Search PubMed⌕ Search

Biomedical subjects

S M Gore

Publications and source records attributed to S M Gore.

At least 145 records · Page 8Linked to original sources
PubMed1988

Matchability in kidney transplantation.

The matchability of a patient awaiting kidney transplantation is his propensity for being 'well-matched'. We present two methods for estimating matchability. It is commonly supposed that phenotype frequency is a good predictor of matchability. We show a correlation of only 0.3 between matchability and phenotype frequency using the definition of 'well-matched' used by the UK Transplant Service. We also show that ABO type and HLA homozygocity can affect matchability.

Blood Group Antigens↗
PubMed1988

Transplantation statistics in the UK--an agenda for the next quinquennium.

Our next quinquennial plan for transplantation studies extends MPI to corneal and unrelated marrow transplantation. It applies Bayesian hierarchical modelling to regional variation in donor procurement and continues a program of special studies to augment national databases with respect to kidney, corneal, heart and liver transplantation. It promotes research collaboration among European and other organ exchange organizations as pioneered in the Council of Europe 1986 Study on High Sensitization, which showed the effectiveness of the network of European organ exchange organizations in liaising with transplant units.

Bayes Theorem↗
PubMed1987

Substantial benefits of tissue matching in renal transplantation.

The purpose of this study was to perform a rigorous statistical analysis of the benefits of HLA-A,B and DR matching in renal transplantation. Graft survival in 2282 first cadaver kidney transplants, recorded and followed up by the United Kingdom Transplant Service (UKTS), was analyzed using the piecewise proportional hazards regression method. The results show that substantial improvements in graft survival are obtained when there is DR compatibility and at most one A or B mismatch, but that there is little advantage in tissue matching unless this degree of matching can be attained. So far, few graft recipients have benefited substantially through tissue matching (24% of kidneys exchanged through UKTS in 1984). This is partly attributable to unresolved technical problems in DR typing. However simulations show that under ideal conditions, with a pool of 3000 patients awaiting transplantation, considerable improvements in graft survival can be obtained in over 60% of recipients.

Graft Survival↗
PubMed1987

Water-soluble methochloride of RU 486 fails to reduce intraocular pressure in normal rabbits.

RU 486 is a new water-insoluble drug which blocks peripheral glucocorticoid and progesterone receptors. As eye drops and by subconjunctival injection, it has been shown to lower normal rabbit intraocular pressure by a small amount. To try to improve the intraocular penetration, a water-soluble methochloride was prepared. In a series of 11 rabbits (initially 12: 1 died) treated in one eye at random with a 1% solution of the methochloride of RU 486 (vehicle drops to the fellow eye) no effect on intraocular pressure was found. The ionic nature of the methochloride may have prevented the drug becoming attached to, and blocking, the postulated glucocorticoid receptors in the rabbit outflow channels, although it may have penetrated the cornea more effectively.

Animals↗
PubMed1987

In defense of organ sharing in kidney transplantation.

1. The risks associated with nonbeneficial matching constitute a persistent hazard to the transplant over a long period. 2. The benefits of HLA matching and CsA are separate and additive. 3. There is no evidence that beneficial matching is not relevant to all (UK) centers. 4. Contemporary typing methods are expected to improve the accuracy of typing and reduce kidney cold-ischemia times. 5. Organ sharing increases the numbers of beneficial matches. 6. Patients with easily matchable ABO-HLA phenotypes should wait for beneficially matched transplants. 7. Patients with phenotypes that are difficult to match should be intelligently mismatched after due consideration of responder status, acceptable mismatches, and cross-reactive groups. 8. Organ sharing does not prejudice graft survival. 9. Wastage is minimized with a central clearing house. 10. Organ sharing reduces the incidence of high sensitization. 11. Organ sharing is cost effective. For these reasons we repudiate the view that organ sharing is now superfluous.

Cyclosporins↗
PubMed1986

Randomized trials of high-versus-low-dose steroids in renal transplantation. Does the evidence favor a consensus?

Published, randomized trials of high-versus-low-dose steroids in renal transplantation, individually and collectively, are too small (median trial size: 72 patients) to reach authoritative conclusions about mortality, graft failure, transplant failure, and the incidence of certain complications. The implications of this review for future therapeutic trials in renal transplantation are that randomization of 400 patients should be seen as minimum Phase III trial size, and that a research strategy is needed to encourage effective multicenter collaboration. One such strategy is described beginning with a single-center randomized Phase II trial to compare times to first rejection episode, thus rendering prior evidence on which the case for multicenter collaboration, effectively in an established trial, can be judged. Analysis by intention to treat and consistent reporting of the number of patients who experience certain classes of complication are two of four ground rules on which we assessed trials when combining evidence from similar studies. The other ground rules are randomization and common treatment theme. The statistical method of formally pooling results is outlined.

Clinical Trials as Topic↗
PubMed1986

Immunogenetic and clinical factors affecting renal transplantation. A rigorous analysis of data recorded by the UK Transplant Service.

A total of 3653 first cadaver kidney transplants in nondiabetic recipients over 15 years of age, performed in 30 transplant centers throughout the United Kingdom between 1978 and 1983, were analyzed to discover which of many recorded recipient, donor, surgical, and tissue-matching variables were important for graft survival, and in which postoperative period they exerted their maximum influence. A considerable effort was invested in checking the validity of the data and the appropriateness of the statistical methods. The duration of dialysis prior to transplantation was associated with a substantially reduced risk of graft failure, particularly at later postoperative times. Good HLA-B locus matching was also found to enhance graft survival--but, by contrast, HLA-A locus matching showed no significant effect on survival. Recipient age over 45 years, high serum reactivity, and grafts with anoxia time (the interval between circulatory arrest and perfusion with ice) exceeding 10 min were found to be associated with poor graft survival. Trends in survival were identified across calendar years of transplant, such that early graft failure (0-15 days) had increased in recent years, whereas later graft failure (greater than 15 days) had declined.

Adolescent↗
PubMed1986

Analyzing transplant survival data.

Stratified proportional hazards regression is described as a method of estimating multifactorially preoperative factor effects on graft survival--and, at the same time, making due allowances for unknown transplant-center-specific influences. The multifactorial aspect of the method overcomes the biases inherent in analyzing transplant survival data one factor at a time, and stratification allows the data from many centers to be used simultaneously without the dangers associated with simple pooling of data from many sources. The proportionality and regression assumptions implicit in the method enable the data to be used efficiently, but must be validated on the data. Methods by which these assumptions may be relaxed are described--in particular, the stratified piece-wise proportional hazards regression method.

Adult↗
PubMed1986

Subconjunctival suspension of RU486 lowers intraocular pressure in normal rabbits.

RU486 is both a progesterone blocker and a corticosteroid blocker (peripheral). Subconjunctival injections of 0.2 ml of a 1% suspension of RU486 powder (2 mg) were given twice weekly to one eye chosen at random of 12 rabbits. The fellow eye received the same volume, 0.2 ml, of vehicle (normal saline) only. Ocular tension was measured twice daily for six days per week by an Alcon pneumatonograph, the tonometrist(s) being unaware of which eyes were treated and which untreated. A small but significant reduction in intraocular pressure, about 0.7 mmHg, occurred in treated eyes. No intereye difference in the ocular hypertensive response to intraperitoneal injections of distilled water (50 ml/kg) was found. Clinical trials are planned in which a larger fall is expected because the trabecular meshwork in patients with open-angle glaucoma or ocular hypertension is presumably more affected by (normal) tissue levels of corticosteroid.

Animals↗