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Biomedical subjects

A F Wright

Publications and source records attributed to A F Wright.

At least 91 records · Page 5Linked to original sources
PubMed1991

Renal, cardiovascular and hormonal characteristics of young adults with autosomal dominant polycystic kidney disease.

We studied young adults with autosomal dominant polycystic kidney disease (ADPKD) to determine the characteristics that precede renal impairment. Nineteen affected (A) and 20 unaffected (U) offspring from families with ADPKD showed no significant differences in basal glomerular filtration rate (A: mean 97, SD 19; U: 100, SD 23 ml/min/1.73 m2) or renal functional reserve, but effective renal plasma flow was significantly lower in affected offspring (A: 532, SD 86; U: 605, SD 118 ml/min/1.73 m2, P less than 0.01). Plasma renin activity [A: median 26 (95% CI: 15 to 37); U: 14 (11 to 27) microU/ml, P less than 0.05, one-tailed test] and aldosterone [A: 2.5 (2.0 to 3.0), U: 1.0 (1.5 to 2.0) micrograms/100 ml, P less than 0.04, one-tailed test] were increased in affected offspring despite the higher systolic blood pressure (A: mean 123, SD 5; U: 115, SD 3 mm Hg, P less than 0.02) and significant expansion of total exchangeable sodium (A: 40.8, SD 2.3; U: 38.0, SD 3.5 mmol/kg, P less than 0.01). The ouabain-sensitive component of red cell sodium efflux was less in affected offspring (A: 0.258; SD 0.040; U: 0.288, SD 0.042 hr-1, P less than 0.04) and in both groups was correlated inversely with total exchangeable sodium. Echocardiography revealed no difference in left ventricular mass index nor prevalence of mitral valve prolapse. Potential cyst growth factors such as the glucocorticoids and somatomedin C were similar in both affected and unaffected groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Education and attitudes in families with adult polycystic kidney disease.

The availability of methods for early accurate identification of individuals at risk of developing adult polycystic kidney disease (ADPKD) has raised a number of important clinical problems. As part of a project on clinical and genetic aspects of ADPKD, we have assessed the knowledge and attitudes of patients and their families. Most had a poor knowledge of the condition and its implications. Despite this, many were in favour of early, including antenatal, diagnosis. A videotape was therefore introduced as part of an educational programme to improve patients' knowledge. This resulted in a marked improvement in understanding of the condition. Although a significant number still wished to consider early diagnosis in their offspring, very few would consider terminating an affected pregnancy.

Adolescent↗
PubMed1991

Genetic localisation of the RP2 type of X linked retinitis pigmentosa in a large kindred.

Genetic linkage and deletion studies have led to the proposal that there are at least two loci on the X chromosome which are responsible for X linked retinitis pigmentosa (XLRP). One locus (RP3) has been closely defined by genetic linkage and deletion analyses and localised to the region between the ornithine transcarbamylase (OTC) and chronic granulomatous disease (CYBB) loci in Xp21.1-p11.4. The other locus (RP2) has been assigned by linkage analysis alone to region Xp11.4-p11.2, but its localisation is less well defined. The results of a multipoint linkage analysis of a single large XLRP kindred using eight informative loci provide further evidence on the localisation of RP2 to this region. The maximum likelihood location of this locus shows a multipoint lod score of 7.17 close to DXS255 (in Xp11.22) and TIMP (in Xp11.3-p11.23), neither of which show recombination with RP2, in an area extending from 2 cM proximal to DXS7 to 1 cM distal to DXS14 (approximate 95% confidence limits).

Bayes Theorem↗
PubMed1990

DXS26 (HU16) is located in Xq21.1.

We have localized a single-copy DNA probe, HU16 (locus DXS26), to Xq21.1. The probe was isolated from a human-mouse hybrid X;13 library and mapped with human-mouse hybrids containing different portions of the human X chromosome and DNA from male patients with different X-chromosomal deletions. The following order of loci is proposed: Xcen-(DXS72,DXS169)-(DXS232,DSX26)-DXS1 21-DXS233-DXS165-TCD-DXS95-DXYS1-Xqter. HU16 will be useful in the study of the putative genes that reside in Xq21 and whose defects lead to deafness and mental retardation.

Animals↗
PubMed1990

No evidence for linkage between late onset autosomal dominant retinitis pigmentosa and chromosome 3 locus D3S47 (C17): evidence for genetic heterogeneity.

Retinitis pigmentosa is an inherited form of blindness caused by progressive retinal degeneration. P. McWilliam et al. (1989, Genomics 5: 619-622) demonstrated close genetic linkage between autosomal dominant retinitis pigmentosa (ADRP) and locus D3S47 (C17) in a single early onset pedigree. The marker C17 maps to the long arm of chromosome 3. Clinically, the disease phenotype has been subdivided into at least two forms on the basis of age of onset, as well as electrodiagnostic criteria. We demonstrate that C17 is unlinked in a late onset pedigree, indicating that the phenotypic variation seen reflects underlying genetic heterogeneity.

