Use of 1,25(OH)2-vitamin D3 in prevention of renal osteodystrophy: preliminary observations

Hypercalcaemia regularly occurs when "prophylactic" 1,25-dihydroxyvitamin D3 (1,25[OH)2D3) in a dose of 1.0 microgram daily is given to haemodialysis patients without clinical biochemical or radiological evidence of osteodystophy. This dose is too large for such patients. Hypercalcaemia may persist for several weeks after withdrawal of 1,25(OH)2D3, particularly when previous attempts at control by dosage reduction have failed. Hypercalcaemia is better managed by stopping 1,25(OH)2D3, albeit temporarily, than by reducing the dose.

Sacred populations of Cercopithecus sclateri: analysis of apparent population increases from census counts

The development of effective conservation and management actions for populations of wild species generally requires monitoring programs that provide reliable estimates of population size over time. Primate researchers have to date given more attention to evaluating techniques for monitoring primates in natural habitats compared to populations that occur in villages or urban areas. We conducted censuses to estimate the abundance and density of two sacred, village-dwelling populations (Lagwa and Akpugoeze) of Sclater's monkey (Cercopithecus sclateri), a threatened species endemic to southeastern Nigeria, and compared these data to previous census results. We recorded population increases in both sites: a 66% increase over 4½ years in Lagwa (from 124 to 206 individuals) at an annual rate of 10.2%, and a 29% increase over 4 years in Akpugoeze (from 193 to 249 individuals) at an annual rate of 5.7%. Mean group size also increased in both sites. Density in Lagwa was 24.2 individuals/km(2) , and density in a core survey area of Akpugoeze was 36-38 individuals/km(2) . Our results may have been affected by monkey ranging and grouping patterns and improved detectability due to our revised census technique, which included secondary observers. With further work on methodology for censusing populations that occur in human-settled environments, techniques can be refined and customized to individual sites for more accurate estimates. Our investigation of Sclater's monkey in Lagwa and Akpugoeze, two sites critical for conservation of the species, indicated that both of these populations have increased, and neither faces immediate risk of extirpation. Such population growth, while encouraging, will likely exacerbate human-monkey conflict and thus should be understood in terms of potential socioeconomic impacts.

Ethylene: A Natural Regulator of Sex Expression of Cucumis melo L

Sex expression in cucumber (Cucumis sativus L.) and muskmelon (C. melo L.) was correlated with endogenous ethylene production. Plants of gynoecious (all female) sex types of the two species produced more ethylene than monoecius (male-female) plants. C. melo plants of a gynoecious sex type that normally produce only pistillate (female) flowers, when grown with hypobaric ventilation to facilitate removal of endogenous gases by diffusion, produced perfect (hermaphroditic) flowers. When either the plant was returned to atmospheric pressure or when the reduced-pressure ventilating stream was supplemented with ethylene, the same plants produced pistillate flowers. Enrichment of the atmosphere at either normal or reduced pressure with CO(2), a competitive inhibitor of ethylene action, also resulted in development of perfect flowers. Foliar application of a benzothiadiazole, a postulated inhibitor of ethylene action, resulted in formation of perfect flowers on gynoecious plants of C. melo and of staminate (male) flowers on gynoecious C. sativus. Based on these findings, it is proposed that ethylene is an endogenous regulator of sex expression in C. sativus and C. melo.

Reduction of left ventricular mass index with blood pressure reduction in chronic renal failure

AIM

We have reported previously in a study of 85 non-diabetic patients with chronic renal failure (CRF) that 24-h ambulatory blood pressure (ABP) recording and echocardiography are required for accurate diagnosis of inadequate blood pressure (BP) control and early left ventricular hypertrophy (LVH). In this study we found that the only independent determinants of left ventricular (LV) mass were hypertension, male sex, body mass index (BMI) and anemia. Little is known about the progression of LVH in patients as they progress from moderate to end-stage renal failure.

PATIENTS AND METHODS

We undertook a follow-up observational study in a cohort of 65 (26 male, 12 black Afro-Caribbean and 7 Asian) of those patients originally investigated. Patients who had reached end-stage renal failure (ESRF) were not studied.

RESULTS

A statistically significant correlation was found between change in left ventricular mass index (LVMI) and change in mean ABP parameters (r = 0.27 (p<0.03) for 24-h systolic, r = 0.21 (p<0.05) for 24-h diastolic, r = 0.29 (p<0.02) for mean arterial pressure (MAP), r = 0.24 (p<0.05) for daytime systolic, r = 0.30 (p<0.02) for nocturnal systolic and r = 0.26 (p<0.05) for nocturnal diastolic BP). Hemoglobin concentration and BMI changed little between the two studies and no other statistically significant correlations were found in respect of any other parameters studied, which has allowed us to isolate the effect of one determinant - adequacy of BP control-upon LVH.

