Renal function following pregnancy in renal transplant recipients.

We set out to analyse the effect of pregnancy and hypertension in renal transplant recipients and review serum creatinine levels as a marker of graft function, before, during and after pregnancy. The study was conducted at a major tertiary referral centre in London. This was a retrospective analysis of renal transplant patients who had achieved a successful pregnancy. During the period 1967-1998, there have been 272 women of childbearing age with successful renal transplants functioning for over 1 year. Within this population there have been 66 pregnancies in 41 patients resulting in 53 births. Among the pregnancies that progressed beyond 24 weeks, preterm delivery occurred in 32 (60.4%). The mean gestation was 35.7 (range 30-41), mean birth weight was 2365 grams (range 908-3430 grams) with 47%of infants weighing <2500 grams. There were vaginal deliveries in 14 (26%), the rest delivered by caesarean section. Patients that developed hypertension in late pregnancy tended to have higher pre-pregnancy creatinine levels and a deterioration of graft function postpartum. Serum creatinine levels greater than 130 micromol/l before pregnancy predict deteriorating renal function postpartum. Kaplan-Meier life survival analysis showed that the risk of subsequent graft loss is associated with increased serum creatinine levels (130-180 micromol/l) before pregnancy. Pregnancy figures in our unit are favourable compared to those reported in the literature. Poor pre-pregnancy renal function (creatinine 130-180 micromol/l) and previous hypertension is associated with a significant risk of graft failure. Creatinine levels currently deemed as being acceptable during the pregnancy of renal transplant recipients may need to be reappraised.

Improving the quality of data used in environmental economics research.

Valuing environmental goods through contingent valuation and through other survey techniques is difficult because of the lack of traditional markets for those goods. EPA provides leadership in overcoming these challenges, using focus groups, workshops, handbooks, and teams of distinguished economists to obtain more reliable economic data from the surveys. Agency economists have provided leadership in employing production economics tools to identify win-win approaches to solve pervasive and neglected environmental problems. In addition, we exploit the speed of sophisticated computers, building field runoff models into economic models and aggregating results from tens of thousands of field sites. These very flexible models provide much more credible, site-specific analyses than previous models, and they offer flexible and efficient remedies to support Total Maximum Daily Loads and other new programs.

Parathyroid carcinoma secondary to prolonged hyperplasia in chronic renal failure and in coeliac disease.

The presentation of parathyroid carcinoma in patients with chronic renal failure is rare, although with improvements in life expectancy associated with this condition there have now been 12 reported cases, including the first case we report here. It has been proposed that in these cases there has been a malignant transformation of benign parathyroid hyperplastic tissue. We also report the first case of parathyroid carcinoma associated with coeliac disease and suggest that the same mechanism may be responsible. We review the presentation, diagnosis, treatment and natural history of the disease.

A controlled trial of two bicarbonate-containing dialysis fluids for CAPD--final report.

BACKGROUND: The combination of a low pH and a high concentration of lactate which is present in most dialysis fluids is found to be cytotoxic in vitro. For these reasons it would seem logical to use a bicarbonate-containing solution and thus automatically provide a solution with a neutral pH. METHODS: A parallel, randomized, open-label, prospective 2-month trial with an optional 4 month extension was undertaken to compare two novel bicarbonate-based solutions; one containing 38 mmol/l of bicarbonate (B), and one containing a mixture of 25 mmol/l bicarbonate and 15 mmol/l of lactate (B/L), with a control solution (C) containing 40 mmol/l lactate. RESULTS: Three groups of 19 (C), 20 (B), and 20 (B/L) patients were recruited and data from approximately 55 patient months were accumulated in each group. The data show that both bicarbonate-based solutions maintain acid-base levels within the normal range, that there were no changes in any of the other blood biochemistry parameters measured in the peritoneal equilibration test or with regard to adequacy of dialysis, and that furthermore, both solutions were well tolerated. CONCLUSIONS: This study showed that either the bicarbonate or bicarbonate/lactate solutions could be utilized efficaciously in patients undergoing CAPD.

