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D Talbot

Publications and source records attributed to D Talbot.

At least 37 records · Page 2Linked to original sources

Variation in organ donation in northeastern England 1986 to 2003.

Renal transplantation is established as the best form of renal replacement therapy, but demand for kidneys exceeds supply from cadaveric donations. It is therefore important to make the best use of the pool of potential cadaveric organ donors. Donation rates are to a large extent dependent on public opinions, which may be influenced by external events. In northeast England from 1986 to 2003, there was a potential pool of 1170 brain stem-dead donors, of whom 190 (16%) could not be retrieved due to relatives' objections. From 1998 to 2003 we were referred 90 potential non-heart-beating donors, of whom relatives refused donation in 10 (11%). A major reason for not retrieving organs from a potential donor has been lack of consent from the relatives. Refusals appear to vary year by year and are consistently lower for non-heart-beating donors. This therefore raises the possibility that negative or positive media publicity plays a role in this variation.

Attitude to Death↗

Anti-vimentin antibody detection in recipients of heart-beating and non-heart beating donor kidneys.

Alternative donor sources include non-heart-beating donors (NHBDs). There donors have been exposed to significant ischemia, so that it is common to utilize machine perfusion to either improve the organs or at least assess their viability. Both prolonged warm ischemia and machine perfusion can potentially damage the vascular endothelium, thereby exposing vimentin to antigenic recognition. The aim of this study was to determine whether anti-vimentin antibodies could be detected in the blood of renal transplant recipients at specific time points after transplant and whether they could be related to the donor source. Fifty-one recipients of NHBD kidneys were compared to 52 recipients of heart-beating donor (HBD) kidneys. All recipients had similar anti-vimentin levels pretransplant. However, at 1 month those kidneys from Maastricht category II NHB donors showed significantly higher levels. At 6 months both Maastricht category II and category III NHB donor recipients displayed significantly higher levels than recipients of HBD kidneys.

Adult↗

Cardiovascular risk assessment scoring system for the determination of cardiovascular mortality in renal transplant patients.

It is well known that the greatest risk for mortality post-renal transplant is cardiovascular death. We compared a modified cardiac risk assessment system among renal transplant patients who subsequently died versus the group that survived. There was a good correlation between the low, medium, and high scores with survival. The deceased group had significantly greater cardiovascular scores than case controls.

Adult↗

A simple cardiovascular risk score can predict poor outcome in NHBD renal transplantation.

A simple cardiovascular risk score used in our center to plan cardiovascular workup for renal transplantation can predict outcome in non-heart-beating donor (NHBD) renal transplantation. Patients in the higher risk group, with a score of >12 out of a maximum of 36 are likely to have a longer duration of delayed graft function, poorer glomerular filtration rate at 6 months, and inferior graft and patient survival, together with an relative rate of graft loss within 60 days of >4 (P = .053). Although a high cardiovascular risk score should not be regarded as a contraindication to NHBD transplantation, the score can be used to facilitate recipient selection.

Adult↗

Synthesis and dispersion of Ni(OH)2 platelet-like nanoparticles in water.

Synthesis of nanometric platelet-like Ni(OH)2 particles is described. The role of several experimental parameters on the particle size is investigated. A colloidal dispersion of particles is produced by adsorbing ionizable organic ligands (trisodium citrate) on the particle surface. The stability of this colloidal dispersion and the particle charge density are determined for different citrate ions concentrations.

Colloids↗

Dynamic EBV gene loads in renal, hepatic, and cardiothoracic transplant recipients as determined by real-time PCR light cycler.

BACKGROUND: Epstein-Barr virus (EBV) is recognised as one of the causative agents for most cases of post-transplant lymphoproliferative disease (PTLD). Elevated levels of EBV DNA are known to be associated with the onset of PTLD, but little information is available regarding how EBV loads change with time in asymptomatic transplant recipients following transplantation. Our aims were to study the trend of EBV loads in renal (RTx), hepatic, and cardiothoracic transplant recipients and to compare their EBV loads with other healthy and patient controls. METHODS: A prospective study was performed using a real-time TaqMan polymerase chain reaction technique to measure EBV DNA loads from three types of organ transplant recipients and haemodialysis patients (HD). Their results were then compared with those from the healthy controls (HC); monospot test negative (MN-) and infectious mononucleosis positive (IM+) patients; patients who were previously treated for PTLD (pPTLD); those who were currently diagnosed to have PTLD (PTLD+); and patients who had a stable renal, hepatic, or cardiothoracic graft for more than a year. RESULTS: Post-transplant EBV loads were significantly higher than the pre-transplant levels. Asymptomatic transplant recipients were differentiated from the PTLD+group at 600 genome copies of EBV/mug DNA, and from IM+group at 100 genome copies. Both HC and MN- groups had significantly lower EBV loads than the three transplant groups. The dynamic change of EBV loads in RTx was greater in the first post-transplant month when compared with the HD group. All transplant recipients had transient rises of EBV loads whereas EBV load continued to rise in one suspected PTLD patient. CONCLUSIONS: Asymptomatic transplant recipients had higher baseline post-transplant EBV levels than the non-transplant and MN- groups. The rising post-transplant EBV load in these transplant recipients did not seem to be sustained for longer than 2 weeks. However, in a PTLD+patient the rising EBV load continued over a period of 4 weeks. Hence, the dynamic pattern of EBV loads is more important than absolute EBV DNA measurements alone in identifying those who might go on to develop PTLD.

Adolescent↗

Prospective randomised trial of the use of Daclizumab in renal transplantation using kidneys from non heart beating donors.