CONCLUSION

In patients with moderate chronic renal impairment, reduction in BP is associated with reduction of LVMI over time. Among the antihypertensive agents ACE inhibitors appeared to have the greatest ability to reduce LV mass in the subjects with LVH at baseline. Larger interventional studies are needed to determine whether ACE inhibitors are superior to other anti-hypertensive agents in LVH regression in chronic renal failure patients.

Temporary vascular access for first dialysis is common, undesirable and usually avoidable

BACKGROUND

When technically feasible, patients with end-stage renal failure should commence regular dialysis treatment with permanent access to the circulation (by arteriovenous fistula) or peritoneum (by soft peritoneal catheter) in situ, thus avoiding the need for initial hemodialysis employing temporary vascular access. We have examined the frequency, consequences and avoidability of temporary access in such patients.

METHODS

178 patients commencing regular dialysis between August 1993 and April 1995 were analysed retrospectively using case notes. Patients were divided into those who had permanent dialysis access in situ when they commenced dialysis and those who required temporary access. If temporary access was required, the patients were further analysed into those who had been first seen by a nephrologist at least 12 weeks before the first dialysis, and those who had been referred "late". It was assumed that 12 weeks was sufficient time for permanent access to be instituted. Mortality within the first 90 days of commencing dialysis was recorded.

RESULTS

Seventy-four of 82 patients opting for regular hemodialysis and 53 of 96 opting for peritoneal dialysis required temporary vascular access. Late referral accounted for 47 and delays within the renal service for 35 of such patients. Late presentation to the medical profession or indecisiveness on the part of the patient accounted for the remainder. Twenty-five of 127 patients requiring temporary access but only one or 51 patients not requiring it died within 90 days of commencement of treatment.

CONCLUSION

Late presentation to a renal unit prior to first dialysis is associated with increased mortality. Late referral or late presentation are associated with an increased need for temporary vascular access for first dialysis. Many patients who require temporary access for first dialysis could have been better managed.

Seminal megavesicles with adult polycystic kidney disease

Adult polycystic kidney disease has been found in association with pathological dilatation of the seminal vesicles in six patients. These men appeared normal on clinical examination, but had azoospermia or severe oligozoospermia. They were investigated by scrotal exploration with vasography, renal and transrectal ultrasound scans (TRUS), and percutaneous puncture of the seminal vesicles in one case, before and after resection of the ejaculatory ducts. This revealed that the gross dilatation of the seminal vesicles was not caused by obstruction, but appeared to be due to atonicity (megavesicles). These ultrasonic appearances, when described previously, were incorrectly thought to be due to seminal vesicle cysts.

Serum C-reactive protein as a marker for infection and inflammation in regular dialysis patients

Serum C-reactive protein (CRP) concentration was measured in 98 hemodialysis (HD) patients and 68 continuous ambulatory peritoneal dialysis patients (CAPD). The effect, if any, of a HD session on serum CRP level and the usefulness of CRP in diagnosing and monitoring proven inflammatory disease were studied. Seventy-five percent of CAPD patients without evidence of inflammation had CRP levels within the quoted normal range (< 10 mg/l), as compared with only 47% of HD patients also without evidence of overt inflammation (p < 0.001). No significant change in the CRP level was detected during a hemodialysis session. Twenty-four patients with overt inflammation (due mainly to infection) were studied, 22 of whom had CRP levels of > 50 mg/l. These increased CRP levels fell with treatment. A CRP level of > 50 mg/l proved highly suggestive of a significant inflammatory process and a value of < 10 mg/l always excluded it. The total period of time on the regular dialysis program was not related to the CRP level. A subclinical inflammatory response resulting in a raised CRP is very common in our hemodialysis patients and less so in CAPD patients. Possible reasons for this are discussed. However, CRP is still useful in the diagnosis and monitoring of response to treatment of inflammatory disease if the level is > 50 mg/l or serial/baseline measurements are available for comparison. Whether any relationship exists between elevation of CRP and the well-documented increased risk of cardiovascular death in dialysis patients is currently unknown.

Treatment of progressive renal failure and nephrotic syndrome with azathioprine and prednisolone

Four patients with idiopathic membranous glomerulonephritis, heavy proteinuria and progressive renal failure received azathioprine and prednisolone. Renal function improved in all four and proteinuria declined sharply in three. We suggest that treatment with azathioprine and prednisolone may be of benefit in this form of idiopathic membranous glomerulonephritis.

