High prevalence of systemic disease and mortality in Asian subjects with systemic lupus erythematosus

All patients with systemic lupus erythematosus (SLE) (American Rheumatism Association criteria with positive antinuclear antibody titre) and who attended any of the three general hospitals in Leicester over a 10 year period were ascertained using several complementary sources. Eighty seven subjects (26 Asian, 61 white) were identified. The estimated prevalence of SLE in Leicester is 0.4/1000 for Asian and 0.2/1000 for white subjects. Mean age of onset of the disease was 24 years in Asian and 31 years in white subjects, with both groups showing a female preponderance. Proteinuria (greater than 1 g/24 h) was noted in 15 (58%) Asian and 21 (35%) white subjects; neuropsychiatric disease in 10 (38%) Asian and 8 (13%) white subjects; myalgic symptoms with raised muscle enzymes in 9 (35%) Asian and 3 (5%) white subjects. Nineteen (73%) Asian subjects were positive for extractable nuclear antigens as well, at some stage of their disease, compared with 6 (10%) white subjects. Immunosuppressive treatment was required in 12 (46%) Asian and 12 (20%) white subjects, and deaths of seven Asian and five white subjects were attributed to SLE. These findings show that Asian subjects have a higher prevalence of SLE with greater systemic disease and mortality.

Plasma erythropoietin levels and acquired cystic disease of the kidney in patients receiving regular haemodialysis treatment

Acquired cystic disease of the kidney (ACDK) in patients with end-stage renal failure can be associated with development of polycythaemia. The relationship between plasma erythropoietin levels and ACDK in 17 patients on long-term haemodialysis treatment was studied. There was a significantly higher level of plasma erythropoietin in patients with multiple renal cysts than in those patients with less than five cysts or no cysts. Haemoglobin tended to be higher in the ACDK group, but the difference was not significant. These results indicate that the development of renal cysts results in increased secretion of erythropoietin.

Skeletal muscle degradation and nitrogen wasting in rats with chronic metabolic acidosis

1. Chronic metabolic acidosis is associated with impaired growth and negative nitrogen balance, suggesting that it promotes endogenous protein catabolism. 2. Skeletal muscle is the major repository of body protein and is a potential target for stimuli of protein catabolism. 3. This study in vivo examines the effects of chronic metabolic acidosis on the relationship between growth, nitrogen disposal and skeletal muscle catabolism in the rat. 4. Growth, nitrogen utilization and acquisition of body mass were significantly impaired in acidotic animals compared with pair-fed controls. 5. Total nitrogen excretion was significantly increased in acidotic rats despite decreased urea production. The time course of this response to acidosis was synchronous with that of accelerated protein catabolism in skeletal muscle. 6. It is proposed that metabolic acidosis impairs growth by stimulating skeletal muscle protein catabolism. It is suggested that this forms part of a co-ordinated multi-organ homoeostatic response to acidosis, skeletal muscle and down-regulated urea production supplying the nitrogen required for renal ammoniagenesis.

Cholesterol feeding following unilateral nephrectomy in the rat leads to glomerular hypertrophy

Experimental glomerulosclerosis is associated with hyperlipidaemia and the deposition of lipid in glomeruli. Glomerulosclerosis is typically preceded by glomerular hypertrophy. To investigate a possible pathogenic role of lipids in glomerulosclerosis, glomerular structure and cellular composition were studied in rats fed either a control diet or one supplemented with 4% cholesterol and 1% cholic acid for 21 weeks following unilateral nephrectomy. On the cholesterol diet there were significant increases in glomerular cross-sectional area (13.11 +/- 0.39 x 10(3) vs. 11.13 +/- 0.44 x 10(3) mu 2, p less than 0.01) and mesangial area (1.81 +/- 0.07 x 10(3) vs. 1.50 +/- 0.08 x 10(3) mu 2, p less than 0.02). These changes were significantly correlated with proteinuria, which was significantly greater on the cholesterol diet (mean area under curve for duration of diet = 3.11 +/- 0.38 vs. 1.42 +/- 0.35 g, p less than 0.02). There was a significant increase in glomerular leukocytes on the cholesterol diet (4.10 +/- 0.44 vs 2.86 +/- 0.25 OX-1 positive cells/10(4) mu 2, p less than 0.05). Mesangial foam cells, derived from macrophages, were associated with adhesions to Bowman's capsule. These results demonstrate that hyperlipidaemia exacerbates the development of glomerular hypertrophy and that this may be mediated by factors released during the phagocytosis of lipoprotein deposits by macrophages.

