Microglia are more susceptible than macrophages to apoptosis in the central nervous system in experimental autoimmune encephalomyelitis through a mechanism not involving Fas (CD95)

Morphological studies have shown that macrophages and microglia undergo apoptosis in the central nervous system (CNS) in acute experimental autoimmune encephalomyelitis (EAE) in the Lewis rat. To assess the relative levels of macrophage and microglial apoptosis, and the molecular mechanisms involved in this process, we used three-colour flow cytometry to identify CD45lowCD11b/c+ microglial cells and CD45highCD11b/c+ macrophages in the inflammatory cells isolated from the spinal cords of Lewis rats 13 days after immunization with myelin basic protein (MBP) and complete Freund's adjuvant. Simultaneously, we analyzed the DNA content of these cell populations to assess the proportions of cells undergoing apoptosis and in different stages of the cell cycle or examined their expression of three apoptosis- regulating proteins, i.e. Fas (CD95), Fas ligand (FasL) and Bcl-2. Microglia were highly vulnerable to apoptosis and were over-represented in the apoptotic population. Macrophages were less susceptible to apoptosis than microglia and underwent mitosis more frequently than microglia. The different susceptibilities of microglia and macrophages to apoptosis did not appear to be due to variations in Fas, FasL or Bcl- 2 expression, as the proportions of microglia and macrophages expressing these proteins were similar, and were relatively high. Furthermore, in contrast to T cell apoptosis, apoptosis of microglia/macrophages did not occur more frequently in cells expressing Fas or FasL, or less frequently in cells expressing Bcl-2. These results indicate that the apoptosis of microglia and CNS macrophages in EAE is not mediated through the Fas pathway, and that Bcl-2 expression does not protect them from apoptosis. Expression of FasL by macrophages and microglia may contribute to the pathogenesis and immunoregulation of EAE through interactions with Fas+ oligodendrocytes and Fas+ T cells. The high level of microglial apoptosis in EAE indicates that microglial apoptosis may be an important homeostatic mechanism for controlling the number of microglia in the CNS following microglial activation and proliferation.      

Catch-up growth up to ten years of age in children born very preterm or with very low birth weight

Background  

Improved survival due to advances in neonatal care has brought issues such as postnatal growth and development more to the focus of our attention. Most studies report stunting in children born very preterm and/or small for gestational age. In this article we study the growth pattern of these children and aim to identify factors associated with postnatal catch-up growth.     

The experimental reconstruction of articular cartilage using autogenous periosteal and perichondreal implants

Injured cartilage has a limited capacity to heal itself. Untreated damage leads to secondary osteoarthritis. There is a need to find a way to reconstruct cartilage in order to prevent secondary osteoarthritis. The aim this study was to evaluate and compare the chondrogenic potential of three different cell materials: perichonrdrial grafts, periosteal grafts and bone marrow in situ. The mesenchemal cells contained in these materials can differentiate in the joint environment into chondrocytes and rebuild articular cartilage.
Forty nine (49) White New Zealand rabbits were used in our experiment. An osteochondrial (full-thickness) defect was created in the joint surface of both ends of the femoral bone. The animals were divided according to the procedure used:
I - cartilage reconstruction by periosteal grat,
II - cartilage reconstruction by perichondrial graft,
III - no graft.
The joint was not immobilized after surgery. Follow-up exams were performed at 4, 8, and 12 weeks. The results were evaluated macroscopically and microscopically.
The results pointed to the chondrogenic potential of periosteum and perichondrium after grafting to cartilage defects. On gross examination the articular surface was found to be reconstructed. Microscopic examination revealed regeneration, with the formation of hyaline-like cartilage. Regenerating tissue was also found in the group without grafts. The structure resembled normal articular cartilage; however, neither the joint surface nor the subchondrial bone were fully reconstructed. No qualitative or quantitative differences were found between the groups treated with periosteal and perichondral grafts.
Our study confirmed that grafts of periosteum or perichondrium have chondrogenic potential, i.e. the ability to generate cartilage tissue whose features are similar to those of the hyaline chondrial tissue in the joint. Both materials have similar chondrogenic potential. The chondrogenic properties of perichondrium and perisostem produce better results in the various categories in comparison to those of bone marrow.     

