Serum lipids and lipoproteins in type 2 diabetic patients with persistent microalbuminuria.

To investigate whether persistent microalbuminuria is related to altered levels of both lipids and apolipoproteins in Type 2 diabetes mellitus serum total-cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, apolipoprotein A-I, and apolipoprotein B were measured by standard methods in a group of Type 2 diabetic patients affected by persistent microalbuminuria (albumin excretion rate (AER) 20-200 micrograms min-1) as compared with a group of sex- and age-matched non-microalbuminuric patients (AER less than 20 micrograms min-1). The groups were stratified according to a short (less than or equal to 5 years) or a longer (greater than 5 years) duration of diagnosed diabetes. Microalbuminuria was not associated with significant changes of serum total-cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, and apolipoproteins in the group of patients with a duration of disease greater than 5 years, while microalbuminuric patients less than or equal to 5 years from diagnosis (n = 11) had serum total-cholesterol, triglycerides, LDL-cholesterol, and apoprotein B higher than non-microalbuminuric control patients (n = 26) (cholesterol 6.2 +/- 0.9 vs 5.1 +/- 1.0 mmol l-1 (p = 0.003); triglycerides 2.1 +/- 0.7 vs 1.7 +/- 1.3 mmol l-1 (p = 0.03); LDL-cholesterol 4.1 +/- 0.8 vs 3.0 +/- 0.7 mmol l-1 (p less than 0.001); apo-B 1.3 +/- 0.3 vs 1.1 +/- 0.3 g l-1 (p = 0.02). In these patients with shorter duration of diabetes many of the serum lipid measures correlated positively with AER.

Serum spermidine oxidase activity in patients with insulin-dependent diabetes mellitus and microvascular complications.

Metabolism of polyamines (spermidine and spermine) is known to be strictly related to the growth processes of eukaryotic cells. Since cell replication processes appear altered in insulin-dependent diabetes mellitus (IDDM), especially when associated with its microvascular complications, the aim of this study was measuring serum spermidine oxidase activity (SOA), a key enzyme in the metabolic pathway of polyamines, in 47 patients with IDDM as compared with 63 healthy control subjects matched for age and sex. Mean SOA levels +/- SD were significantly lower in IDDM patients (177.4 +/- 57.2 mu kat/l) than in controls (247.6 +/- 68.1 mu kat/l; p less than 0.001), being SOA inversely related with daily insulin dose. SOA was moreover significantly higher (but similar to controls) in the group with increased urinary albumin excretion rate (AER persistently greater than 20 micrograms/min); (n = 17; 213.1 +/- 62.6 mu kat/l) in comparison with normoalbuminuric subjects (n = 30; 156.6 +/- 43.5 mu kat/l; F = 21.78; p = 0.0001). SOA was correlated with AER (r = 0.45; p = 0.001), independently of age, duration of disease, serum creatinine, body weight, blood pressure and metabolic control, as shown by a multiple regression analysis model (p = 0.003). Presence of background retinopathy was not associated with modified levels of SOA, which was conversely higher, although not significantly, in the patients with proliferative retinal lesions. In conclusion serum SOA is deeply altered in IDDM patients, being markedly reduced in the whole group of patients and conversely independently increased up to the mean values of controls in presence of increased AER or advanced retinopathy.

Simultaneous liquid-chromatographic determination of urinary vanillylmandelic acid, homovanillic acid, and 5-hydroxyindoleacetic acid.

We describe a liquid-chromatographic method for quantifying, simultaneously by a single procedure, vanillylmandelic acid (VMA), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) in urine. After solvent extraction of acidified urine, the analytes were chromatographed on a C8 column, with use of a mobile phase of phosphate buffer (20 mmol/L, pH 4.0) and methanol with a variable gradient elution, and detected fluorometrically. We report the analytical recovery, sensitivity, precision, working linear range, and potential for interference from similar molecules or drugs. The results of such tests demonstrate that the proposed method is sensitive and reproducible. It is, furthermore, easy to perform, and thus is suitable for use in the clinical laboratory.

[Determination of plasma fibronectin (Fn) levels. Comparison between normal subjects and patients with various pathological conditions]. / Determinazione dei livelli di fibronettina (Fn) plasmatica. Confronto tra soggetti normali e pazienti con vari tipi di patologia.

Fibronectin is a glycoprotein secreted by connective tissue cells into their environment and into the blood. Plasma fibronectin in circulation exhibits some important interactions with other proteins in several diseases. We have detected plasma fibronectin levels in 187 normal subjects and in 126 patients. The mean value of this glycoprotein was strongly influenced by age but not by sex. 99 cancer patients showed lightly lower fibronectin levels than in normal controls. On the contrary, 25 chronic hepatic failure patients had higher values than normal controls. The mean level of plasma fibronectin in 20 hemodialyzed patients and in 7 plasmocytoma patients did not offer from what we detected in normal controls.