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Biomedical subjects

G Cummins

Publications and source records attributed to G Cummins.

11 recordsLinked to original sources

Analysis of the RET proto-oncogene in sporadic parathyroid adenomas.

Missense germline mutations of the RET proto-oncogene have recently been identified in the hereditary cancer syndromes MEN2A, MEN2B, and FMTC, all characterized by medullary carcinoma, but also including phaeochromocytoma in MEN2A and MEN2B and parathyroid disease in MEN2A. In addition, somatic RET proto-oncogene mutations have been identified in a subset of sporadic medullary carcinomas and phaeochromocytomas. This study investigated the possibility that RET plays a role in sporadic parathyroid neoplasia. Firstly, normal and neoplastic parathyroid tissues were screened for expression of the RET proto-oncogene, using an RT-PCR approach on autopsy material. Secondly, 20 archival parathyroid adenomas were screened for somatic mutations in the transmembrane region of RET, the region associated with germline mutations in MEN2A and hence parathyroid disease, using a PCR-solid phase direct sequencing approach. RET expression was identified in all the parathyroid tissues analysed. However, no mutations were identified in any of the 20 adenomas, suggesting either that other mechanisms of RET activation occur, such as translocation, or that RET plays a more minor role in the growth control of the parathyroid cells than in C cells or phaeochromocytes.

Adenoma↗

RET activation in adult and childhood papillary thyroid carcinoma using a reverse transcriptase-n-polymerase chain reaction approach on archival-nested material.

Activation of the RET tyrosine kinase domain occurs in a proportion of thyroid papillary carcinomas. Three chromosomal rearrangements have been described, of which PTC1 is the commonest. Wide differences (2.5-25%) in frequency of PTC1 in different populations have been reported; it is not clear whether these are due to environmental factors, racial differences or technical reasons. We have developed a simple and rapid reverse transcriptase nested polymerase chain reaction (RT-nPCR) method enabling the detection of gene expression from single 5 microns sections of formalin-fixed paraffin wax-embedded archival material. We have applied this approach to detect expression of the RET tyrosine kinase domain, allowing identification of RET activation resulting from any rearrangement, whether characterised or not, or from overexpression. A retrospective study was performed on 22 adult and 21 childhood papillary carcinomas. Thirteen of 22 (59%) adult and 10 of 21 (48%) childhood carcinomas showed evidence of RET activation, demonstrating a major role for the RET oncogene in UK thyroid papillary carcinogenesis. This study also shows a similar frequency of RET activation in both children and adults. The use of a technique that allows reliable amplification of RNA from archival material, using primers chosen in different exons so that amplified products are readily distinguished from genomic DNA, will allow correlation of translocations and chromosomal rearrangements with a variety of specific tumour types.

Actins↗

Alcohol attributable fractions for trauma in South Africa.

The misuse and abuse of alcohol is widespread in South African society and is likely to have a large impact on the economy. A major burden is borne by the hospital care system, in particular the cost of alcohol-related trauma. The purpose of this study was to estimate the cost of alcohol misuse in terms of fatal and non-fatal trauma. The design of the study was a cross-sectional survey of key informants. Each key informant was mailed a list of 11 trauma categories found to be linked to alcohol in both the local and international literature. They were asked to make an estimate of the alcohol attributable fraction (AAF) for each trauma category, based on their clinical experience and knowledge of empirical research. The median estimates for each trauma category showed that alcohol misuse could be linked to a substantial amount of mortality and morbidity, particularly with respect to motor vehicle trauma and interpersonal violence. These AAF estimates were supported by the findings of other empirical research conducted in South Africa, as well as by the literature on mortality data in the U.S.A. This suggests that there is potential for a vast amount of injuries and deaths to be eliminated if alcohol misuse could be controlled or eliminated.

Adolescent↗

Outcome of surgery for biliary atresia.

Forty-seven infants (26 male, 21 female) with biliary atresia under- went hepatic portoenterostomy during the 16-year period 1971-87. Twenty-six patients (55%) are alive 1-17 years after surgery, with 21 (45%) being jaundice-free. For children who became jaundice-free, the mean age at surgery was 78 days (range: 34-125 days), compared with 97 days (range: 48-224 days) for those who did not. Of 39 patients operated on at less than 120 days of age, 24 (60%) are alive. All four patients operated on after 125 days of life died. Of 31 patients operated on more than 5 years ago, 12 (39%) have survived, the oldest being 17 years. Ten (32%) have normal serum bilirubin concentrations, have non-active cirrhosis on liver biopsy, have had normal growth and development, and lead normal lives. The oldest two patients suffered variceal haemorrhage in their teenage years. In our recent experience, 11 of 16 patients (69%) have had complete clearing of jaundice, lead normal lives and do not currently require assessment for liver transplantation. It is believed that early referral of children with biliary atresia to experienced surgical units for portoenterostomy will lead to long-term survival, without the need for liver transplantation in a majority of cases. Liver transplantation should be offered in infancy only after failed portoenterostomy, except for patients presenting after 120 days in whom transplantation may be considered primary therapy.

Age Factors↗

Prenatal screening.

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Congenital Abnormalities↗

Gastroschisis treated with lyophilized dura.

At the Royal Alexandra Hospital for Children, Sydney, we have found that primary closure in gastroschisis is usually successful. However, in a small number of cases such closure is found to be impossible. In such patients we have not been satisfied with silastic sheeting and have on two occasions successfully used lyophilized dura.

Abdominal Muscles↗