Retinal abnormalities characteristic of inherited renal disease.

Many inherited renal diseases have retinal features that are helpful diagnostically. These include coloboma, drusen, atrophy and pigmentation (retinitis pigmentosa), hamartoma, vascular anomalies, and crystals. Retinal abnormalities occur because the kidney and retina share developmental pathways and structural features including basement membrane collagen IV protomer composition and their vascularity, and because both the kidney and retina are functionally dependent on ciliated cells.

Challenging the glucose challenge test.

Background: To reduce the number of patients needing oral glucose tolerance test (OGTT), screening options have been considered, balancing patient comfort, cost and risk of missed diagnosis. Australian Diabetes in Pregnancy Society (ADIPS) recommends glucose challenge test (GCT) as screening for gestational diabetes mellitus (GDM), while others suggest fasting plasma glucose (FPG). International Association of Diabetes and Pregnancy Study Group (IADPSG) recently recommended new diagnostic criteria for GDM using one-step OGTT.

Serial increased cardiac troponin T predicts mortality in asymptomatic patients treated with chronic haemodialysis.

Background: A single detectable cardiac troponin predicts mortality in patients treated with dialysis. There are limited data on changes in troponin concentration over time and the clinical implications of serial troponin measurement.

Methods: Serial cardiac troponin T (cTnT) was assayed five times over 12 months in a prospective cohort study of patients with end-stage kidney disease treated with haemodialysis.

B-type natriuretic peptides strongly predict mortality in patients who are treated with long-term dialysis.

Background And Objectives: Left ventricular abnormalities contribute to cardiovascular disease in patients with chronic kidney disease and may be detected by measurement of B-type natriuretic peptide in serum.

Design, Setting, Participants, & Measurements: In a prospective cohort study of predialysis patients, patients who were on dialysis, and kidney transplant recipients, serum was collected and assayed for both B-type natriuretic peptide and its N-terminal fragment. Median levels were compared using nonparametric tests, and predictors of B-type natriuretic peptide were determined by linear regression.

N-Acetylcysteine does not artifactually lower plasma creatinine concentration.

Background: All randomized controlled trials of N-acetylcysteine (NAC) in contrast media-induced nephropathy used creatinine as a marker of renal function. However, it has been suggested that NAC may lower plasma creatinine levels independent of any effects on glomerular filtration rate (GFR).

Methods: At a tertiary hospital 110 cardiac surgical patients were randomly allocated to peri-operative infusion of NAC (300 mg/kg over 24 h, N = 30) or placebo (N = 80).

The accuracy of cystatin C and commonly used creatinine-based methods for detecting moderate and mild chronic kidney disease in diabetes.

Background: The accuracy of measuring serum cystatin C levels for detecting various stages of chronic kidney disease (CKD) in diabetes is still unclear.

Methods: In a cross-sectional study of 251 subjects, a reference glomerular filtration rate (GFR) was measured using (99c)Tc-DTPA plasma clearance (iGFR). Multivariate analysis was used to identify independent clinical and biochemical associations with serum cystatin C and iGFR levels.

Cardiovascular biomarkers in CKD: pathophysiology and implications for clinical management of cardiac disease.

Cardiovascular disease (CVD) is a major cause of morbidity and mortality in patients with all forms of chronic kidney disease (CKD). The underlying pathological state is caused by a complex interplay of traditional and nontraditional risk factors that results in atherosclerosis, arteriosclerosis, and altered cardiac morphological characteristics. This multifactorial disease introduces new challenges in predicting and treating patients with CVD sufficiently early in the course of CKD to positively alter patient outcome.

Estimating glomerular filtration rate in diabetes: a comparison of cystatin-C- and creatinine-based methods.

Aims/hypothesis: We compared the predictive performance of a GFR based on serum cystatin C levels with commonly used creatinine-based methods in subjects with diabetes.

