Risk of elevated intraocular pressure after ranibizumab injection in patients with neovascular age-related macular degeneration

Objectif : Nous avons voulu évaluer le risque d’élévation chronique de la pression intraoculaire suite à des injections de ranibizumab dans le traitement de la dégénérescence maculaire liée à l’âge de type néovasculaire. Méthode : Nous avons réalisé une étude rétrospective sur 161 patients ayant reçu des injections de ranibizumab dans un œil seulement. Les critères excluent les patients ayant du glaucome non contrôlé au départ (PIO>21mmHg) et ceux qui ont eu moins de 9 semaines de suivi après l’injection. L’élévation de la PIO est définie comme une augmentation de >5mmHg sur deux visites consécutives. Résultats : Nous n’avons pas déterminé de différence de pourcentage entre les yeux ayant reçus des injections pour lesquels il y a une élévation de la PIO (n=8.5%), comparé au pourcentage de yeux n’ayant pas reçus d’injections pour lesquels il y a une élévation de la PIO (n=9.6%). Cependant, un plus grand nombre d’injections d’anti-VEGF est associé avec une élévation chronique de la PIO (P=0.032). D’autres facteurs de risque de l’élévation chronique de la PIO sont le diabète, une PIO faible au départ, et une PIO maximale plus élevée (P<0.05). Conclusion : Un plus grand nombre d’injections semble augmenter le risque d’élévation de la PIO. Les patients atteints de diabète semblent être plus à risque et nécessiter une étroite surveillance.Purpose: Conflicting evidence exists about the risk of chronic elevation of intraocular pressure (IOP) after ranibizumab injections for neovascular age-related macular degeneration. The goal of this study is to evaluate this risk. Methods: A retrospective cohort study of 161 people. Inclusion criteria included receiving at least three ranibizumab injections in one eye only and having at least 9 weeks of follow-up. Exclusion criteria included the presence of uncontrolled glaucoma or ocular hypertension at baseline (IOP>=21mmHg). Chronic IOP elevation was defined as an increase >5mmHg of IOP on at least 2 consecutive visits. Results: There was no difference in the percentage of injected eyes that experienced a chronic IOP increase (n=8, 5%) compared to the percentage of uninjected eyes that experienced an IOP increase (n=9, 6%). However, a greater number of anti-VEGF injections was associated with chronic IOP elevation (P=0.032). Other risk factors for chronic IOP elevation included diabetes, a lower baseline IOP, and a higher maximum IOP (P<0.05). Conclusions: A greater number of injections appears to increase the risk of chronic IOP elevation. Also, diabetics appear to be more at risk and may need more careful follow-up or preventive pharmacological treatment

Optimization of growth, lipid and chlorophyll contents in Chlorella vulgaris under different conditions of nitrate, phosphate and photoperiod by central composite design (CCD)

The effects of nitrate (750-2250 mg/L), phosphate (20-60 mg/L) and photoperiod (8-24 h) on the growth, chlorophyll content and lipid yield of Chlorella vulgaris were studied using central composite design (CCD) method. The second-order quadratic model was used to predict the effects of input variables on the output responses and the results were verified by F test, ANOVA and regression analyses. Results showed that maximum growth (255.88 ×106 ) as well as highest chlorophyll content (15.34%) were observed at 16 h of light, 1500 mg/L of nitrate and 40 mg/L of phosphate concentration. Also, condition of 24 h of light, 750 mg/L nitrate and 20 mg/L phosphate concentrations resulted in maximum percent of lipid content (17.74%). The optimization of culture condition for simultaneous achievement of highest levels of growth, chlorophyll and lipid content were investigated

ADAM12 induces actin cytoskeleton and extracellular matrix reorganization during early adipocyte differentiation by regulating beta1 integrin function

Changes in cell shape are a morphological hallmark of differentiation. In this study we report that the expression of ADAM12, a disintegrin and metalloprotease, dramatically affects cell morphology in preadipocytes, changing them from a flattened, fibroblastic appearance to a more rounded shape. We showed that the highest levels of ADAM12 mRNA were detected in preadipocytes at the critical stage when preadipocytes become permissive for adipogenic differentiation. Furthermore, as assessed by immunostaining, ADAM12 was transiently expressed at the cell surface concomitant with the reduced activity of beta1 integrin. Co-immunoprecipitation studies indicated the formation of ADAM12/beta1 integrin complexes in these preadipocytes. Overexpression of ADAM12 at the cell surface of 3T3-L1 preadipocytes achieved by transient transfection or retroviral transduction led to the disappearance of the extensive network of actin stress fibers that are characteristic of these cells, and its reorganization into a cortical network located beneath the cell membrane. The cells became more rounded, exhibited fewer vinculin-positive focal adhesions, and adhered less efficiently to fibronectin in attachment assays. Moreover, ADAM12-expressing cells were more prone to apoptosis, which could be prevented by treating the cells with beta1-activating antibodies. A reduced and re-organized fibronectin-rich extracellular matrix accompanied these changes. In addition, beta1 integrin was more readily extracted with Triton X-100 from cells overexpressing ADAM12 than from control cells. Collectively, these results show that surface expression of ADAM12 impairs the function of beta1 integrins and, consequently, alters the organization of the actin cytoskeleton and extracellular matrix. These events may be necessary for early adipocyte differentiation