Factors influencing peritoneal catheter survival in continuous ambulatory peritoneal dialysis

The success of continuous ambulatory peritoneal dialysis (CAPD) is to a great extent determined by the survival of the peritoneal catheter. The aim of this study was to identify technical factors which influence CAPD catheter survival. A total of 453 CAPD catheters inserted into 310 patients over an 8-year period were analysed. Access to the peritoneum was gained either by an open surgical technique (n = 290) or by a closed technique using a trocar and introducer (n = 163). Data relating to a number of potentially significant risk/benefit factors were analysed using multiple regression analysis (proportional hazards method of Cox). Three factors were found to be independently associated with improved catheter survival. They were: using an open surgical insertion technique, performing a partial omentectomy at the time of catheter insertion and the procedure being performed by a consultant.

Adrenal dysfunction in patients with renal amyloid

Amyloidosis is a multi-system disease. Renal involvement often leads to end-stage renal failure, which carries a poor prognosis. This paper reports the adrenal status of 22 patients with renal amyloid who were considered for or who had been commenced on renal replacement therapy. Twelve patients were considered or found to have AA amyloid and the remaining 10 had AL amyloid. Of 16 patients tested, seven demonstrated an abnormal response to a synacthen test. Four patients died at Addisonian crisis and hypo-adrenalism probably contributed to the deaths of a further two patients. Amyloid deposition was found in the adrenal glands in seven patients who died of systemic amyloidosis and renal failure. It is recommended that all patients with renal amyloid should have an assessment of adrenal function performed and if abnormal replacement steroid therapy should be commenced.

The role of continuous ambulatory peritoneal dialysis in end-stage renal failure due to multiple myeloma

A study in 10 patients (eight male, two female; mean age 61.9 +/- 10.7 years) suffering from multiple myeloma (MM) and end-stage renal failure (ESRF) is detailed. Continuous ambulatory peritoneal dialysis (CAPD) was the preferred mode of chronic dialysis in all the patients. Survival after diagnosis was 32.2 +/- 23.9 months. Survival after starting dialysis was 24.6 +/- 20.6 months. All patients on CAPD were adequately dialyzed and in good fluid control. Peritonitis was the main problem on CAPD (one episode per 5.6 patient-months). The majority of peritonitis episodes responded to intraperitoneal antibiotic therapy. One patient with Staphylococcus aureus peritonitis, septicemia, and neutropenia secondary to chemotherapy, died. Recommendations for prophylaxis and treatment of peritonitis are given. Three patients were transferred to hemodialysis. The use of subclavian vein catheters during hemodialysis was associated with a high incidence of gram-positive septicemia. Alkylating agent-based chemotherapy resulted in hematological responses in five patients. Survival after diagnosis in those responders was 47.4 +/- 25.6 months, compared with 17.0 +/- 7.2 months in the nonresponders (P less than 0.05). All responders subsequently relapsed. Four patients died with progressive myeloma. Bone marrow suppression resulted in a high blood transfusion requirement, neutropenia, and thrombocytopenia associated with bleeding into the gastrointestinal tract and central nervous system. Uremic myeloma patients can be adequately dialyzed using CAPD. Those patients who do not have an initial hematological response have a poor prognosis.

