Approaching the Coverability Problem Continuously

The coverability problem for Petri nets plays a central role in the verification of concurrent shared-memory programs. However, its high EXPSPACE-complete complexity poses a challenge when encountered in real-world instances. In this paper, we develop a new approach to this problem which is primarily based on applying forward coverability in continuous Petri nets as a pruning criterion inside a backward coverability framework. A cornerstone of our approach is the efficient encoding of a recently developed polynomial-time algorithm for reachability in continuous Petri nets into SMT. We demonstrate the effectiveness of our approach on standard benchmarks from the literature, which shows that our approach decides significantly more instances than any existing tool and is in addition often much faster, in particular on large instances.Comment: 18 pages, 4 figure

Molecular characterization of corona radiata cells from patients with diminished ovarian reserve using microarray and microfluidic-based gene expression profiling

BACKGROUND: Diminished ovarian reserve (DOR) is one of the causes of infertility in young women. In this prospective study, gene expression profiling (GEP) of corona radiata cells (CRC) was performed to identify genes deregulated in DOR patients. METHODS: Microarray-based GEP of CRC isolated from eight women undergoing IVF was performed to identify genes differentially expressed between patients with normal ovarian reserve and DOR patients. Microfluidic-based quantitative RT-PCR assays were used to validate selected transcripts on 40 independent patients. A principal component analysis was used to identify more homogeneous subgroups of DOR patients. In silico analyses focusing on cis-regulation were performed to refine the interactions between patient\u27s biological characteristics and their GEP. RESULTS: Forty-eight transcripts were differentially expressed, including CXXC finger protein 5 (CXXC5), forkhead box C1 (FOXC1) (down-regulated in DOR) as well as connective tissue growth factor (CTGF), follistatin-like 3 (FSTL3), prostaglandin-endoperoxide synthase 2 (PTGS2) and suppressor of cytokine signaling 2 (SOCS2) (up-regulated in DOR). According to these transcripts, two DOR patients\u27 subgroups (DOR Gr1 and Gr2) were identified. In DOR Gr2 patients, C-terminal domain 2 (CITED2), CTGF, growth arrest-specific 1 (GAS1), insulin receptor substrate 2 (IRS2), PTGS2, SOCS2 and Versican (VCAN) were expressed at significantly higher levels and CXXC5, FOXC1, guanylate-binding protein 2 (GBP2) and zinc finger MIZ-domain containing 1 (ZMIZ1) at significantly lower levels. Higher baseline estradiol (E(2)) levels were observed in DOR Gr2 patients (P < 0.006). The in silico analyses suggested that all 11 genes differentially expressed between DOR Gr1 and DOR Gr2 subgroups could be transcriptional targets of estrogen. CONCLUSIONS: Despite small sample size limitations, 12 genes deregulated in the CRC of DOR patients were identified, which could be involved in DOR pathogenesis. A DOR patient\u27s subgroup with high baseline E(2) levels and deregulated estrogen-responsive genes was also identified

The mitochondrial DNA content of cumulus granulosa cells is linked to embryo quality

STUDY QUESTION: Could the mitochondrial DNA (mtDNA) content of cumulus granulosa cells (CGCs) be related to oocyte competence? SUMMARY ANSWER: The quality of embryos obtained during IVF procedures appears to be linked to mtDNA copy numbers in the CGCs. WHAT IS KNOWN ALREADY: Oocyte quality is linked to oocyte mtDNA content in the human and other species, and the mtDNA copy number of the oocyte is related to that of the corresponding CGCs. Moreover, the quantification of CGC mtDNA has recently been proposed as a biomarker of embryo viability. STUDY DESIGN SIZE, DURATION: An observational study was performed on 452 oocyte-cumulus complexes retrieved from 62 patients undergoing ICSI at the ART Center of the University Hospital of Angers, France, from January to May 2015. PARTICIPANTS/MATERIALS, SETTING, METHODS: The average mtDNA content of CGCs was assessed by using a quantitative real-time PCR technique. The relationship between CGC mtDNA content and oocyte maturity and fertilizability, on one hand, and embryo quality, on the other, was investigated using univariate and multivariate generalized models with fixed and mixed effects. MAIN RESULTS AND THE ROLE OF CHANCE: No relationship was found between CGC mtDNA content and oocyte maturity or fertilizability. In contrast, there was a significant link between the content of mtDNA in CGCs surrounding an oocyte and the embryo quality, with significantly higher mtDNA copy numbers being associated with good quality embryos compared with fair or poor quality embryos [interquartile range, respectively, 738 (250-1228) and 342 (159-818); P = 0.006]. However, the indication provided by the quantification of CGC mtDNA concerning the eventuality of good embryo quality was seriously subject to patient effect (AUC = 0.806, 95%CI = 0.719-0.869). The quantity of CGC mtDNA was influenced by BMI and smoking. LARGE SCALE DATA: N/A. LIMITATIONS REASONS FOR CAUTION: The quantification of CGC mtDNA may indicate embryo quality. However, since it is affected by patient specificity, it should be used with caution. It remains to be seen whether this marker could directly predict the implantation capacity of the embryo, which is the main objective in IVF practice. WIDER IMPLICATIONS OF THE FINDINGS: Our study suggests that the quantification of CGC mtDNA may be a novel biomarker of embryo viability. However, patient specificity makes it impossible to establish a general threshold value, valid for all patients. Nevertheless, further studies are needed to determine whether the quantification of CGC mtDNA may, in combination with the morpho-kinetic method, offer an additional criterion for selecting the best embryo for transfer from a given cohort. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the University Hospital of Angers, the University of Angers, France, and the French national research centres INSERM and the CNRS. There were no competing interests

