PCR on RNA from reciprocal mouse crosses harboring a sequence polymorphism, revealed biallelic expression of Mtr1 transcripts at all stages and tissues examined.

Alleles↗
PubMed2000

Epidemiology and prevention of coronary heart disease in families.

Although family histories are used primarily to aid in diagnosis and risk assessment, their value is enhanced when the family is considered as a unit for research and disease prevention. The value of a family history of coronary heart disease (CHD) is increased when the age, sex, number of relatives, and age at onset of disease are incorporated in a quantitative family risk score. Medical and lifestyle risk factors that aggregate in families include dyslipidemia, hypertension, obesity, hyperfibrinogenemia, diabetes mellitus, smoking habits, eating patterns, alcohol consumption, physical activity, and socioeconomic status. Advances in detecting and understanding interactions between genetic susceptibility and modifiable risk factors should lead to improvements in prevention and treatment. However, working with families can be difficult. In the United States, families are usually small, are often widely dispersed, and may not be intact. Family histories may be unknown, affected relatives may be dead, and secular trends mask similarities among generations. Many exposures occur outside the home, and families change over time. Ethical, legal, and social issues arise when dealing with families. Nevertheless, opportunities are missed when research, clinical practice, and prevention focus on individual patients. Greater emphasis on families is needed to reduce the burden of CHD.

Coronary Disease↗
PubMed2000

Identification and characterization of MTR1, a novel gene with homology to melastatin (MLSN1) and the trp gene family located in the BWS-WT2 critical region on chromosome 11p15.5 and showing allele-specific expression.

Alterations within human chromosomal region 11p15.5 are associated with the Beckwith-Wiedemann syndrome (BWS) and predisposition to a variety of neoplasias, including Wilms' tumors (WTs), rhabdoid tumors and rhabdomyosarcomas. To identify candidate genes for 11p15. 5-related diseases we compared human genomic sequence with expressed sequence tag and protein databases from different organisms to discover evolutionarily conserved sequences. Herein we describe the identification and characterization of a novel human transcript related to a putative Caenorhabditis elegans protein and the trp (transient receptor potential) gene. The highest homologies are observed with the human TRPC7 and with melastatin 1 ( MLSN1 ), whose transcript is downregulated in metastatic melanomas. Other genes related to and interacting with the trp family include the Grc gene, which codes for a growth factor-regulated channel protein, and PKD1/PKD2, involved in polycystic kidney disease. The novel gene presented here (named MTR1 for MLSN1 - and TRP -related gene 1) resides between TSSC4 and KvLQT1. MTR1 is expressed as a 4.5 kb transcript in a variety of fetal and adult tissues. The putative open reading frame is encoded in 24 exons, one of which is alternatively spliced leading to two possible proteins of 872 or 1165 amino acids with several predicted membrane-spanning domains in both versions. MTR1 transcripts are present in a large proportion of WTs and rhabdomyosarcomas. RT-PCR analysis of somatic cell hybrids harboring a single human chromosome 11 demonstrated exclusive expression of MTR1 in cell lines carrying a paternal chromosome 11, indicating allele-specific inactivation of the maternal copy by genomic imprinting.

Adult↗
PubMed2000

Evidence for major genes influencing pulmonary function in the NHLBI family heart study.

Segregation analysis was performed on the pulmonary measures forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and the ratio of FEV1/FVC in 455 randomly ascertained families from the NHLBI Family Heart Study (FHS). Gender specific standardized residuals were used as the phenotypic variable in both familial correlation and segregation analyses. These residuals represented adjustments for the effects of age, age(2), age(3), Body Mass Index (BMI, kg/m(2)), height, the ratio of waist to hip measurements (WHR), the presence of coronary heart disease, smoking history, and pack years for current smokers. Sibling correlations were not different from parent-offspring correlations for all three traits, and heritability estimates for FEV1, FVC, and the FEV1/FVC ratio were 0. 515, 0.540, and 0.449, respectively. Segregation analysis of FEV1, a trait that measures airflow, indicated that a dominant major gene best fits the data, although a residual familial correlation supports the presence of an additional polygenic or common environmental component. For FVC, a trait that measures lung volume, alternative models could not be statistically differentiated, but the transmission probabilities do not support a Mendelian major gene. The best model for FEV1/FVC ratio is a non-Mendelian codominant model, perhaps due to the mixing of the individual underlying distributions influencing airflow and lung volume. These results support the hypothesis that complex relationships exist for lung function traits and that multiple genes and environmental factors influence lung function.

Anthropometry↗