AraC interacts with p75NTR transmembrane domain to induce cell death of mature neurons.

Cytosine arabinoside (AraC) is one of the main therapeutic treatments for several types of cancer, including acute myeloid leukaemia. However, after a high-dose AraC chemotherapy regime, patients develop severe neurotoxicity and cell death in the central nervous system leading to cerebellar ataxia, dysarthria, nystagmus, somnolence and drowsiness. AraC induces apoptosis in dividing cells. However, the mechanism by which it leads to neurite degeneration and cell death in mature neurons remains unclear. We hypothesise that the upregulation of the death receptor p75NTR is responsible for AraC-mediated neurodegeneration and cell death in leukaemia patients undergoing AraC treatment. To determine the role of AraC-p75NTR signalling in the cell death of mature neurons, we used mature cerebellar granule neurons' primary cultures from p75NTR knockout and p75NTRCys259 mice. Evaluation of neurite degeneration, cell death and p75NTR signalling was done by immunohistochemistry and immunoblotting. To assess the interaction between AraC and p75NTR, we performed cellular thermal shift and AraTM assays as well as Homo-FRET anisotropy imaging. We show that AraC induces neurite degeneration and programmed cell death of mature cerebellar granule neurons in a p75NTR-dependent manner. Mechanistically, Proline 252 and Cysteine 256 residues facilitate AraC interaction with the transmembrane domain of p75NTR resulting in uncoupling of p75NTR from the NFκB survival pathway. This, in turn, exacerbates the activation of the cell death/JNK pathway by recruitment of TRAF6 to p75NTR. Our findings identify p75NTR as a novel molecular target to develop treatments for counteract AraC-mediated cell death of mature neurons.

Piriform cortex alterations in the Ts65Dn model for down syndrome.

The piriform cortex is involved in olfactory information processing, that is altered in Down Syndrome. Moreover, piriform cortex has a crucial involvement in epilepsy generation and is one of the first regions affected in Alzheimer's Disease, both maladies being prevalent among Down Syndrome individuals. In this work, we studied the alterations in neuronal morphology, synaptology and structural plasticity in the piriform cortex of the Ts65Dn mouse model, which is the most used model for the study of this syndrome and mimics some of their alterations. We have observed that Ts65Dn piriform cortex displays: a reduction in dendritic arborisation, a higher density of inhibitory synapses (GAD67), a lower density of excitatory synapses (vGLUT1) and a higher density of inhibitory postsynaptic puncta (gephyrin). Under electron microscopy the excitatory presynaptic and postsynaptic elements were larger in trisomic mice than in controls. Similar results were obtained using confocal microscopy. There were less immature neurons in piriform cortex layer II in addition to a reduction in the expression of PSA-NCAM in the neuropil that subsequently can reflect impairment in structural plasticity. These data support the idea of an impaired environment with altered ratio of inhibition and excitation that involves a reduction in plasticity and dendritic atrophy, providing a possible substrate for the olfactory processing impairment observed in DS individuals.

mTOR Suppresses Macroautophagy During Striatal Postnatal Development and Is Hyperactive in Mouse Models of Autism Spectrum Disorders.

Macroautophagy (hereafter referred to as autophagy) plays a critical role in neuronal function related to development and degeneration. Here, we investigated whether autophagy is developmentally regulated in the striatum, a brain region implicated in neurodevelopmental disease. We demonstrate that autophagic flux is suppressed during striatal postnatal development, reaching adult levels around postnatal day 28 (P28). We also find that mTOR signaling, a key regulator of autophagy, increases during the same developmental period. We further show that mTOR signaling is responsible for suppressing autophagy, via regulation of Beclin-1 and VPS34 activity. Finally, we discover that autophagy is downregulated during late striatal postnatal development (P28) in mice with in utero exposure to valproic acid (VPA), an established mouse model of autism spectrum disorder (ASD). VPA-exposed mice also display deficits in striatal neurotransmission and social behavior. Correction of hyperactive mTOR signaling in VPA-exposed mice restores social behavior. These results demonstrate that neurons coopt metabolic signaling cascades to developmentally regulate autophagy and provide additional evidence that mTOR-dependent signaling pathways represent pathogenic signaling cascades in ASD mouse models that are active during specific postnatal windows.

Dislocation Density Based Flow Stress Model Applied to the PFEM Simulation of Orthogonal Cutting Processes of Ti-6Al-4V.