Subjects, Materials And Methods: In a cross-sectional study of 251 consecutive clinic patients, the mean reference (plasma clearance of (99m)Tc-diethylene-triamine-penta-acetic acid) GFR (iGFR) was 88+/-2 ml min(-1) 1.73 m(-2).

Single and serial measurements of cardiac troponin I in asymptomatic patients on chronic hemodialysis.

Aims: Coronary artery disease is the major cause of death in patients with end-stage renal failure on dialysis. This study aimed to assess the predictive value of a single cardiac troponin I (cTnI), and also the kinetics of serial values.

Methods: Since cTnI is a potential biomarker of cardiac outcome, the present study examined single cTnI measurements (n = 88 patients) and its predictive value for future cardiac events, and a kinetic substudy of serial weekly cTnI measured for 8 weeks (n = 57) in a group of patients on hemodialysis.

Cystatin C for estimation of glomerular filtration rate in patients with spinal cord injury.

Background: Serum creatinine is not a satisfactory marker of glomerular filtration rate (GFR) in patients with spinal cord injury (SCI) who have varying degrees of muscle atrophy. In contrast to serum creatinine, serum cystatin C, a 13-kDa protein, is not affected by muscle mass and is therefore potentially a useful marker of GFR in patients with SCI. In addition, cystatin C is not dependent on sex or age and is not secreted by the renal tubule.

Capillary electrophoresis of hemoglobin.

Capillary electrophoresis (CE) has been used in a variety of in-house capillary isoelectric focusing (CIEF) and capillary zone electrophoresis (CZE) assays for the detection of hemoglobin (Hb) variants and the quantitation of HbA2 and HbF. A commercial kit has also been produced for the analysis of hemoglobin variants and thalassemia screening. Though CE methods have been shown to be able to detect many variants, final identification of the variant needs specialized testing such as DNA technology.

Multiple sclerosis: use of light-chain typing to assist diagnosis.

Although the presence of oligoclonal IgG with abnormal kappa/lambda light-chain ratio in multiple sclerosis (MS) has been known for many years, this finding has not been put to diagnostic use in most routine clinical laboratories. In a retrospective study we report differences in the oligoclonal banding patterns between multiple sclerosis and non-MS patients. We had sufficient cerebrospinal fluid (CSF) on 36 from 71 patients with oligoclonal bands for immunofixation for kappa and lambda light chains, and for free kappa and free lambda.

Measurement of iohexol by capillary electrophoresis: minimizing practical problems encountered.

Iohexol is a non-ionic contrast agent, which has been widely described in recent literature as an accurate marker for the measurement of glomerular filtration rate (GFR). Our aim was to establish a capillary electrophoresis assay, based on a previously described method, that had adequate reproducibility to be used as part of a clinical trial. In this paper, we examine the practical aspects, pitfalls and steps we took to achieve a precise and reproducible assay.

Effect of hepatobiliary disease, chronic hepatitis C and hepatitis B virus infections and interferon-alpha on porphyrin profiles in plasma, urine and faeces.

Background: Documentation of the profiles of porphyrins in hepatobiliary disease is limited. Strong associations of hepatitis B and C virus infections with porphyria cutanea tarda have suggested causal relationships. This study aimed to determine the nature of porphyrin abnormalities in hepatobiliary disease and the effect of interferon-alpha on porphyrin profiles.

An unusual alkaline phosphatase isoenzyme associated with gastric carcinoma.

We describe a 50-year-old man with a diagnosis of gastric carcinoma made on gastroscopy after X-rays of the thoracolumbar spine had revealed multiple lytic metastases. A bone marrow aspirate showed adenocarcinoma cells. Polyacrylamide gel electrophoresis incorporating wheat germ lectin was used to separate the serum alkaline phosphatase isoenzymes.

Capillary isoelectric focusing of haemoglobin variants in the clinical laboratory.

