Using iPSC-derived neurons to uncover cellular phenotypes associated with Timothy syndrome

Monogenic neurodevelopmental disorders provide key insights into the pathogenesis of disease and help us understand how specific genes control the development of the human brain. Timothy syndrome is caused by a missense mutation in the L-type calcium channel Ca(v)1.2 that is associated with developmental delay and autism. We generated cortical neuronal precursor cells and neurons from induced pluripotent stem cells derived from individuals with Timothy syndrome. Cells from these individuals have defects in calcium (Ca(2+)) signaling and activity-dependent gene expression. They also show abnormalities in differentiation, including decreased expression of genes that are expressed in lower cortical layers and in callosal projection neurons. In addition, neurons derived from individuals with Timothy syndrome show abnormal expression of tyrosine hydroxylase and increased production of norepinephrine and dopamine. This phenotype can be reversed by treatment with roscovitine, a cyclin-dependent kinase inhibitor and atypical L-type-channel blocker. These findings provide strong evidence that Ca(v)1.2 regulates the differentiation of cortical neurons in humans and offer new insights into the causes of autism in individuals with Timothy syndrome.     

Semi-Supervised Segmentation of Ultrasound Images Based on Patch Representation and Continuous Min Cut

Ultrasound segmentation is a challenging problem due to the inherent speckle and some artifacts like shadows, attenuation and signal dropout. Existing methods need to include strong priors like shape priors or analytical intensity models to succeed in the segmentation. However, such priors tend to limit these methods to a specific target or imaging settings, and they are not always applicable to pathological cases. This work introduces a semi-supervised segmentation framework for ultrasound imaging that alleviates the limitation of fully automatic segmentation, that is, it is applicable to any kind of target and imaging settings. Our methodology uses a graph of image patches to represent the ultrasound image and user-assisted initialization with labels, which acts as soft priors. The segmentation problem is formulated as a continuous minimum cut problem and solved with an efficient optimization algorithm. We validate our segmentation framework on clinical ultrasound imaging (prostate, fetus, and tumors of the liver and eye). We obtain high similarity agreement with the ground truth provided by medical expert delineations in all applications (94% DICE values in average) and the proposed algorithm performs favorably with the literature.     

Clinical effects of intrathecal administration of expanded Wharton jelly mesenchymal stromal cells in patients with chronic complete spinal cord injury: a randomized controlled study

Background aimsSpinal cord injury (SCI) represents a devastating condition leading to severe disability related to motor, sensory and autonomic dysfunction. Stem cell transplantation is considered a potential emerging therapy to stimulate neuroplastic and neuroregenerative processes after SCI. In this clinical trial, the authors investigated the safety and clinical recovery effects of intrathecal infusion of expanded Wharton jelly mesenchymal stromal cells (WJ-MSCs) in chronic complete SCI patients.MethodsThe authors designed a randomized, double-blind, crossover, placebo-controlled, phase 1/2a clinical trial (NCT03003364). Participants were 10 patients (7 males, 3 females, age range, 25–47 years) with chronic complete SCI (American Spinal Injury Association A) at dorsal level (T3-11). Patients were randomly assigned to receive a single dose of intrathecal ex vivo-expanded WJ-MSCs (10 × 10⁶ cells) from human umbilical cord or placebo and were then switched to the other arm at 6 months. Clinical evaluation (American Spinal Injury Association impairment scale motor and sensory score, spasticity, neuropathic pain, electrical perception and pain thresholds), lower limb motor evoked potentials (MEPs) and sensory evoked potentials (SEPs), Spinal Cord Independence Measure and World Health Organization Quality of Life Brief Version were assessed at baseline, 1 month, 3 months and 6 months after each intervention. Urodynamic studies and urinary-specific quality of life (Qualiveen questionnaire) as well as anorectal manometry, functional assessment of bowel dysfunction (Rome III diagnostic questionnaire) and severity of fecal incontinence (Wexner score) were conducted at baseline and at 6 months after each intervention.ResultsIntrathecal transplantation of WJ-MSCs was considered safe, with no significant side effects. Following MSC infusion, the authors found significant improvement in pinprick sensation in the dermatomes below the level of injury compared with placebo. Other clinically relevant effects, such as an increase in bladder maximum capacity and compliance and a decrease in bladder neurogenic hyperactivity and external sphincter dyssynergy, were observed only at the individual level. No changes in motor function, spasticity, MEPs, SEPs, bowel function, quality of life or independence measures were observed.ConclusionsIntrathecal transplantation of human umbilical cord-derived WJ-MSCs is a safe intervention. A single intrathecal infusion of WJ-MSCs in patients with chronic complete SCI induced sensory improvement in the segments adjacent to the injury site.     