Machining of metals is an essential operation in the manufacturing industry. Chip formation in metal cutting is associated with large plastic strains, large deformations, high strain rates and high temperatures, mainly located in the primary and in the secondary shear zones. During the last decades, there has been significant progress in numerical methods and constitutive modeling for machining operations. In this work, the Particle Finite Element Method (PFEM) together with a dislocation density (DD) constitutive model are introduced to simulate the machining of Ti-6Al-4V. The work includes a study of two constitutive models for the titanium material, the physically based plasticity DD model and the phenomenology based Johnson-Cook model. Both constitutive models were implemented into an in-house PFEM software and setup to simulate deformation behaviour of titanium Ti6Al4V during an orthogonal cutting process. Validation show that numerical and experimental results are in agreement for different cutting speeds and feeds. The dislocation density model, although it needs more thorough calibration, shows an excellent match with the results. This paper shows that the combination of PFEM together with a dislocation density constitutive model is an excellent candidate for future numerical simulations of mechanical cutting.

Alterations in reelin and reelin receptors in Down syndrome.

Reelin is an extracellular matrix glycoprotein that modulates synaptic function and plasticity, with a crucial role in neuronal migration. Changes in the expression of this protein have been reported in neurodegenerative diseases, such as Alzheimer's disease (AD). This molecule is produced by Cajal-Retzius neurons during development and by inhibitory neurons in the adult nervous system. Individuals with Down syndrome (DS) present an early development of AD; therefore, we analyzed the alterations in this molecule and its receptors in the murine model for DS Ts65Dn as well as in human with DS. We performed immunofluorescence analysis for reelin and its receptors very-low-density lipoprotein receptor and apolipoprotein R receptor 2 in the temporal cortex of mice and humans and have quantified the density of reelin-expressing neurons and the intensity of expression of both receptors. We have observed an increment in the density of reelin immunoreactive neurons in both the temporal cortex of adult Ts65Dn mice and humans with DS. Moreover, these reelin immunoreactive neurons displayed a disorganized distribution when compared with wild-type mice. Regarding reelin receptors, very-low-density lipoprotein receptor expression remained unaltered in both Ts65Dn and humans with DS, whereas apolipoprotein R receptor 2 decreased in both individuals with DS and Ts65Dn mice. These alterations are similar to those observed in individuals with AD.

Coronal advanced flap in combination with a connective tissue graft. Is the thickness of the flap a predictor for root coverage? A prospective clinical study.

AIM: Evaluate if there is any relationship between the flap thickness (FT) and the presence of complete root coverage (CRC) when performing coronally advanced flaps in combination with a connective tissue graft (CTG). MATERIALS AND METHODS: Prospective clinical study, in which multiple Miller class I and II recessions were treated with a coronally advanced flap and a CTG standardized at 1 mm of thickness. Individual stents permitted repeated measurements of conventional periodontal parameters at the same point. The primary outcome variable was CRC. Secondary outcomes were recession reduction, gingival thickness and width of keratinized tissue (KT) achieved at 6 months post-surgery. RESULTS: Forty-five recessions (2.4 ± 0.75 mm) were treated in 20 patients. Mean root coverage was 93.4 ± 10.98%; 65% achieved CRC. The mean FT was 1.01 mm ± 0.64 mm and 1.01 ± 0.61 mm at 2 and 5 mm from the gingival margin, respectively. No relationship could be found between FT and CRC (p > .05). Statistical significant changes (p < .05) were observed for recession depth, clinical attachment level, KT and soft tissue thickness at the end of the study. CONCLUSIONS: Flap thickness seems not to be a predictor for CRC when performing a coronally advanced flap plus a CTG. This technique may be of choice when treating thin biotypes.

Mifepristone 5 mg versus 10 mg for emergency contraception: double-blind randomized clinical trial.

PURPOSE: To estimate the efficacy and safety of 5 mg and 10 mg mifepristone for emergency contraception up to 144 hours after unprotected coitus. METHODS: This double-blind randomized clinical trial was carried out at Eusebio Hernandez Hospital (Havana, Cuba). A total of 2,418 women who requested emergency contraception after unprotected coitus received either 5 mg or 10 mg mifepristone. The variables for assessing efficacy were the pregnancies that occurred and the fraction of pregnancies that were prevented. Other variables assessed were the side effects of mifepristone, vaginal bleeding, and changes in the date of the following menstruation. RESULTS: There were 15/1,206 (1.2%) and 9/1,212 (0.7%) pregnancies in the 5 mg and 10 mg group, respectively (P=0.107). There were 88% and 93% prevented pregnancies in the 5 mg and un ≥7 days was experienced by 4.9% and 11.0% of subjects in the 5 mg and 10 mg group, respectively (P=0.001). There was a significant high failure rate for women weighing >75 kg in the 5 mg group. CONCLUSION: It would be advisable to use the 10 mg dose of mifepristone for emergency contraception as there was a trend suggesting that the failure rate of the larger dose was lower.

