P38 mitogen-activated protein kinase mediates hexosamine-induced TGFbeta1 mRNA expression in human mesangial cells.

AIMS/HYPOTHESIS: The hexosamine pathway has been implicated in the induction of TGFbeta1 expression and in the pathophysiology of diabetic glomerulopathy. Glucose-induced TGFbeta1 expression is mediated by p38 mitogen-activated-protein-kinase (p38-MAPK) and this kinase is activated in the diabetic glomeruli. We examined whether the p38-MAPK is implicated in hexosamine-induced TGFbeta1 mRNA expression in human mesangial cells. GFAT overexpression induced an increase in p38-MAPK activation after 6 and 12 h incubation in normal glucose, and this was prevented by the GFAT inhibitor azaserine. Furthermore, high glucose enhanced p38-MAPK activation in GFAT tranfected cells ( p

Effect of nutrient ingestion on glucagon-like peptide 1 (7-36 amide) secretion in human type 1 and type 2 diabetes.

Exogenous glucagon-like peptide 1(GLP-1) bioactivity is preserved in type 2 diabetic patients, resulting the peptide administration in a near-normalization of plasma glucose mainly through its insulinotropic effect. GLP-1 also reduces meal-related insulin requirement in type 1 diabetic patients, suggesting an impairment of the entero-insular axis in both diabetic conditions. To investigate this metabolic dysfunction, we evaluated endogenous GLP-1 concentrations, both at fasting and in response to nutrient ingestion, in 16 type 1 diabetic patients (age = 40.5 +/- 14yr, HbA1C = 7.8 +/- 1.5%), 14 type 2 diabetics (age = 56.5 +/- 13yr, HbA1C = 8.1 +/- 1.8%), and 10 matched controls. In postabsorptive state, a mixed breakfast (230 KCal) was administered to all subjects and blood samples were collected for plasma glucose, insulin, C-peptide and GLP-1 determination during the following 3 hours. In normal subjects, the test meal induced a significant increase of GLP-1 (30', 60': p < 0.01), returning the peptide values towards basal concentrations. In type 2 diabetic patients, fasting plasma GLP-1 was similar to controls (102.1 +/- 1.9 vs. 97.3 +/- 4.01 pg/ml), but nutrient ingestion failed to increase plasma peptide levels, which even decreased during the test (p < 0.01). Similarly, no increase in postprandial GLP-1 occurred in type 1 diabetics, in spite of maintained basal peptide secretion (106.5 +/- 1.5 pg/ml). With respect to controls, the test meal induced in both diabetic groups a significant increase in plasma glucagon levels at 60' (p < 0.01). In conclusion, either in condition of insulin resistance or insulin deficiency chronic hyperglycemia, which is a common feature of both metabolic disorders, could induce a progressive desensitization of intestinal L-cells with consequent peptide failure response to specific stimulation.

Detection of a new variant of the mitochondrial glycerol-3-phosphate dehydrogenase gene in Spanish type 2 DM patients.

To evaluate if potential defects in the FAD-binding domain of the mitochondrial glycerol-3-phosphate dehydrogenase (mGPDH) gene could contribute to susceptibility to type 2 diabetes mellitus, we have screened 151 type 2 DM patients for mutations using PCR single-strand conformational polymorphism. Both a single substitution (T to A) at position 18 and a 6-base-pair deletion (TTTTAA) at position 26 of intron 3 have been detected in five type 2 DM patients and in one control subject. The evolution time of diabetes was longer in patients with these mutations than in patients without (24.2 +/- 11.1 vs 12.6 +/- 8.7 years, p < 0.02). These mutations generate a cryptic site that may have functional significance in the correct mechanism of the FAD-binding domain. In the process of PCR amplification of the mGPDH gene we also unexpectedly amplified the mGPDH retropseudogene. Subsequently, we decided to further characterize and completely sequence 2213 bp of this mGPDH retropseudogene. Our results suggest that two previously reported mGPDH pseudogene partial sequences may be identical copies of the mGPDH gene inserted in two different genomic locations and provide information about the alternative 5'- and 3'-untranslated regions. The data obtained are also important in order to avoid artifactual amplification of the mGPDH pseudogene in the process of screening for mGPDH mutations in diabetic patients.

[Severe diabetic retinopathy and renal function in non-insulin-dependent (type-2) diabetes mellitus]. / Retinopatia diabetica ingravescente e funzionalità renale nel diabete mellito non insulino-dipendente (tipo 2).

The existence of a linkage between retinal and renal microvascular complications in type 2 diabetes has been so far little investigated. For this purpose we evaluated the presence and degree of renal dysfunction in the most serious clinical conditions of diabetic retinopathy. On the basis of the alterations evidenced by fluorescein angiography 73 type 2 diabetic patients were recruited and divided into the following groups: 19 patients were affected by "clinically significant" Macular Edema (ME), 25 subjects had Preproliferative Retinopathy (PrePR) and 29 patients showed Proliferative Retinopathy (PR). Mean values (M +/- SD) of glycosylated hemoglobin, plasma basal C-peptide, lipid profile, blood pressure, glomerular filtration rate, body mass index, age and known duration of diabetes were similar between the groups. Urinary albumin excretion rate (UAE) was determined for each patient on three consecutive overnight collections (pg/min). Even though the distribution of normo (UAE < 20 micrograms/min), micro (UAE:20-200) and macroalbuminuric (UAE > 200) patients did not significantly differ between the groups, mean values of UAE increased significantly in PrePR (371.1 +/- 532.2) and PR (300.7 +/- 717.3) with respect to ME (35.4 +/- 73.1; p < 0.05). The evaluation of all patients recruited for the study, independently of the kind of retinal alteration, showed that 56.8% of them had no sign of even incipient renal dysfunction, in spite of the advanced retinal damage. When considering those patients affected by both retinal and renal complications (43.2%) the prevalence of renal involvement resulted different in the three conditions investigated.(ABSTRACT TRUNCATED AT 250 WORDS)

A case of facial hemiatrophy associated with linear scleroderma and homolateral masseter spasm.

The rare combination of progressive facial hemiatrophy, linear scleroderma and spasm of the homolateral masseter muscle was observed in a 39 year old woman. The possible pathogenetic meaning of the association is discussed on the electrophysiological evidence and in the light of published cases.

[3 cases of essential blepharospasm: pathogenetic problems correlated]. / Tre casi di blefarospasmo essenziale: problemi patogenetici correlati.

Three clinical cases of essential blepharospasm are discussed. On the basis of both therapeutical results and a review of the literature, pathogenetic hypothesis concerning such pathology are reexamined.

[Bell's palsy. Longitudinal study of 120 cases]. / Paralisi di Bell. Studio longitudinale su 120 casi.

The Authors have studied 120 cases of Bell's palsy, who underwent regular controls along 360 days from the beginning of the disease. The study has been carried out by means of two different parameters of evaluation, a clinical and electrophysiological one, which allowed us to obtain very interesting results, especially as regards the prognostic aspect.