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Biomedical subjects

C A Graham

Publications and source records attributed to C A Graham.

At least 91 records · Page 5Linked to original sources
PubMed1995

A fluorescent multiplex ARMS method for rapid mutation analysis.

The amplification refractory mutation system (ARMS) is a powerful technique for the identification of mutations. We present a modification of this technique involving coamplification of normal and mutant alleles with primers that differ in length by three to five bases. Fluorescent labelling allows exact sizing of the amplification products on an automated DNA fragment analyser. We have used the fluorescent multiplex ARMS method for the identification of common phenylketonuria mutations in Northern Ireland (R408W, 165T and F39L) together with the analysis of a polymorphic short tandem repeat site at the human phenylalanine hydroxylase locus. This provides an efficient and inexpensive first step for diagnostic mutation analysis in our population.

Alleles↗
PubMed1995

The effects of steroidal contraceptives on the well-being and sexuality of women: a double-blind, placebo-controlled, two-centre study of combined and progestogen-only methods.

A placebo-controlled, double-blind study was carried out to assess the direct hormonal effects of combined and progestogen-only oral contraceptives on well-being and sexuality of women in two contrasting cultures. One-hundred-fifty women, who had been sterilised or whose partners had been vasectomised, were recruited from two centres-Manila, Philippines, and Edinburgh, Scotland. After one month pretreatment assessment, women were randomly assigned to one of three treatments (combined oral contraceptive (COC), progestogen-only pill (POP), or placebo; 50 within each treatment group, 25 per centre) and continued on treatment for four months. Assessment was by daily ratings, questionnaires and interviews. The COC adversely affected sexuality in the Edinburgh women, with 12 of the 25 women in this group also reporting the side effect of reduced sexual interest. There were modest negative effects of the combined pill on mood, more noticeable in the Edinburgh women. The POP was associated with no adverse effects on sexuality and some improvement in well-being in both centres. Possible explanations for the apparent lack of adverse effects in the Manila women are discussed. The negative effects reported may be less evident in women using the COC for contraceptive purposes but may lead to discontinuation in some women and warrant further investigation.

Adult↗
PubMed1995

Detection of maternal cell contamination in amniotic fluid cell cultures using fluorescent labelled microsatellites.

A rapid PCR based assay was used to ascertain the presence of maternal cell contamination (MCC) in amniotic fluid cell cultures and to exclude MCC in cases where cytogenetic analysis was possible only from one primary cell culture. Six 6-carboxyfluorescein (FAM) and three 6-carboxyfluorescein hexachloride (HEX) labelled primer sets were used to amplify two tetra- and seven dinucleotide repeat polymorphisms. The PCR amplifications were multiplexed in (three) three primer set reactions and visualised on an Applied Biosystems 373A sequencer running Genescan 672 software. The microsatellite products obtained from 200 amniotic fluid cell cultures where the karyotype was female were compared against corresponding maternal blood PCR products. A single case of MCC was detected indicating the usefulness of such assays. We suggest that screening for MCC should be considered in instances where the amniotic fluid sample is bloodstained or was obtained with difficulty, or where the karyotype is female and chromosome analysis is not possible from more than one primary cell culture.

Amniocentesis↗
PubMed1995

Phenylketonuria mutation analysis in Northern Ireland: a rapid stepwise approach.

We present a multistep approach for the rapid analysis of phenylketonuria (PKU) mutations. In the first step, three common mutations and a polymorphic short tandem repeat (STR) system are rapidly analyzed with a fluorescent multiplex assay. In the second step, minihaplotypes combining STR and VNTR data are used to determine rare mutations likely to be present in an investigated patient, which are then confirmed by restriction enzyme analysis. The remaining mutations are analyzed with denaturant gradient-gel electrophoresis and sequencing. The first two steps together identify both mutations in 90%-95% of PKU patients, and results can be obtained within 2 d. We have investigated 121 Northern Irish families with hyperphenylalaninemia, including virtually all patients born since 1972, and have found 34 different mutations on 241 of the 242 mutant alleles. Three mutations (R408W, I65T, and F39L) account for 57.5% of mutations, while 14 mutations occur with a frequency of 1%-6%. The present analysis system is efficient and inexpensive and is particularly well suited to routine mutation analysis in a diagnostic setting.

Base Sequence↗
PubMed1994

Non-phenylketonuria hyperphenylalaninaemia in Northern Ireland: frequent mutation allows screening and early diagnosis.

Up to 10% of newborn children with a positive Guthrie test have non-phenylketonuria hyperphenylalaninaemia, i.e., mild elevation of serum phenylalanine that does not require dietary treatment. Depending on the relative frequencies of different phenylalanine hydroxylase mutations in a particular population, non-PKU HPA is usually caused by the combined effect of a mild HPA mutation and a severe PKU mutation. Presented here is a comprehensive analysis of non-PKU HPA in Northern Ireland. Of particular interest is one prevalent HPA mutation (T380M), which is present in over 70% of non-PKU HPA patients in Northern Ireland. Screening for this mutation is easy and inexpensive and can help confirm the diagnosis of non-PKU hyperphenylalaninaemia in the majority of cases at a very early stage. This may be clinically useful and reassuring for the parents. Other mutations described are V245A, L194P, and E390G.

Adolescent↗
PubMed1994

Automated sequencing detects all mutations in Northern Irish patients with phenylketonuria and mild hyperphenylalaninaemia.

