Expression of sterol 27-hydroxylase in glial cells and its regulation by liver X receptor signaling.

Cholesterol is required in the brain for synaptogenesis and its turnover is critical for cerebral functions. Several proteins involved in cholesterol handling and metabolism are transcriptionally regulated by the nuclear liver X receptor (LXR) alpha and beta. Sterol 27-hydroxylase (CYP27) is a ubiquitously expressed enzyme involved in cholesterol metabolism. Notably, its deficiency causes a disease characterized by progressive neurologic impairment. With the final goal to understand the pathophysiological role of CYP27A1 in the CNS, we studied the expression pattern of Cyp27a1 and other related genes in primary cultures of rat glia and neurons. Secondly, given the pivotal role of LXR in the regulation of cholesterol homeostasis, we investigated the effects of its activation on the expression of Cyp27a1.We found that primary astrocytes express different sterol hydroxylases and are able to uptake exogenous 27-hydroxycholesterol. We found that both microglia and astrocytes express preferentially Lxrbeta. However, despite this similarity, we observed cell-specific responsiveness of known and novel (including Cyp27a1) target genes to LXR activation. The increase of mRNA and protein levels in treated astrocytes is paralleled by transactivation of the proximal Cyp27a1 promoter in transfected astrocytes. We suggest that the astrocyte-restricted up-regulation of Cyp27a1 may be ascribable to differential expression of transcriptional co-activators. Given the role of astrocytes in maintaining brain homeostasis, we hypothesize that impairment of CYP27 activity in these cells may alter critical features of the astrocytes, from the handling and delivery of cholesterol to neurons to the release of signaling molecules.

[Biology of root resorption process in deciduous teeth. Review of the literature]. / Biologia dei processi di riassorbimento radicolare dei denti decidui. Revisione della letteratura.

Aim of this paper, is to examine, with a review of the literature the different aspects of physiological process of root resorption of deciduous teeth. The process of development of mouth and teeth and their structure is also described. Studies made during the last period, in most part by Japanese authors, improved our knowledge about the process of root resorption of deciduous teeth, even if many aspects are still unknown. The involvement of the pulp and the periodontal ligament and the presence of enzimatic activity and immunologic cells have been confirmed; all these elements seem to have a definite role in the process of root resorption of the deciduous teeth.

[Neutropenia in glycogenesis I B]. / Neutropenia nella glicogenosi IB.

Type IB Glycogen storage disease (GSD) is a new variant of type I Glycogen storage disease. It is characterized by same clinical findings: hepatomegaly, fasting hypoglycemia, hyperlipidemia, hyperuricemia, lactic acidosis, renal enlargement, short stature; but it distinguish for normal glucose-6-phosphatase hepatic activity in vitro. The involvement is in G-6-P transport system. Recently has been described in some patients with GSD IB, neutropenia and defective neutrophil mobility. In this report the authors described two family cases of GDS IB that one characterized by severe neutropenia.

[Lawrence Moon Biedl Bardet, a polymorphic syndrome]. / Laurence Moon Biedl Bardet, una sindrome polimorfa.

The Laurence Moon Biedl Bardet syndrome is a polymorphous disease whose pathogenesis is still obscure. It is characterize by obesity, oligophrenia, polidactylia, retinitis pigmentosa, hipogonadism, but often there are various others symptoms. AA describe two cases. After a short explanation of de main features of this disease, they dwell upon the study of clinical objective symtomatology and upon instrumental and laboratory parameters regarding hormonal, metabolic and functional order of various organs and apparatuses. Both cases present all classic symptoms of this disease. In the first case we have noticed a deficit in LH and FSH, besides we have also noticed an asymmetry of the lateral ventricles of the brain prevalently on the right and a small increase in 17-KS and 17-OH-KS urinary. On the contrary in the second case we have noticed an EEG of epileptic type.

[Rare case of intestinal malrotation: duodenal-jejunal stenosis caused by ileal hyperrotation (180 degrees) in a newborn (author's transl)]. / Rare cas de malrotation intestinale: sténose duodéno-jéjunale due à une hyperotation iléale (180 degrees) chez un nouveau-né.

The authors present a case of intestinal malrotation characterized by a hyperotation of ileal loops (180 degrees) causing a stenosis of the duodenal-jejunal junction. Some ileal loops were situated, through a defect of the ascendent mesocolon, behind the ascendent colon. The difference between the ileal volvulus and this malformation is: 1. There was no vascular sufference of hyperrotated ileum. 2. The ileal loops were fixed in that hyperrotated position. 3. Some loops were located behind the colon ascendent. 4. After the derotation of ileal loops the stenosis at the duodenal-jejunal level persisted and we proceded to surgery of the stenotic point.