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Biomedical subjects

R H Lord

Publications and source records attributed to R H Lord.

At least 19 recordsLinked to original sources
PubMed2001

Tenckhoff catheters post-renal transplantation: the 'pull' technique?

BACKGROUND: Tenckhoff catheters are used widely for the provision of continuous ambulatory peritoneal dialysis. Traditionally these catheters are removed surgically under anaesthesia. We set out to introduce and monitor prospectively a technique for removal of the Tenckhoff catheter by a 'pull' technique. The intention was to avoid the discomfort, risk and cost of traditional surgery. METHODS: Over a 1-year period all renal transplant patients having their Tenckhoff catheter removed by this technique were monitored prospectively. All patients were followed for a minimum 2-year period after removal. In the pull technique steady non-jerky traction is applied to the catheter. Complications such as catheter breakage and cuff related sepsis were recorded. RESULTS: Sepsis related to a retained cuff occurred in only one patient early in the series. There were no other complications. The procedure was well tolerated. Use of local anaesthesia used initially, was largely phased out over the course of study and the procedure moved from the theatre to the ward. CONCLUSIONS: The pull technique is safe and well tolerated. The technique has significant advantages in selected patients without a history of recent peritonitis or exit site infection, in reducing risk to the patients, the pain of abdominal wall surgery and reduced usage of costly theatre time and in-patient beds.

Adult↗
PubMed1998

Management of inguinal herniae in patients on continuous ambulatory peritoneal dialysis: an audit of current UK practice.

Patients receiving continuous ambulatory peritoneal dialysis are at increased risk for the development of inguinal herniae, with a reported prevalence of 14%. Elective hernia repair is indicated for these patients as strangulation is associated with a high mortality in this population. There are currently no national guidelines relating to the optimal peri-operative management of these patients, in particular the appropriate pre- and post-operative dialysis regimen. The aim of the current study was to evaluate current practice in the UK by means of a postal questionnaire sent to all centres undertaking renal transplantation. Replies were received from 34/37 centres. The principal study finding was the wide variation in surgical practice between different centres with regard to pre- and post-operative dialysis regimes. Only 44% of centres had an established protocol. Based upon the study findings we have devised a protocol that we hope to see implemented into UK practice. Following its introduction, a re-assessment will be performed and the audit cycle completed.

Clinical Protocols↗
PubMed1998

Simple technique for non-operative removal of ureteric stents after renal transplantation.

Ureteric stents are employed peroperatively in renal transplantation when there is actual or suspected damage to the donor ureter. We describe a simple technique of suturing the distal end of the stent to the tip of a urinary catheter at the time of construction of the ureteric anastomosis. The stent is simply removed by gentle traction on the urinary catheter. This method obviates the need for a minor operative procedure or exposure to ionising radiation, which are the techniques commonly utilised at present. The procedure is also applicable to reconstructive urological procedures in which short-term stenting may be required.

Adolescent↗
PubMed1994

A double-blind, randomized, placebo-controlled study of nifedipine on early renal allograft function.

A double-blind, randomized, placebo-controlled study was conducted to determine the effect of nifedipine on early renal allograft function when added to a triple therapy immunosuppression regime comprising low-dose cyclosporin (CsA), prednisolone and azathioprine. Fifty adult cadaveric renal allograft recipients were randomized to placebo (group P n = 17), nifedipine 10 mg preoperatively and 20 mg b.d. postoperatively for 48 h, followed by matching placebo for 3 months (group NS n = 16) or nifedipine 10 mg preoperatively and 20 mg b.d. postoperatively for 3 months (group NL n = 17). Donor and recipient exclusion criteria included recent calcium antagonist treatment. At 3 months after transplantation mean GFR adjusted for graft loss was significantly higher in group NL than in NS (mean +/- SD 61 +/- 28 versus 34 +/- 25 ml/min/1.73 m2; P < 0.05), group P being intermediate (45 +/- 34 ml/min/1.73 m2). Similarly, effective renal blood flow (ERBF) at 3 months was higher in group NL than in groups P and NS (mean +/- SD 351 +/- 175 versus 216 +/- 166 and 220 +/- 162 ml/min/1.73 m2; P < 0.05). The differences were not significant by 6 months post-transplantation. This study suggests that oral nifedipine commenced preoperatively and continued for 3 months following transplantation has beneficial effects on early renal allograft function when incorporated as part of an immunotherapy regimen based on cyclosporin.