Left ventricular hypertrophy and ambulatory blood pressure monitoring in chronic renal failure

BACKGROUND

Left ventricular hypertrophy (LVH) is both common and an important predictor of risk of death in end-stage renal failure (ESRF). In mild to moderate chronic renal failure (CRF), the timing of onset of LVH and the factors involved in its initial development have not been fully elucidated. The present study was undertaken to examine the prevalence and potential determinants of echocardiographically determined LVH in this connection, and to compare 24-h ambulatory blood pressure (BP) recordings with BP measured at a previous clinic visit.

METHODS

From a cohort of 120 non-diabetic patients who had been attending a nephrology clinic, 118 agreed to participate in the study. Of these we selected for analysis 85 stable patients (37 male). Patients with known cardiovascular disease, those with a history of poor compliance with antihypertensive medication, and those in whom such medication had been changed in the previous 3 months were excluded. Clinic BP, 24-h ambulatory BP, echocardiography, body mass index (BMI), serum creatinine (SCr), creatinine clearance (CrCl), haemoglobin (Hb), fasting cholesterol (CHOL), triglyceride TRIGL), plasma glucose, calcium (Ca), phosphate (PO4), alkaline phosphatase (ALK PHOS), parathyroid hormone (PTH) concentrations, and 24-h urinary protein were assessed in all patients. Seventy-seven per cent were on antihypertensive medication.

RESULTS

LVH was detected in 16% of patients with CrCL > 30 ml/min, and 38% of patients with CrCl < 30 ml/min. By stepwise regression analysis, ambulatory systolic BP (P < 0.0001), male gender (P < 0.0001), BMI (P < 0.0002), and Hb concentration (P < 0.002) were the only independent determinants of left ventricular (LV) mass. Nocturnal systolic BP (P < 0.02) was the main determinant of LVH in the group of patients with advanced CRF. The correlation between left ventricular mass index (LVMI) and mean 24-h ambulatory systolic BP (r = 0.52, 95% confidence interval 0.50-0.54) was statistically significantly stronger than with outpatient systolic BP (r = 0.25, 95% confidence interval 0.23-0.27). The same was true for the correlation between LVMI and mean 24-h ambulatory diastolic BP (r = 0.42, 95% confidence interval 0.40-0.44), and outpatient diastolic BP (r = 0.22, 95% confidence interval 0.20-0.24).

CONCLUSIONS

Twenty-four hour ambulatory BP recording and echocardiography are required for accurate diagnosis of inadequate BP control and early LVH in patients with chronic renal impairment, independent determinants of which are hypertension, male sex, BMI, and anaemia.

Technetium-99m methoxy isobutyl isonitrile (MIBI) imaging of the parathyroid glands in patients with renal failure

BACKGROUND

Technetium-99m methoxy isobutyl isonitrile (Tc-99m MIBI) scintigraphy has been reported to be at least as reliable as thallium-technetium subtraction imaging in the preoperative localization of hyperplastic parathyroid glands in patients with renal failure. Reports have suggested that 50% of glands can be identified correctly by this method. The aim of this study was to improve on previous results and demonstrate that Tc-99m MIBI imaging has an important place in the preoperative work-up of these patients.

METHODS

Eighteen patients on renal replacement therapy were studied. All had tertiary hyperparathyroidism and had Tc-99m MIBI imaging prior to parathyroidectomy. A refined reporting method was employed. The imaging results were compared to the subsequent surgical and histological findings.

RESULTS

In the 12 patients in whom serum parathyroid hormone levels fell postoperatively to within or below the normal range, 38 of 46 glands (82.6%) were correctly identified and located in the correct quadrant of the thyroid gland. There were two false positive results where the imaging predicted glands not subsequently found by the surgeon. In the patients who had post-operative hyperparathyroidism, repeat Tc-99m MIBI imaging was able to locate accurately the site of the residual parathyroid tissue.

CONCLUSIONS

Tc-99m MIBI imaging is able to identify more than 80% of hyperplastic parathyroid glands in renal failure patients if this reporting process is used, and locate them in the correct quadrant of the thyroid gland. Tc-99m MIBI imaging is of particular value when re-exploration of the neck is required for post-parathyroidectomy hyperparathyroidism. These results represent a significant improvement on the sensitivity of this imaging technique when compared to previous published data.

A randomized controlled study of iron supplementation in patients treated with erythropoietin

