NXF1 and CRM1 nuclear export pathways orchestrate nuclear export, translation and packaging of murine leukaemia retrovirus unspliced RNA.

Cellular mRNAs are exported from the nucleus as fully spliced RNAs. Proofreading mechanisms eliminate unprocessed and irregular pre-mRNAs to control the quality of gene expression. Retroviruses need to export partially spliced and unspliced full-length RNAs to the cytoplasm where they serve as templates for protein synthesis and/or as encapsidated RNA in progeny viruses. Genetically complex retroviruses such as HIV-1 use Rev-equivalent proteins to export intron-retaining RNA from the nucleus using the cellular CRM1-driven nuclear export machinery. By contrast, genetically simpler retroviruses such as murine leukaemia virus (MLV) recruit the NXF1 RNA export machinery. In this study, we reveal for the first time that MLV hijacks both NXF1 and CRM1-dependent pathways to achieve optimal replication capacity. The CRM1-pathway marks the MLV full-length RNA (FL RNA) for packaging, while NXF1-driven nuclear export is coupled to translation. Thus, the cytoplasmic function of the viral RNA is determined early in the nucleus. Depending on the nature of ribonucleoprotein complex formed on FL RNA cargo in the nucleus, the FL RNA will be addressed to the translation machinery sites or to the virus-assembly sites at the plasma membrane.

Modeling of DNA transport in viscoelastic electro-hydrodynamic flows for enhanced size separation.

DNA separation and analysis have advanced over recent years, benefiting from microfluidic systems that reduce sample volumes and analysis costs, essential for sequencing and disease identification in body fluids. We recently developed the µLAS technology that enables the separation, concentration, and analysis of nucleic acids with high sensitivity. The technology combines a hydrodynamic flow actuation and an opposite electrophoretic force in viscoelastic polymer solutions. Combining hydrodynamics first principles and statistical mechanics, we provide, in this paper, a quantitative model of DNA transport capable of predicting device performance with the exclusive use of one adjustable parameter associated with the amplitude of transverse viscoelastic forces. The model proves to be in remarkable agreement with DNA separation experiments, and allows us to define optimal conditions that result in a maximal resolution length of 7 bp. We finally discuss the usefulness of our model for separation technologies involving viscoelastic liquids.

EFFECT OF EXPERIMENTAL DYSGLYCEMIA ON UNDER-CARBOXYLATED OSTEOCALCIN PRODUCTION IN HUMAN PRIMARY OSTEOBLAST-LIKE CELL CULTURES.

CONTEXT: The undercarboxylated form of osteocalcin (ucOC) and osteoprotegerin (OPG) are bone-derived molecules involved in the endocrine crosstalk governing the bone, the adipose tissue and the pancreas. In addition, glucocorticoids are major determinants of both insulin resistance and osteoporosis. OBJECTIVE: We aimed to investigate the response of ucOC and OPG to dysglycemia and/or dexamethasone (DXM) in primary human osteoblastic cell (HOC) cultures. DESIGN AND METHODS: Third-passage sub-confluent primary HOC cultures were treated with glucose: 2.8 mmol/L, 5.6 mmol/L, 11.1 mmol/L and 28 mmol/L, respectively. Alternatively, HOC cultures were subjected to DXM 1 µmol/L. In more complex experiments, HOC cultures were pre-treated with glucose (5.6 mmol/L) with/without insulin (1 pmol/L) followed by DXM (1 µmol/L). 24-hours post-treatment, culture medium ucOC and OPG were measured by ELISA. RESULTS: ucOC production differed significantly (p<0.05) between cell groups, decreasing in a dose-dependent manner as glucose concentration in the medium increased. Insulin prevented this effect. OPG levels appeared not to be significantly influenced by the hyperglycemic culture medium and were not related to ucOC concentration (p>0.05). Addition of DXM resulted in significantly lower ucOC concentrations compared to vehicle-treated cells (p<0.05). However, the effect of insulin co-treatment on ucOC was not counteracted by DXM (p<0.05). CONCLUSIONS: An obvious alteration of OC production/metabolism was observed as glucose levels changed in the bone microenvironment, to potentially be involved in diabetes-related osteopenia. DXM suppressed ucOC levels however not in insulin-rich environment.

