Identification of Nucleoside Analogs as Inducers of Neuronal Differentiation in a Human Reporter Cell Line and Adult Stem Cells

Nucleoside analogs (NSAs) were among the first chemotherapeutic agents and could also be useful for the manipulation of cell fate. To investigate the potential of NSAs for the induction of neuronal differentiation, we developed a novel phenotypic assay based on a human neuron‐committed teratocarcinoma cell line (NT2) as a model for neuronal progenitors and constructed a NT2‐based reporter cell line that expressed eGFP under the control of a neuron‐specific promoter. We tested 38 structurally related NSAs and determined their activity to induce neuronal differentiation by immunocytochemistry of neuronal marker proteins, live cell imaging, fluorometric detection and immunoblot analysis. We identified twelve NSAs, which induced neuronal differentiation to different extents. NSAs with highest activity carried a halogen substituent at their pyrimidine nucleobase and an unmodified or 2′‐O‐methyl substituted 2‐deoxy‐β‐D‐ribofuranosyl residue as glyconic moiety. Cladribine, a purine nucleoside with similar structural features and in use to treat leukemia and multiple sclerosis, induced also differentiation of adult human neural crest‐derived stem cells. Our results suggest that NSAs could be useful for the manipulation of neuronal cell fate in cell replacement therapy or treatment of neurodegenerative disorders. The data on the structure and function relationship will help to design compounds with increased activity and low toxicity.     

Head impact exposure in youth football—Are current interventions hitting the target?

Restrictions on heading in youth football have been implemented in some countries to limit head impact exposure. However, current interventions remain poorly guided by evidence. Our objective was to quantify heading exposure in youth football, assessing the effects of sex and age. Football matches played during an international youth football tournament with no heading restrictions were directly observed, including players from both sexes (11-19 years). The elite senior level was included for comparison, using video analysis. All heading events were registered, classified, and assigned to individual players. Heading rates were calculated for each sex and age group. We observed a total of 267 matches, corresponding to 4011 player hours (1927 player hours for females, 2083 player hours for males). Males headed more frequently than females (2.7 vs 1.8 headers/player hour; P < .001). Heading rates increased with age (ANOVA, P < .001), approaching the elite senior level for players 16 years and older. There was substantial variation within teams for all age and sex groups, with the widest range (1-18 headers) observed for girls aged 19. Girls younger than 12 years had the lowest exposure, with an average of <2 players per team heading the ball, each with 1-2 headers. In conclusion, age and sex influence head impact exposure in youth football, and warrants careful consideration when introducing injury prevention measures. Males are more frequently exposed than females, heading rates increase with age, and there is substantial variation between players. Heading is a rare event in the youngest age groups, especially among females.     

Lenalidomide in relapsed and refractory multiple myeloma disease: feasibility and benefits of long-term treatment

Lenalidomide in combination with dexamethasone is an effective and well-established treatment of relapsed or refractory multiple myeloma (rrMM) disease. Due to the scarcity of reports assessing benefit and risk of long-term lenalidomide treatment in non-selected rrMM patients, we retrospectively analysed the long-term outcome in patients with rrMM treated with lenalidomide and dexamethasone. Sixty-seven patients (pts) who were treated with lenalidomide/dexamethasone for rrMM in the approved indication from 2007 to 2011 were included in this retrospective, single-centre analysis. Kaplan-Meier survival estimates were compared between total population, patients on lenalidomide for more than 12 months (mo) and patients discontinuing therapy earlier than 12 months. Median overall survival (OS) of the total patient population was 33.2 mo. OS of pts treated beyond 12 mo was 42.9 mo compared to 20.2 mo (p?=?0.027) for pts stopping lenalidomide earlier than 12 mo for other reasons than progression disease (PD). OS of pts >12 mo on lenalidomide treatment did not significantly differ between pts who had received previous autologous transplantation, allogeneic transplantation or conventional therapy. Main non-hematologic toxicities were infections of grade 3/4 in 25 % and thrombembolic events of all grades in 18 % of patients. To the best of our knowledge, this is the first report on feasibility and efficacy of long-term lenalidomide treatment in a non-selected patient cohort. OS of pts >12 mo on lenalidomide is superior when compared to pts discontinued earlier for reasons other than PD. Our data confirm the current use of lenalidomide as a continuous long-term treatment strategy.     

Oxidative Stress Promotes Uptake,Accumulation, and Oligomerization of Extracellular α-Synuclein in Oligodendrocytes