In view of current uncertainty regarding the optimum route for iron supplementation in patients receiving recombinant human erythropoietin (EPO), a prospective randomized controlled study was designed to investigate this issue. All iron-replete renal failure patients commencing EPO who had a hemoglobin concentration < 8.5 g/dl and an initial serum ferritin level of 100 to 800 micrograms/liter were randomized into three groups with different iron supplementation: Group 1, i.v. iron dextran 5 ml every 2 weeks; Group 2, oral ferrous sulphate 200 mg tds; Group 3, no iron. All patients were treated with 25 U/kg of EPO thrice weekly subcutaneously. The hemoglobin concentration, reticulocyte count, serum ferritin, transferrin saturation, and EPO dose were monitored every two weeks for the first four months. Thirty-seven patients entered the study (12 i.v., 13 oral, 12 no iron). The three groups were equivalent with regard to age, sex, and other demographic details. Even allowing for dosage adjustments, the hemoglobin response in the group receiving i.v. iron (7.3 +/- 0.8 to 11.9 +/- 1.2 g/dl) was significantly greater than that for the other two groups (7.2 +/- 1.1 to 10.2 +/- 1.4 g/dl and 7.3 +/- 0.8 to 9.9 +/- 1.6 g/dl for Groups 2 and 3, respectively; P < 0.005 for both groups vs. Group 1 at 16 weeks). There was no difference between the groups supplemented with oral iron and no iron. Serum ferritin levels remained constant in those receiving i.v. iron (345 +/- 273 to 359 +/- 140 micrograms/liter), in contrast to the other two groups in which ferritin levels fell significantly (309 +/- 218 to 116 +/- 87 micrograms/liter and 458 +/- 206 to 131 +/- 121 micrograms/liter for Groups 2 and 3, respectively; P < 0.0005 for Group 1 vs. Group 2, and P < 0.005 for Group 1 vs. Group 3 at 16 weeks). Dosage requirements of EPO were less in Group 1 (1202 +/- 229 U/kg/16 weeks) than in Group 2 (1294 +/- 314 U/kg/16 weeks) or Group 3 (1475 +/- 311 U/kg/16 weeks; P < 0.05 vs. Group 1). The results of this study suggest that, even in iron-replete patients, those supplemented with i.v. iron have an enhanced hemoglobin response to EPO with better maintenance of iron stores and lower dosage requirements of EPO, compared with those patients receiving oral iron and no iron supplementation.

Antineutrophil cytoplasmic antibody-positive crescentic glomerulonephritis associated with anti-thyroid drug treatment

Two cases of antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis following treatment with propylthiouracil and carbimazole are described. Both patients had crescentic glomerulonephritis proven by renal biopsy and responded to immunosuppressive therapy and withdrawal of the anti-thyroid drugs. Though systemic vasculitis associated with propylthiouracil is reported, this is the first report to our knowledge of renal biopsy-proven vasculitis associated with either of these drugs.

Prostate-specific antigen levels in patients receiving long-term dialysis

OBJECTIVE

To investigate the effect, if any, of renal failure upon prostate-specific antigen (PSA) levels and the validity of PSA estimation as a marker of prostatic disease in renal failure.

PATIENTS AND METHODS

PSA was measured in 65 men (median age 67 years, range 39-84) on regular haemodialysis and 37 men (median age 70 years, range 42-77) on continuous ambulatory peritoneal dialysis (CAPD). Patients with a PSA level > 4 ng/mL underwent prostatic biopsy guided by transrectal ultrasonography.

RESULTS

There was no evidence of an artefactual elevation of PSA attributable solely to renal failure. All eight patients with a PSA level > 4 ng/mL had prostatic disease.

CONCLUSION

PSA measurements in patients with end-stage renal failure treated by dialysis remain a useful marker of prostatic disease.

Bacteraemia due to recurrent reinfection with Staphylococcus epidermidis associated with defective opsonisation and procidin function in serum

AIMS

To differentiate between reinfection and relapsing infection with Staphylococcus epidermidis in a middle-aged woman with defective opsonisation and procidin function in serum.

METHODS

Microbiological typing was done by biotyping, phage typing, and polyacrylamide gel electrophoresis of radiolabelled bacterial proteins (radioPAGE method). Polymorphonuclear cell function was assessed in vitro by phagocytosis and killing of Candida albicans; measurement of neutrophil random locomotion and chemotaxis; reduction of nitroblue tetrazolium after stimulation by opsonised Candida and a radiometric saccharomyces opsonisation assay. The effect of plasma infusions on opsonic activity was assessed by chemiluminescence using control polymorphonuclear leucocytes with a laboratory strain of S epidermidis opsonised with either patient or control serum.

RESULTS

Recurrent reinfection with different strains of Staphylococcus epidermidis rather than relapsing infection was confirmed as having occurred by typing bacterial strains. The RadioPAGE method detected all the S epidermidis strains involved in this patient's illness. The patient's serum was shown to be defective in both opsonin and procidin function. The defects were correctable in vitro by the addition of normal serum. Clinical recovery occurred after repeated infusions of normal fresh frozen plasma and prolonged antibacterial treatment; antibacterial treatment alone was insufficient.

CONCLUSIONS

The radioPAGE method is useful in distinguishing recurrent reinfection with S epidermidis from relapsing infection with this organism. Elucidation of the nature of, and underlying predisposition to, infection in the patient studied allowed a rational treatment plan of plasma infusion combined with antibacterial treatment to be devised which ultimately proved successful.