ASSOCIATION OF COL1A1 SP1 AND FOK-I VDR GENETIC POLYMORPHISMS IN YOUNG MALE IDIOPATHIC OSTEOPOROSIS.

INTRODUCTION: Primary osteoporosis during childhood and adolescence represents an uncommon condition, and secondary forms are more likely to manifest at this age due to chronic disease and adverse effects of medical treatment. CASE REPORT: The authors report the case of a young male patient with a history of multiple idiopathic non-vertebral fragility fractures in addition to a family history of maternal osteoporosis and fracture, in whom osteoporosis was confirmed according to 2013 International Society for Clinical Densitometry (ISCD) criteria. Bone markers indicated low bone formation marker osteocalcin. Genetic testing revealed homozygosity for Sp1 COL1A1 gene polymorphism in combination to Fok-I vitamin D receptor (VDR) heterozygous polymorphism, to contribute to low bone mass and increased fracture risk. Severe premenopausal osteoporosis was present in the patient's mother, who was also tested positive for both gene polymorphisms. CONCLUSION: This case report highlights the association between COL1A1 and VDR candidate gene polymorphisms and fragility fractures in a family. Individual genetic testing might be of clinical value in idiopathic osteoporosis in young patients, identifying subjects at increased fracture risk.

Nucleobases thin films deposited on nanostructured transparent conductive electrodes for optoelectronic applications.

Environmentally-friendly bio-organic materials have become the centre of recent developments in organic electronics, while a suitable interfacial modification is a prerequisite for future applications. In the context of researches on low cost and biodegradable resource for optoelectronics applications, the influence of a 2D nanostructured transparent conductive electrode on the morphological, structural, optical and electrical properties of nucleobases (adenine, guanine, cytosine, thymine and uracil) thin films obtained by thermal evaporation was analysed. The 2D array of nanostructures has been developed in a polymeric layer on glass substrate using a high throughput and low cost technique, UV-Nanoimprint Lithography. The indium tin oxide electrode was grown on both nanostructured and flat substrate and the properties of the heterostructures built on these two types of electrodes were analysed by comparison. We report that the organic-electrode interface modification by nano-patterning affects both the optical (transmission and emission) properties by multiple reflections on the walls of nanostructures and the electrical properties by the effect on the organic/electrode contact area and charge carrier pathway through electrodes. These results encourage the potential application of the nucleobases thin films deposited on nanostructured conductive electrode in green optoelectronic devices.

Transport of nano-objects in narrow channels: influence of Brownian diffusion, confinement and particle nature.

This paper presents experimental results about transport of dilute suspensions of nano-objects in silicon-glass micrometric and sub-micrometric channels. Two kinds of objects are used: solid, rigid latex beads and spherical capsule-shaped, soft polymersomes. They are tracked using fluorescence microscopy. Three aspects are studied: confinement (ratio between particle diameter and channel depth), Brownian diffusion and particle nature. The aim of this work is to understand how these different aspects affect the transport of suspensions in narrow channels and to understand the different mechanisms at play. Concerning the solid beads we observe the appearance of two regimes, one where the experimental mean velocity is close to the expected one and another where this velocity is lower. This is directly related to a competition between confinement, Brownian diffusion and advection. These two regimes are shown to be linked to the inhomogeneity of particles distribution in the channel depth, which we experimentally deduce from velocity distributions. This inhomogeneity appears during the entrance process into the sub-micrometric channels, as for hydrodynamic separation or deterministic lateral displacement. Concerning the nature of the particles we observed a shift of transition towards the second regime likely due to the relationships between shear stress and polymersomes mechanical properties which could reduce the inhomogeneity imposed by the geometry of our device.

Elements for optimizing a one-step enzymatic bio-refinery process of shrimp cuticles: Focus on enzymatic proteolysis screening.

