Cerebrotendinous xanthomatosis: a family study of sterol 27-hydroxylase mutations and pharmacotherapy.

We examined the phenotypic characteristics, molecular genetics and optimal pharmacological treatment of cerebrotendinous xanthomatosis (CTX) in an English family with combined hyperlipidaemia. The proband presented in adulthood with classical clinical characteristics of CTX, a greater than tenfold elevation in plasma cholestanol and combined hyperlipidaemia. His brother also had typical features of CTX without the presence of dyslipidaemia. Genotyping revealed that the two brothers were compound heterozygotes for a novel missense mutation in exon 2 (R94Q) and for a recently described nonsense mutation in exon 5, of the sterol 27-hydroxylase gene (CYP27). Analysis of all available family members revealed that hyperlipidaemia did not co-segregate with the presence of a CYP27 mutant allele. Trial of therapy showed that the lowest plasma sterol and triglyceride concentrations and cholestanol:cholesterol ratio were achieved with the combination of chenodeoxycholic acid (CDCA) 750 mg/day, a primary bile acid, and simvastatin 40 mg/day, an inhibitor of 3-hydroxy-3-methyl-glutaryl coenzyme A reductase. CDCA alone and simvastatin alone significantly lowered plasma cholestanol concentration, but the decrease was greater with the former. After 1 year there was significant improvement in both cognitive and motor function with regression of tendon xanthomata on computerized tomography. We conclude that CTX in this English pedigree is probably due to compound mutant alleles in CYP27, that combined hyperlipidaemia in this family is unrelated to CTX, and that this complicated condition responds optimally to the combination of CDCA and simvastatin.

Hypothyroidism in the elderly: clinical assessment versus routine screening.

A total of 304 patients aged 65 years or over were prospectively studied over a four-month period to assess whether clinical findings or routine screening were more helpful in diagnosing biochemical hypothyroidism. The most useful symptom relevant to a possible diagnosis of hypothyroidism in the elderly was found to be dry skin. Dermatological signs and certain ECG abnormalities (especially atrial fibrillation) were helpful when querying a diagnosis of hypothyroidism. Almost 50% of patients receiving amiodarone had abnormal thyroid function tests (TFTs). Routine screening for hypothyroidism does not seem justifiable from our available data although this conclusion may have been different had hospital clinicians and general practitioners followed their patients up more closely after an initial abnormal result was obtained.

Effect of low protein diet on the renal response to meat ingestion in diabetic nephropathy.

We measured the renal haemodynamic and proteinuric response to a meat meal (MM) in ten persistently proteinuric insulin-dependent diabetic patients in a randomized cross-over study of 3 weeks on low protein diet (LPD) or normal protein intake (NPD). On LPD, protein intake (0.64 +/- 0.05 vs 1.15 +/- 0.09 g kg-1 body weight (BW) per day, P less than 0.001), plasma urea (6.6 +/- 1.3 vs 11.0 +/- 2.0 mmol l-1, P less than 0.01) and urea appearance (0.06 +/- 0.01 vs 0.16 +/- 0.03 gN kg-1 body weight per day, P less than 0.001) were lower. Baseline glomerular filtration rate (GFR), renal plasma flow (RPF) and renal vascular resistance (RVR) were similar on the two diets and there were no significant average changes in these variables after the meat meal on either diet (NPD, before vs after MM: GFR: 67 +/- 11 vs 71 +/- 13 ml min-1 1.73 m-2; RPF: 479 +/- 70 vs 512 +/- 81 ml min-1 1.73 m-2; RVR: 181 +/- 45 vs 179 +/- 52 mmHg min-1 l-1); (LPD, before vs after MM: GFR: 64 +/- 10 vs 67 +/- 11 ml min-1 1.73 m-2; RPF: 506 +/- 60 vs 533 + 52 ml min-1 1.73 m-2; RVR: 151 +/- 28 vs 146 +/- 32 mmHg min-1 l-1). However, all patients with baseline GFR above 60 ml min-1 1.73 m-2 showed a GFR rise in response to the meat meal on both diets, while patients with lower baseline values tended to reduce their GRF.(ABSTRACT TRUNCATED AT 250 WORDS)

Restriction of dietary protein and progression of renal failure in diabetic nephropathy.

