PubMed Health⌕ Search

Biomedical subjects

R Clifford

Publications and source records attributed to R Clifford.

At least 19 recordsLinked to original sources
PubMed2001

High-throughput development and characterization of a genomewide collection of gene-based single nucleotide polymorphism markers by chip-based matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

We describe here a system for the rapid identification, assay development, and characterization of gene-based single nucleotide polymorphisms (SNPs). This system couples informatics tools that mine candidate SNPs from public expressed sequence tag resources and automatically designs assay reagents with detection by a chip-based matrix-assisted laser desorption/ionization time-of-flight mass spectrometry platform. As a proof of concept of this system, a genomewide collection of reagents for 9,115 gene-based SNP genetic markers was rapidly developed and validated. These data provide preliminary insights into patterns of polymorphism in a genomewide collection of gene-based polymorphisms.

Alleles↗
PubMed2001

Mercury-reactive lymphocytes in peripheral blood are not a marker for dental amalgam associated disease.

OBJECTIVES: The popular press and publications associated with alternative medicine increasingly report that chronic ill health, particularly myalgic encephalitis like conditions, are associated with mercury amalgam fillings. There are no scientifically proven definitive tests to support these claims. One of the more scientific tests in vogue is to assess the level of blood-borne mercury-reactive lymphocytes and to conclude that patients with high levels have developed a hypersensitivity reaction to mercury. The objective of this study was to determine the diagnostic value of this test. METHODS: This study represents an open comparison of mercury-reactive lymphocyte levels in healthy control individuals with those in patients complaining of symptoms associated with adverse effects of dental metal amalgam fillings. The healthy control group consisted of 51 male and female individuals, aged between 12 and 82 years, with and without dental amalgam fillings. The patient group consisted of 70 male and female individuals, aged between 12 and 87 years, and with the exception of one patient, with three or more mercury amalgam fillings of more than 1 year's duration. In vitro lymphocyte responses to mercury, and to nickel, as an example of a metal commonly associated with hypersensitivity reactions, and to more conventional protein antigens were determined. RESULTS: In the blood of patients and controls, there were similar levels of specifically reactive lymphocytes to all of the in vitro stimulating agents, but there were significantly higher numbers of sub-normal and non-responders within the patient group. CONCLUSIONS: The incidence and quantity of mercury-reactive lymphocytes in the blood are not pathogenic markers of illness associated with dental metal amalgams, but may rather reflect exposure to mercury. The clinical relevance of the decreased in vitro lymphocyte responses in the patient group needs further investigation.

Adolescent↗
PubMed2001

Analysis of medication incidents and development of a Medication Incident Rate Clinical Indicator.

Most health service organisations depend solely upon spontaneous voluntary reporting of medication incidents and a wide variety of available denominators are used in order to calculate the Medication Incident Rate (MIR). This paper describes how nursing staff and clinical pharmacists reviewed medication incident data, revised and established new systems of reporting and developed a clinically useful, rate-based MIR Clinical Indicator. In order to make the MIR more meaningful, the frequency of occurrence of incidents was considered within the context of the total number of medications given to patients. This was achieved by undertaking a point prevalence audit of all inpatient medication charts (n=372) to determine the total number of doses of medication given to patients during a 24 hour period (n=3211). This value was then used as the denominator for the MIR indicator. During 1998, a total of 475 medication incidents were reported; the average number of incidents was 1.3 per 24 hours. The MIR per 1000 doses was calculated to be 0.4. In most cases (77%) the incident caused no harm to the patient and no change in treatment was required, and the most 'severe' category for any incident was that active treatment was required (3% of reported incidents). The most common type of incident was the omission of a dose of medication (50%). A wide range of drugs were involved in the incidents, most commonly morphine (3.4%). The authors consider that the development and use of the MIR Clinical Indicator has positively influenced clinical practice in some areas at the authors' hospital.

Databases, Factual↗
PubMed2000

Disperse: a simple and efficient approach to parallel database searching.

SUMMARY: A general system for performing multiple independent database searches in parallel is presented. Run-time addition and removal of clients, robust failure and error trapping and near 100% efficiency with very large numbers of clients are achieved by a flexible asynchronous, client-driven approach.