This article complements an earlier work published in 2015 Baron et al. (2015) that showed the interest of a shrimp shells bio-refining process. We compare here the effect of eleven commercial proteases at pH 3.5 or 4.0 on a residual amount of shrimp shells proteins after 6 h at 50 °C. The two pH are obtained when respectively 40 and 25 mmol of formic acid are added to 5 g of mild dried shell. Deproteinisation yield above 95% are obtained. Residual amino acids profile in the solid phase was identical for the eleven proteases except for pepsin which was similar to the raw material profile. A significant relative increase in the proportion of Glycine is observed for the ten other cases. Likewise, shapes of size exclusion chromatograms of the dissolved phase are similar except with pepsin.

Diurnal variations in maternal and fetal steroids in pregnant rhesus monkeys.

To examine diurnal changes in maternal and fetal steroids in chronically catheterized pregnant rhesus monkeys, we have measured cortisol (F), progesterone (P4), estone, and estradiol in maternal blood and F, P4, and dehydroepiandrosterone sulphate (DHAS) in simultaneous samples of fetal blood taken in the morning (0700--1000 h) and in the evening (1700--2100 h). In the mother, the concentrations of F, estradiol, and estrone were higher in the morning than in the evening. In contrast, progesterone was higher in evening than in morning samples. In fetal blood, there was no significant morning-evening difference for F; however, the concentrations of P4 and DHAS were higher in the evening than in the morning samples. In three individual monkeys, the concentrations of P4 and DHAS in serial samples of fetal blood were correlated. We conclude 1) that there are marked diurnal changes in the concentration of several steroids in samples of maternal and fetal blood and 2) that the concentration of F in maternal blood shows the opposite pattern to that of possible fetal adrenal steroids in fetal blood.

Vaginal birth after cesarean: an appraisal of fetal risk.

OBJECTIVE: To expand on prior investigations and further evaluate the fetal risk associated with vaginal birth after cesarean (VBAC) by examining the incidence not only of a depressed Apgar score at 5 minutes but also of fetal acidemia. METHODS: Between January 1, 1991, and December 31, 1996, the following groups of patients who delivered a singleton fetus with birth weight greater than 750 g were identified: 2082 patients with one or more prior cesarean deliveries who were allowed a trial of labor, 1677 of whom delivered vaginally and 405 of whom delivered by repeat cesarean; 920 patients delivered by elective repeat cesarean; 22,863 patients without a prior cesarean who delivered vaginally; and 2432 patients delivered by primary cesarean after laboring. Umbilical cord arterial blood gases were obtained in 88.3% of these deliveries. Comparisons of Apgar scores at 5 minutes and umbilical cord arterial pH measurements were made between groups with chi2 or Fisher exact test, and odds ratios (ORs) were calculated. RESULTS: The only significant differences were noted between those patients who delivered vaginally after a prior cesarean and those patients who delivered vaginally without a prior cesarean. Neonates in the successful VBAC group were more likely to have an Apgar score at 5 minutes less than 7 (OR 1.52) or an umbilical arterial pH less than 7.1 (OR 1.69). Those neonates, however, were not at greater risk for an Apgar score less than 4 or a pH less than 7.0. CONCLUSION: Our experience suggests that VBAC poses a low level of fetal risk, although a much larger sample size would be required to exclude a two-fold increase in potentially damaging fetal acidemia.

Ultrasonic fetal weight prediction: role of head circumference and femur length.

The accurate sonographic estimate of fetal weight is helpful in those instances when the fetal weight estimate might alter clinical management. Most sonographic weight predicting formulas have been based predominantly on measurements from the term fetus and then applied to the preterm fetus. Yet, the morphology of the preterm and term fetus differs considerably. The authors have examined the predictive accuracy of three published sonographic formulas in 69 preterm fetuses scanned within 48 hours of delivery. The mean birth weight was 1396 g. Thirty-nine of the infants were less than 1500 g. Sixty-two percent were products of pregnancies complicated by premature rupture of membranes. The results were compared with new equations derived from combinations of head and abdominal circumferences, biparietal diameter, and femur length obtained from the first 33 fetuses and then tested on the remaining 36. Whereas each formula correlated highly with birth weight, the selected new formula was more accurate than the published formulas by each criteria examined. In contrast to the latter, the mean error (actual minus predicted weight) of most new equations did not significantly differ from zero when tested prospectively. In addition, it appeared that the accuracy of two new formulas not incorporating femur length could be further enhanced in the group of fetuses whose femur length differed from the mean by at least 2 standard deviations by multiplying the predicted weight by the ratio of actual to mean femur length. The authors conclude that the use of head circumference and femur length coupled with a population restricted to the preterm fetus enhances the accuracy of sonographic weight predictions.

