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Biomedical subjects

J C Dean

Publications and source records attributed to J C Dean.

At least 55 records · Page 3Linked to original sources
PubMed1994

Tuberous sclerosis--an unusual cause of seizures in an 18 year old.

An 18 year old man presenting with seizures was found to have hypomelanotic macules and a cardiac rhabdomyoma. These features suggested a diagnosis of tuberous sclerosis (TS) but there were no other clinical signs, no family history and cranial imaging failed to reveal the characteristic appearances. The diagnostic criteria for TS are reviewed and the importance of thorough clinical examination and appropriate investigation in this disease is stressed.

Adolescent↗
PubMed1993

Calibration of the NPL secondary standard radionuclide calibrator for 192Ir brachytherapy sources.

Safe and effective treatment with brachytherapy sources requires an accurate knowledge of the local tissue absorbed dose rate derived from the source reference air kerma rate. It is desirable that these air kerma rate measurements be traceable to national standards. The NPL has embarked on a programme that will enable the user to assay brachytherapy sources in a convenient manner prior to treatment. Calibration figures have been derived for the NPL secondary standard radionuclide calibrator for 192Ir brachytherapy sources manufactured by Amersham International plc. The calibration figures enable the user to accurately estimate the reference air kerma rate and activity of such sources by measuring the ionization chamber response. Calibration figures for other brachytherapy sources are also being derived.

Brachytherapy↗
PubMed1993

Restrictive dermopathy: a disorder of skin differentiation with abnormal integrin expression.

Clinical features and histological findings in two sibs who died from restrictive dermopathy in the neonatal period are described. Fibroblasts cultured from a skin biopsy from the second sib and fibroblasts from normal neonatal skin were studied using monoclonal antibodies to visualise integrin subunits by immunocytochemistry. Restrictive dermopathy fibroblasts displayed increased expression of the alpha-1 and alpha-2 subunits of integrin, those responsible for collagen binding. The increase was not matrix dependent. Integrins may play an important role in tissue differentiation, and our findings support the hypothesis that restrictive dermopathy is a disorder of skin differentiation.

Abnormalities, Multiple↗
PubMed1993

Study of left and right ventricular function in Romano-Ward syndrome.

OBJECTIVE: To examine left and right ventricular contraction in Romano-Ward syndrome: does abnormal myocardium affect the predisposition to arrhythmia? DESIGN: Tomographic radionuclide ventriculography was performed after the red blood cells were labelled conventionally with stannous pyrophosphate and technetium-99m. SETTING: Department of Nuclear Medicine, Aberdeen Royal Infirmary. PATIENTS: Eight subjects from two families known to have Romano-Ward syndrome, four of whom (two from each family) had had symptoms. RESULTS: The five subjects from family 1 had normal left ventricular contraction; two had subtle abnormalities of right ventricular phase. in family 2 all three subjects had abnormal left ventricular contraction (reduced amplitude in three, abnormal phase in two). All had subtle abnormalities of right ventricular phase. CONCLUSION: Abnormal right or left ventricular myocardium may be partly or wholly responsible for the repolarisation changes seen on the electrocardiogram of these families or may act as an ectopic focus to start ventricular tachycardias in a susceptible heart.

Adult↗
PubMed1993

Evidence of genetic and phenotypic heterogeneity in the Romano-Ward syndrome.

We report two families with phenotypically different forms of Romano-Ward syndrome. In one family, only five of 18 affected subjects are symptomatic, whereas in the other the proportion is three out of five. The families show distinct ECG morphologies, in addition to QT prolongation. Previous reports have shown genetic linkage either to the HLA locus on chromosome 6 or the Harvey-ras oncogene on chromosome 11. No linkage was found to either locus in the families reported here. The implications of phenotypic and genotypic heterogeneity in Romano-Ward syndrome are discussed in relation to the neurogenic and intrinsic models of pathogenesis.

Chromosomes, Human, Pair 11↗
PubMed1993

Prevalence of cystic fibrosis mutations in the Grampian region of Scotland.

We have identified all known sufferers of cystic fibrosis (CF) alive in the Grampian region, north east Scotland, on 1 January 1989. DNA samples were obtained for a prevalence study of the common mutations with near to complete ascertainment. A relatively high prevalence of the delta F508 mutation was found (82%), with one of four mutations being present on 92% of CF chromosomes. The high prevalence of these four easily detectable mutations in Grampian has local implications for genetic counselling, the efficacy of population carrier screening, and the usefulness of mutation analysis in cases where the diagnosis of CF is in doubt.

