Biomedical subjects

J M Macleod

Publications and source records attributed to J M Macleod.

3 recordsLinked to original sources

PubMed2000

Measurement of glomerular volume in needle biopsy specimens. The ESPRIT Study Group (European Study of the Progression of Renal Disease in Type 1 Diabetes).

BACKGROUND: Various methods have been used to determine mean glomerular volume, some requiring measurement of over 30 glomerular profiles for a satisfactory estimate. Needle biopsies are useful diagnostically, but if small, provide insufficient tissue for the use of such methods. METHODS: We performed glomerular volume measurements on renal biopsies from 10 normotensive, non-uraemic patients with Type 1 diabetes. Sections were taken at 10 microm intervals through 10 glomeruli per biopsy and points landing on glomerular tuft counted under light microscopy. Volume was calculated from the measured cross-sectional area and known section thickness using the Cavalieri principle. RESULTS: Estimating the volume of 10 glomeruli per biopsy gave an overall mean glomerular volume of 4.21x10(6) microm(3) and standard deviation between patient means 1.23x10(6) microm(3.) Using a sample size of five glomeruli per biopsy only increased the standard deviation between patient mean values by 3%. Using sections taken at 20 microm intervals made little difference to the mean glomerular volume and standard deviation estimates (MGV 4.20x10(6) microm(3)+/-1.24). Further increases in the sectioning interval resulted in an appreciable increase in the variance of the estimate. CONCLUSIONS: The results suggest that a satisfactory estimate of mean glomerular volume can be obtained from a sample size of five glomeruli per biopsy using a sectioning interval of 20 microm. This represents a great saving in analysis time and effort, making widespread use of this method of glomerular volume measurement in renal disease more practicable, in both research and clinical settings.

Biopsy, Needle↗

PubMed1996

Renal function in long-duration type I diabetes.

OBJECTIVE: The development of persistent proteinuria is reported to be uncommon after 30 years of type I diabetes, and the significance of microalbuminuria in patients with long-duration diabetes is unclear. We therefore undertook to study, in detail, renal function in patients with long-duration type I diabetes. RESEARCH DESIGN AND METHODS: We measured albumin excretion rate (AER), glomerular filtration rate (GFR), and serum creatinine in 140 patients with > or = 30 years of type I diabetes. We also assessed patients for other micro- macrovascular complications of diabetes together with factors implicated in the development of diabetic renal disease. RESULTS: Of the patients, 23% had microalbuminuria (AER 20-200 micrograms/min and/or urinary albumin-to-creatinine ratio [ACR] > 2.5 mg/mmol [men] or > 3.5 mg/mmol [women] and dipstick negative for proteinuria), 4% had overt nephropathy (AER > 200 micrograms/min or persistent dipstick positive proteinuria), and 73% were normoalbuminuric (AER < 20 micrograms/min or ACR < 2.5 mg/mmol [men], < 3.5 mg/mmol [women]). Patients with microalbuminuria had lower GFR (81.5 +/- 30.2 vs. 96.0 +/- 20.3 ml.min-1.1.73 m-2; P = 0.06) and higher serum creatinine (104 +/- 32 vs. 92 +/- 16 mumol/l; P = 0.06) than those patients with normoalbuminuria. Both serum creatinine (P < 0.05) and tobacco consumption (P = 0.01) were significantly and independently related to elevated albumin excretion. CONCLUSIONS: A substantial proportion of these patients have microalbuminuria and evidence of impaired renal function, suggesting that progression to end-stage renal failure may still be inevitable. Clinicians should continue to monitor renal function in these patients. The relationship between tobacco consumption and nephropathy also makes clear the need to reduce cigarette smoking in the diabetic population.

Adult↗

PubMed1976

A 12-month double-blind assessment of betamethasone valerate aerosol in the management of asthma.

A double-blind trial of the topically active corticosteroid, betamethasone valerate in aerosol form, in the control of chronic asthma is reported. The results show that this is an extremely effective therapeutic agent in non-steroid dependent but nonetheless moderately severe asthmatics. Patients were well controlled on 800 mug of betamethasone valerate daily and control was maintained over a 12-month period. This form of treatment has few undersirable side effects but there is probably an increased incidence of oropharyngeal and laryngeal candidiasis. In particular, adrenocortical suppression was not noted.

Adolescent↗