Effect of nifedipine on renal haemodynamics in an animal model of cyclosporin A nephrotoxicity

1. This study investigates the effect of nifedipine on cyclosporin A nephrotoxicity in the spontaneously hypertensive rat. 2. Cyclosporin A, administered daily by subcutaneous injection at 25 mg/kg body weight for 14 days, induced a significant reduction in glomerular filtration rate (35.3%) and effective renal plasma flow (45.0%), and an increase in renal vascular resistance (219%). Using this regimen, tubular, glomerular or vascular morphological damage was not evident on light microscopy. 3. The administration of nifedipine simultaneously with cyclosporin A from day 1 prevented the characteristic decline in renal function and increase in renal vascular resistance. However, the administration of nifedipine to spontaneously hypertensive rats previously exposed to cyclosporin A for 7 days failed to improve renal haemodynamics. 4. This study suggests that the beneficial effect conferred by nifedipine on cyclosporin A nephrotoxicity is present only when treatment is initiated simultaneously with cyclosporin A.

The prevalence and risk factors associated with the onset of diabetic nephropathy in juvenile-onset (insulin-dependent) diabetics diagnosed under the age of 17 years in Leicestershire 1930-1985

The prevalence of diabetic nephropathy was studied in a population of 847 juvenile-onset (insulin-dependent) diabetics diagnosed under the age of 17 years who attended diabetic clinics in Leicestershire between 1930 and 1985. Seven hundred and eighty-nine patients (93.2 per cent) were traced. Eight patients with non-diabetic proteinuria and four classified as maturity-onset diabetics of the young were excluded from further analysis. The mean age at onset was 9.3 +/- 4.2 years (mean +/- SD) and the mean duration of diabetes 17.0 +/- 10.6 years (range 3-63 years). Overall, 28 patients (3.6 per cent) developed persistent proteinuria and 39 patients (five per cent) intermittent proteinuria. End-stage renal failure developed in eight patients. In patients with diabetes of 20 years duration (n = 254) the prevalence of persistent proteinuria was 9.1 per cent and of intermittent proteinuria, 7.9 per cent. Systolic and diastolic blood pressures were elevated in diabetics with persistent proteinuria compared to patients without proteinuria (154/89 +/- 27/15 vs 123/76 +/- 15/9 mm Hg mean +/- SD; p less than 0.001). Systolic blood pressure was also raised in patients with intermittent proteinuria (133/77 +/- 17/12, p less than 0.005). In addition, proteinuria (intermittent and persistent) was significantly associated with the use of once-daily insulin therapy in childhood and poor clinic attendance. This study suggests that twice-daily insulin therapy from diagnosis in childhood and regular contact with the diabetic clinic decreased the prevalence of diabetic nephropathy in this population.

A clinical audit of thallium-technetium subtraction parathyroid scans

Eighty six consecutive thallium-technetium subtraction parathyroid scans performed over a three year period for hypercalcaemia have been evaluated. Twelve had chronic renal failure, 11 had hypercalcaemia due to non-hyperparathyroid causes and in 10 the imaging study was technically inadequate. The remaining 53 technically adequate studies performed for hypercalcaemia clinically thought to be possibly due to hyperparathyroidism have been analysed. Of 20 (38%) positive scans, 13 came to surgery (10 correctly localized parathyroid adenomas, 2 with multiple gland hyperplasia, and 1 papillary carcinoma of the thyroid). Of 33 (62%) negative scans, 9 had surgical exploration on the basis of strong clinical grounds and all had parathyroid adenomas. Multiple biochemical parameters have been assessed in relation to a positive outcome on scan. The adjusted calcium-phosphate product and the ratio of the adjusted calcium-phosphate product to creatinine (Ca x P/Cr) were both significantly lower in the scan positive group (P less than 0.01). The scan positive group had a significantly higher mean level of PTH (P less than 0.001) and lower mean level of phosphate (P less than 0.001). The present experience shows that parathyroid imaging is useful in localizing parathyroid adenomas in 50% of cases (10 out of 19). This figure is at the lower end of the range of previously published results. It is less effective in demonstrating multiple gland hyperplasia. The decision as to whether to undertake surgical exploration when the scan is negative has been based successfully on clinical judgement. We feel that an analysis of this nature is important, as it gives insights into the practical relevance of parathyroid imaging in the context of routine clinical work.

