[Long-term use of silicone oil: indications and tolerance]. / Tamponnement prolongé par huile de silicone: indications et tolérance.

PURPOSE: The aim of this study was to analyze the indications and the effect of permanently maintaining silicone oil in the treatment of certain cases of vitreoretinal pathology. PATIENTS AND METHODS: Twenty-seven cases seen from January 2002 to December 2008 were retrospectively studied. Silicone oil was kept in the eyes for more than 2years. The surgical file was analyzed in all cases. The evaluation criteria were ocular pressure, emulsification, cataract, corneal dystrophy, and the functional response of the retina and optic nerve. Ultrasound echography (12 MHz), magnetic resonance imaging, and electrophysiological explorations (visual evoked potential and electroretinography) were performed. RESULTS: Twenty-seven eyes of 27 patients were included in this study. The main reasons for maintaining long-term silicone oil are recurrent vitreous hemorrhage, retinal detachment with severe proliferative vitreoretinopathy, and penetrating injury. The patients were distributed into two groups: group 1 included patients with both functional and anatomic failure, group 2 patients had achieved ambulatory vision. Follow-up ranged from 27 to 72months. Cataract incidence was approximately 91% in group 2. Emulsification was noted without high pressure in 50% of the cases in group 1. High pressure averaged 31.8% in group 2. Keratopathy was observed in 9% of the cases in group 2. Intraorbital migration of silicone oil was found in one case. The visual field was improved in 77% of the cases in group 2. CONCLUSION: This study provided interesting insights into certain clinical situations in which silicone oil has to be maintained permanently. The complications stem not only from the presence of silicone oil, but also from the preoperative status of the eye and the vitreoretinal surgery.

Immunology in the clinic review series; focus on type 1 diabetes and viruses: enterovirus, thymus and type 1 diabetes pathogenesis.

Thymus dysfunction, especially immune suppression, is frequently associated with various virus infections. Whether viruses may disturb the thymus function and play a role in the pathogenesis of autoimmune diseases is an open issue. Enteroviruses, especially Coxsackievirus B4 (CV-B4), have been largely suggested as potential inducers or aggravating factors of type 1 diabetes (T1D) pathogenesis in genetically predisposed individuals. Several pathogenic mechanisms of enterovirus-induced T1D have been suggested. One of these mechanisms is the impairment of central self-tolerance due to viral infections. Coxsackievirus-B4 is able to infect murine thymus in vitro and in vivo and to infect human thymus in vitro. Thymic epithelial cells and thymocytes are targets of infection with this virus, and several abnormalities, especially disturbance of maturation/differentiation processes, were observed. Altogether, these data suggest that CV-B infection of thymus may be involved in the pathogenesis of T1D. Further investigations are needed to explore this hypothesis.

Coxsackievirus B4 and type 1 diabetes pathogenesis: contribution of animal models.

The role of enteroviruses, in particular type B coxsackieviruses (CV-B), in type 1 diabetes (T1D) pathogenesis is supported by epidemiological, clinical and experimental observations.The investigation of T1D pathogenesis benefits from the contribution of animal models called spontaneously diabetic. Among these animals the non-obese diabetic (NOD) mouse and the bio-breeding diabetes-prone (BBDP) rat present a genetic susceptibility manifested by the expression of an autoimmune diabetes similar to the pathology observed in human beings. Other models whose genetic predisposition is less known are of considerable contribution as well. Numerous major observations relative to several aspects of T1D pathogenesis in the context of CV-B infections, such as susceptibility, diabetogenicity, pancreatotropism, mechanisms of beta cells destruction and others, have been deduced thanks to investigations with animal models. Despite their limits, these models are necessary in improving our knowledge of the role of enteroviruses, like CV-B4, in the pathogenesis of T1D, and the recent advances ensuing from their contribution may have important therapeutic and preventive spin-offs.

[Relationship between enteroviruses and diabetes]. / Vers une meilleure compréhension de la relation entre entérovirus et diabète de type 1.

Environmental factors, especially viruses, are involved in the initiation or the acceleration of type 1 diabetes (T1D) pathogenesis. Epidemiological data strongly suggest that enteroviruses, like coxsackievirus B4 (CV-B4), can be associated with T1D. It has been demonstrated that enterovirus infections were significantly more prevalent in at risk individuals, such as siblings of diabetic patients, when they developed anti-b cells autoantibodies or T1D, and in recently diagnosed diabetic patients, compared with control subjects. The isolation of CV-B4 from the pancreas of diabetic patients strengthened the hypothesis of a relationship between the virus and the disease. Studies performed in vitro and in vivo in animal models helped in discovering mechanisms of the infection of pancreas and other tissues, able to play a role in the pathogenesis of T1D. Interestingly, it cannot be excluded that enteroviruses behave as half-devil half-angel since experimental studies suggest that, in certain conditions, these agents would be able to protect individuals against the disease.

[Neuromeningeal enterovirus infections in Tunisia: epidemiology, clinical presentation, and outcome of 26 pediatric cases]. / Entéroviroses neuroméningées en Tunisie: profil épidémiologique, clinique et évolutif. A propos de 26 cas pédiatriques.