Chromosomes, Human, Pair 3↗
PubMed1990

Linkage studies and deletion screening in choroideremia.

Fourteen families with choroideremia (TCD) have been examined for linkage to nine genetic markers located on the proximal long arm of the X chromosome. Linkage to three markers (DXYS1, DXS72, DXS3) located in Xq21 was found with a four point lod score of 8.25. No evidence of submicroscopic deletions was observed using DXS233 and DXS232, both thought to lie within about 1 Mb of the TCD gene.

Choroideremia↗
PubMed1990

A study of the presentation of somatic symptoms in general practice by patients with psychiatric disturbance.

A computerized questionnaire was used to collect information on the presentation of symptoms in all 125 new patients presenting to one general practitioner in the course of one year who were considered to be suffering clinically significant psychiatric disturbance. Comparison was made between the 73 (58%) patients presenting with psychological symptoms and the 52 (42%) patients presenting with somatic symptoms for which no physical explanation was evident at the time of the consultation. Important differences emerged between the groups. Those patients presenting somatic symptoms had lower scores on the tests of psychiatric distress (indicating severity), fewer individual symptoms and fewer severe symptoms than patients presenting with psychological problems. This group also had statistically significant differences in personality profile and reported significantly fewer social problems. Prognosis for both groups was similar in that patients in both groups were equally likely to have a normal psychiatric distress score after six months. Adequate management of somatizing patients calls for vigilance and for improved detection and negotiating skills. Reviewing the computer results with patients helped them discuss their symptoms and the system allowed the general practitioner not only a clinical assessment of these patients' problems but a measure of psychological, social and personality components.

Adult↗
PubMed1990

Linkage to D3S47 (C17) in one large autosomal dominant retinitis pigmentosa family and exclusion in another: confirmation of genetic heterogeneity.

Recently Dryja and his co-workers observed a mutation in the 23d codon of the rhodopsin gene in a proportion of autosomal dominant retinitis pigmentosa (ADRP) patients. Linkage analysis with a rhodopsin-linked probe C17 (D3S47) was carried out in two large British ADRP families, one with diffuse-type (D-type) RP and the other with regional-type (R-type) RP. Significantly positive lod scores (lod score maximum [Zmax] = +5.58 at recombination fraction [theta] = .0) were obtained between C17 and our D-type ADRP family showing complete penetrance. Sequence and oligonucleotide analysis has, however, shown that no point mutation at the 23d codon exists in affected individuals in our complete-penetrance pedigree, indicating that another rhodopsin mutation is probably responsible for ADRP in this family. Significantly negative lod scores (Z less than -2 at theta = .045) were, however, obtained between C17 and our R-type family which showed incomplete penetrance. Previous results presented by this laboratory also showed no linkage between C17 and another large British R-type ADRP family with incomplete penetrance. This confirms genetic heterogeneity. Some types of ADRP are being caused by different mutations in the rhodopsin locus (3q21-24) or another tightly linked gene in this region, while other types of ADRP are the result of mutations elsewhere in the genome.

Base Sequence↗
PubMed1989

Adaptive evolution of G-protein coupled receptor genes.

The phylogeny and patterns of nucleotide substitutions in the visual pigment genes, adrenergic receptor genes, muscarinic receptor genes, and in the human mas oncogene were studied by comparing their DNA sequences. The evolutionary tree obtained shows that the visual pigment genes and mas oncogene form one cluster and that the receptor genes form another. In the evolution of rhodopsin genes, synonymous substitutions outnumber nonsynonymous substitutions. This is consistent with the neutral theory of molecular evolution. However, the early evolutionary stages of alpha- and beta-adrenergic and muscarinic receptors are notable for significantly more nonsynonymous substitutions than synonymous substitutions, suggesting the acquisition of novel functional adaptations. Variable rates of nonsynonymous changes in different domains of these proteins reveal DNA segments that might have been important in their functional adaptations.

Amino Acids↗
PubMed1988

Psychological distress: outcome and consultation rates in one general practice.

This paper reports a one-year follow-up of random samples of 90 male and 96 female patients attending one general practitioner. There was no statistically significant difference between men and women in the total score on the 28-item general health questionnaire or any of the subscores. However, the diagnostic labels applied to the two sexes were strikingly different as was the prescribing of psychotropic drugs. Outcome of psychological distress was assessed in terms of change in total general health questionnaire score. Two thirds of the patients (65%) showed normal scores at the beginning and end of the follow-up period, 19% changed from abnormal to normal and 8% changed from normal to abnormal. The remaining 9% had persistently high scores though less than half had been given a psychiatric diagnosis. They had very high consultation rates persisting over several years and three-quarters were known to have chronic physical illness. It seems possible that some patients with persistently high consultation rates who present with chronic, mainly somatic, symptoms may be or may become psychologically distressed to a significant degree and that this psychological distress goes unrecognized in the presence of physical disease.

Adolescent↗