Autonomic dysfunction and the development of hypertension in patients treated with recombinant human erythropoietin (r-HuEPO)

Hypertension is the most common complication of r-HuEPO therapy in dialysis patients. The aim of this study was to test the hypothesis that hypertension develops in patients who fail to autoregulate adequately their hemodynamic response to correction of anemia. Twenty-five dialysis patients (17-71 yrs, 13 male, 13 CAPD) initially received r-HuEPO 50 U/kg 3 times/week intravenously or subcutaneously. Hypertension, defined as a rise in mean blood pressure (BP) of greater than 15 mmHg during therapy developed in 44% (Group 1: stable BP; Group 2: rise in BP). There was no difference in sex, age, mode of dialysis or route of administration of r-HuEPO between the groups. Before commencement and after 6-12 months of r-HuEPO therapy, assessment of the baroreflex arc was performed using the Valsalva ratio and orthostatic BP testing, sympathetic efferent nerve function was assessed by the cold pressor test and afferent parasympathetic function by the 30:15 ratio and heart rate variation (HRV). No difference was detected prior to r-HuEPO therapy between the two groups in Valsalva ratio (Group 1: 1.26 +/- 0.06 vs Group 2: 1.23 +/- 0.06, mean +/- SEM); 30:15 ratio (1.06 +/- 0.02 vs 1.03 +/- 0.01), or systolic, diastolic, mean BP or pulse rate after standing for 3 minutes or following hand immersion in ice slush. Both groups had a fall in systolic and diastolic BP (p < 0.05) and a rise in pulse rate (p < 0.05) on standing. HRV during deep respiration between the 2 groups was not different (9.6 +/- 2.3 vs 7.1 +/- 1.4 beats/minute).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of oxygen breathing and erythropoietin on hypoxic vasodilation in uremic anemia

Loss of hypoxic vasodilation has been proposed as a causative factor in the development of hypertension in dialysis patients treated with recombinant human erythropoietin (rHuEPO). Venous occlusion plethysmography was therefore performed on 22 dialysis patients (aged 23 to 71 years, dialysis duration 6 to 260 months, 8 males) before and after correction of anemia with rHuEPO, 50 U/kg 3x/week (Hb: 7.4 +/- 0.3 vs. 10.8 +2- 0.3 g/dl, P less than 0.0001). Hypertension (greater than 15 mm Hg rise in mean BP) occurred in 11 patients. The study was performed while breathing room air and repeated after breathing 60% O2 for 10 to 12 minutes. Before rHuEPO therapy, total blood O2 content increased from 10.01 +/- 0.39 to 10.32 +/- 0.29 ml O2/100 ml blood with breathing 60% O2 (P less than 0.01). After correction of anemia it was 14.65 +/- 0.40 ml O2/100 ml blood on room air (P less than 0.001). There was a significant decrease in forearm blood flow (7.9 +/- 0.5 vs. 6.5 +/- 0.6 ml/min/100 ml tissue, P less than 0.05) and increase in forearm vascular resistance (12.8 +/- 0.1 vs. 16.8 +/- 0.2 mm Hg/ml/min/100 ml tissue, P less than 0.05) with O2 breathing prior to rHuEPO therapy in the blood pressure responders, but no change in these parameters in the group in which blood pressure remained unchanged. When all patients were studied on room air, forearm vascular resistance rose significantly after correction of anemia (13.0 +/- 0.8 vs. 16.3 +/- 0.8 mm Hg/ml/min/100 ml tissue, P less than 0.05), compared with that prior to rHuEPO therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Platelet cytosolic free calcium concentration and parathyroid hormone: changing relationships with haemodialysis in end-stage renal disease

1. Twelve patients receiving haemodialysis for end-stage renal failure were studied at a single dialysis session. Platelet cytosolic calcium concentration, plasma ionized calcium concentration and serum parathyroid hormone concentration were measured before dialysis, mid-dialysis and 30 min after dialysis. 2. Plasma ionized calcium concentration increased towards dialysate calcium concentrations, falling insignificantly after cessation of dialysis. Serum parathyroid hormone concentration fell by 39% during dialysis, with incomplete recovery afterwards. There was no overall change in platelet cytosolic calcium concentration. 3. Patients were divided into two subgroups: low parathyroid hormone (serum parathyroid hormone concentration less than 10 pmol/l) and high parathyroid hormone (serum parathyroid hormone concentration greater than 10 pmol/l). Before dialysis, values of platelet cytosolic calcium concentration or plasma ionized calcium concentration were not statistically different between the subgroups, but the platelet cytosolic calcium concentration was higher in the high-parathyroid hormone subgroup during and after dialysis. 4. Before haemodialysis there was a linear correlation between plasma ionized calcium concentration and platelet cytosolic calcium concentration, which disappeared during dialysis. In contrast, there was no relationship between serum parathyroid hormone concentration and platelet cytosolic calcium concentration before dialysis, but after dialysis a hyperbolic relationship was evident. 5. These results suggest that uraemic toxins may interfere with cytosolic calcium homoeostasis, allowing passive diffusion of extracellular calcium to influence the resting concentration, and that this effect is reversible by haemodialysis.