Adult↗
PubMed1993

The two faces of development.

An intrinsic connection exists between mission and money. As both are extended to their maximum point, the institution can role through its life effectively.

Fund Raising↗
PubMed1992

Prenatal diagnosis for the cystic fibrosis mutation 1717-1, G-->A using arms.

A family carrying two cystic fibrosis mutations, delta F508 and 1717-1, G-->A, requested prenatal diagnosis. In order to eliminate the need for labelling of allele-specific oligonucleotides and to simplify the analysis, 1717-1, G-->A was detected using an ARMS (amplification refractory mutation system) method (Newton et al., 1989). Fetal DNA was obtained by chorionic villus sampling (CVS) and the ARMS technique was used to exclude the 1717-1, G-->A mutation. The fetus was found to be heterozygous for the delta F508 mutation. ARMS is a simple, quick, non-radioactive method suitable for detecting DNA mutations in various clinical situations.

Adenine↗
PubMed1992

Development of assays for the detection of photomutagenicity of chemicals during exposure to UV light. II. Results of testing three sunscreen ingredients.

Three sunscreen ingredients, derivatives of benzylidene camphor, were tested for photomutagenic potential. These were benzenesulfonic acid, 4-[(4,7,7,-trimethyl-3-oxo-bicyclo [2.2.1] hept-2-ylidene) methyl] (Mexoryl SL), 4-(2-oxo 3-bornylidenemethyl) phenyl trimethylammonium methyl sulphate (Mexoryl SO) and 3,3'-(1,4-phenylenedimethylidyne) bis [7,7-dimethyl-2-oxo-bicyclo [2.2.1] heptane-1-methanesulfonic acid] (Mexoryl SX). Two complementary assay systems were used, one involving the induction of reverse mutations in Escherichia coli strain WP2, the other measuring the induction of chromosome damage in Chinese hamster ovary (CHO) cells. Irradiation with UVA and/or UVB was provided by an Osram Ultra-Vitalux sunlamp. None of the three sunscreens, tested either to the limit of solubility or toxicity, gave any indication of photomutagenicity in either assay, under conditions in which the positive control compound, 8-methoxypsoralen, was extremely photomutagenic. It is concluded that Mexoryls SL, SO and SX can be exposed to UV light without producing photomutagenicity measurable using a bacterial reverse mutation or a mammalian chromosome aberration assay.

Animals↗
PubMed1992

Cardiofaciocutaneous syndrome with new ectodermal manifestations.

We describe a 7 year old girl whose features satisfy the diagnosis of cardiofaciocutaneous syndrome. Her ectodermal features consist of fine, sparse hair, thin, opalescent nails, finger tip pads, generalised pigmentation of the skin, but no hyperkeratosis. Skin pigmentation and finger tip pads have not been previously reported in this syndrome. Twenty-two cases of CFC have been described but there is debate as to whether it is distinct from Noonan syndrome.

Abnormalities, Multiple↗
PubMed1992

Weyers' ulnar ray/oligodactyly syndrome and the association of midline malformations with ulnar ray defects.

We describe a two generation family with variable ulnar and radial ray reduction and midline craniofacial abnormalities. The features suggest a diagnosis of Weyers' ulnar ray/oligodactyly syndrome originally described in two isolated cases. Syndromes of ulnar ray reduction are briefly reviewed and the relationship between limb bud and midline development discussed.

Abnormalities, Multiple↗
PubMed1992

Therapeutic bioequivalency study of brand name versus generic carbamazepine.

We performed a randomized double-blind crossover therapeutic bioequivalency study of a generic (Epitol) versus a brand name (Tegretol) carbamazepine product under steady-state conditions in 40 epileptic patients. Each patient received 90-day supplies of Epitol or Tegretol and placebo, which replaced the usual dosage of the alternate product. Group A consisted of 20 seizure-free (from 5 months to 2 years) patients and group B of 20 patients with seizures refractory to drug therapy. In group A, four patients had seizures, two on both Epitol and Tegretol and two on Tegretol. In group B, the average seizure frequencies were 0.25 seizures per day on Epitol and 0.22 seizures per day on Tegretol. Average seizure frequencies were statistically the same (at a 20% difference, p less than 0.05). Areas under the curve were statistically the same (at a 20% difference, p = 0.05). Average peak heights were statistically the same (at a 20% difference, p less than 0.05). Average time to peak was earlier with Epitol. Epitol and Tegretol performed equally well in clinical efficacy and bioequivalency.

Adolescent↗