For capillary isoelectric focusing (CIEF) to be accepted in the clinical laboratory, it must be reproducible and cost effective. The advent of polyAAEE coated capillaries (Bio-Rad Laboratories, Hercules, CA, USA) has provided the means of obtaining over 100 runs per capillary, something which previously had not always been possible with coated capillaries. Using the Clinical Data Management computer program on the BioFocus 2000 Capillary Electrophoresis System (Bio-Rad Laboratories), we have used a one-step salt mobilization to achieve focusing of haemoglobin variants.

Five unusual serum protein presentations found by capillary electrophoresis in the clinical laboratory.

Capillary electrophoresis (CE) has been used in our teaching hospital clinical laboratory to assay approximately 13 000 specimens for serum protein electrophoresis (SPE) in 4 1/2 years. During that period we have found several unusual samples, five of which are discussed here. These samples are from separate patients with IgD myeloma, IgG heavy chain disease, a triple IgG(Kappa) monoclonal band, a rapidly changing abnormal/monoclonal band and a mixed type-11 cryoglobulinaemia.

Three new mutations in the uroporphyrinogen decarboxylase gene in familial porphyria cutanea tarda. Mutation in brief no. 237. Online.

We have characterised three new mutations in the uroporphyrinogen decarboxylase gene in familial porphyria cutanea tarda. The first of these was a G to A substitution in the 5' splice junction of exon 4 which generated an mRNA that lacked exon 4. The second was a nonsense mutation in exon 5 which changed the arginine residue at position 142 to a stop codon, and the third mutation, also in exon 5, was a triple base substitution from nucleotide position 417 to 419.

Lambda light chain induced nephropathy: a rare cause of the Fanconi syndrome and severe osteomalacia.

The Fanconi syndrome is a generalized disorder of proximal renal tubular transport characterized by wasting of phosphate, amino acids, glucose, bicarbonate, and uric acid. The association of the acquired Fanconi syndrome with lambda light-chain proteinuria is rare. We report the third case in the English language literature.

Effects of perindopril on renal histomorphometry in diabetic subjects with microalbuminuria: a 3-year placebo-controlled biopsy study.

We conducted a 3-year randomized placebo-controlled double-blind study to determine the effects of the angiotensin-converting enzyme (ACE) inhibitor perindopril (PE) on the progress of renal function and histology in subjects with diabetes and microalbuminuria. Forty non-insulin-dependent (NIDDM) and insulin-dependent (IDDM) diabetic subjects, either normotensive or hypertensive, were randomly assigned to receive PE (n = 20) or placebo (n = 20). A percutaneous renal biopsy was performed initially in all patients and repeated in 29 patients after 3 years.

A study of laboratory based faecal occult blood testing in Melbourne, Australia. The Faecal Occult Blood Testing Study Group.

Faecal occult blood tests (FOBT) are widely used in clinical practice and are under increasing scrutiny as a tool for colorectal cancer screening. However, there is little information regarding the quality of testing performed in pathology laboratories. Therefore, we asked 13 pathology laboratories in Melbourne, Australia, to test coded contrived faecal samples prepared from a composite stool specimen which had been spiked to various concentrations of haemoglobin.

A novel form of hereditary sideroblastic anaemia with macrocytosis.

We describe a pedigree with maternally inherited sideroblastic anaemia in which the red cells are dimorphic with a raised MCV. To our knowledge, this form of hereditary sideroblastic anaemia (HSA) has not been reported previously. 16 members of the family were investigated, revealing eight affected members.

Five new mutations in the uroporphyrinogen decarboxylase gene identified in families with cutaneous porphyria.

We describe five new mutations in the uroporphyrinogen decarboxylase (UROD) gene. All mutations were observed in conjunction with decreased erythrocyte UROD and clinical familial porphyria cutanea tarda (fPCT), (four families) or hepatoerythropoietic porphyria (HEP), (one family). The fPCT mutations included three point mutations that resulted in amino acid substitutions: a lysine to glutamine at amino acid position 253 (exon 7); a glycine to arginine at position 318 (exon 10); an isoleucine to threonine at position 334 (exon 10).