Adenylosuccinic acid: an orphan drug with untapped potential

Adenylosuccinic acid (ASA) is an orphan drug that was once investigated for clinical application in Duchenne muscular dystrophy (DMD). Endogenous ASA participates in purine recycling and energy homeostasis but might also be crucial for averting inflammation and other forms of cellular stress during intense energy demand and maintaining tissue biomass and glucose disposal. This article documents the known biological functions of ASA and explores its potential application for the treatment of neuromuscular and other chronic diseases

Xlinked myotubular and centronuclear myopathies

Abstract Recent work has significantly enhanced our understanding of the centronuclear myopathies and, in particular, myotubular myopathy. These myopathies share similar morphologic appearances with other diseases, namely the presence of hypotrophic myofibers with prominent internalized or centrally placed nuclei. Early workers suggested that this alteration represented an arrest in myofiber maturation, while other hypotheses implicated either failure in myofiber maturation or neurogenic causes. Despite similarities in morphology, distinct patterns of inheritance and some differences in clinical features have been recognized among cases. A severe form, known as X-linked myotubular myopathy (XLMTM), presents at or near birth. Affected males have profound global hypotonia and weakness, accompanied by respiratory difficulties that often require ventilation. Most of these patients die in infancy or early childhood, but some survive into later childhood or even adulthood. The responsible gene (MTM1) has been cloned; it encodes a phosphoinositide lipid phosphatase known as myotubularin that appears to be important in muscle maintenance. In autosomal recessive centronuclear myopathy (AR CNM), the onset of weakness typically occurs in infancy or early childhood. Some investigators have divided AR CNM into 3 subgroups: 1) an early-onset form with ophthalmoparesis, 2) an early-onset form without ophthalmoparesis, and 3) a late-onset form without ophthalmoparesis. Clinically, autosomal dominant CNM (AD CNM) is relatively mild and usually presents in adults with a diffuse weakness that is slowly progressive and may be accompanied by muscle hypertrophy. Overall, the autosomal disorders are not as clinically uniform as XLMTM, which has made their genetic characterization more difficult. Currently the responsible gene(s) remain unknown. This review will explore the historical evolution in understanding of these myopathies and give an update on their histopathologic features, genetics and pathogenesis

Ex vivo correction of selenoprotein N deficiency in rigid spine muscular dystrophy caused by a mutation in the selenocysteine codon

Premature termination of translation due to nonsense mutations is a frequent cause of inherited diseases. Therefore, many efforts were invested in the development of strategies or compounds to selectively suppress this default. Selenoproteins are interesting candidates considering the idiosyncrasy of the amino acid selenocysteine (Sec) insertion mechanism. Here, we focused our studies on SEPN1, a selenoprotein gene whose mutations entail genetic disorders resulting in different forms of muscular diseases. Selective correction of a nonsense mutation at the Sec codon (UGA to UAA) was undertaken with a corrector tRNASec that was engineered to harbor a compensatory mutation in the anticodon. We demonstrated that its expression restored synthesis of a full-length selenoprotein N both in HeLa cells and in skin fibroblasts from a patient carrying the mutated Sec codon. Readthrough of the UAA codon was effectively dependent on the Sec insertion machinery, therefore being highly selective for this gene and unlikely to generate off-target effects. In addition, we observed that expression of the corrector tRNASec stabilized the mutated SEPN1 transcript that was otherwise more subject to degradation. In conclusion, our data provide interesting evidence that premature termination of translation due to nonsense mutations is amenable to correction, in the context of the specialized selenoprotein synthesis mechanism

Identification of a signature motif for the eIF4a3–SECIS interaction

eIF4a3, a DEAD-box protein family member, is a component of the exon junction complex which assembles on spliced mRNAs. The protein also acts as a transcript-selective translational repressor of selenoprotein synthesis during selenium deficiency. Selenocysteine (Sec) incorporation into selenoproteins requires a Sec Insertion Sequence (SECIS) element in the 3′ untranslated region. During selenium deficiency, eIF4a3 binds SECIS elements from non-essential selenoproteins, preventing Sec insertion. We identified a molecular signature for the eIF4a3-SECIS interaction using RNA gel shifts, surface plasmon resonance and enzymatic foot printing. Our results support a two-site interaction model, where eIF4a3 binds the internal and apical loops of the SECIS. Additionally, the stability of the complex requires uridine in the SECIS core. In terms of protein requirements, the two globular domains of eIF4a3, which are connected by a linker, are both critical for SECIS binding. Compared to full-length eIF4a3, the two domains in trans bind with a lower association rate but notably, the uridine is no longer important for complex stability. These results provide insight into how eIF4a3 discriminates among SECIS elements and represses translation