Cost-effectiveness of elective cesarean delivery after one prior low transverse cesarean.

OBJECTIVE: This analysis was undertaken to better understand the costs and health consequences of a trial of labor after cesarean when compared with a policy of routine elective repeat cesarean delivery. METHODS: A decision-tree model incorporating a Markov analysis was used to examine the reproductive life of a hypothetical cohort of 100,000 pregnant women whose only prior pregnancy was delivered through a low transverse cesarean incision. Using this model, the policy of performing routine elective cesarean delivery was compared with a policy of allowing a trial of labor. Main outcome measures were maternal and neonatal morbidity and mortality, total costs to the health care system, and cost per major neonatal complication avoided (death or permanent neurologic sequelae). RESULTS: The consequences of routine elective cesarean delivery for a second birth are significant, with an additional 117,748 cesarean deliveries, 5500 maternal morbid events, and $179 million incurred during the reproductive life of 100,000 women. The prevention of one major adverse neonatal outcome requires 1591 cesarean deliveries and $2.4 million. Sensitivity analysis confirms the robustness of the analysis. CONCLUSION: Routine elective cesarean for a second delivery for women with a prior low transverse cesarean incision results in an excess of maternal morbidity and mortality and a high cost to the medical system.

Diminished biparietal diameter and abdominal circumference growth in twins.

Forty-three women with uncomplicated twin pregnancies and reliable menstrual dates had serial ultrasonic measurements of the fetal biparietal diameter (BPD) and abdominal circumference. The 25th, 50th, and 75th fetal BPD and abdominal circumference growth percentiles were generated from this normal twin population and compared with those for singletons. A slowing of both BPD and abdominal circumference growth in twins was noted in the third trimester. However, newborn anthropometric data were collected that suggest that the head circumference of twins is comparable to that of singletons. This discrepancy between ultrasonic BPD and neonatal head circumference in predicting head size may possibly be explained by dolichocephaly attributed to uterine crowding. For the antenatal assessment of growth in twins the authors recommend the use of BPD and abdominal circumference charts derived specifically from such uncomplicated twin pregnancies. When the BPD growth is abnormal, the head circumference and abdominal circumference should be measured to assess whether or not fetal growth is normal.

Urinary estriols in diabetic pregnancy: a reappraisal.

The clinical usefulness of serial urinary estriols was tested in 138 insulin-dependent diabetic pregnant women. No action was taken on an estriol drop if fetal well-being was demonstrated by a reactive nonstress test and/or negative contraction stress test within 24 hours. Of 3085 estriol values, a greater than or equal to 40% estriol drop, confirmed by a greater than or equal to 40% decrease in the estriol-creatine ratio, was observed in 21 tests. In only two of these tests, was fetal distress indicated by a nonstress test or contraction stress test. A significant linear correlation was demonstrated between the mean level of estriol excretion and birth weight, placental weight, and fetal abdominal circumference measured by ultrasound. Chronically low estriol excretion (less than 12 mg per 24 hours at greater than 36 weeks' gestation) related to smaller placentas but not to fetal jeopardy.

Placenta accreta is associated with elevated maternal serum alpha-fetoprotein.