Treatment of Uterine Myoma with 2.5 or 5 mg Mifepristone Daily during 3 Months with 9 Months Posttreatment Followup: Randomized Clinical Trial.

Objectives. To evaluate the efficacy, safety, and quality of life by using 2.5 and mifepristone 5 mg daily doses to treat uterine fibroids over 3 months with a 9-month followup period. Design. Randomized clinical trial. Place. "Eusebio Hernández" Hospital, Havana, Cuba. Subjects. 220 women with symptomatic uterine fibroids. Treatment. One-half (2.5 mg) or one-whole 5 mg mifepristone tablet. Variables to Evaluate Efficacy. Changes in fibroid and uterine volumes, in symptomatic prevalence and intensity, and in quality of life. Results. After 3-month treatment, fibroid volume decreased by 27.9% (CI 95% 20-35) and 45.5% (CI 95% 37-62), in the 2.5 and 5 mg groups, respectively, P = 0.003. There was no difference in the prevalence of symptoms at the end of treatment, unlike after 6- and 9-month followup when there was a difference. Amenorrhea was significantly higher in the 5 mg group, P = 0.001. There were no significant differences in mifepristone side effects between the groups. Both groups displayed a similar improvement in quality of life. Conclusions. The 2.5 mg dosage resulted in a lesser reduction in fibroid size but a similar improvement in quality of life when compared to the 5 mg dose. This trial is registered with ClinicalTrials.gov NCT01786226.

Safety and effectiveness of different dosage of mifepristone for the treatment of uterine fibroids: a double-blind randomized clinical trial.

OBJECTIVES: The aim of this study was to evaluate the safety and improvement in quality of life using 10 mg and 5 mg daily doses of mifepristone for the treatment of uterine fibroids. DESIGN: The research was a randomized double-blind clinical study undertaken at the Eusebio Hernández Hospital in Havana, Cuba. SUBJECTS AND METHODS: Seventy subjects with symptomatic uterine fibroids took one daily capsule of 10 mg or 5 mg mifepristone orally for 9 months. One to three endometrial biopsies were performed. In evaluating safety, the variables studied were endometrial changes associated with mifepristone, elevation of hepatic transaminases, side effects of mifepristone, and instances and duration of irregular bleeding. RESULTS: There were 30/49 (61.2%) and 13/24 (54.2%) diagnoses of endometrial changes associated with mifepristone in the 10 mg and 5 mg groups, respectively (P = 0.282). At every evaluation visit the average endometrial thickness was significantly greater in the 10 mg group than in the 5 mg group (P = 0.013, P = 0.002, and P = 0.013, respectively). Only five subjects had slight elevations in their hepatic transaminases after 9 months' treatment. Sixteen of 35 (45.7%) and eight of 33 (24.2%) subjects had the occasional hot flush in the 10 mg and 5 mg groups, respectively (P = 0.032). In total, there were 12.9 ± 4.6 (n = 21) and 9.1 ± 3.9 (n = 18) days of irregular bleeding in the 10 mg and 5 mg groups, respectively (P = 0.009). CONCLUSION: According to the study findings, a 5 mg daily dose over 9 months has a relatively better safety profile than the 10 mg dose.

The influence of oceanographic fronts and early-life-history traits on connectivity among littoral fish species.

The spatial distribution of neutral genetic diversity is mainly influenced by barriers to dispersal. The nature of such barriers varies according to the dispersal means and capabilities of the organisms concerned. Although these barriers are often obvious on land, in the ocean they can be more difficult to identify. Determining the relative influence of physical and biotic factors on genetic connectivity remains a major challenge for marine ecologists. Here, we compare gene flow patterns of 7 littoral fish species from 6 families with a range of early-life-history traits sampled at the same geographic locations across common environmental discontinuities in the form of oceanic fronts in the Western Mediterranean. We show that these fronts represent major barriers to gene flow and have a strong influence on the population genetic structure of some fish species. We also found no significant relation between the early-life-history traits most commonly investigated (egg type, pelagic larval duration, and inshore-offshore spawning) and gene flow patterns, suggesting that other life-history factors should deserve attention. The fronts analyzed and the underlying physical mechanisms are not site-specific but common among the oceans, suggesting the generality of our findings.

Second-trimester pregnancy termination with 600-microg vs. 400-microg vaginal misoprostol and systematic curettage postexpulsion: a randomized trial.