The role of lipids in the pathogenesis of glomerulosclerosis in the rat following subtotal nephrectomy

Similarities between atherosclerosis and glomerulosclerosis suggest that hyperlipidaemia may contribute to glomerular injury. Dietary supplementation with 4% cholesterol + 1% cholic acid was administered to rats 4 weeks after 1 1/3 nephrectomy and continued for 7 weeks. There was a significant increase in serum cholesterol (peak = 11.52 +/- 1.09 mmol l-1 vs. 4.73 +/- 0.31 on control diet, P less than 0.001) and triglyceride concentrations (peak = 2.31 +/- 0.27 mmol l-1 vs. 1.41 +/- 0.29, P less than 0.05) and a marked increase in beta-migrating lipoproteins. The severity of hypercholesterolaemia was significantly correlated with proteinuria (control diet: r = 0.600, cholesterol diet: r = 0.672, P less than 0.0001) as was hypertriglyceridaemia (control diet: r = 0.544, cholesterol diet: r = 0.678, P less than 0.0001). The percentage of glomeruli containing lipid deposits was increased from 21% to 60% (P less than 0.05). The kidney total cholesterol content was increased from 29.2 +/- 0.8 to 47.7 +/- 3.3 mumols g-1 dry weight (P less than 0.0001), with esterified cholesterol increasing from 7.5 +/- 0.4% to 14.5 +/- 2.1% of total (P less than 0.01). Serum cholesterol concentration was significantly correlated with both glomerular lipid deposition (rs = 0.7195, P less than 0.0001) and tissue total cholesterol content (rs = 0.6053, P less than 0.001). Lipid vacuolation was prominent in the paramesangium and within mesangial cells. Despite these changes hypertension, uraemia, proteinuria and glomerulosclerosis were not significantly increased on the cholesterol diet. Cholesterol deposition in the glomeruli occurs secondary to hyperlipidaemia in rats following subtotal nephrectomy but over 7 weeks no exacerbation of glomerulosclerosis is detectable.

Acute renal failure associated with a labetalol overdose

A case of acute renal failure in association with a deliberate labetalol overdose is described. The possible pathogenetic mechanisms behind the deterioration in renal function are discussed. Treatment of beta-blockade overdose, with special emphasis on the place of glucagon in such poisoning, is reviewed.

The effect of nifedipine on renal function in normotensive cyclosporin-A-treated renal allograft recipients

Intrarenal vasoconstriction is a characteristic feature of CsA nephrotoxicity. The influence of nifedipine, a dihydropyridine calcium channel blocker and potent renal vasodilator, on renal haemodynamics was investigated in 11 cyclosporin A (CsA)- and 9 azathioprine (Aza)-treated normotensive long-term renal allograft recipients. Baseline Cr51-EDTA clearance and effective renal plasma flow (ERPF) were similar in both groups. Nifedipine 20 mg twice daily for 28 days significantly increased Cr51-EDTA clearance (+14.8%) in the CsA group; however, ERPF, renal vascular resistance (RVR), and filtration fraction did not change. Nifedipine did not influence renal haemodynamics in the azathioprine group. The increase in Cr51-EDTA clearance in the CsA group did not correlate with baseline renal function, CsA dose or whole blood levels, donor age, duration of graft, or renal functional reserve capacity. This study suggests that nifedipine confers a beneficial effect on renal haemodynamics in long-term CsA-treated renal allograft recipients and appears to improve renal function by a non-haemodynamic mechanism.

Receptor-mediated endocytosis of low-density lipoprotein by cultured human glomerular cells

Lipoproteins might be involved in the pathogenesis of glomerular damage. Uptake of low-density lipoprotein (LDL) by cultured human glomerular cells has been studied using LDL, labelled with the fluorescent probe 1,1'-dioctadecyl-3,3,3'3'-tetramethyl-indocarbocyanine perchlorate (diI). Cells have been characterised using phase-contrast microscopy, monoclonal antibodies and lectins. Differentiated glomerular epithelial cells, epithelial-like cells and mesangial cells all took up diI-LDL. Uptake was specific for LDL, of high affinity and inhibited by excess unlabelled LDL, heparin and preloading the cells with cholesterol. Binding of diI-LDL to the cell surface was restricted to discrete areas which were arranged in linear arrays on mesangial cells. Endocytosis of surface-bound diI-LDL occurred within 3 min and breakdown of internalised diI-LDL within 30 min. These results indicate that cultured human glomerular cells take up LDL by receptor-mediated endocytosis.