Adult↗
PubMed1993

Effects of plasma exchange on sperm antibody levels in males with subfertility.

Three men with subfertility secondary to sperm antibodies with measurable serum sperm antibody levels underwent a course of 3 plasma exchanges over a period of 1 week. The levels of serum anti-sperm antibodies fell by a mean of 3.3 dilutions. This fall was maintained for approximately 4 weeks, after which there was a return to the original levels. Plasma exchange is time-consuming and relatively expensive but it offers a possible alternative to steroid treatment (with its potential side effects) in men with sperm antibodies and warrants further investigation.

Adult↗
PubMed1991

Ureteric obstruction in renal transplants: the role of percutaneous balloon dilatation.

With widespread use of balloon dilatation catheters outside the vascular system, percutaneous balloon dilatation has become an accepted alternative to surgery. Seventeen patients who developed ureteric stenosis following renal transplantation underwent 21 transrenal angioplastic balloon dilatations. Fifteen patients had lower ureteric strictures (2-22 mm long), and two had multiple strictures. The time interval between transplantation and obstruction ranged from 11 to 1370 days (median 71, mean 228.9 days). Nine patients were treated successfully (53%) with no stricture recurrence during the follow-up period, which ranged from 3 to 44 months (median 16, mean 17.8 months). In eight of nine patients in this group, the stricture impression on the inflation balloon was eliminated, and this appears to correlate best with a successful outcome. The eight patients who failed balloon dilatation and restenosed, did so within 7-42 days in seven patients; one patient had late stricturing at 238 days. Serious complications occurred in only one patient, who developed an A-V fistula not amenable to correction and necessitating transplant nephrectomy.

Adult↗
PubMed1991

Ureteroureterostomy and pyeloureterostomy without native nephrectomy in renal transplantation.

A series of 23 patients, receiving full immunosuppression following renal transplantation, underwent a uretero- or pyelo-ureterostomy with ligation of the native ureter and no nephrectomy. In 5 patients this was carried out at the time of transplantation because of a short donor ureter and in 18 patients, at a median of 47 days after transplantation, following ureteric complications. With a median follow-up of 22 months, no complications have been seen in relation to the native kidney. Ureteroureterostomy was successful in all but 3 patients. A ureteroureterostomy without native nephrectomy is a safe and effective treatment for the management of ureteric complications following renal transplantation.

Anastomosis, Surgical↗
PubMed1988

Synergy between subtherapeutic doses of cyclosporine and immunologic enhancement in rat recipients of cardiac allografts.

We have analyzed the adjunctive effect of subtherapeutic doses of cyclosporine (CsA, 1.5 mg/kg/day x 7 or 14 days) on cardiac allograft survival in actively and passively enhanced rats. This CsA dose, one tenth of the effective dose, when administered after, but not before, transplantation into enhanced hosts produced permanent graft acceptance; cardiac allografts survive c. 25 days in recipients enhanced only and 1 week in untreated animals. Adoptive transfer of spleen T cells of OX8+ or W3/25+ phenotype from long-term (greater than 200 days) graft recipients prolonged donor-specific test graft survival in naive rats (c. 16 days and c. 14 days, respectively, P less than 0.001) and delayed rejection in reconstituted B rats from 7 days to 21-23 days (P less than 0.001). Indeed, both T subsets were separately equally potent and with no overlap responsible for the suppressor activity. The phenotypic profile of the immune cells in the maintenance phase of enhanced or enhanced + CsA-treated recipients was comparable to naive or isografted controls as demonstrated by flow cytometry and immunohistologic studies. Furthermore, the activation status of the graft infiltrate in long-term survivors was similar regardless of the initial immunosuppressive protocol. CsA contributed selectively to the enhancing regimen in the induction phase of unresponsiveness, diminishing the cellularity of graft infiltrate and preventing intragraft T cell activation. These studies stress synergy between subtherapeutic doses of CsA and immunologic active/passive enhancement, 2 immunosuppressive modalities that spare T cells with suppressor capabilities but differ in the inhibition of T helper cell activation.