Reactogenicity and immunogenicity of a double-strength acellular pertussis vaccine

The reactogenicity and immunogenicity of a double-strength acellular pertussis vaccine were evaluated after administration to 16 4-6-year-old children. The vaccine contained toxoided lymphocytosis-promoting factor (6.0 micrograms/dose), filamentous haemagglutinin (70 micrograms/dose), agglutinogens (1.4 micrograms/dose) and the 69 kDa protein (approximately 8.0 micrograms/dose). The vaccine was extremely well tolerated with few minor side effects following immunization. Significant increases in antibodies to all pertussis vaccine components were noted. In summary, this double-strength acellular pertussis vaccine, containing a very high dose of filamentous haemagglutinin, had minimal reactogenicity and was immunogenic. These findings, as well as other studies with this vaccine, indicate that filamentous haemagglutinin is not a major determinant of vaccine reactogenicity.

Comparison of haemostatic activity in haemodialysis and peritoneal dialysis patients with a novel technique, haemostatometry

Bleeding due to impaired primary haemostasis is common in uraemia. However, thrombo-embolic episodes are also a clinical problem in dialysis patients. Platelet reactivity to shear stress (haemostasis, H1 and H2), exposure to collagen fibre (thrombus growth) and coagulation of flowing blood (clotting time, CT1 and CT2) were measured in non-anticoagulated blood samples taken immediately before and 18-24 h after haemodialysis (n = 26) and from patients maintained on continuous ambulatory peritoneal dialysis (CAPD, n = 30). H1 (p < 0.001), H2 (p < 0.01), percent thrombus growth rate (p < 0.03), CT1 (p < 0.01 and CT2 (p < 0.05) were restored towards normal after haemodialysis. Results obtained in the CAPD patients demonstrated that the mean values for formation of the haemostatic plug lay between the pre- and posthaemodialysis values; however, CT1 (p < 0.01) and CT2 (p < 0.05) were prolonged in CAPD compared with values after haemodialysis. These data, which indicate platelet function from non-anticoagulated blood and coagulation under flow conditions, (1) confirm that there is impaired haemostasis in uraemia; (2) demonstrate an improvement in haemostasis after haemodialysis; (3) show that peritoneal dialysis results in a haemostatic profile which falls between the pre- and posthaemodialysis pattern, and (4) show that neither dialysis modality returns haemostasis to normal.

Recurrent CAPD peritonitis caused by coagulase-negative staphylococci: re-infection or relapse determined by clinical criteria and typing methods

Four hundred consecutive episodes of continuous ambulatory peritoneal dialysis (CAPD)-associated peritonitis in 105 patients were analysed. Of these episodes 161 (40.25%) were caused by coagulase-negative staphylococci (CNS). Thirty-seven patients developed recurrent attacks (3-10) of peritonitis and CNS accounted for 72 (60%) of these episodes. Classification of reinfection or relapse in 67 of these recurrent episodes of peritonitis was based on clinical criteria alone. This was compared with the results of three typing methods of CNS strains: biotyping plus antibiograms, immunoblotting and 35S-methionine-labelled protein patterns (radio-PAGE). Radio-PAGE was the most discriminatory method followed by biotyping with antibiograms and then immunoblotting. There was total agreement between clinical diagnosis and the three typing methods in 67.2% of episodes but there was total disagreement between the clinical diagnosis and the three typing methods in 11.9%, suggesting inaccurate clinical diagnosis, and in 20.8% typing by at least one method differed from the clinical criteria. Thus, clinical criteria alone are inadequate for the accurate distinction of reinfection from relapse in recurrent CNS peritonitis. This distinction is desirable for optimal management and accurate assessment of different therapies. We suggest that CNS strains from peritoneal dialysate are stored for future typing should the patient develop repeated episodes of peritonitis, to aid in the diagnosis and management of such patients.

Combined hepatic and renal transplantation in primary hyperoxaluria type I: clinical report of nine cases

PURPOSE AND PATIENTS AND METHODS

The purpose of this article is to report the experience of three centers with combined hepatic and renal transplantation for pyridoxine-resistant primary hyperoxaluria type I (alanine:glyoxylate aminotransferase [EC 2.6.1.44] deficiency), with particular emphasis on the selection criteria and timing of the operation. Nine patients with this inherited disease were treated by combined hepatic and renal transplantation. The former replaces the enzyme-deficient organ while the latter replaces the functionally affected organ.