Vitamin A and bone formation. Different responses to retinol and retinoic acid of chick bone cells in organ culture

The response of bone cells in organ culture to retinol and retinoic acid was studied. Both stimulated incorporation of [3H]thymidine into DNA by 16-day embryonic chick calvaria, but the time-course of the responses differed; the peak responses to retinol and retinoic acid occurred at about 18 h and 48 h, respectively. Although retinol inhibited chick bone collagen synthesis retinoic acid had no effect, but it did stimulate non-collagenous protein synthesis, whereas the effect on the latter of retinol was, if anything, inhibitory. When present with retinol, retinoic acid was able to attenuate the inhibitory effect of the former on chick bone collagen synthesis, but preincubation with retinoic acid had no such effect. In neonatal murine calvarial cultures, retinoic acid inhibited collagen synthesis selectively in the same manner as did retinol. The ability of chick osteoblasts to respond differently to retinol and retinoic acid suggests that both forms of the vitamin may have a role in bone formation and that their intracellular models of action may differ although the attenuation response indicates there may be some interaction between the two.

Different types of segmental sclerosing glomerular lesions in six experimental models of proteinuria

From 133 to 615 glomeruli were examined in sections of kidneys from each of 60 animals, representing six rodent models of proteinuria. Particular attention was paid to the position of segmental lesions. Lewis rats given sheep anti-rat glomerular basement membrane antibodies had lesions almost exclusively at the glomerulo-tubular junction. Wistar rats on a diet of 24 per cent casein or with subtotal nephrectomy and a diet of 24 per cent soya had lesions mainly at the hilum. Wistar rats given bovine serum albumin had global lesions but virtually no segmental lesions. Wistar rats given puromycin aminonucleoside had lesions at the glomerulo-tubular junction and global mesangial abnormalities shortly after the treatment but later developed segmental lesions at all parts of the glomerulus. Untreated BUF/Mna rats had lesions at the glomerulo-tubular junction early in life but later had lesions at all parts of the glomerulus. Untreated NZB/NZW hybrid mice had various types of glomerulonephritis and also had lesions at the glomerulo-tubular junction. These findings showed that (1) segmental lesions at the glomerulo-tubular junction, or glomerular tip, occur in experimental animals, a fact not previously reported, and these tip changes are a common feature in several different models of proteinuria; (2) hilar segmental lesions are seen in conditions with hyperfiltration of protein; and (3) segmental lesions at various parts of the glomerulus are seen in some models of proteinuria and probably indicate late effects of random toxic damage to the glomerulus. Thus, there are at least three different types of segmental glomerular lesions in experimental animals--tip, hilar, and random--with different morphology and pathogenesis. It is likely that these findings can be extended to human renal diseases with segmental glomerular lesions. This will help to clarify the controversial and unsatisfactory term focal segmental glomerulosclerosis.

Formulation change in VLCD in response to DHSS recommendations: comparative evaluation

Response to recommendations of the Committee on Medical Aspects of Food Policy prompted reformulation of the 330 kcal Cambridge diet to 405 kcal per day with 42 g protein. Developmental trials demonstrated that clinical performance of VLCD formulations at comparable calorie levels could not be assumed. Studies using the formulation commercially produced as Cambridge diet extra with female subjects showed no significant difference in weight losses between the original and the new diet products over 2 or 8 week study periods. The percentage of body weight represented by FFM rose in the 8-week trial by 5 per cent in each group. Blood analyses were carried out before and after 8 weeks dieting with the 405 kcal formula. All parameters remained in the normal range, except iron, which was slightly below normal prior to the trial and rose into the normal range by week 8. These findings compared favourably with previous blood profiles of subjects using the 330 kcal formula. Modifications of the formula which increased the protein and calorie content to 42 g and 405 kcal respectively did not significantly alter the efficacy and safety of the product.