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E S Mayall

Publications and source records attributed to E S Mayall.

10 recordsLinked to original sources
PubMed1997

RT-PCR method specific for the detection of transgenic CFTR mRNA in the presence of transgene plasmid DNA and endogenous CFTR mRNA.

A major problem with experiments involving the correction of cystic fibrosis by gene transfer has been reliably detecting the transgenic message and distinguishing this from an endogenous message and from vector DNA. We have exploited the SV40 small T antigen intron present in an expression vector containing the CFTR cDNA (pCFAS) using a primer directed to the spliced sequence to allow specific and precise detection of the transgeneic message.

Antigens, Polyomavirus Transforming↗
PubMed1996

Prevalence of cystic fibrosis mutations in pregnancies with fetal echogenic bowel.

OBJECTIVE: To determine the prevalence of the most common cystic fibrosis mutations in pregnancies complicated by fetal echogenic bowel by using DNA testing. METHODS: Forty-five pregnancies with fetal echogenic bowel were studied prospectively for cystic fibrosis mutations. Using polymerase chain reaction, DNA from fetal amniocytes (n = 21), fetal blood (n = 5), or parental blood (n = 19) was amplified and tested for delta F508, G551D, G542X, and 621 + 1G-->T cystic fibrosis mutations, which account for about 85% of the mutations in the British population. In selected cases, further mutations were tested according to the parental ethnic background. RESULTS: Only one of the 26 fetuses screened was heterozygous for cystic fibrosis mutations. Among 38 parental samples screened from the remaining 19 pregnancies, cystic fibrosis mutations were detected in two cases, only one of the parents being a carrier in each case. The prevalence of cystic fibrosis carrier status in fetal and parental samples (1:26 and 1:19, respectively) is within the expected prevalence in the British population (1:25). No fetuses were affected by cystic fibrosis in this series, but five were found to have growth restriction, two trisomy 21, two congenital infection, and two bowel obstruction. CONCLUSION: Our results suggest that ultrasonographic detection of fetal echogenic bowel is not associated with an increased prevalence of cystic fibrosis mutations in pregnancies at low risk for this disease.

Adolescent↗
PubMed1992

Psychological and social consequences of community carrier screening programme for cystic fibrosis.

We have assessed the effect of screening for cystic fibrosis (CF) carrier status on anxiety levels, attitudes, knowledge and actions of participants in a pilot programme conducted through primary health care services. Over 3000 individuals were screened and 100 carriers with no previous family history were identified. Varying degrees of anxiety were found to be associated initially with a positive result, but most of this was allayed by genetic counselling, and we find no adverse long-term psychological consequences in carriers. Most discussed carrier status with their partner (89%), parents, other relatives and also with friends; 87% of partners to whom testing was suggested have been screened. Those testing positive indicated that knowledge of carrier status would be considered in future reproductive decisions, and after 6 months carriers retained a reasonable level of knowledge about CF and its inheritance. Carriers and non-carriers uniformly approve of screening and are glad to have been tested. Knowledge of CF in the sample of non-carriers has also increased after testing, suggesting screening may improve understanding of CF among the entire target population. Fears of possible social costs of screening may be ill-founded.

Adolescent↗
PubMed1990

The incidence of delta F508 CF mutation, and associated haplotypes, in a sample of English CF families.

Data are presented for delta F508 screening and KM19/XV2c haplotype analysis of 195 cystic fibrosis (CF) chromosomes from the British Caucasian population. We report the frequency of delta F508 in this group to be 80% and find pronounced disequilibrium between the deletion and the KM 2, XV 1 haplotype. Haplotype analysis of 71 normal chromosomes is also presented. We report one individual who had meconium ileus and who does not have the delta F508 mutation on either chromosome.

Cystic Fibrosis↗
PubMed1989

Characterisation of human thyroid epithelial cells immortalised in vitro by simian virus 40 DNA transfection.

Human primary thyroid follicular epithelial cells were transfected with a plasmid containing an origin-defective SV40 genome (SVori-) to produce several immortal cell lines. Two of the 10 cell lines analysed expressed specific features of thyroid epithelial function (iodide-trapping and thyroglobulin production). These two lines were characterised in detail and found to be growth factor-independent, capable of anchorage-independent growth at low frequency but non-tumorigenic in nude mice. These differentiated, These differentiated, partially transformed cell lines were shown to be suitable for gene transfer at high frequency using simple coprecipitation techniques.

Adult↗
PubMed1989

High frequency of ras oncogene activation in all stages of human thyroid tumorigenesis.

Using polymerase chain reaction amplification and oligonucleotide probing, the activation of ras oncogenes in 24 benign and 20 malignant human thyroid neoplasms was examined. The frequency of ras oncogene activation was similar at all stages of tumorigenesis in this system, being found in 33% of adenomas overall (50% of microfollicular tumours), 53% of differentiated follicular carcinomas and 60% of undifferentiated carcinomas. This supports the contention that mutation of these oncogenes occurs at an early step in tumorigenesis. The predominant amino acid substitution in the differentiated tumours was glutamine to arginine at position 61 of Ha-ras or N-ras, but this mutation was not found in any of the undifferentiated tumours. It was noted that while transition mutations predominated in differentiated tumours (both benign and malignant), transversions were more common in the undifferentiated tumours.

Adenoma↗
PubMed1988

Activated ras oncogenes in human thyroid cancers.

Human thyroid epithelial (follicular) cells give rise to two malignant tumors--"follicular" carcinomas, which metastasize almost exclusively via the bloodstream, and "papillary" carcinomas, which metastasize predominantly via lymphatics (Williams, E. D. In: W. Duncan (ed.), Recent Results in Cancer Research: Thyroid Cancer, pp. 47-55. Berlin: Springer-Verlag, 1980). We have investigated whether this contrast in biological behavior might be associated with different patterns of oncogene activation. DNA transfection analysis of five follicular and ten papillary cancers indeed showed a statistically significant difference in the pattern of genes responsible, activated ras oncogenes being found in 80% of follicular tumors but only 20% of papillary tumors. In addition, in follicular cancers we have found activation of all three ras oncogenes (H-ras, K-ras, and N-ras), the first time that this has been demonstrated in a primary human tumor type (as opposed to cell lines). We suggest therefore that ras activation may be an important determinant of metastatic capability in these epithelial cancers.

Animals↗
PubMed1988

Agent-specific ras oncogene activation in rat thyroid tumours.

Activated ras oncogenes have been detected in a number of rodent tumour model systems (Balmain et al., 1986; Barbacid 1987), in which chemical carcinogens have been the most widely used inducing agents. We have investigated the involvement of activated oncogenes in a single well-characterised tumour model, rat thyroid neoplasia, produced not only by chemical carcinogen (nitrosomethylurea, NMU) and by ionizing radiation but also by elevated trophic stimulation alone. We have indentified a striking specificity in patterns of ras oncogene activation, with exclusively Ha-ras activated in 87% of NMU-induced tumours and exclusively Ki-ras activated in 60% of radiation-induced tumours.

Amitrole↗