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Biomedical subjects

D Taube

Publications and source records attributed to D Taube.

At least 37 records · Page 2Linked to original sources
PubMed1997

Stripping of failing haemodialysis catheters using the Ampltaz gooseneck snare.

The development of a fibrin sheath at the tip of a long-term haemodialysis catheter may lead to deteriorating blood flow rates, resulting in inadequate haemodialysis. Restoration of functional patency has been described using the technique of percutaneous fibrin sheath stripping (PFSS) using a wire snare device. Our purpose was to assess this technique within an established renal vascular access service. All catheters referred for the assessment of low blood flow rates on dialysis were considered for the procedure. Initial fluoroscopic assessment of the catheter was followed by stripping of the tip of the catheter using a gooseneck snare. Seventeen of 22 well-positioned catheters undergoing a single PFSS attempt were restored to function with a median prolongation of patency of 4.25 months. Two catheters underwent a second PFSS procedure providing additional patency. Nineteen of a total of 24 (79%) PFSS procedures successfully restored catheter function. Seven catheters with poorly positioned tips or a kink were not restored to functional patency using PFSS. Two patients developed a puncture site haematoma. No patient developed symptoms of pulmonary emoblism. In conclusion, PFSS restored function in 79% of attempts in well positioned catheters. The method is technically straightforward, with a low complication rate and has become a routine part of the renal vascular access service.

Catheterization, Central Venous↗
PubMed1997

The diagnosis and racial origin of 394 patients undergoing renal biopsy: an association between Indian race and interstitial nephritis.

BACKGROUND: There is a high incidence of renal disease in the ethnically Indian population in the United Kingdom, the pathological basis for which is only partly understood. This study attempted to define associations between renal biopsy diagnosis and race. The aim was thereby to identify types of renal disease which may contribute to the observed predisposition to renal failure in the Indian population served by our centre. METHOD: A single-centre-based retrospective analysis of the final diagnosis and corresponding ethnicity in 394 consecutive patients undergoing native renal biopsy for the investigation of abnormal renal function or urinary sediment. RESULTS: A highly significant association between a diagnosis of interstitial nephritis and Indian race was observed. There were 30 cases of interstitial nephritis, of whom 17 were Indian. In 15 of the Indian patients no aetiology could be established. The clinical features, outcomes, and the effect of steroid therapy in the Indian patients with idiopathic interstitial nephritis are described. CONCLUSION: Idiopathic interstitial nephritis is associated with Indian racial origin. This pathology may significantly contribute to the high incidence of end-stage renal failure in Indian patients resident in the United Kingdom.

Adult↗
PubMed1995

Inhibition of the pig to human xenograft reaction, using soluble Gal alpha 1-3Gal and Gal alpha 1-3Gal beta 1-4GlcNAc.

Natural anti-carbohydrate antibodies are central to hyperacute rejection in ABO-incompatible allotransplantation and in discordant xenotransplantation. ABO-incompatible rejection has been inhibited successfully using intravenous soluble carbohydrates as antibody inhibitors. The approach has been less successful previously in pig to primate xenotransplantation, where the necessary concentrations of a partial inhibitor (Gal alpha 1-6Glc) proved highly toxic. In this study, we have identified more effective inhibitors of the dominant human anti-pig antibodies that bind to the pentasaccharide Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-. The inhibitors are the terminal disaccharide (Gal alpha 1-3Gal) and terminal trisaccharide (Gal alpha 1-3Gal beta 1-4GlcNAc) of the target pentasaccharide. Twelve sera (3 from each ABO blood group) were tested in 3 different assays: lymphocytotoxic, lymphocyte flow cytometry, and solid-phase antigen ELISA. Fifty percent to 75% inhibition of human IgG and IgM was achieved using the disaccharide and trisaccharide inhibitors in the range of 10-50 mM. Disaccharide (70 mM) was used to inhibit hyperacute thrombosis in pig kidneys perfused for 40 min with heparinized human AB whole blood. The disaccharide completely inhibited red cell occlusion of glomerular but not of intertubular capillaries, although there was residual platelet thrombus in glomeruli. Disaccharide and trisaccharide can, therefore, be used in concentrations shown for other carbohydrate inhibitors to be nontoxic, for inhibition of hyperacute pig-to-human xenograft rejection. The inhibition is incomplete, however, and other antigen specificities and other rejection mechanisms are likely to be involved.

ABO Blood-Group System↗
PubMed1995

Anti-CD45 monoclonal antibody perfusion of human renal allografts prior to transplantation. A safety and immunohistological study. CD45 Study Group.

