Orphan gene in Littorina: An unexpected role of symbionts in the host evolution

Mechanisms of reproductive isolation between closely related sympatric species are of high evolutionary significance as they may function as initial drivers of speciation and protect species integrity afterwards. Proteins involved in the establishment of reproductive barriers often evolve fast and may be key players in cessation of gene flow between the incipient species. The five Atlantic Littorina (Neritrema) species represent a notable example of recent radiation. The geographic ranges of these young species largely overlap and the mechanisms of reproductive isolation are poorly understood. In this study, we performed a detailed analysis of the reproductive protein LOSP, previously identified in Littorina. We showed that this protein is evolutionary young and taxonomically restricted to the genus Littorina. It has high sequence variation both within and between Littorina species, which is compatible with its presumable role in the reproductive isolation. The strongest differences in the LOSP structure were detected between Littorina subgenera with distinctive repetitive motifs present exclusively in the Neritrema species, but not in L. littorea. Moreover, the sequence of these repetitive structural elements demonstrates a high homology with genetic elements of bacteria, identified as components of Littorina associated microbiomes. We suggest that these elements were acquired from a symbiotic bacterial donor via horizontal genetic transfer (HGT), which is indirectly confirmed by the presence of multiple transposable elements in the LOSP flanking and intronic regions. Furthermore, we hypothesize that this HGT-driven evolutionary innovation promoted LOSP function in reproductive isolation, which might be one of the factors determining the intensive cladogenesis in the Littorina (Neritrema) lineage in contrast to the anagenesis in the L. littorea clade.

Live birth after treatment of a spontaneous ovarian heterotopic pregnancy: A case report

Spontaneous heterotopic pregnancies occur in about 1/30000 pregnancies, with the ovarian subtype comprising 2.3% of the total. We report the case of a healthy 32-year-old woman, gravida 4, para 3, who presented to the emergency room with severe abdominal pain. Two weeks earlier, pelvic ultrasound had revealed a 6-week intrauterine pregnancy. She was hemodynamically stable, but had rebound tenderness on the right iliac fossa. Transvaginal ultrasound revealed an evolutive intrauterine pregnancy with a gestational age (GA) of 8 weeks, with a synchronous evolutive adnexal pregnancy of the same GA and some free fluid in the pouch of Douglas. She underwent an urgent laparoscopy which showed an intact gestational sac containing an embryo on the right ovary associated with mild hemoperitoneum. An ovarian wedge resection was performed to preserve ovarian tissue. The intrauterine pregnancy had no complications and the patient delivered vaginally at term. Heterotopic pregnancy is potentially life-threatening. Despite being extremely rare after natural conception, and even more so in the absence of major risk factors, it should be considered in any pregnant woman with abdominal pain. A high index of suspicion is important for a prompt diagnosis, selection of the appropriate surgical treatment and successful obstetric outcomes.

Hydrocele of the canal of Nuck presenting as a sausage-shaped mass

A 23-year-old woman presented with a painless vulval swelling. On physical examination, a soft fluctuant sausage-shaped mass was found, measuring approximately 4 cm, extending from the right inguinal region to the labia majora. Ultrasound revealed a well-defined hypoechoic elongated mass, septated, extending from the superficial inguinal canal to labia majora. Sonographic findings were consistent with the diagnosis of a hydrocele of the canal of Nuck. Surgical exploration revealed an elongated cystic lesion with a total length of 13 cm, mucous component and internal septations. Histopathological examination of the surgical specimen confirmed the suspected diagnosis.

Clinical features and long-term progression of reticular pseudodrusen in age-related macular degeneration: findings from a multicenter cohort

PurposeTo determine whether reticular pseudodrusen (RPD) confer a long-term increased risk of progression to late age-related macular degeneration (AMD) in the fellow eye of patients with unilateral wet-AMD.Patients and methodsThis was a multicenter, combined prospective and retrospective, longitudinal, observational, study. Patients with wet-AMD in one eye were recruited from two centers and evaluated on the risk of progression to late-AMD in the second eye (study eye). A minimum follow-up of 5 years was required, unless progression occurred first. Baseline retinal profile of patients was evaluated using multimodal imaging. Baseline images were graded by two separate centers.ResultsWe recruited 88 patients (48 female) with a mean age of 75.6±7.1 years and mean follow-up of 65.7±20.9 months. Baseline prevalence of RPD was 58% (n=51). There was no statistically significant association of RPD with increased age (P=0.29) or sex distribution (P=0.39). The most sensitive image modality for RPD was IR (93%), followed by FAF (92%), OCT (74%, RF (33%) and CFP (29%). After 5 years, 54.50% (n=48) of the study eyes progressed to late-AMD. Of those, 81.25% (n=39) developed CNV and 18.75% (n=9) geographic atrophy. After correcting for age and sex, the presence of RPD was significantly associated with development of late-stage AMD (OR=2.55, P=0.03).ConclusionA multimodal approach is mandatory for RPD detection. RPD are highly prevalent in the fellow eyes of patients with unilateral neovascular AMD. Presence of RPD is associated with increased long-term risk of progression, highlighting the importance of comprehensive multimodal retinal imaging and careful monitoring of at-risk patients.