In a study of the effect of a low-protein diet on the progression of renal disease 19 insulin-dependent diabetic patients with persistent clinical proteinuria were observed for 12-39 (mean 29) months while they were on a normal-protein diet (1.13 [0.06] g/kg per day), then for 12-49 (mean 33) months on a low-protein diet (0.67 [0.03] g/kg per day). The low-protein diet had no adverse effect on nutrition or glycosylated haemoglobin concentration. Mean supine blood pressure (BP) fell slightly on the low-protein diet and was probably due to the start or modification of antihypertensive medication in 9 patients. The mean rate of decline in glomerular filtration rate fell from 0.61 (SEM 0.14) ml/min per month with the normal-protein diet to 0.14 (0.08) with the low-protein diet, and this effect remained highly significant after adjustment for blood pressure, energy intake, and glycosylated haemoglobin. The rise in the fractional clearance of albumin during a normal-protein diet stopped with the low-protein diet, and there was a significant fall in albumin excretion from 467 (95% CI 234-895) micrograms/24 h on the normal-protein to 340 (138-719) on the low-protein diet. Thus, a low-protein diet, with its reduction in protein and possibly other dietary components such as phosphate or fat, seems to retard the rate of decline of glomerular filtration rate in diabetic nephropathy independently of blood pressure changes and glycaemic control.

Renal response to restricted protein intake in diabetic nephropathy.

Proteinuria in diabetes is associated with progressive glomerular damage. We studied the effects of 3-wk dietary protein restriction on proteinuria and renal function in 10 insulin-dependent diabetic men with diabetic nephropathy. Patients were randomly assigned by a crossover design to 40-g low-protein diet (LPD) or usual-protein diet (UPD). Glomerular filtration rate and renal plasma flow were measured by inulin and p-aminohippurate clearance at the end of each period under conditions of sustained euglycemia. Total calorie intake, body weight, serum albumin and total protein concentrations, hematocrit, blood pressure, and glucose control were similar during the two diets. Achieved protein intake was 46 +/- 3 g/day during LPD and 81 +/- 4 g/day during UPD (P less than .001). Urinary urea appearance and plasma urea were significantly lower on LPD. Median total urinary protein was reduced from 3.9 g/day (range 0.5-12.3) on UPD to 2.4 (range 0.2-9.0) on LPD (P less than .006), and there was a significant fall in the median fractional clearance of albumin from 2.0 x 10(-4) (range 0.1-90.9) on UPD to 1.0 x 10(-4) (range 0.1-51.4) on LPD and IgG from 2.1 x 10(-5) (range 0.2-238) to 1.5 x 10(-5) (range 0.1-77) (P less than .006 and P less than .02, respectively). The reabsorption rate of beta 2-microglobulin was similar on the two diets and glomerular filtration rate, renal plasma flow, and filtration fraction remained unchanged. Thus, short-term dietary protein restriction reduces diabetic proteinuria independently of blood glucose or systemic blood pressure changes by improving glomerular permselectivity.

Proteinuria and activated T-lymphocytes in diabetic nephropathy.

The reasons for the presence of activated T-lymphocytes (ATL) in some long-standing insulin-dependent diabetic (IDDM) patients are unknown. These cells have been implicated in the genesis of proteinuria in some forms of immune-mediated renal disease. We measured ATL in 18 IDDM patients with diabetic nephropathy, 10 with nonnephrotic proteinuria (total urinary protein excretion rate greater than 0.5 and less than 3.5 g/24 h) and 8 with nephrotic proteinuria (total urinary protein excretion rate greater than 3.5 g/24 h), and in 17 age-, sex-, and duration-of-diabetes-matched diabetic control subjects without clinical proteinuria (total urinary protein less than 0.5 g/24 h). T-lymphocytes purified from peripheral blood were stained by direct immunofluorescence with the fluorescein-labeled monoclonal antibody anti-HLA-DR. Absolute number and percent of DR-positive T-lymphocytes were significantly higher in patients with nonnephrotic proteinuria (median and range 162 x 10(6)/ml, 40-320 x 10(6)/ml; 13.9%, 8.1-19.4%) compared with nonproteinuric control subjects (81 x 10(6)/ml, 2-240 x 10(6)/ml, P less than .05; 6.2%, 0-13.1%, P less than .01). In 8 patients with nephrotic proteinuria, absolute and percent DR-positive T-lymphocytes tended to be lower (36 x 10(6)/ml, 14-56 x 10(6)/ml; 3.4%, 1.1-5.4%) than in nonproteinuric control subjects. An increased number of activated T-lymphocytes may be part of an immune-mediated process associated with the development of proteinuria in diabetic nephropathy. In advanced renal disease with nephrotic proteinuria, this immune process may become exhausted.