The perfusion of kidneys with anti-CD45 monoclonal antibodies prior to transplantation offers a means of targeting passenger antigen-presenting cells with the aim of reducing the subsequent incidence of rejection episodes. A safety study was performed in humans of such pretreatment in 40 unsensitized recipients of first cadaveric renal grafts, who were followed for 3 months after transplantation. A 50-ml solution containing 2 mg of each of the rat anti-CD45 mAbs YTH 24.5 and YTH 54.12 was injected into the allograft renal artery ex vivo and just before transplantation while the renal vein was kept clamped. No patients died, but 4 grafts were lost. Two were lost due to primary nonfunction, 1 was lost because of late renal artery thrombosis, and 1 was lost to rejection. There were no cases of renal vein thrombosis and 1 trivial renal artery stenosis, and only 2 patients produced human anti-rat antibodies. Between 63.5% and 100% (median 96.4%) of CD45+ cells in the postperfusion biopsies were coated with anti-CD45 as determined by double-immunolabeling. The number of patients experiencing rejection episodes was inversely associated with this "antibody uptake": 75% of the low uptake group (< 95%) had at least 1 rejection episode, compared with 22% of the high uptake group (> or = 95%) (P = 0.001). The complement components C3 and C5b-9 colocalized with perfused anti-CD45 in 32/33 (97.0%) and 11/33 (33.3%) of the biopsy specimens, respectively. We conclude that: (1) this technique appears free of adverse effects, (2) high antibody uptake within the kidney is associated with a lower incidence of rejection, and (3) the antibodies used fix and activate complement in vivo.

Adult↗
PubMed1995

Magnetic resonance angiography of renal artery stenosis.

Renal artery stenosis is a common cause of renal impairment which in many cases may be potentially reversible. The diagnosis and follow-up of this condition is commonly carried out using the relatively invasive technique of intra-arterial angiography. Magnetic resonance angiography (MRA) is emerging as a possible alternative technique to conventional angiography. We have studied 60 patients who were referred for investigation of possible renal artery stenosis using both 3-D phase contrast MRA techniques and conventional digital arteriography. Studies were assessed prospectively and conventional angiography was assumed to be the gold standard for the purposes of this study. Calculated sensitivity and specificity results were 84% and 91% respectively, for 3-D phase contrast MRA of the renal arteries. We conclude that 3-D phase contrast MRA is a very promising technique for the noninvasive investigation of renal artery stenosis with high sensitivity and specificity levels acting as a screening test in the future for patients with this potential diagnosis, diminishing the amount of conventional angiograms that are performed.

Adult↗
PubMed1995

The use of expandable metal stents in transplant renal artery stenosis.

The management of resistant transplant renal artery stenosis (TRAS) poses difficult problems. There is no consensus on the most appropriate course of action if severe stenosis recurs despite repeated percutaneous transluminal balloon angioplasty (PTA). Expandable metallic vascular stents have been increasingly successful as an adjunct to PTA in the coronary and peripheral circulation and more recently in the management of resistant native renal artery stenosis. We report four cases in which such stents were successfully used to treat resistant stenosis in transplant renal arteries. The cases illustrate the range of problems that may be caused by TRAS, from resistant hypertension to impending graft failure. The stents were successfully deployed in all four patients. One patient had an acute stent thrombosis successfully treated with immediate thrombolysis and two patients required repeat stenting. In all the cases there was arrest or slowing of previously aggressive recurrent TRAS and at the close of follow-up (4-24 months) all patients had adequate stable allograft function, and satisfactory blood pressure control including the one patient with a significant residual stenosis.

Acute Kidney Injury↗
PubMed1994

Pretreatment of renal transplants with anti-CD45 antibodies: optimization of perfusion technique.

Pig kidneys were perfused ex vivo with a monoclonal anti-pig CD45 antibody to determine optimum conditions for human kidney anti-CD45 perfusion, as such pretreatment may prolong renal allograft survival. Efficacy of perfused antibody uptake was assessed by immunohistochemical double-labelling of multiple renal biopsies. Antibody uptake by CD45+ cells was rapid, and maximal within one hour of perfusion. An antibody concentration of 40 micrograms/ml more effectively saturated available CD45 binding sites than lower concentrations. Whilst cortical perfusion was homogeneous (median uptake > 99%, minimum 90.0%) after 25, 50 or 100 ml perfusion with 40 micrograms/ml monoclonal antibody (mAb), the medulla was less evenly perfused with 25 ml (median uptake 82.6%) than with 50 or 100 ml (median uptake 98.5% and 98.7%, respectively). Prolongation of renal cold ischaemia of up to 46 hours prior to mAb perfusion did not adversely affect antibody binding. Clamping of the renal vein during and after mAb perfusion was associated with better cortical and medullary mAb uptake than if the vein was left unclamped. These data show that the vast majority of the kidney's CD45+ antigen-presenting cells can be bound by anti-CD45 mAb perfused ex vivo, if an adequate volume and concentration of mAb perfusate is employed and the renal vein is clamped during and after the process.

Animals↗