Temporal SNR characteristics in segmented 3D-EPI at 7T

Three-dimensional segmented echo planar imaging (3D-EPI) is a promising approach for high-resolution functional magnetic resonance imaging, as it provides an increased signal-to-noise ratio (SNR) at similar temporal resolution to traditional multislice 2D-EPI readouts. Recently, the 3D-EPI technique has become more frequently used and it is important to better understand its implications for fMRI. In this study, the temporal SNR characteristics of 3D-EPI with varying numbers of segments are studied. It is shown that, in humans, the temporal variance increases with the number of segments used to form the EPI acquisition and that for segmented acquisitions, the maximum available temporal SNR is reduced compared to single shot acquisitions. This reduction with increased segmentation is not found in phantom data and thus likely due to physiological processes. When operating in the thermal noise dominated regime, fMRI experiments with a motor task revealed that the 3D variant outperforms the 2D-EPI in terms of temporal SNR and sensitivity to detect activated brain regions. Thus, the theoretical SNR advantage of a segmented 3D-EPI sequence for fMRI only exists in a low SNR situation. However, other advantages of 3D-EPI, such as the application of parallel imaging techniques in two dimensions and the low specific absorption rate requirements, may encourage the use of the 3D-EPI sequence for fMRI in situations with higher SNR.

Prenatal diagnosis of persistent urogenital sinus with duplicated hydrometrocolpos and ascites--a case report

We report a successful case of persistent urogenital sinus associated with a duplicated nonsyndromic form of hydrometrocolpos and ascites diagnosed prenatally. Though urogenital malformations are extremely rare and variable in presentation, the conjugation of those anomalies in a newborn is reported here for the first time. Prenatal ultrasound diagnosis was suspected at 25 weeks' gestation and MRI imaging supported the diagnosis. Periodic ultrasound surveillance was conducted until birth at 35 weeks' gestation by cesarean section. The presumptive diagnosis was confirmed after birth. One month later, the newborn underwent reconstructive surgical intervention with good outcome.

MicroRNA expression variability in human cervical tissues

MicroRNAs (miRNAs) are short (∼22 nt) non-coding regulatory RNAs that control gene expression at the post-transcriptional level. Deregulation of miRNA expression has been discovered in a wide variety of tumours and it is now clear that they contribute to cancer development and progression. Cervical cancer is one of the most common cancers in women worldwide and there is a strong need for a non-invasive, fast and efficient method to diagnose the disease. We investigated miRNA expression profiles in cervical cancer using a microarray platform containing probes for mature miRNAs. We have evaluated miRNA expression profiles of a heterogeneous set of cervical tissues from 25 different patients. This set included 19 normal cervical tissues, 4 squamous cell carcinoma, 5 high-grade squamous intraepithelial lesion (HSIL) and 9 low-grade squamous intraepithelial lesion (LSIL) samples. We observed high variability in miRNA expression especially among normal cervical samples, which prevented us from obtaining a unique miRNA expression signature for this tumour type. However, deregulated miRNAs were identified in malignant and pre-malignant cervical tissues after tackling the high expression variability observed. We were also able to identify putative target genes of relevant candidate miRNAs. Our results show that miRNA expression shows natural variability among human samples, which complicates miRNA data profiling analysis. However, such expression noise can be filtered and does not prevent the identification of deregulated miRNAs that play a role in the malignant transformation of cervical squamous cells. Deregulated miRNAs highlight new candidate gene targets allowing for a better understanding of the molecular mechanism underlying the development of this tumour type.

Prenatal ultrasonographic diagnosis of vein of Galen aneurysms--report of two cases

Aneurysms of the vein of Galen (AVG) represent less than 1% of all intracranial arteriovenous malformations. Two cases of prenatal diagnosis made by color Doppler ultrasonography at 32 weeks of gestation are reported. Both cases presented with antenatal mild cardiomegaly and both developed severe cardiac failure in the neonatal period. Embolization was unsuccessful and both infants died. These cases highlight the need for a careful evaluation of the time and mode of delivery; embolization must be performed after a fully informed decision.

[B-Lynch suture in post partum hemorrhage]

Post partum hemorrhage is a major cause of maternal morbidity and mortality. We describe a case of a woman with post partum hemorrhage due to uterine atony, successfully treated with B-Lynch suture. The authors review the causes and risk factors, and the range of medical and surgical options that may be considered for the management of post partum hemorrhage.

Intermolecular multiple quantum coherences at high magnetic field: The nonlinear regime

Experiments have been carried at magnetic-field strengths of 9.4, 14.1, and 17.6 T to explore the evolution of intermolecular multiple quantum coherences in the nonlinear regime where the system evolves for times that are much greater than the characteristic time of action of the long-range dipolar field, tau(d). The results show the expected Bessel function form of the recorded signal as a function of time of evolution, with evident zeros and sign changes. As expected, the rate of signal evolution increases at higher-field strengths as a result of the increased equilibrium magnetization. A numerical method for calculating the evolution of magnetization under the action of the distant dipolar field, relaxation, and diffusion that is based on Fourier analysis of the magnetization distribution has been applied to the correlated two-dimensional spectroscopy revamped by asymmetric z-gradient echo detection sequence in the nonlinear regime and shown to produce results that are in good agreement with experimental data acquired at different magnetic fields and rates of spatial modulation. Experiments and simulations have also been used to explore the evolution of magnetization in a mixture of two interacting spin species in the nonlinear regime.