Increased sodium-lithium countertransport activity in red cells of patients with insulin-dependent diabetes and nephropathy.

Susceptibility to diabetic nephropathy may be related to a predisposition to arterial hypertension. We have studied the activity of sodium-lithium countertransport in red cells, a marker of risk for essential hypertension, in white European adults with insulin-dependent diabetes and diabetic nephropathy, a matched group of patients with diabetes without renal disease, and nondiabetic patients with renal disease. Measures of metabolic control and concentrations of plasma free insulin and growth hormone were similar in the two diabetic groups. The degree of impairment in renal function was similar in the diabetic and nondiabetic patients with renal disease. Body-mass index and plasma potassium concentrations were similar in all three groups. Diastolic blood pressure was elevated to a similar degree in the two groups with renal disease, as compared with that in the diabetic patients without renal disease. The rates of sodium-lithium countertransport in red cells were significantly higher in the diabetic patients with renal disease (mean +/- SD, 0.55 +/- 0.19 mmol of lithium per liter of red cells per hour) than in the diabetic patients without renal disease (0.33 +/- 0.16; P less than 0.005) and in the nondiabetic patients with renal disease (0.31 +/- 0.14; P less than 0.001). Predisposition to hypertension, as indicated by elevated sodium-lithium countertransport activity in red cells, may serve as a marker for the risk of renal disease in patients with insulin-dependent diabetes.

Protein restriction, blood pressure and the progression of diabetic nephropathy.

Diabetic nephropathy is the long-term complication of diabetes responsible for the greatest increased mortality. Clinical nephropathy is characterised by a triad consisting of persistent proteinuria (total urinary protein greater than 0.5 g/24 h), rising arterial pressure and declining renal function. The role of treatment of raised blood pressure and the influence of dietary protein restriction on the established progressive phase of the disease are discussed. Subclinical elevations of urinary albumin excretion rates (greater than 30 micrograms/min; microalbuminuria), glomerular hyperfiltration and marginal elevations of arterial pressure are early markers of later clinical nephropathy which appear to respond to strict blood glucose control, blood pressure treatment and lowered dietary protein intake. Recent evidence to suggest that an inherited predisposition to raised arterial pressure may confer the susceptibility to diabetic nephropathy is presented.

Human cysticercosis and intestinal parasitism amongst the Ekari people of Irian Jaya.

A random sample of 242 people showed that 42 had palpable cysts of Taenia solium. Faecal examination recovered eggs of T. solium in seven (3%), while Trichuris (83%), Ascaris (83%), hookworms (76%), Strongyloides stercoralis (10%) and Strongyloides sp. (29%), Entamoeba histolytica (14%), Entamoeba coli (22%), Entamoeba hartmanni (7%), Entamoeba polecki (7%), Balantidium coli (9%) and Dientamoeba fragilis (21%) were the most common other intestinal parasites encountered. ELISA tests, using antigens prepared from adults and eggs of T. solium and from cysticerci of T. saginata were not very sensitive, the last diagnosing less than half of known positives while still retaining good specificity.

Diabetogenic effect of cyclosporin.

A young woman given a renal allograft for polycystic kidney disease developed insulin dependent diabetes mellitus 25 days after transplantation. There was no family history of diabetes, plasma glucose concentrations had been normal at presentation and on five subsequent occasions, and at no time were islet cell antibodies detectable. Plasma C peptide concentrations, however, were greatly suppressed after transplantation and remained so for up to six months. The immunosuppressive regimen had included cyclosporin A, which had been difficult to regulate and caused definite signs of toxicity in the patient. By virtue of its reported toxicity for beta cells and the reversal of the diabetes several months after the dose was reduced cyclosporin was incriminated as the probable causative agent. Dose related beta cell toxicity of cyclosporin A may be a risk in recipients of this drug and warrants careful monitoring of drug and glucose concentrations.