Allelic heterogeneity of glycogen storage disease type Ib in French patients: a study of 11 cases.

Eleven patients with glycogen storage disease type Ib (GSD Ib) were studied. Using a combination of single-strand conformation polymorphism (SSCP) analysis, restriction enzyme digestion and direct sequencing, we were able to identify 21/22 mutant alleles comprising 12 different mutations in the glucose-6-phosphate translocase gene (G6PT). Among these, one is a novel mutation of G6PT: 855T>C (L229P).

[Refinement and role of the diagnosis of Gilbert disease with molecular biology]. / Mise au point et intérêt du diagnostic de la maladie de Gilbert par biologie moléculaire.

Gilbert syndrome (GS), characterized by mild, chronic and isolated unconjugated hyperbilirubinemia is due to a partial deficiency of bilirubin-UDP-glucuronosyltransferase (UGT1A1). Recently, the genetic basis of GS has been identified in caucasian populations : it is related to the insertion of a dinucleotide (TA) in the promoter region of the UGT1A1 gene. In Asian populations, GS is due to missense mutations (either homozygous or heterozygous) in the coding sequence. The aim of this study was to develop a simple and rapid method to detect both genetic polymorphisms and mutations. This technique was performed (1) to explore unrelated unconjugated hyperbilirubinemia; (2) to evaluate the frequency of GS in a population of 97 healthy caucasian volunteers: 17% of them were homozygous for the TA7/TA7 polymorphism; (3) to determine the incidence of this syndrome in a population of 105 neonates with unconjugated hyperbilirubinemia. The incidence of GS (15%) was not significantly higher than it was in the control group. A correlation between GS genotype and neonatal jaundice was not established; (4) to seek a relationship between GS and preeclampsia with or without Hellp syndrome. The incidence in the Hellp syndrome group (n = 19) was 26%, two fold higher than in preeclampsia group (n = 22) and control group (n = 50) with only 14% and 13% respectively, (5) to start a study regarding the toxicity of irinotecan treatment in a population of homozygous children for the UGT1A1 polymorphism.

Genetic heterogeneity of glycogen storage disease type Ia in France: a study of 48 patients.

Forty-eight patients with glycogen storage disease type Ia (GSD Ia) were studied. Using a combination of single-strand conformation polymorphism (SSCP) analysis, restriction enzyme digestion and direct sequencing, we were able to identify 93/96 mutant alleles, comprising 23 different mutations in the glucose-6-phosphatase gene (G6PC). Among these, 7 are novel mutations of G6PC: M5R, T111I, A241T, C270R, F322L, and two deletions, 793delG and 872delC, resulting in the same mutation at the amino acid level, fs300Ter (300X).

Apolipoprotein E polymorphism and serum concentrations in patients with glycogen storage disease type Ia.

In patients with glycogen storage disease type Ia (glucose-6-phosphatase deficiency), serum triglyceride concentrations are markedly raised, whereas phospholipids and cholesterol levels are only moderately elevated. In addition, both VLDL and LDL lipoprotein fractions are raised. Despite these abnormalities, endothelial vascular dysfunction and atherosclerosis seem to be rare in such patients. In view of the crucial role of apolipoprotein E (apoE) in lipid metabolism, we studied both apoE polymorphism (40 patients) and serum concentration (20 patients) in patients with glycogen storage disease type Ia. The distribution of each allele at the apoE locus was similar to that reported in the general population, whereas serum apoE concentrations were raised in our patients. Raised apoE levels in the serum could play an important role in counterbalancing the at-risk-for-atherosclerosis lipid profile of patients with glycogen storage disease type Ia. Moreover, E3 and E4 polymorphisms, predominant in our patients, have a high triglyceride binding capacity and are thus able to increase triglyceride clearance. However, the origin of raised concentrations of apoE is not completely clear though, bearing in mind previous reports regarding serum protein concentrations in such patients, increased hepatic synthesis is likely.

Oxidized-LDL induce apoptosis in HUVEC but not in the endothelial cell line EA.hy 926.