RESULTS

One patient with gross systemic oxalosis died in the immediate postoperative period and another died 8 weeks postoperatively of a generalized cytomegalovirus infection, having shown evidence of biochemical correction. One patient with particularly severe osteodystrophy at the time of the operation died 14 months postoperatively from renal failure due to progressive calcium oxalate nephrocalcinosis involving the transplanted kidney, plus thromboembolic disease. He also had very extensive systemic oxalosis. An additional patient with severe osteodystrophy died 9 months postoperatively. One patient developed hyper-rejection of the kidney and died later of gastrointestinal hemorrhage. The four long-term survivors (22 to 38 months) have remained asymptomatic from the standpoint of their renal disease, with resolution of any manifestations of systemic oxalosis that they may have had. They are either employed or continuing their education.

CONCLUSIONS

A prolonged period of end-stage renal failure treated by dialysis regimens that are suitable for non-hyperoxaluric renal failure and extensive systemic oxalosis, particularly oxalotic osteodystrophy, are poor prognostic features. We propose that hepatic transplantation should be considered as definitive treatment before end-stage renal failure develops. This should be supplemented by renal transplantation with vigorous pre- and perioperative hemodialysis to deplete the body stores of oxalate. Although some authorities would reserve hepatic transplantation for patients in whom renal transplantation has failed, we suggest that combined liver and kidney transplantation is appropriate in patients who have never had a renal graft. Furthermore, the time has come to consider hepatic transplantation before any irreversible renal damage has occurred in these patients.

Epidemiology of CAPD-associated peritonitis caused by coagulase-negative staphylococci: comparison of strains isolated from hands, abdominal Tenckhoff catheter exit site and peritoneal fluid

We identified twenty patients maintained on continuous ambulatory peritoneal dialysis who suffered repeated episodes of peritonitis caused by coagulase-negative staphylococci. We documented hand and exist-site coagulase-negative staphylococcus-associated peritonitis over a total period of 32 months, and compared hand and exit-site strains with strains isolated from dialysate fluid using three typing methods: biotyping using the API Staph kit plus antibiograms, immunoblotting using sera raised in rabbits to three standard strains of coagulase-negative staphylococci, and 35S-methionine-labelled coagulase-negative staphylococcal profiles separated on sodium dodecylsulphate polyacrylamide gel electrophoresis and visualised by autoradiography (radioPAGE). In 5 of 84 episodes, strains isolated from skin were indistinguishable by all three typing methods from the dialysate strain. In a further two episodes, hand or exit-site isolates were indistinguishable by all three typing methods from the dialysate strain isolated in the subsequent, but not the same, episode. Thus in the majority of episodes, no inference of hand or exit-site origin of dialysate infection could be drawn.

Pitfalls after total parathyroidectomy and parathyroid autotransplantation in chronic renal failure

We have described 4 patients with chronic renal failure receiving regular haemodialysis treatment who underwent total parathyroidectomy with autotransplantation of parathyroid fragments into the forearm musculature for hypercalcaemic hyperparathyroidism. In all, there was an immediate and profound fall in plasma calcium levels. Hypercalcaemia recurred 1-5 years post-operatively and was resistant to resection of the autograft. In 3 cases, thallium-technetium subtraction scanning and multiple venous sampling for estimation of parathyroid hormone levels suggested multiple sites of hypersecretion of parathyroid hormone in the neck. In 1 case, these investigations revealed a mediastinal adenoma which was successfully removed. These cases reinforce previous suggestions that total parathyroidectomy is frequently incomplete and undermine the procedure of total parathyroidectomy with autotransplantation in patients with persisting uraemia.

Enhanced in vitro hemostasis and reduced thrombolysis in cyclosporine-treated renal transplant recipients

In vitro hemostatometry and assessment of thrombolysis was carried out in three groups of 72 renal transplant recipients. In one (triple, n = 21) immunosuppression was with cyclosporine, azathioprine, and prednisolone, while a second group (CsA, n = 29) received cyclosporine and prednisolone alone, and the third group (Aza, n = 22) azathioprine and prednisolone. Results were compared with those in 30 normal controls. A statistically significant increase in hemostasis compared with controls was seen in the triple group and in patients in the CsA group studied within 2 years of transplantation. Hemostasis in the Aza group did not differ from normal. All patients in this group had been transplanted more than 2 years before study. Thrombolysis times were significantly prolonged compared with controls in all three groups. Cyclosporine treatment is associated with enhanced hemostasis and reduced thrombolysis, especially during the first 2 years after renal transplantation. If these in vitro findings reflect events in vivo, this may throw light upon the pathogenesis of the obliterative arteriolopathy that is a feature of cyclosporine nephrotoxicity.