OPA1 functions in mitochondria and dysfunctions in optic nerve

OPA1 is the major gene responsible for Dominant Optic Atrophy (DOA), a blinding disease that affects specifically the retinal ganglion cells (RGCs), which function consists in connecting the neuro-retina to the brain. OPA1 encodes an intra-mitochondrial dynamin, involved in inner membrane structures and ubiquitously expressed, raising the critical question of the origin of the disease pathophysiology. Here, we review the fundamental knowledge on OPA1 functions and regulations, highlighting their involvements in mitochondrial respiration, membrane dynamic and apoptosis. In light of these functions, we then describe the remarkable RGC mitochondrial network physiology and analyse data collected from animal models expressing OPA1 mutations. If, to date RGC mitochondria does not present any peculiarity at the molecular level, they represent possible targets of numerous assaults, like light, pressure, oxidative stress and energetic impairment, which jeopardize their function and survival, as observed in OPA1 mouse models. Although fascinating fields of investigation are still to be addressed on OPA1 functions and on DOA pathophysiology, we have reached a conspicuous state of knowledge with pertinent cell and animal models, from which therapeutic trials can be initiated and deeply evaluated

Multiorgan failure after sickle cell vaso occlusive attack: integrated clinical and biological emergency

We describe the case of a 30-year-old patient, suffering from composite S/beta + sickle cell disease. He was hospitalized following a vaso-occlusive attack with acute bone pains. Despite an analgesic treatment and transfusion of three units of red blood cells, a non-regenerative anemia appeared within 24 hours. One day later an acute chest syndrome with atelectasis of the left lung and desaturation and multi-organ failure occurred and necessitated the patient\u27s intubation and required him to be placed in an artificial coma. A bronchoalveolar lavage was performed, which eliminated pneumonia but proved, after staining with oil red O, many neutral fatty acid microvacuoles in more than 80% of macrophages, suggesting a pulmonary fat embolism. The hypothesis of a bone marrow necrosis causing a pulmonary fat embolism was discussed and confirmed the next day by the characteristic appearance of the bone marrow. A therapeutic protocol associating iteratively bleeding and red blood cells transfusion was administered on the second day with the objective of maintaining haemoglobin S at less than 20% rate. Successive haemoglobin S assay was applied using a high performance liquid chromatography (HPLC) technique with a quick response within one hour after transfusion or bleeding. This protocol resulted in an improvement in the patient\u27s condition, with a gradual normalization of vital signs and extubation twelve days later and discharge without sequelae twenty-five days later. The succession of rare but serious sickle cell complications anaemia which occurred in this patient could be controlled by adapting the laboratory for the clinical emergency

Current mechanistic insights into the CCCP-induced cell survival response

The ring-substituted derivatives of carbonyl cyanide phenylhydrazone, CCCP and FCCP, are routinely used for the analysis of the mitochondrial function in living cells, tissues, and isolated mitochondrial preparations. CCCP and FCCP are now being increasingly used for investigating the mechanisms of autophagy by inducing mitochondrial degradation through the disruption of the mitochondrial membrane potential (ΔΨm). Sustained perturbation of ΔΨm, which is normally tightly controlled to ensure cell proliferation and survival, triggers various stress pathways as part of the cellular adaptive response, the main components of which are mitophagy and autophagy. We here review current mechanistic insights into the induction of mitophagy and autophagy by CCCP and FCCP. In particular, we analyze the cellular modifications produced by the activation of two major pathways involving the signaling of the nuclear factor erythroid 2-related factor 2 (Nrf2) and the transcription factor EB (TFEB), and discuss the contribution of these pathways to the integrated cellular stress response