We studied the cytotoxic effect of copper-oxidized LDL in human primary human umbilical vein endothelial cells (HUVEC) and the immortalized EA.hy 926 cell line. Copper oxidized LDL (50-200 microg apoB/ml) induced concentration-dependent apoptotic cell death in HUVEC but did not induce apoptosis in EA.hy 926 cells. Only necrotic EA.hy 926 cells were evidenced at all copper oxidized LDL concentrations (25-200 microg apoB/ml), oxidation states (lightly, moderately and extensively copper-oxidized LDL) and incubation periods (4, 8 and 20 h). The different mechanisms of cell death induced by copper-oxidized LDL in EA.hy 926 cells and HUVEC may be related to various factors such as cytokines. In this study, we investigated whether interleukin-8 may be implicated in this process. The interleukin-8 production was increased in EA.hy 926 cells but not in HUVEC incubated with oxidized LDL. This increase in EA.hy 926 cells was associated with necrosis but not apoptosis. Nevertheless, the addition of interleukin-8 to HUVEC did not inhibit apoptosis induced by oxidized LDL. As the lower antioxidant capacity of EA.hy 926 cells results in higher sensitivity to oxidized LDL cytotoxicity (as we previously described), the redox status of cells may also control the form of endothelial cell death. In atherosclerotic lesions, the formation of apoptotic endothelial cells may result in part from the induction by oxidized LDL.

Jaundice with hypertrophic pyloric stenosis as an early manifestation of Gilbert syndrome.

Jaundice associated with hypertrophic pyloric stenosis was recognised in three patients; previous reports have suggested that this is a possible early manifestation of Gilbert syndrome. Most patients with Gilbert syndrome are homozygous for a (TA)(7)TAA polymorphism in the gene promoter coding for bilirubin glucuronosyltransferase. Two of the reported patients were homozygous for the (TA)(7)TAA polymorphism whereas the third was heterozygous for the same polymorphism. Furthermore, no other factors contributing to jaundice in the three patients were found. These results suggest that jaundice associated with hypertrophic pyloric stenosis is due to molecular defects within the gene promoter.

Identification of three novel mutations (Q54P, W70X and T108I) in the glucose-6-phosphatase gene of patients with glycogen storage disease type Ia. Mutation in brief no. 256. Online.

Three novel mutations, Q54P, W70X and T1081, were identified in the gene encoding glucose-6-phosphatase in three patients with glycogen storage disease type Ia. Two sibs of Portuguese origin were homozygous for the Q54P mutation whereas the third patient, originating from both France and Lebanon, was a compound heterozygote for the W70X and T108I mutations. Glycogen storage disease type Ia is a heterogeneous autosomal recessive condition.

Oxidized low-density lipoprotein induces the production of interleukin-8 by endothelial cells.

The concentration of interleukin-8 (IL-8) and RANTES was measured in culture supernatants of human EA.hy 926 endothelial cells incubated with oxidized low-density lipoproteins (LDL). Oxidized LDL induced a 3-fold increase in IL-8 production (p < 0.01), whereas RANTES was not detected. Native LDL did not stimulate IL-8 production. IL-8 production in oxidized-LDL-treated cells was mediated by reactive oxygen species, as it was partially inhibited by catalase and completely inhibited by glutathione peroxidase and N-acetylcysteine (p < 0.01).

Lung crackles in bronchiectasis.

The inspiratory timing of lung crackles in patients with bronchiectasis was compared with the inspiratory timing of the lung crackles in chronic bronchitis and alveolitis. In severe obstructive chronic bronchitis the lung crackles are typically confined to early inspiration while in alveolitis the lung crackles continue to the end of inspiration but may begin in the early or the mid phase of inspiration. In uncomplicated bronchiectasis on the other hand, the lung crackles typically occur in the early and mid phase of inspiration, are more profuse, and usually fade by the end of inspiration. In addition in bronchiectasis, crackles are also usually present in expiration, they are gravity independent and become less profuse after coughing.

Respiratory function changes after asbestos pleurisy.

Six patients with radiographic evidence of diffuse pleural thickening after industrial asbestos exposure are described. Five had computed tomography of the thorax. All the scans showed marked circumferential pleural thickening often with calcification, and four showed no significant evidence of intrapulmonary fibrosis (asbestosis). Lung function testing showed reduction of the inspiratory capacity and the single-breath carbon monoxide transfer factor (TLCO). The transfer coefficient, calculated as the TLCO divided by the alveolar volume determined by helium dilution during the measurement of TLCO, was increased. Pseudo-static compliance curves showed markedly more negative intrapleural pressures at all lung volumes than found in normal people. These results suggest that the circumferential pleural thickening was preventing normal lung expansion despite abnormally great distending pressures. The pattern of lung function tests is sufficiently distinctive for it to be recognised in clinical practice, and suggests that the lungs are held rigidly within an abnormal pleura. The pleural thickening in our patients may have been related to the condition described as "benign asbestos pleurisy" rather than the interstitial fibrosis of asbestosis.