Early therapy of renal bone disease with calcitriol: a prospective double-blind study

The value of calcitriol administration in the management and prevention of renal bone disease was studied in a prospective double-blind manner in 16 patients with chronic renal impairment (creatinine clearance 20 to 59 ml per min). They were given either calcitriol at a dose of 0.25 to 0.5 micrograms daily (eight patients), or placebo. Transiliac crest bone biopsies were performed before entrance into the study and after 12 months of experimental observation. None of the patients were symptomatic or had biochemical or radiological evidence of bone disease. Of the thirteen patients who completed the study, initial serum 1,25(OH)2D levels were low in seven patients and parathyroid hormone levels were elevated in seven patients. Bone histology was abnormal in all patients. Calcitriol treatment was associated with a significant fall in serum phosphorus concentrations and alkaline phosphatase levels as well as with histological evidence of an amelioration of hyperparathyroid changes. In contrast to previous reports, no deterioration of renal function attributable to the treatment occurred, perhaps because a modest dose of calcitriol was employed combined with meticulous monitoring. Further investigation is required to determine whether alternative therapeutic strategies (smaller doses or intermittent therapy) may avoid the potential for suppressing bone turnover to abnormally low levels in the long term.

Head scan appearances and cognitive function in renal failure

Cognitive function was assessed, and unenhanced CT head scans were carried out in 44 patients with renal failure. Thirteen had been on regular hemodialysis for 5 years or more (long-term hemodialysis group, LTHD), 12 had received hemodialysis for less than 5 years (short-term hemodialysis, STHD), 9 were on continuous ambulatory peritoneal dialysis (CAPD group) and 10 had severe chronic renal failure and were near to-but had not reached-dialysis dependence (chronic renal failure group, CRF). Employing an index of deterioration (the "discrepancy score") based on the discrepancy between current reading skills and current performance on the Wechsler Adult Intelligence Scale, 6 LTHD patients, 2 STHD patients, 2 CAPD patients and 5 CRF patients were identified as functioning below their predicted premorbid optimum level. Cerebral sulci were abnormally wide in 22 patients (8 LTHD, 2 STHD, 6 CAPD and 6 CRF) and one of the STHD group also had cerebral ventricular dilatation. Nine patients had both an abnormal scan and evidence of cognitive deterioration, 13 had an abnormal scan in the absence of such evidence and 6 had evidence of cognitive deterioration and a normal scan. Both cognitive deterioration and the CT scan finding of widening of cerebral sulci were commoner in these patients than would be expected in an age-matched sample of the general population, but no simple relationship was found between anatomical abnormality and cognitive functioning. Statistically significant correlations were found between discrepancy score and the cumulative amount of aluminum prescribed to be taken orally in both LTHD and CAPD groups.

Renal biopsy in patients with unexplained renal impairment and normal kidney size

We report renal biopsy findings in 109 patients with unexplained renal impairment (serum creatinine greater than 0.15 mmol/l) and normal-sized non-obstructed kidneys. The most common histological lesions were interstitial nephritis, rapidly progressive glomerulonephritis and a variety of other types of glomerulonephritis. The groups could not be distinguished by the presence or absence of hypertension, haematuria, proteinuria, or features of systemic disease. However interstitial nephritis was found more frequently in patients presenting with one or none of these features and rapidly progressive glomerulonephritis in patients presenting with three or more. All four patients with none of these features had interstitial lesions. Fifty-two per cent of patients with interstitial nephritis improved and 60 per cent of the patients with rapidly progressive glomerulonephritis who received immunosuppressive treatment improved or remained stable with treatment. The benefits of a biopsy diagnosis were almost wholly confined to these two groups. Complications were recorded in nine patients - prolonged macroscopic haematuria in six and symptomatic perirenal haematomata in three. Six required blood transfusion. One required nephrectomy to control haemorrhage and subsequently died. Percutaneous renal biopsy is not without risk in patients with renal impairment but the benefits of diagnosing interstitial nephritis and rapidly progressive glomerulonephritis outweigh the disadvantages.

Silicone in the liver: possible late effects

We describe two renal transplant recipients who presented with clinical and biochemical abnormalities of liver function in whom liver scarring and silicone particles were identified in the liver by light microscopy. The presence of silicon in the particles was confirmed by x-ray energy dispersive spectroscopy. In one patient liver abnormalities were first noted more than two years after haemodialysis was discontinued and in a second patient abnormalities were still present more than four years after successful kidney transplantation. No other specific cause for the chronic liver abnormalities was determined and we consider that these may be related to the presence of silicone degradation products in the liver. Other patients haemodialysed using a siliconised peristaltic blood pump insert system may also be a risk of developing similar late complications.