One carbon metabolism disturbances and the C677T MTHFR gene polymorphism in children with autism spectrum disorders

Autism spectrum disorders (ASDs), which include the prototypic autistic disorder (AD), Asperger’s syndrome (AS) and pervasive developmental disorders not otherwise specified (PDD‐NOS), are complex neurodevelopmental conditions of unknown aetiology. The current study investigated the metabolites in the methionine cycle, the transsulphuration pathway, folate, vitamin B₁₂ and the C677T polymorphism of the MTHFR gene in three groups of children diagnosed with AD (n= 15), AS (n= 5) and PDD‐NOS (n= 19) and their age‐ and sex‐matched controls (n= 25). No metabolic disturbances were seen in the AS patients, while in the AD and PDD‐NOS groups, lower plasma levels of methionine (P= 0.01 and P= 0.03, respectively) and α‐aminobutyrate were observed (P= 0.01 and P= 0.001, respectively). Only in the AD group, plasma cysteine (P= 0.02) and total blood glutathione (P= 0.02) were found to be reduced. Although there was a trend towards lower levels of serine, glycine, N, N‐dimethylglycine in AD patients, the plasma levels of these metabolites as well as the levels of homocysteine and cystathionine were not statistically different in any of the ASDs groups. The serum levels of vitamin B₁₂ and folate were in the normal range. The results of the MTHFR gene analysis showed a normal distribution of the C677T polymorphism in children with ASDs, but the frequency of the 677T allele was slightly more prevalent in AD patients. Our study indicates a possible role for the alterations in one carbon metabolism in the pathophysiology of ASDs and provides, for the first time, preliminary evidence for metabolic and genetic differences between clinical subtypes of ASDs.     

Evaluation of the LIVE/DEAD BacLight kit for detection of extremophilic archaea and visualization of microorganisms in environmental hypersaline samples

Extremophilic archaea were stained with the LIVE/DEAD BacLight kit under conditions of high ionic strength and over a pH range of 2.0 to 9.3. The reliability of the kit was tested with haloarchaea following permeabilization of the cells. Microorganisms in hypersaline environmental samples were detectable with the kit, which suggests its potential application to future extraterrestrial halites.     

Importance of flood zones for nitrogen and phosphorus dynamics in the Danube Delta

The change of concentration of total reactive phosphorus (TRP) and dissolved inorganic nitrogen (DIN) was studied in the lower Danube river and in selected lakes situated in the wetland area of the Danube Delta. The differences Danube Delta in nutrient concentration in the river waters entering the delta and the delta in different sites (especially lakes) of the wetland area are considered to reflect retention in the system. The highest retention was found in periods of moderate and low water level when the surface-to-volume ratio of the lakes was high. In these periods the in-lake concentration of TRP and DIN could be as low as 11 and 23% of the values found in the inflowing river.     

Synthesis of purine and pyrimidine bases and nucleosides under the cold plasma conditions (IX)

Living-matter precursors are obtained by the action of the high-frequency electrical discharges on a methane-ammonia-water mixture. Some purine and pyrimidine bases as well as nucleosides are detected and estimated quantitatively by column chromatography, one- and two-dimensional paper chromatography, paper chromatography with standard addition, colour tests as well as by optical density measurement within the UV region.     

Paraoxonase 1 activities and polymorphisms in autism spectrum disorders

Autism spectrum disorders (ASD) comprise a complex and heterogeneous group of conditions of unknown aetiology, characterized by significant disturbances in social, communicative and behavioural functioning. Recent studies suggested a possible implication of the high-density lipoprotein associated esterase/lactonase paraoxonase 1 (PON1) in ASD. In the present study, we aimed at investigating the PON1 status in a group of 50 children with ASD as compared to healthy age and sex matched control participants. We evaluated PON1 bioavailability (i.e. arylesterase activity) and catalytic activity (i.e. paraoxonase activity) in plasma using spectrophotometric methods and the two common polymorphisms in the PON1 coding region (Q192R, L55M) by employing Light Cycler real-time PCR. We found that both PON1 arylesterase and PON1 paraoxonase activities were decreased in autistic patients (respectively, P < 0.001, P < 0.05), but no association with less active variants of the PON1 gene was found. The PON1 phenotype, inferred from the two-dimensional enzyme analysis, had a similar distribution in the ASD group and the control group. In conclusion, both the bioavailability and the catalytic activity of PON1 are impaired in ASD, despite no association with the Q192R and L55M polymorphisms in the PON1 gene and a normal distribution of the PON1 phenotype.     

Evolution of robust and efficient system topologies

Mutation/selection algorithms were applied to increase the efficiency and the robustness of sparse random networks. Selection for better efficiency leads to the well-known star topology, while selection for robustness only results in a relatively dense core and a small periphery. Concomitant selection for both efficiency and robustness leads to networks with intermittent center/periphery values. Networks evolving under multiple attack regimes develop distinct topologies with larger cores, and are characterized by parameter distributions different from those developing under single-attack regimes.     

Roles of CD147 on T lymphocytes activation and MMP-9 secretion in systemic lupus erythematosus

The cellular and molecular mechanisms involved in many abnormalities described in Systemic Lupus Erythematosus (SLE) are still unclear. Some of these abnormalities referred to the hyperactivation of T lymphocytes and the enhanced secretion of MMP-9 by peripheral blood mononuclear cells (PBMCs). Therefore, in this paper we investigated the potential role of CD147 molecule in these abnormalities. Our results demonstrated that CD147 molecule is overexpressed on CD3+T lymphocytes from SLE patients when compared with CD3+T lymphocytes from healthy donors. Monoclonal anti-CD147 antibodies, MEM-M6/1 clone, were able to inhibit protein tyrosine phosphorylation only in CD3 x CD28 costimulated T lymphocytes from SLE patients. However, this monoclonal antibody was unable to inhibit the enhanced activity of MMP-9 secreted by SLE PBMCs.