Topical corticosteroids of limited potency promote adenovirus replication in the Ad5/NZW rabbit ocular model

PURPOSE: To determine the effect of topical therapy with several corticosteroids with limited potency on viral clearance in the adenovirus type 5 (Ad5) rabbit ocular model. METHODS: Sixty rabbits were inoculated in both eyes with Ad5. On the first day, the rabbits were equally divided into four topical treatment groups: 0.12% prednisolone acetate (PA), 0.1% fluorometholone (FM), 1% rimexolone (RMX), and control. Treatment was administered four times daily, in both eyes, for 3 days. All eyes were cultured for virus on days 0, 1, 3, 4, 5, 7, 9, 11, 14, 16, 18, and 21. RESULTS: Compared with the control group, treatment with PA, FM, and RMX significantly increased the number of Ad5 positive eye cultures from days 7-21. Fluorometholone and RMX prolonged the duration of Ad5 shedding, and FM increased the mean combined Ad5 titer from days 1-5 and 7-21. CONCLUSIONS: Treatment of an experimental ocular adenovirus infection with PA, FM, and RMX for 3 days significantly enhanced adenovirus replication compared with the control group. Short-term treatment of EKC with several commercially available topical corticosteroids with limited potency may offer symptomatic relief, but may also delay viral clearance and promote office and community epidemics.     

Pericardial effusion complicating a percutaneous central venous line in a neonate

A premature infant developed pericardial effusion four days after the insertion of a 25-gauge silastic percutaneous central venous catheter. The effusion contained parenteral nutrition fluid and resolved rapidly after withdrawal of the catheter. Pericardial effusion is a potential complication of percutaneous, as well as surgically placed, central venous catheters.     

Epogam evening primrose oil treatment in atopic dermatitis and asthma

Essential fatty acids are claimed to have positive effects in atopic diseases. In a double blind, placebo controlled, parallel group study 58 out of 60 children, with atopic dermatitis and the need for regular treatment with topical skin steroids, completed a 16 weeks' treatment period with either Epogam evening primrose oil or placebo capsules. Twenty two of these subjects also had asthma. The parents used diaries to record symptom scores and concomitant medication. Peak expiratory flow was measured and disease activity was monitored by the clinician every four weeks. The plasma concentrations of essential fatty acids increased significantly in the group treated with Epogam capsules. The study demonstrated significant improvements of the eczema symptoms but no significant difference was found between the placebo and the Epogam groups. No therapeutic effect was shown on asthma symptoms or fidget.     

The STR system in the human phenylalanine hydroxylase gene: true fragment length obtained with fluorescent labelled PCR primers

We present a simple, fast, non-radioactive method for the analysis of the polymorphic short tandem repeat (STR) system in the human phenylalanine hydroxylase gene. Previously, sizing of the STR marker involved radiolabelling of PCR amplified fragments and resolution on denaturing polyacrylamide gels using M13 sequencing ladder as a standard. However, this method consistently gave sizes 2 bp longer than the known sequence. The fluorescent method presented here employs internal lane standards and enables accurate sizing of the fragments. To avoid confusion, we suggest that the true fragment lengths are used as reference values in the future. The analysis of STR alleles is valuable for population genetic studies and for targeted mutation screening in phenylketonuria (PKU). It can replace RFLP-based haplotype analysis for carrier detection, and we report its use for prenatal diagnosis in a Northern Irish family with PKU. The analysis of 250 Northern Irish chromosomes, including 128 PKU alleles, showed no significant difference between normal and PKU alleles, with fragment lengths of 238 and 242 bp most common in both groups.