UNLABELLED: Non-polio enteroviruses are the most common identified cause of viral neuromeningeal infections following the introduction of the mumps and polio vaccines. OBJECTIVE: The aim of this study was to describe the epidemiology, clinical presentation, and the outcome of enteroviral infections of the CNS. METHOD AND PATIENTS: We performed a prospective study on 41 children admitted for viral neuromeningeal infections in the pediatric department of Monastir between December 2001 and November 2002. Enteroviruses were detected from cerebrospinal fluid by RT-PCR. RESULTS: This study showed that enteroviruses were responsible for 63.4% of the infections. The mean age of patients was 6.1 years. Aseptic meningitis was diagnosed in 14 cases and encephalitis in 10. The most frequent symptom was fever (61.5%), followed by seizures (42.3%), and confusion (23%). On follow-up, all patients with meningitis had recovered without sequels. Neurological complications in patients with encephalitis were epilepsy (3 cases), cerebral palsy (2 cases), and mental retardation (1 case). CONCLUSION: This study confirmed that enteroviruses were the most common cause of viral infections of the CNS. Common use of RT-PCR can have a significant impact on the outcome of patients with enterovirus infections.

Variations in the recognition of echovirus type 11 strains by a group-specific anti-VP1 monoclonal antibody.

BACKGROUND: Mab 5-D8/1 is a monoclonal antibody (Mab) that was shown to be directed towards a conserved epitope of the capsid protein VP1 among the genus enterovirus. The use of this Mab for the routine detection of enteroviruses in clinical specimens led to the observation that several strains of echovirus type 11 (EV-11) could not be detected on spontaneously detached cells from 26-h cultures using a two-step immunofluorescence (IF) assay. Conversely, these strains were detected positive with the same Mab when tested on adherent or trypsinizated cells. OBJECTIVES: The aim of this study was to understand the misrecognition of some strains of EV-11 by this Mab. STUDY DESIGN AND RESULTS: IF tests at different times of the viral cycle brought evidence that the detection of a variant strain of EV-11 decreased rapidly with time, becoming undetectable 26 h post-infection, since the reference strain remained positive up to 46 h post-infection. The infective titres of the variant strains were shown to be high in comparison with those of well-recognised strains. Sequencing the Mab binding epitope confirmed that the variant strains exhibited no antigenic shift. CONCLUSION: These results suggest that the poor recognition of some strains of EV-11 by Mab 5-D8/1 is due to a rapid decrease of the expression of the binding epitope in the cell, maybe in relation with the high lytic power of these strains. From a practical point of view, our data indicate that a negative result when Mab 5-D8/1 is used for enterovirus typing must be interpreted cautiously with highly replicative strains and that detached cells should not be used for enterovirus identification under these circumstances.

Comparison of a rapid culture method combining an immunoperoxidase test and a group specific anti-VP1 monoclonal antibody with conventional virus isolation techniques for routine detection of enteroviruses in stools.

In order to shorten the time required for the detection of enteroviruses in stool specimens, an 18-h immunoperoxidase test combining low-speed centrifugation and the use of a group specific anti-VP1 monoclonal antibody (5-D8/1, Dako) was developed. This rapid culture assay (RCA) was compared blindly to a conventional culture assay (CCA) on a panel of 180 children's stool specimens received for routine diagnosis of enterovirus infection. The same cell lines (human embryonic fibroblasts and KB continuous cell line) were used in both tests. Discrepancies in results were analysed by a PCR technique with primers located in a conserved part of the 5' non-coding region of the enterovirus genome. Fourteen specimens were positive and 158 were negative with both tests. Four samples were positive with the RCA yet negative with the CCA and 3 others showed the opposite pattern; an additional sample positive by RCA was uninterpretable by CCA due to bacterial contamination. Subsequent PCR testing of these 8 samples showed no discrepancies; all were positive. Using CCA as the reference, the sensitivity and specificity of RCA were 77.8 and 98% respectively. Kinetic studies using enterovirus isolates demonstrated that RCA was much more sensitive than CCA during the first three days of culture. These results further suggested that RCA sensitivity could be improved by a factor of at least 10 times by prolonging the incubation period by 24 hr. With this change, the RCA assay described below is suggested as a rapid alternative to CCA for the routine diagnosis of enterovirus infection in stool specimens. When an identification at the serotype level is required, samples found positive using RCA could then be subjected to CCA.

New Ecdysteroids from Serratula tinctoria.

Six new ecdysteroids have been isolated from SERRATULA TINCTORIA; these are: the 2,22- and 3,22-diacetates of 20-hydroxyecdysone, 5beta-hydroxyrubrosterone, 3-epi-poststerone, 3-epi-rubrosterone, and 22-oxo-20-hydroxyecdysone. These minor compounds were found together with the known ecdysteroids, 20-hydroxyecdysone, its 2-, 3-, and 22-monoacetates, rubrosterone, poststerone, polypodine B (5beta,20-dihydroxyecdysone), pterosterone (25-deoxy-20,24-dihydroxyecdysone), and makisterone C (24-ethyl-20-hydroxyecdysone). All these ecdysteroids were isolated by a combination of several chromatographic techniques (liquid chromatography on alumina, DCCC, and HPLC), then identified using standard mass spectrometric and 2D (1)H-NMR techniques.