OBJECTIVE: To determine whether placenta accreta/percreta/increta is associated with elevation of second-trimester maternal serum alpha-fetoprotein (MSAFP) levels. METHODS: We reviewed the medical records of 44 women who had emergency cesarean hysterectomy. Twenty women had placenta accreta/percreta/increta (study group) and 24 underwent cesarean hysterectomy for other indications (control group). Pertinent maternal and neonatal variables were abstracted from the prenatal records and hospital charts. Chi-square and Fisher exact tests were used to analyze categorical variables. Student t test was used to analyze continuous variables. RESULTS: Nine of 20 patients (45%) with placenta accreta/percreta/increta and none of 24 subjects in the control group had an elevated MSAFP value (P < .001). Maternal estimated blood loss was also significantly greater in the study group (4469 +/- 1851 versus 1885 +/- 1113 mL; P < .0001), as was the number of blood units transfused (7.7 +/- 4.7 versus 3.0 +/- 2.2; P < .001). None of the other examined variables were different between the groups. CONCLUSIONS: A significant association exists between placenta accreta/percreta/increta and elevated MSAFP values. Patients with an unexplained elevation of MSAFP may have an increased risk for placenta accreta and associated blood loss at cesarean hysterectomy.

Soluble tumor necrosis factor receptors and interleukin-6 levels in patients with severe preeclampsia.

OBJECTIVE: To investigate whether serum and amniotic fluid (AF) levels of soluble tumor necrosis factor receptors and interleukin-6, markers of immune activation and endothelial dysfunction, are altered in patients with severe preeclampsia. METHODS: Plasma was collected before induction of labor, at delivery, and postpartum from 19 patients with severe preeclampsia. Amniotic fluid was also obtained in early labor from these patients. Similar samples were obtained from an antepartum control group matched for gestational age and a term control group without preeclampsia. All plasma and AF samples were assayed for p55 and p75 soluble tumor necrosis factor receptors and for interleukin-6 by specific enzyme-linked immunoassays. Levels in preeclamptic patients and the control groups were compared. RESULTS: Levels of both receptors were significantly elevated in AF and all maternal plasma samples except those collected 24 hours postpartum for patients with preeclampsia relative to levels in controls. Interleukin-6 was detected more frequently and in higher concentrations in the plasma collected before labor for preeclamptic patients compared with controls, but no difference was noted in interleukin-6 detection rates or plasma concentrations at delivery. Conversely, AF concentrations of interleukin-6 were significantly reduced in patients with preeclampsia. CONCLUSION: The increased levels of soluble tumor necrosis factor receptors found in patients with severe preeclampsia may represent a protective response to increased tumor necrosis factor activity and be a marker for immune activation. Increased interleukin-6 concentrations in maternal plasma before labor suggest the involvement of this cytokine as well in the altered immune response and its contribution to endothelial cell dysfunction.

Diabetic macrosomia: accuracy of third trimester ultrasound.

Sonar biparietal diameter, head circumference, and abdominal circumference percentile values obtained late in the third trimester were compared with birth weight percentile (relative to dates) in 147 diabetic mothers and 40 control fetuses of nondiabetics. Estimates of fetal weight by the method of Shepard et al were also calculated from these sonar data and compared with birth weight percentile. Abdominal circumference values greater than the 90th percentile correctly predicted macrosomia (defined as birth weight greater than 90th percentile) in 78% of cases. Biparietal diameter and head circumference percentiles were significantly less predictive of macrosomia. When analyzed in a similar manner, estimated fetal weights greater than the 90th percentile correctly predicted macrosomia at birth in 74% of cases. However, when both the abdominal circumference and the estimated fetal weight exceeded the 90th percentile, macrosomia was correctly diagnosed in 88.8% of pregnant women with diabetes mellitus.

Risk of cesarean delivery with elective induction of labor at term in nulliparous women.