OBJECTIVES: Transplantation using non-heart beating donors (NHBD) is one way of reducing the global kidney shortage. Unfortunately the large warm ischaemic insult sustained by the graft leads to a high rate of delayed graft function (DGF). We have investigated the use of a regimen utilising an II-2r blocker (DZB) in place of Tacrolimus for the initial post-operative immunosupression with the aim of reducing the incidence of DGF. METHODS: Prospective randomised controlled trial based in two NHBD UK centres (Leicester and Newcastle). 51 patients were enrolled over two years and randomised into two treatment arms: 1. DZB/MMF/Steroids (Tacrolimus started when creatinine dropped below 350 micromol/l) 2. Tacro/MMF/Steroids. RESULTS: There was one death, during the study period, in a patient who had had a non-functioning graft removed. The overall incidence of immediate function (IF) was higher than expected (28%), no significant difference was found in the incidence of immediate graft function between the two groups (35% group 1 and 22% group 2). Sub-group analysis however has shown a significant advantage for the delayed introduction of Tacrolimus for machine perfused grafts (IF: 53% vs 13%, chi2 p=0.015). There was no difference in the rate of rejection. CONCLUSIONS: The delayed introduction of Tacrolimus reduces the incidence of DGF in machine-perfused NHBD kidney transplantation.

Antibodies, Monoclonal↗

Weight increase during machine perfusion may be an indicator of organ and in particular, vascular damage.

OBJECTIVES: Hypothermic machine perfusion preservation has been shown to improve the outcome of renal grafts from non-heartbeating donors. We have noticed that organs gain a variable amount of weight during perfusion. METHODS: All grafts, whether used or discarded, were assessed with respect to their weight gain. Primary outcome measures were the results of viability testing. Secondary outcomes were early transplant variables including incidence and duration of delayed graft function and histological examination of protocol graft biopsies. RESULTS: Weight increase data was available on 97 grafts. There were no significant differences in weight gain between kidneys used and discarded (17% vs 20%). 14 patients received grafts which gained over 30% of their initial retrieval weight. There were no significant differences in secondary outcome measures between this group of recipients and patients who had received less "waterlogged" kidneys. Histological changes including endothelial inflammation and oedema were observed. CONCLUSIONS: Kidney grafts which have gained over 30% of weight on hypothermic machine perfusion preservation can be transplanted successfully. Complex interactions between the period of warm ischaemia, in situ flushing, perfusion pressures and perfusate probably lead to the phenomenon of excessive graft weight gain.

Blood Vessels↗

Reperfusion injury in renal transplantation: comparison of LD, HBD and NHBD renal transplants.

Comparison of reperfusion injury in kidneys transplanted from LD, HBD or NHBD donors is presented in the paper. Central venous blood samples (taken during perioperative period) was assessed for free radicals, total antioxidant activity and various markers of tissue injury. There was demonstrable ischemia reperfusion injury occurring at the time of revascularization, which was particularly notable in kidneys transplanted from NHBD donors.

Adult↗

Experiences learned in the successful establishment of a nonheart beating donor program for renal transplantation.

PURPOSE: With the continuing shortage of suitable donors increasing interest is being shown in nonheart beating donation. Such a resource is a new and, therefore, an underused source of donor organs. However because of the nature of such donors, the kidneys so derived have been damaged by primary warm ischemia, and so potentially they may never function. We introduced viability testing to identify such organs and, thus, avoid transplantation. We reviewed sentinel cases in our developing program from which we have learned. MATERIALS AND METHODS: Machine perfusion was developed locally and used to test the kidneys derived from such donors. Flow characteristics and enzyme analysis were used to define usable kidneys. The definitions of acceptable criteria evolved through the study during a 3-year period. RESULTS: As previously defined, acceptable criteria were initially adhered with decreasing resistance and a glutathione S-transferase of less than 200 IU/l/100 gm. After the series described acceptable limits were changed in favor of a high perfusion flow index, low temperature, low weight increase and low glutathione S-transferase. CONCLUSIONS: If such criteria are adhered to, graft survival becomes reliable from such donors.

Adult↗

Use of real-time PCR to measure Epstein-Barr virus genomes in whole blood.

The measurement of the Epstein-Barr viral load in peripheral blood has been recognised as an important way of monitoring the response to treatment in patients with Epstein-Barr virus (EBV)-related malignancies. In particular, EBV load in transplant recipients can be used as a predictive parameter for Post-transplant Lymphoproliferative Disorder (PTLD). The aim was to develop a rapid and reliable PCR protocol for the quantification of the cell-associated EBV genome. Real-time PCR using TaqMan methodology was established. This technique was applied to determine the EBV load in various study groups including healthy controls, transplant recipients, patients on haemodialysis, and patients with infectious mononucleosis. The baseline level of EBV genomes in the immunosuppressed renal transplant recipients was significantly different from that in the healthy controls.

DNA, Viral↗

Size-selective chemical synthesis of tartrate stabilized cobalt ferrite ionic magnetic fluid.

Ionic magnetic fluid (ferrofluid) is a stable suspension of magnetic nanoparticles in water. Cobalt ferrite nanoparticles are interesting in view of high-density recording storage. The size of the magnetic particles strongly influences the physical properties of the ferrofluids. In this study, we describe the synthesis of ionic magnetic fluid in the presence of tartrate ions. By varying the amount of organic ligands, nanoparticles in a large range of size are obtained: the mean diameter varies from 3 to 10 nm. The effect of tartrate ions on the stability of the ionic magnetic fluid is also studied in relation with the size of the magnetic particles and the amount of adsorbed ligand.

Journal Article↗