Computational Biology↗
PubMed2000

Expression-based genetic/physical maps of single-nucleotide polymorphisms identified by the cancer genome anatomy project.

SNPs (Single-Nucleotide Polymorphisms), the most common DNA variant in humans, represent a valuable resource for the genetic analysis of cancer and other illnesses. These markers may be used in a variety of ways to investigate the genetic underpinnings of disease. In gene-based studies, the correlations between allelic variants of genes of interest and particular disease states are assessed. An extensive collection of SNP markers may enable entire molecular pathways regulating cell metabolism, growth, or differentiation to be analyzed by this approach. In addition, high-resolution genetic maps based on SNPs will greatly facilitate linkage analysis and positional cloning. The National Cancer Institute's CGAP-GAI (Cancer Genome Anatomy Project Genetic Annotation Initiative) group has identified 10,243 SNPs by examining publicly available EST (Expressed Sequence Tag) chromatograms. More than 6800 of these polymorphisms have been placed on expression-based integrated genetic/physical maps. In addition to a set of comprehensive SNP maps, we have produced maps containing single nucleotide polymorphisms in genes expressed in breast, colon, kidney, liver, lung, or prostate tissue. The integrated maps, a SNP search engine, and a Java-based tool for viewing candidate SNPs in the context of EST assemblies can be accessed via the CGAP-GAI web site (http://cgap.nci.nih.gov/GAI/). Our SNP detection tools are available to the public for noncommercial use.

Chromosome Mapping↗
PubMed2000

FOG-2, a novel F-box containing protein, associates with the GLD-1 RNA binding protein and directs male sex determination in the C. elegans hermaphrodite germline.

Male sex determination in the Caenorhabditis elegans hermaphrodite germline requires translational repression of tra-2 mRNA by the GLD-1 RNA binding protein. We cloned fog-2 by finding that its gene product physically interacts with GLD-1, forming a FOG-2/GLD-1/tra-2 3'untranslated region ternary complex. FOG-2 has an N-terminal F-box and a novel C-terminal domain called FTH. Canonical F-box proteins act as bridging components of the SCF ubiquitin ligase complex; the N-terminal F-box binds a Skp1 homolog, recruiting ubiquination machinery, while a C-terminal protein-protein interaction domain binds a specific substrate for degradation. However, since both fog-2 and gld-1 are necessary for spermatogenesis, FOG-2 cannot target GLD-1 for ubiquitin-mediated degradation. We propose that FOG-2 also acts as a bridge, bringing GLD-1 bound to tra-2 mRNA into a multiprotein translational repression complex, thus representing a novel function for an F-box protein. fog-2 is a member of a large, apparently rapidly evolving, C. elegans gene family that has expanded, in part, by local duplications; fog-2 related genes have not been found outside nematodes. fog-2 may have arisen during evolution of self-fertile hermaphroditism from an ancestral female/male species.

3' Untranslated Regions↗
PubMed1999

Monitoring for nitrate in UK-grown lettuce and spinach.

To comply with European Commission requirements, the UK is carrying out a monitoring programme on nitrate concentrations in lettuce and spinach. This paper reports the results obtained between June 1996 and April 1998. A total of 182 samples of protected lettuce, 131 samples of outdoor-grown lettuce and 34 samples of fresh spinach were taken from the main growing areas of the UK. Nitrate concentrations in protected lettuce were influenced by the season with summer-grown crops (mean of 2382 mg/kg) having lower levels than those grown in the winter (mean of 3124 mg/kg). Weather conditions also affected concentrations in protected lettuces with long hours of sunshine and low rainfall associated with low nitrate levels. Nitrate concentrations in outdoor-grown lettuces were lower (mean of 1085 mg/kg) than those in protected lettuces but there were insufficient data to determine if they were affected by the weather conditions or season. Similarly there were insufficient data to determine if weather conditions or season influenced nitrate concentrations in spinach (mean of 1900 mg/kg) but regional differences were observed.

Food Contamination↗