Targeting of EGFP chimeras within chloroplasts

We have tested the potential of EGFP, a derivative of the green fluorescent protein (GFP), as a passenger protein for the analysis of protein transport processes across the thylakoid membranes in chloroplasts. In contrast to the majority of fusion proteins commonly used in such studies, EGFP is not of plant origin and can therefore be assumed to behave like a "neutral" passenger protein that is unaffected by any internal plant regulatory circuits. Our in vitro transport experiments clearly demonstrate that EGFP is a suitable passenger protein that can be correctly targeted either to the stroma or to the thylakoid lumen if fused to the appropriate transit peptide. The transport of EGFP across the thylakoid membrane shows, however, a clear pathway preference. While the protein is efficiently targeted by the deltapH/TAT pathway, transport by the Sec pathway is barely detectable, either with isolated thylakoids or with intact chloroplasts. This pathway specificity suggests that EGFP is folded immediately after import into the chloroplast stroma, thus preventing further translocation across the thylakoid membrane by the Sec translocase. The data obtained provide a good basis for the development of molecular tools for transport studies using EGFP as a passenger protein. Furthermore, plant lines expressing corresponding EGFP chimeras are expected to allow in vivo studies on the transport and sorting mechanisms involved in the biogenesis of the chloroplast.

Optimizing the sequence parameters for double-quantum CRAZED imaging

The evolution of magnetization during repeated application of the double-quantum-(DQ)-CRAZED sequence is analyzed, with the aim of identifying sequence parameters that maximize sensitivity to signal produced by the distant dipole field (DDF). Phase cycling schemes that allow cancellation of signals following undesired coherence pathways are also described. Simulations and imaging experiments carried out at 3 T on phantoms and the human head were used to verify the analysis. The results indicate that in the absence of phase cycling, the DDF-related signal-to-noise ratio (SNR) per unit time is maximized using TR=2.05 T1, along with values of the RF flip angles (alpha approximately 90 degrees and beta approximately 60 degrees ), and echo time (TE=T2) that have previously been shown to maximize the DDF-related signal at long TR. However, with TR=2.05 T1 there can also be a significant signal contribution due to stimulated echo effects (up to 40% of the signal for water at 3 T and TE=70 ms). Using a two-step phase cycle, the stimulated echo signal is eliminated and the maximum SNR per unit time occurs for TR=2.76 T1. It is also demonstrated that sensitivity to signal changes caused by small variations in T2 is maximized by setting TE=2T2.

An upstream U-snRNA gene-like promoter is required for transcription of the Arabidopsis thaliana 7SL RNA gene

The genes transcribed by RNA polymerase (pol) III can be placed into four distinct groups based on the nature and position of their promoter elements. In the higher eukaryotes equivalent genes usually belong to the same sub-type of pol III promoters and there are few examples of genes which have changed promoter type during evolution. In this work we demonstrate that the promoter of the Arabidopsis thaliana 7SL RNA gene is located upstream of the coding region and is identical to the promoters of pol III-specific plant U-small nuclear RNA (U-snRNA) genes. Sequence analysis of two different 7SL genes from A. thaliana revealed that both genes contain two sequence elements in their 5' flanking regions identical in sequence and position to the highly conserved USE and TATA elements of the pol III-transcribed plant U-snRNA genes. Mutational analysis of these elements in the At7SL-2 gene indicates that the USE and TATA elements are both necessary and account for > or = 90% of the transcriptional activity of this gene in transfected plant protoplasts. Within the coding region of both genes there is a sequence element which is a 10/11 nt match to the consensus B-box element of tRNA genes, however, this element is not important for gene activity. These findings distinguish the plant genes from the human 7SL gene, which has both internal and upstream promoter elements and its upstream elements are different from those found in the human U-snRNA genes.

[Relationship between the Steuart resistance index of the umbilical artery in non-pathologic pregnancy and the weight and ponderal index of the newborn]

Umbilical artery Doppler velocimetry was performed at 28-32 and 36-38 weeks of gestation in a low risk population to correlate the Stuart's resistance index (Sistole/Diastole--S/D) to the weight and ponderal index of the newborn, and to determine the preditive value of S/D ratio greater than the 95 centil in the screening of newborns of weight or ponderal index lower than the 10 centil. Two hundred and eight two pregnant women were studied (146 at 28-32 weeks; 221 at 36-38 weeks) and Stuart Resistance Index was obtained by a continuous wave Doppler System. In both periods we had an inversely proportional correlation between the resistance index and the weight and ponderal index of the newborn; nevertheless the low sensibility and preditive value of the test shows that it should not be used as an isolated diagnostic tool to screen a low risk population for newborns with a low weight or low ponderal index.