In the first phase of the Northern Ireland PKU Study, we used automated sequencing to identify the spectrum of mutations in a random group of 32 unrelated phenylketonuria (PKU) families. We also investigated 7 Northern Irish patients with mild hyperphenylalaninaemia not requiring dietary intervention (MHP, previously referred to as non-PKU HPA). Disease-causing mutations were identified on all 78 investigated chromosomes. We found 23 different mutations, including 20 missense, 1 nonsense and 2 splice site mutations. All mutations were located within exons or at intron-exon boundaries of the phenylalanine hydroxylase gene. Seven mutations occurred at CpG sites, confirming these sites as mutation hot-spots in PKU. Mutations R408W and I65T are the two commonest PKU mutations in the Northern Irish population. Two mutations (T380M and V245A) can be characterized as MHP mutations; they are quasi dominant markers for MHP since they cause mild hyperphenylalaninaemia even when occurring in conjunction with the most severe PKU mutations. The results have proven valuable for the development of a routine PKU mutation analysis system in Northern Ireland.

DNA Mutational Analysis↗
PubMed1994

The STR system in the human phenylalanine hydroxylase gene: true fragment length obtained with fluorescent labelled PCR primers.

We present a simple, fast, non-radioactive method for the analysis of the polymorphic short tandem repeat (STR) system in the human phenylalanine hydroxylase gene. Previously, sizing of the STR marker involved radiolabelling of PCR amplified fragments and resolution on denaturing polyacrylamide gels using M13 sequencing ladder as a standard. However, this method consistently gave sizes 2 bp longer than the known sequence. The fluorescent method presented here employs internal lane standards and enables accurate sizing of the fragments. To avoid confusion, we suggest that the true fragment lengths are used as reference values in the future. The analysis of STR alleles is valuable for population genetic studies and for targeted mutation screening in phenylketonuria (PKU). It can replace RFLP-based haplotype analysis for carrier detection, and we report its use for prenatal diagnosis in a Northern Irish family with PKU. The analysis of 250 Northern Irish chromosomes, including 128 PKU alleles, showed no significant difference between normal and PKU alleles, with fragment lengths of 238 and 242 bp most common in both groups.

Genetic Testing↗
PubMed1994

Cardiopulmonary resuscitation. Paper 1: A survey of undergraduate training in UK medical schools.

This paper presents the results of a UK national survey of Basic Life Support (BLS) and Advanced Cardiac Life Support (ACLS) training for undergraduate medical students. In all responding medical schools, undergraduates are taught BLS at least once during their course but the assessment and refresher aspects of BLS training are not uniformly covered. There are inconsistencies in ACLS teaching, with some schools providing formal courses, some teaching specific techniques and others providing no ACLS teaching. Most interestingly, of those completing the questionnaire, only 52% considered present undergraduate training adequate to enable junior house officers to provide an effective resuscitation service. We recommend that all aspects of BLS and ACLS training for medical undergraduates be improved and standardized throughout the UK.

Cardiopulmonary Resuscitation↗
PubMed1994

Cardiopulmonary resuscitation. Paper 2: A survey of basic life support training for medical students.

This paper presents the results of a survey of Basic Life Support (BLS) training, based on experience gained by undergraduate medical students who had just completed their first clinical year (third year) at the University of Glasgow. Data were collected on the amount and quality of BLS training received, along with students' own perceptions of their confidence in providing BLS in a cardiac arrest resuscitation attempt. The results made interesting, but not surprising, reading with only 15% of students appearing to have been adequately taught BLS at any point during their third year. Students want more training and 98% see resuscitation as an important topic in the curriculum. Self-perceived confidence in performing BLS in an acute resuscitation situation is low. With no evidence to suggest that the situation is any different elsewhere in the UK, it is recommended that undergraduate resuscitation training is improved to reflect the importance that medical students attach to it.

Attitude of Health Personnel↗
PubMed1993

The relationship between mood and sexuality in women using an oral contraceptive as a treatment for premenstrual symptoms.

This study investigated the effects of a triphasic oral contraceptive (OC) on mood and on sexual interest in a group of 45 women with premenstrual complaints. Subjects made daily ratings of mood and sexual interest for one baseline cycle and were then randomly assigned to receive either placebo or OC for 3 mo. Women who received the OC reported decreased sexual interest during the menstrual and postmenstrual phases of the cycle. The predominant effect of both the OC and the placebo on mood was one of improvement, particularly during the premenstrual phase. There was little evidence of co-variation of mood and sexual interest in either group. Although the mechanism for the adverse effects of the OC on levels of sexual interest in unknown, it is clear that this effect was not simply a consequence of pill-induced negative mood change. The findings provide evidence that mood and sexual desire are dissociable and suggest that OCs can have direct effects on women's sexuality.

Adolescent↗
PubMed1993

Significant linkage disequilibrium between the Huntington's disease locus and markers at loci D4S10, D4S95, and D4S111 in Northern Ireland.

An analysis of the Northern Ireland Huntington's disease (HD) population of 75 families showed significant linkage disequilibrium between the HD gene and DNA markers at D4S95, D4S10, and D4S111. As the linkage disequilibrium at loci D4S10 and D4S111 is different from previous studies in the UK, but similar at locus D4S95, this suggests either that the HD mutation(s) in the Northern Ireland and British populations is not of common origin or that the haplotype of the common HD mutation has changed over time subsequent to divergence from a common origin.

Alleles↗