The accumulation and aggregation of α-synuclein (α-Syn) in glial cytoplasmic inclusions originating in oligodendrocytes is a characteristic hallmark of multiple system atrophy, a progressive adult onset neurodegenerative disorder. The origin of α-Syn deposition in oligodendrocytes in multiple system atrophy is still unclear, but the uptake of α-Syn from the environment after neuronal secretion has been discussed. The present study was undertaken to investigate the consequences of α-Syn uptake from the environment in cultured oligodendroglial cells and its localization and potential to form intracellular aggregates in the absence or presence of the microtubule-associated protein tau, which has been demonstrated to act synergistically with α-Syn. Primary rat brain oligodendrocytes and clonal oligodendroglial OLN-93 cells were incubated with human recombinant soluble and pre-aggregated α-Syn. The data show that oligodendrocytes are capable to take up and internalize soluble and pre-aggregated α-Syn from their growth medium. In a time-dependent manner, α-Syn oligomerizes and small intracellular aggregates are formed. These do not exert cytotoxic responses or mitochondrial impairment. Oxidative stress exerted by hydrogen peroxide further promotes α-Syn oligomer formation and leads to an enlargement of the aggregates. This process is not affected or modified by the presence of tau in OLN-93 cells. Furthermore, membrane lipid modification by docosahexaenoic acid promotes α-Syn uptake and oligomerization, indicating that changing the membrane lipid composition and structure contributes to the protein aggregation process and pathological events. Hence, although α-Syn taken up by oligodendrocytes from the environment is not toxic per se, under conditions of oxidative stress, which might occur during chronic disease progression and aging, aggregates are enlarged and eventually may contribute to cytotoxicity and cellular death.     

Prevalence of cortical superficial siderosis in patients with cognitive impairment

Cortical superficial siderosis (cSS) is a magnetic resonance imaging marker of cerebral amyloid angiopathy (CAA) and can be its sole imaging sign. cSS has further been identified as a risk marker for future intracranial hemorrhage. Although uncommon in the general population, cSS may be much more prevalent in high risk populations for amyloid pathology. We aimed to determine the frequency of cSS in patients with cognitive impairment presenting to a memory clinic. We prospectively evaluated consecutive patients presenting to our memory clinic between April 2011 and April 2013. Subjects received neuropsychological testing using the Consortium to Establish a Registry for Alzheimer’s Disease battery (CERAD-NP). Two hundred and twelve patients with documented cognitive impairment further underwent a standardized 3T-MR-imaging protocol with T2*-weighted gradient-echo sequences for detection of cSS. Thirteen of 212 patients (6.1 %) displayed cSS. In seven of them (54 %) cSS was the only imaging sign of CAA. Patients with cSS did not differ from patients without cSS with regard to medical history, age or cardiovascular risk profile. Subjects with cSS performed worse in the mini-mental state examination (p = 0.001), showed more white matter hyperintensities (p = 0.005) and more often had microbleeds (p = 0.001) compared to those without cSS. cSS is common in patients with cognitive impairment. It is associated with lower cognitive scores, white matter hyperintensities and microbleeds and can be the only imaging sign for CAA in this patient group.     

Gut inflammation and expression of ICC in a fetal lamb model of fetoscopic intervention for gastroschisis

Background

The pathogenesis of intestinal dysmotility in gastroschisis is not completely understood. Peel formation and disorganization of interstitial Cajal cells (ICC) have been proposed in humans. The aim of this study was to evaluate the impact of prenatal coverage of gastroschisis on gut inflammation and expression of ICC in a fetal lamb model.

Methods

Twenty-one German blackhead sheep with an abdominal wall defect that was created fetoscopically on day 77 of 145 days gestation were used in this study. Intrauterine surgery with the aim to cover the defect was performed 3 weeks later; two fetuses were covered completely, 5 partially and 11 remained uncovered. Three fetuses without gastroschisis were used as controls. All fetuses were retrieved by cesarean section at day 135. Samples of the small intestine were stained with hematoxylin and eosin for histologic analysis of peel formation and serosal and muscular thickness. For ICC detection, immunohistochemistry using anti-CD117 (c-Kit) antibody was used.

Results

In all samples with exposure to amniotic fluid, peel formation and significantly decreased ICC were found. Complete coverage reduced peel formation and disorganization of ICC compared to uncovered animals almost to the level of controls.

Conclusions

Peel formation and ICC derangement were significantly reduced by prenatal coverage of gastroschisis. Moreover, this animal model mimics the histopathological bowel changes as seen in human gastroschisis and may, therefore, be used for further research on the pathophysiology and fetal therapy of this malformation.     

The rectovaginal septum: visible on magnetic resonance images of women with Mayer-Rokitansky-Küster-Hauser syndrome (Müllerian agenesis)

Introduction and hypothesis

Ongoing debate exists about whether the rectovaginal septum (Denonvilliers’ fascia) is myth or reality. This study evaluates magnetic resonance images (MRI) of women with Müllerian agenesis for the presence of fascial layers between the rectum and the bladder to test the hypothesis that this layer exists in the absence of the vagina.

Methods

This is a secondary analysis of a study describing MRI aspects in women with vaginal agenesis before and after laparoscopic Vecchietti procedure. Study participants (n?=?16) had a multiplanar pelvic MR scan. Images were evaluated independently by two investigators (MH, JOLD) for the appearance of layers separate from the bladder and rectum in the area of interest, with characteristic anatomical features of the septum.

Results

Participants’ mean age was 19.4?±?2.6 years ± standard deviation (SD). In 12 of 16 patients (75 %) a distinct layer between rectum and bladder was identified in either the axial (4/16; 25 %) or sagittal (12/16; 75 %) scan or both. Characteristic anatomical features included lateral attachment to the levator ani muscle, cranial fusion to the cul-de-sac peritoneum, and caudal insertion into the perineal body.

Conclusions

Three quarters of women with Müllerian agenesis have a visible layer between bladder and rectum. As none of the participants had a vagina, these results support the existence of a rectovaginal septum, separate from a vaginal adventitia.