OBJECTIVE: To quantify the risk of cesarean delivery associated with elective induction of labor in nulliparous women at term. METHODS: We performed a cohort study on a major urban obstetric service that serves predominantly private obstetric practices. All term, nulliparous women with vertex, singleton gestations who labored during an 8-month period (n = 1561) were divided into three groups: spontaneous labor, elective induction, and medical induction. The risk of cesarean delivery in the induction groups was determined using stepwise logistic regression to control for potential confounding factors. RESULTS: Women experiencing spontaneous labor had a 7.8% cesarean delivery rate, whereas women undergoing elective labor induction had a 17.5% cesarean delivery rate (adjusted odds ratio [OR] 1.89; 95% confidence interval [CI] 1.12, 3.18) and women undergoing medically indicated labor induction had a 17.7% cesarean delivery rate (OR 1.69; 95% CI 1.13, 2.54). Other variables that remained significant risk factors for cesarean delivery in the model included: epidural placement at less than 4 cm dilatation (OR 4.66; 95% CI 2.25, 9.66), epidural placement after 4 cm dilatation (OR 2.18; 95% CI 1.06, 4.48), chorioamnionitis (OR 4.61; 95% CI 2.89, 7.35), birth weight greater than 4000 g (OR 2.59; 95% CI 1.69, 3.97), maternal body mass index greater than 26 kg/m2 (OR 2.36; 95% CI 1.61, 3.47), Asian race (OR 2.35; 95% CI 1.04, 5.34), and magnesium sulfate use (OR 2.18; 95% CI 1.04, 4.55). CONCLUSION: Elective induction of labor is associated with a significantly increased risk of cesarean delivery in nulliparous women. Avoiding labor induction in settings of unproved benefit may aid efforts to reduce the primary cesarean delivery rate.

Iatrogenic respiratory distress syndrome following elective repeat cesarean delivery.

OBJECTIVE: To determine the incidence of iatrogenic respiratory distress syndrome (RDS) following elective repeat cesarean delivery and to identify whether it was associated with departures from accepted management guidelines. METHODS: Between January 1986 and March 1991, there were 23,125 deliveries at Northwestern Memorial Hospital, of which 1207 were repeat cesarean births without labor. During this period, 18 neonates of 37 weeks' gestation or greater or 2500 g or greater who were delivered by elective repeat cesarean were admitted to the neonatal intensive care unit (NICU) for respiratory difficulties. RESULTS: Five of the 18 neonates admitted to the NICU with respiratory difficulty following elective repeat cesarean delivery met the criteria for RDS. This represents an incidence of 0.41% (five of 1207), or one case of RDS for every 241 repeat cesarean deliveries without labor. Four of the five neonates required mechanical ventilation for an average of 6.8 days. The average NICU stay was 11.2 days. Complications included pneumothorax (one) and pulmonary hemorrhage (one). Departures from accepted management guidelines included a discrepancy between ultrasound and menstrual dates (two), no confirmation of menstrual dates (one), and delivery before 39 weeks' gestation (two). CONCLUSION: Iatrogenic RDS continues to occur in the setting of elective repeat cesarean delivery and is associated with a failure to adhere to clinical protocols.

Diagnosis of fetal death in utero by real-time ultrasound.

The efficacy of real-time ultrasound for the diagnosis of fetal death or hydatidiform mole was evaluated during a 1-year period. During this time, 116 patients were referred to the obstetric ultrasound service for the confirmation of clinical diagnoses. In 24 of 46 patients (52%) presenting in the first half of pregnancy, the referring diagnosis was confirmed. In 1 case of an early intrauterine pregnancy with a degenerating myoma, the ultrasound diagnosis of molar pregnancy was in error. In 48 of 70 patients (69%) referred after 20 weeks' gestation, the clinical diagnosis was confirmed. In no instance was either a false-positive or false-negative diagnosis made with real-time ultrasound in the last half of pregnancy. This method should prove to be the method of choice in diagnosing intrauterine fetal death.

Active management of labor.

The active management of labor may be one approach to achieving lower rates of intervention. Numerous institutions have reported lower CS rates since initiating this labor management scheme, and concurrent decreases in the length of labor and infectious morbidity have been demonstrated. Sufficient data now exist to conclude that such programs can be instituted without deleterious effects on neonatal outcomes. Nevertheless, success in decreasing CS rates has not been uniform and may be confined to certain settings. Other approaches to labor management may be as good or better at achieving low rates of intervention with minimum morbidity. Any approach that emphasizes advocacy for vaginal birth is likely to produce some success and should receive support.