Retinal organization in the retinal degeneration 10 (rd10) mutant mouse: a morphological and ERG study

Retinal degeneration 10 (rd10) mice are a model of autosomal recessive retinitis pigmentosa (RP), identified by Chang et al. in 2002 (Vision Res. 42:517-525). These mice carry a spontaneous mutation of the rod-phosphodiesterase (PDE) gene, leading to a rod degeneration that starts around P18. Later, cones are also lost. Because photoreceptor degeneration does not overlap with retinal development, and light responses can be recorded for about a month after birth, rd10 mice mimic typical human RP more closely than the well-known rd1 mutants. The aim of this study is to provide a comprehensive analysis of the morphology and function of the rd10 mouse retina during the period of maximum photoreceptor degeneration, thus contributing useful data for exploiting this novel model to study RP. We analyzed the morphology and survival of retinal cells in rd10 mice of various ages with quantitative immunocytochemistry and confocal microscopy; we also studied retinal function with the electroretinogram (ERG), recorded between P18 and P30. We found that photoreceptor death (peaking around P25) is accompanied and followed by dendritic retraction in bipolar and horizontal cells, which eventually undergo secondary degeneration. ERG reveals alterations in the physiology of the inner retina as early as P18 (before any obvious morphological change of inner neurons) and yet consistently with a reduced band amplification by bipolar cells. Thus, changes in the rd10 retina are very similar to what was previously found in rd1 mutants. However, an overall slower decay of retinal structure and function predicts that rd10 mice might become excellent models for rescue approaches.     

A new CYP21A1P/CYP21A2 chimeric gene identified in an Italian woman suffering from classical congenital adrenal hyperplasia form

Background  

More than 90% of Congenital Adrenal Hyperplasia (CAH) cases are associated with mutations in the 21-hydroxylase gene (CYP21A2) in the HLA class III area on the short arm of chromosome 6p21.3. In this region, a 30 kb deletion produces a non functional chimeric gene with its 5' and 3' ends corresponding to CYP21A1P pseudogene and CYP21A2, respectively. To date, five different CYP21A1P/CYP21A2 chimeric genes have been found and characterized in recent studies. In this paper, we describe a new CYP21A1P/CYP21A2 chimera (CH-6) found in an Italian CAH patient.     

Micro-CT studies on 3-D bioactive glass–ceramic scaffolds for bone regeneration

The aim of this study was the preparation and characterization of bioactive glass–ceramic scaffolds for bone tissue engineering. For this purpose, a glass belonging to the system SiO₂–P₂O₅–CaO–MgO–Na₂O–K₂O (CEL2) was used. The sponge-replication method was adopted to prepare the scaffolds; specifically, a polymeric skeleton was impregnated with a slurry containing CEL2 powder, polyvinyl alcohol (PVA) as a binding agent and distilled water. The impregnated sponge was then thermally treated to remove the polymeric phase and to sinter the inorganic one. The obtained scaffolds possessed an open and interconnected porosity, analogous to cancellous bone texture, and with a mechanical strength above 2 MPa. Moreover, the scaffolds underwent partial bioresorption due to ion-leaching phenomena. This feature was investigated by X-ray computed microcomputed tomography (micro-CT). Micro-CT is a three-dimensional (3-D) radiographic imaging technique, able to achieve a spatial resolution close to 1 μm³. The use of synchrotron radiation allows the selected photon energy to be tuned to optimize the contrast among the different phases in the investigated samples. The 3-D scaffolds were soaked in a simulated body fluid (SBF) to study the formation of hydroxyapatite microcrystals on the scaffold struts and on the internal pore walls. The 3-D scaffolds were also soaked in a buffer solution (Tris–HCl) for different times to assess the scaffold bioresorption according to the ISO standard. A gradual resorption of the pores walls was observed during the soakings both in SBF and in Tris–HCl.     