Retinal Neuronal Loss in Visually Asymptomatic Patients With Myoclonic Epilepsy With Ragged-Red Fibers

BACKGROUND: Myoclonic epilepsy with ragged-red fibers (MERRF, OMIM, #545000) is a rare neurological condition mostly caused by the m.8344A>G mitochondrial DNA pathogenic variant, which can variably affect multiple tissues, including the retina and optic nerve. We report detection of visually asymptomatic neuroretinal loss in 3 patients with genetically confirmed MERRF, using spectral domain optical coherence tomography (SD-OCT). METHODS: All patients underwent a complete ophthalmic examination including assessments of visual acuity, color vision, pupillary reactions, extraocular movements, applanation tonometry, slit-lamp, and dilated fundus examinations. Standard automated perimetry or Goldmann kinetic perimetry was performed, as well as fundus photographs and SD-OCT of the optic nerve head and macula. RESULTS: Despite the absence of visual symptoms in all patients, and normal visual acuity and visual fields in 1 patient, the 3 genetically confirmed patients (point mutations m.8344A>G; age range: 18-62 years) with MERRF-related neurological manifestations, displayed thinning of the retinal nerve fiber layer and variable alterations of the macular ganglion cell complex. CONCLUSIONS: Visually asymptomatic patients with genetically confirmed MERRF can display features of structural neuroretinal loss, quantifiable with SD-OCT. Further investigations are needed to establish whether OCT can assess early neurodegeneration in MERRF

Metabolomic Profiling of Aqueous Humor in Glaucoma Points to Taurine and Spermine Deficiency: Findings from the Eye-D Study

We compared the metabolomic profile of aqueous humor from patients with primary open-angle glaucoma (POAG; n = 26) with that of a group of age- and sex-matched non-POAG controls (n = 26), all participants undergoing cataract surgery. Supervised paired partial least-squares discriminant analysis showed good predictive performance for test sets with a median area under the receiver operating characteristic of 0.89 and a p-value of 0.0087. Twenty-three metabolites allowed discrimination between the two groups. Univariate analysis after the Benjamini-Hochberg correction showed significant differences for 13 of these metabolites. The POAG metabolomic signature indicated reduced concentrations of taurine and spermine and increased concentrations of creatinine, carnitine, three short-chain acylcarnitines, 7 amino acids (glutamine, glycine, alanine, leucine, isoleucine, hydroxyl-proline, and acetyl-ornithine), 7 phosphatidylcholines, one lysophosphatidylcholine, and one sphingomyelin. This suggests an alteration of metabolites involved in osmoprotection (taurine and creatinine), neuroprotection (spermine, taurine, and carnitine), amino acid metabolism (7 amino acids and three acylcarnitines), and the remodeling of cell membranes drained by the aqueous humor (hydroxyproline and phospholipids). Five of these metabolic alterations, already reported in POAG plasma, concern spermine, C3 and C4 acylcarnitines, PC aa 34:2, and PC aa 36:4, thus highlighting their importance in the pathogenesis of glaucoma

Retinal Neuronal Loss in Visually Asymptomatic Patients With Myoclonic Epilepsy With Ragged-Red Fibers

BACKGROUND: Myoclonic epilepsy with ragged-red fibers (MERRF, OMIM, #545000) is a rare neurological condition mostly caused by the m.8344A>G mitochondrial DNA pathogenic variant, which can variably affect multiple tissues, including the retina and optic nerve. We report detection of visually asymptomatic neuroretinal loss in 3 patients with genetically confirmed MERRF, using spectral domain optical coherence tomography (SD-OCT). METHODS: All patients underwent a complete ophthalmic examination including assessments of visual acuity, color vision, pupillary reactions, extraocular movements, applanation tonometry, slit-lamp, and dilated fundus examinations. Standard automated perimetry or Goldmann kinetic perimetry was performed, as well as fundus photographs and SD-OCT of the optic nerve head and macula. RESULTS: Despite the absence of visual symptoms in all patients, and normal visual acuity and visual fields in 1 patient, the 3 genetically confirmed patients (point mutations m.8344A>G; age range: 18-62 years) with MERRF-related neurological manifestations, displayed thinning of the retinal nerve fiber layer and variable alterations of the macular ganglion cell complex. CONCLUSIONS: Visually asymptomatic patients with genetically confirmed MERRF can display features of structural neuroretinal loss, quantifiable with SD-OCT. Further investigations are needed to establish whether OCT can assess early neurodegeneration in MERRF