Presymptomatic detection of familial juvenile hyperuricaemic nephropathy in children.

We studied 34 apparently healthy children and 2 propositi from kindreds with familial juvenile hyperuricaemic nephropathy (FJHN) - a disorder characterised by early onset, hyperuricaemia, gout, familial renal disease and a similarly low urate clearance relative to glomerular filtration rate (GFR) [fractional excretion of uric acid (FEur) 5.1+/-1.6%] in young men and women. In addition to the propositi, 17 asymptomatic children were hyperuricaemic -- mean plasma urate (368+/-30 micromol/l), twice that of controls (154+/-41 micromol/l). Eight of them had a normal GFR ( > 80 ml/min per 1.73 m2), and 11 renal dysfunction, which was severe in 5. The FEur in the 14 hyperuricaemic children with a GFR > 50 ml/min was 5.0+/-0.5% and in the 5 with a GFR < or =50 ml/min was still low (11.5+/-0.2%) compared with controls (18.4+/-5.1%). The 17 normouricaemic children (185+/-37 micromol/l) had a normal GFR (>80 ml/min) and FEur (14.0+/-5.3%). The results highlight the dominant inheritance, absence of the usual child/adult difference in FEur in FJHN and presence of hyperuricaemia without renal disease in 42% of affected children, but not vice versa. Since early allopurinol treatment may retard progression to end-stage renal failure, screening of all relatives in FJHN kindreds is essential.

Contribution of individual drugs to gingival overgrowth in adult and juvenile renal transplant patients treated with multiple therapy.

Drug regimens for transplantation often consist of multiple therapeutic agents and may result in drug-induced gingival overgrowth (DIGO). The aim of this study was to investigate the contribution of individual drugs in renal transplant patients. 147 adults (19-84 years) and 60 juveniles (3-18 years) were scored for DIGO and other clinical variables. Duration of treatment, dosage of drugs per kg body weight and serum cyclosporin levels were recorded. 44% of adults and 27% of children had DIGO. All patients were receiving prednisolone. More adults than children were administered cyclosporin, the reverse was true of azathioprine (p<0.01). Explanatory models were evaluated by stepwise ordinal polynomial logistic regression. Statistically significant explanation (p<0.05) of DIGO was afforded by prednisolone, nifedipine and azathioprine concentrations in adults and by cyclosporin, nifedipine and azathioprine concentrations in juveniles. Prednisolone and azathioprine were inversely related to the degree of DIGO. Plaque and irregularity scores, lip coverage and mouthbreathing status showed significant additional explanation in adults, replacing nifedipine and azathioprine in the final model. Irregularity was additionally explanatory in children, but no other clinical variables. A larger proportion of the variance of DIGO was explained by the available variables in children than in adults (pseudo r2=0.50 versus 0.25). The degree of DIGO in renal transplant patients is influenced by the dosage of a number of individual components of multiple drug therapy independently of the presence of local clinical factors.

Computer aided design of a polarised source for in vivo X-ray fluorescence analysis.

A system has been developed which uses Monte Carlo computer simulations to aid the design and optimisation of a polarised source for in vivo X-ray fluorescence (XRF) analysis of heavy metals: The system is based on a version of the Monte Carlo code EGS4 which includes polarised photon interactions, running on a personal computer. The code was used to construct a model of a clinical polarised XRF system (based on a 300 kV therapy X-ray source) under development at Swansea for the measurement of Pt-based chemotherapy drugs in head and neck tumours. Several simulations were performed to investigate the variation of XRF measurement sensitivity with the material composition and geometry of the system components. Pt XRF spectra generated by the model were found to be in good agreement with experimental data. The optimum operating voltage for the system, predicted by the simulations and confirmed by experiment, was approx. 200 kV. The accuracy of the results obtained to date indicates that this technique will greatly facilitate future design and optimisation studies of a wide variety of XRF systems.