Neurosteroids and epileptogenesis in the pilocarpine model: Evidence for a relationship between P450scc induction and length of the latent period

Purpose:   Cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc) catalyzes the initial step in the biosynthesis of neurosteroids within the brain. We sought to determine which cells express P450cc and whether neurosteroids play a role in the regulation of epileptogenesis following pilocarpine-induced status epilepticus (SE).
Methods:   Rats experienced uninterrupted SE or SE terminated with diazepam at 60, 120, and 180 min. P450scc induction in CA3 hippocampus was determined by double immunolabeling with P450scc antiserum and monoclonal antibodies against GFAP (astrocytes), RIP (oligodendrocytes), or heme oxygenase-1 (microglia).
Results:   SE was associated with P450scc induction in many astrocytes and a small number of microglia and oligodendrocytes in the hippocampal CA3 strata radiatum and lacunosum-moleculare. The extent of P450scc induction increased with increasing SE duration. Paradoxically, increased P450scc induction in rats experiencing SE for 180 min or more was associated with the delayed onset of spontaneous recurrent seizures. Treatment with the 5α-reductase inhibitor finasteride (100 mg/kg/day for 25 days), which inhibits the synthesis of γ-aminobutyric acid (GABA)_A receptor modulating neurosteroids such as allopregnanolone, was associated with a significant reduction in time to the onset of spontaneous seizures in rats exposed to 180-min but not 90-min SE.
Discussion:   P450scc is induced by SE in a diverse population of hippocampal glia. Induction of P450scc is associated with the delayed onset of spontaneous seizures. Conversely, inhibition of neurosteroid synthesis accelerated the onset of spontaneous seizures, but only in animals exhibiting significant increases in P450scc. These findings suggest that induction of neurosteroid synthesis in reactive glial cells is associated with delayed onset of spontaneously recurrent seizures.     

DCEP chemotherapy followed by a single, fixed dose of pegylated filgrastim allows adequate stem cell mobilization in multiple myeloma patients

BACKGROUND: Pegylated filgrastim (PEG-f), a long-lasting granulocyte-colony-stimulating factor, has been used in different hematologic conditions to shorten chemotherapy-induced neutropenia and to mobilize peripheral blood stem cells. Data on mobilization efficacy in patients with multiple myeloma are, however, still limited. STUDY DESIGN AND METHODS: The feasibility and mobilizing capacity of DCEP chemotherapy followed by a single subcutaneous dose of 6 mg of PEG-f in 23 myeloma patients (11 females and 12 males) whose median age was 55 years (range, 31-67 years) were investigated. RESULTS: The median number of CD34+ cells collected was 5.72 x 10(6) per kg body weight with a range between 0 x 10(6) and 29.4 x 10(6) per kg body weight. Twenty patients (87%) yielded more than 2 x 10(6) per kg body weight CD34+ cells. Among the 22 patients who mobilized some CD34+ cells, 27 leukapheresis procedures were carried out (a single leukapheresis procedure in 17 patients and 2 leukapheresis procedures in 5). The median interval between the start of chemotherapy and the first leukapheresis procedure was 12 days (range, 11-16 days). With regard to tolerability, 7 patients complained of mild to moderate back pain, controlled with oral analgesics. No patient was hospitalized, and no fever or infections occurred. CONCLUSION: These results, compared with those previously reported for the DCEP-filgrastim combination, suggest that DCEP chemotherapy followed by PEG-f is a promising combination to mobilize peripheral blood stem cells in myeloma patients.     

Family function in cognitively normal children with epilepsy: impact on competence and problem behaviors

A cross-sectional cohort of 82 cognitively normal children with epilepsy attending the pediatric neurology clinic, who were aged 6-17 years and who had a similarly aged sibling without seizures or cognitive delay, were identified. The parent was asked to complete the Family Assessment Measure III (FAM-III) as well as the Child Behavior Checklist (CBCL) for both the child with epilepsy and his or her sibling. The Overall Rating Score on FAM-III did not differ significantly from the normative mean, although families scored significantly better on the Involvement subscale and significantly worse on the Role Performance subscale. Moderate correlations were found between competence and behavior problems and family function in both children with epilepsy and their siblings. In families functioning at the highest level, both cohorts did well. In those at the lowest level, approximately half of the children in either cohort had problems. For average functioning families, behavior and competence issues were more frequent in children with epilepsy than their siblings.