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Biomedical subjects

R A Sells

Publications and source records attributed to R A Sells.

At least 55 records · Page 3Linked to original sources

Human T cells expressing V beta 8 do not predominantly recognize DR2 alloantigen.

A panel of seven monoclonal antibodies recognizing human T-cell antigen receptor (TcR) V alpha or V beta subsets has been used to measure TcR gene expression in peripheral blood lymphocytes and mixed lymphocyte culture responses (MLR) between DR2- and DR2+ (DRw15+) donors. There were no significant differences between DR2- and DR2+ donors in per cent T cells in fresh peripheral blood labelled with any of these antibodies, which included an antibody recognizing V beta 8. This indicates strongly that increased negative selection of V beta 8+ T cells does not occur in DR2+ compared with DR2- individuals. In MLR between DR2- and DR2+ donors the only significant change compared with fresh peripheral lymphocytes was that T cells expressing V beta 5.1 were decreased in DR2- lymphocyte populations responding to DR2 alloantigen. No changes in levels of V beta 8+ T cells were detected in MLR between DR2- and DR2+ donors. This suggests that V beta 8+ T cells are not predominantly reactive against DR2 (DRw15). The data support the concept that alloreactivity against a single class II major histocompatibility complex (MHC) mismatch is mediated by T cells expressing a range of different TcR V beta molecules.

Antibodies, Monoclonal↗

Some ethical issues in organ retrieval, 1982 to 1992.

The debate on incentive payments and related issues will continue so long as dialysis and cadaver donation remain out of the reach of physicians in developing countries. This article (from a Western doctor) steps outside the usual debate on these issues by making a practical suggestion which aims at easing the ethical tension of incentive donation rather than insisting on its abolition. "Donors' trusts" may help the situation in India, but should not be applied in any country where effective dialysis is generally available. Nor would I be happy for such a model to be developed in any country where the aim to introduce cadaveric organ donation was not being energetically pursued.

Contracts↗

Evaluation of sequential plasma and urinary tumor necrosis factor alpha levels in renal allograft recipients.

The macrophage cytokine tumor necrosis factor-alpha is released early in immune activation and may be detected in the peripheral circulation. This study has investigated the occurrence of plasma and urinary TNF in 30 renal allograft recipients. Although circulating TNF may be detected in 20% of pretransplant or normal control samples, levels were significantly elevated during 65% of allograft rejection episodes. Plasma TNF levels did not rise in graft failure due to acute tubular necrosis, but were always highly raised in systemic infection. In contrast, urinary TNF was only detected in association with acute rejection (49%) or tubular necrosis (14%), and no controls had detectable urinary TNF. These findings indicate that evaluation of circulating and excreted TNF may give further insight into the immunobiology of graft rejection.

Communicable Diseases↗

A new splint for use in axillary surgery.

The surgical options for the treatment of axillary hidradenitis suppurativa are discussed. A new light-weight splint is described which will allow comfortable immobilisation of the shoulder at 45 degrees yet permit full forearm movement and adequate access to the axilla for dressings. We have found the splint of benefit in the management of this conditions by promoting the primary healing of split skin grafts.

Apocrine Glands↗

Method for home monitoring of urinary amylase after pancreas transplantation.

Urinary amylase activity (UAA) is used for diagnosis of rejection in bladder-drained pancreas grafts. Unfortunately, most rejection episodes occur after the patient has been discharged. In those cases, an early diagnosis is often difficult, and a method for home UAA monitoring is needed. We have developed a method that can be used for this purpose. The method, based on Kodak dry-film technology, is shown to have good response to the wide range of UAA seen in these patients compared with responses to standard laboratory kinetic methods. The analysis (performed by the patient) involves 1) collecting urine for 24 h in a 4-L container, 2) diluting the urine with tap water to a total urine of 4 L, and 3) placing a drop of this dilution onto a slide. The slide is read by a handheld spectrophotometer that displays the UAA in secreted units per hour. The reliability of this system has been tested for wide changes of urine pH, volume of the drop applied to the slide, and tap water from different sources. Temperature coefficients have been determined to correct changes in ambient temperatures. The final handheld prototype is being developed based on these preliminary studies. This device could be of benefit for the early diagnosis of rejection episodes in recipients of bladder-drained pancreas grafts after hospital discharge.

Amylases↗

Amoxycillin-clavulanic acid (Augmentin) antibiotic prophylaxis against wound infections in renal failure patients.

A randomized, controlled trial of the use of amoxycillin with clavulanic acid (Augmentin) for prophylaxis against wound infections following major surgery, including transplantation, in patients with chronic renal failure, was undertaken. Six of 22 control patients developed wound infections (27%) whereas no patient in the treatment group (24) developed a wound infection (P less than 0.05). After the termination of this trial, the next 35 consecutive patients received prophylactic amoxycillin/clavulanate; of these only two developed wound infections associated with leakage from their pancreatic anastomoses. All the wound infections were shown to be caused by bacteria sensitive to amoxycillin/clavulanate. Pharmacokinetic studies in patients have shown that a bactericidal concentration of the drugs was present for up to 20 h post-operatively in patients on dialysis, and in recipients of non-functioning renal transplants. In patients with normal renal transplant function excretion of the drug within 12 h was observed.

Adult↗