BACKGROUND: This study was conducted to compare efficacy and safety of 600 mcg of misoprostol vaginally every 6 h up to four doses vs. 400 mcg of misoprostol vaginally every 4 h up to five doses, followed by systematic curettage of the uterine cavity, for pregnancy termination between 12 and 20 weeks' gestation. STUDY DESIGN: We used a randomized clinical trial conducted at Hospital Gineco-Obstétrico "Eusebio Hernández", Havana, Cuba. Subjects were women requesting voluntary termination of pregnancies between 12 and 20 weeks' gestation. Two hundred ten women were randomly assigned to receive 600 mcg of vaginal misoprostol every 6 h up to four doses (Group I) vs. 400 mcg of vaginal misoprostol every 4 h up to five doses (Group II), followed by curettage 1 h after expulsion. The main outcomes measured were successful abortion rate and mean expulsion time. RESULTS: Successful abortion occurred in 103/105 women (98.1%) in Group I and in 99/105 (94.3%) in Group II [p=.279, relative risk (RR)=3.121 and 95% confidence interval for RR=0.615 to 15.833]. Fetus mean expulsion time was 10.7+/-1.3 (SD) h in Group I and 11.5+/-5.0 (SD) h in Group II (p=.209). CONCLUSIONS: Six hundred micrograms of misoprostol administered vaginally every 6 h was as effective as 400 mcg of misoprostol every 4 h for second-trimester pregnancy termination.

Vaginal vs. sublingual misoprostol with mifepristone for cervical priming in second-trimester abortion by dilation and evacuation: a randomized clinical trial.

OBJECTIVES: The study was conducted to assess the effectiveness of mifepristone 200 mg 48 h before administering misoprostol 600 mug, sublingual vs. vaginal route, prior to dilation and evacuation (D&E) in 12- to 20-week pregnancies. DESIGN: Randomized clinical trial. SETTING: Clínica Mediterrania Médica, Valencia, Spain. SUBJECTS: Women with 12- to 20-week pregnancies wanting a voluntary abortion between July 9, 2004, and February 9, 2006. METHODS: Nine hundred women were randomized to be included in one of the following four groups: (I) mifepristone 200 mg plus sublingual misoprostol 600 microg before D&E, (II) mifepristone 200 mg plus vaginal misoprostol 600 microg before D&E, (III) sublingual misoprostol 600 microg before D&E and (IV) vaginal misoprostol 600 microg before D&E. MAIN OUTCOMES MEASURED: The degree of cervical dilation achieved before D&E, surgical time necessary to terminate the pregnancy and side effects of misoprostol. RESULTS: The average cervical dilation in the mifepristone groups was 12.5+/-2.8 mm (SD) [95% confidence interval (CI), 12.3-12.8] vs. 8.5+/-3.2 mm (SD) (95% CI, 8.2-8.8) in those receiving only misoprostol. Surgical time in the mifepristone sublingual misoprostol group was 11.9+/-4.3 min (SD) vs. 13.0+/-5.3 min (SD) in the sublingual misoprostol group without mifepristone (p=.007); in the mifepristone vaginal misoprostol group, the average surgical time was 12.3+/-5.0 min (SD) vs. 13.0+/-6.2 (SD) in the vaginal misoprostol group without mifepristone (p=.031). CONCLUSIONS: Administering mifepristone before D&E with misoprostol in second-trimester abortions makes surgery easier and shorter and, to a certain extent, lessens the risk of cervical injuries, especially in D&E in advanced gestational periods.

Rapid radiation and cryptic speciation in mediterranean triplefin blennies (Pisces: Tripterygiidae) combining multiple genes.

The genus Tripterygion is the unique genus of the family Tripterygiidae in the Mediterranean Sea and in the northeastern Atlantic coast. Three species and four subspecies had been described: Tripterygion tripteronotus and Tripterygion melanurus (T. m. melanurus and T. m. minor) are endemic of the Mediterranean, and T. delaisi (T. d. delaisi and T. d. xanthosoma) is found in both areas. We used five different genes (12S, 16S, tRNA-val, COI, and 18S) to elucidate their taxonomy status and their phylogenetic relationships. We employed different phylogenetic reconstructions that yielded different tree topologies. This discrepancy may be caused by the speciation process making difficult the reconstruction of a highly supported tree. All pair comparisons between these three species showed the same genetic divergence indicating that the speciation process could have been resolved by a rapid radiation event after the Messinian Salinity Crisis (5.2Mya) leading to a trichotomy. Our molecular data revealed two clearly supported clades within T. tripteronotus, whose divergence largely exceeded that found between other fish species, consequently these two groups should be considered two cryptic species diverging 2.75-3.32Mya along the Pliocene glaciations. On the contrary, none of the genes studied supported the existence of two subspecies of T. melanurus. Finally, the two subspecies of T. delaisi were validated and probably originated during the Quaternary climatic fluctuations (1.10-1.23Mya), however their distribution ranges should be redefined.