Animals↗
PubMed1988

Synergy between subtherapeutic doses of cyclosporine and immunobiological manipulations in rat heart graft recipients.

Cyclosporine in combination with other chemical or biological immunosuppressive modalities has been useful in clinical and experimental organ transplantation. In these studies, the efficacy of adjunctive subtherapeutic doses of CsA given to immunologically enhanced heart graft recipients or to animals treated with an anti-IL-2 receptor monoclonal antibody (ART18) are described. Individually, the treatment entities are only partially effective. In rats undergoing active and passive enhancement alone, heart allograft survival was increased to 25 +/- 12 days in two-thirds, indefinitely in one-third. After ART18 treatment, grafts survive 21 +/- 1 days. Grafts are accepted permanently in animals receiving full-dose CsA (15 mg/kg X 7), but are rejected acutely (c. 7 days) when subtherapeutic doses (1.5 mg/kg X 7) are used. However, when subtherapeutic doses of CsA are given in combination with immunological enhancement or with interleukin-2-receptor-targeted therapy, graft survival increases dramatically, with permanent or markedly prolonged engraftment occurring in all instances. In the early phases of host unresponsiveness, both enhancement and IL-2R-targeted therapy, graft survival increases dramatically, with permanent or markedly prolonged engraftment occurring in all instances. In the early phases of host unresponsiveness, both enhancement and IL-2R-targeted therapy spare selectively T cells with suppressor activity in vivo; in enhanced animals, the W3/25+ subset is responsible for prolonged graft survival, the OX8+ fraction is responsible in ART18-treated animals and in CsA-treated animals. Both subpopulations show suppressor activity in the later stages of combination treatment. IL-3 production is increased significantly in these states of unresponsiveness, an observation also noted during maintenance CsA treatment; this seems to correlate with suppressor activity. Immunoperoxidase studies of the graft infiltrates emphasize the synergistic effects of combination treatments. Thus, subtherapeutic doses of CsA plus biologic host manipulations produce greatly increased graft survival by affecting selectively different host immune mechanisms.

Animals↗
PubMed1987

Two phenotypically distinct populations of T cells have suppressor capabilities simultaneously in the maintenance phase of immunologic enhancement.

The events leading to immunologic enhancement in LEW rats immunized actively with Brown Norway (BN) rat spleen cells and passively with LEW anti-BN hyperimmune serum 11 and 10 days before receiving (LEW X BN)F1 cardiac allografts, respectively, have been studied. Cellular suppressor mechanisms developing during the induction phase of this phenomenon have recently been shown to be mediated by W3/25+ T cells in an antigen-specific manner. The present study suggests that the late maintenance phase of immunologic enhancement is mediated in vivo by simultaneously present separate donor-specific T cell subpopulations of W3/25+ and OX8+ phenotypes. Splenocyte subsets from grafted recipients greater than 100 days after transplantation were adoptively transferred into unmodified syngeneic LEW rats that received a specific test allograft 24 hr later, or into B recipients bearing indefinitely surviving heart grafts. Test graft survival was prolonged significantly in the first group and not altered in the second. Indeed, nonoverlapping W3/25+ and OX8+ cell fractions were separately responsible for suppression. However, when suppressor activity was tested in vitro in a three-component coculture mixed lymphocyte reaction, no suppression by T cells was obtained; this lack of correlation between in vivo and in vitro results has also been noted by other investigators in different systems. Thus, in the maintenance phase of actively and passively induced immunologic enhancement, interplay between two phenotypically distinct T cells with suppressor characteristics, but not putative cell-surface blocking factors, seems to prevent development of an alloreactive response and mediate host unresponsiveness.

Animals↗