Radiomic-based nonlinear supervised learning classifiers on non-contrast CT to predict functional prognosis in patients with spontaneous intracerebral hematoma

PURPOSE

To evaluate if nonlinear supervised learning classifiers based on non-contrast CT can predict functional prognosis at discharge in patients with spontaneous intracerebral hematoma.

METHODS

Retrospective, single-center, observational analysis of patients with a diagnosis of spontaneous intracerebral hematoma confirmed by non-contrast CT between January 2016 and April 2018. Patients with HIE > 18 years and with TCCSC performed within the first 24 h of symptom onset were included. Patients with secondary spontaneous intracerebral hematoma and in whom radiomic variables were not available were excluded. Clinical, demographic and admission variables were collected. Patients were classified according to the Modified Rankin Scale (mRS) at discharge into good (mRS 0-2) and poor prognosis (mRS 3-6). After manual segmentation of each spontaneous intracerebral hematoma, the radiomics variables were obtained. The sample was divided into a training and testing cohort and a validation cohort (70-30% respectively). Different methods of variable selection and dimensionality reduction were used, and different algorithms were used for model construction. Stratified 10-fold cross-validation were performed on the training and testing cohort and the mean area under the curve (AUC) were calculated. Once the models were trained, the sensitivity of each was calculated to predict functional prognosis at discharge in the validation cohort.

RESULTS

105 patients with spontaneous intracerebral hematoma were analyzed. 105 radiomic variables were evaluated for each patient. P-SVM, KNN-E and RF-10 algorithms, in combination with the ANOVA variable selection method, were the best performing classifiers in the training and testing cohort (AUC 0.798, 0.752 and 0.742 respectively). The predictions of these models, in the validation cohort, had a sensitivity of 0.897 (0.778-1;95%CI), with a false-negative rate of 0% for predicting poor functional prognosis at discharge.

CONCLUSION

The use of radiomics-based nonlinear supervised learning classifiers are a promising diagnostic tool for predicting functional outcome at discharge in HIE patients, with a low false negative rate, although larger and balanced samples are still needed to develop and improve their performance.

SQ HDM sublingual immunotherapy tablet for the treatment of HDM allergic rhinitis and asthma improves subjective sleepiness and insomnia: an exploratory analysis of the real-life CARIOCA study

BACKGROUND AND OBJECTIVE

There are still gaps in the knowledge regarding the effectiveness of house dust mite (HDM) sublingual immunotherapy (SLIT) on allergic rhinitis (AR) and asthma (AA)-associated sleep disorders. A non-interventional study was conducted to assess the effect of the Standardized quality (SQ) HDM SLIT-tablet on safety and symptoms in adults with HDM respiratory allergies. The aim was to describe the status of insomnia and daytime sleepiness in AR and/or AA patients treated with the SQ HDM SLIT-tablet.

METHODS

This was a 12-month multicenter, longitudinal and prospective study. Participants started the SQ HDM SLIT-tablet for moderate-to-severe HDM AR, persistent despite the use of symptom-relieving medication; or HDM AA not well controlled by inhaled corticosteroids and associated with mild-to-severe HDM AR. Sleep symptoms were measured using the Insomnia Severity Index (ISI) questionnaire and the Epworth Sleepiness Scale (ESS).

RESULTS

A total of 1,526 adult patients were enrolled and 1,483 were included in the analysis. At baseline, 41.5% of patients reported sleep disorders: 77.0% of them had insomnia and 28.9% suffered from excessive daytime sleepiness. Insomnia was significantly more frequent among patients with uncontrolled AR (83.1%) than those with controlled AR (52.6%) (p<0.0001). Over time, 48.3% and 59.7% of patients reported an improvement greater than the minimal clinically important difference on the ISI and ESS scales respectively.

CONCLUSION

In patients with HDM AR and/or asthma associated sleep disorders, an improvement in subjective insomnia and sleepiness was observed after one year of treatment with the SQ HDM SLIT-tablet in a real-life setting.

Dual pathogenicity island transfer by piggybacking lateral transduction

Lateral transduction (LT) is the process by which temperate phages mobilize large sections of bacterial genomes. Despite its importance, LT has only been observed during prophage induction. Here, we report that superantigen-carrying staphylococcal pathogenicity islands (SaPIs) employ a related but more versatile and complex mechanism of gene transfer to drive chromosomal hypermobility while self-transferring with additional virulence genes from the host. We found that after phage infection or prophage induction, activated SaPIs form concatamers in the bacterial chromosome by switching between parallel genomic tracks in replication bubbles. This dynamic life cycle enables SaPIbov1 to piggyback its LT of staphylococcal pathogenicity island vSaα, which encodes an array of genes involved in host-pathogen interactions, allowing both islands to be mobilized intact and transferred in a single infective particle. Our findings highlight previously unknown roles of pathogenicity islands in bacterial virulence and show that their evolutionary impact extends beyond the genes they carry.

Difficult withdrawal of an inferior vena cava filter: Technical considerations and associated variables

OBJECTIVE

To analyse the efficacy of the procedure for withdrawing an inferior vena cava (IVC) filter and the clinical and radiological factors associated with difficult withdrawal.

MATERIAL AND METHODS

This retrospective observational study included patients who underwent IVC filter withdrawal at a single centre between May 2015 and May 2021. We recorded demographic, clinical, procedural, and radiological variables: type of IVC filter, angle with the IVC > 15°, hook against the wall, and legs embedded in the IVC wall > 3 mm. The efficacy variables were fluoroscopy time, success of IVC filter withdrawal, and number of attempts to withdraw the filter. The safety variables were complications, surgical removal, and mortality. The main variable was difficult withdrawal, defined as more than 5 min fluoroscopy or more than 1 attempt at withdrawal.

RESULTS

A total of 109 patients were included; withdrawal was considered difficult in 54 (49.5%). Three radiological variables were more common in the difficult withdrawal group: hook against the wall (33.3% vs. 9.1%; p = 0.027), embedded legs (20.4% vs. 3.6%; p = 0.008), and >45 days since IVC filter placement (51.9% vs. 25.5%; p = 0.006). These variables remained significant in the subgroup of patients with OptEase IVC filters; however, in the group of patients with Celect IVC filters, only the inclination of the IVC filter >15 ° was significantly associated with difficult withdrawal (25% vs 0%; p = 0.029).

CONCLUSION

Difficult withdrawal was associated with time from IVC placement, embedded legs, and contact between the hook and the wall. The analysis of the subgroups of patients with different types of IVC filters found that these variables remained significant in those with OptEase filters; however, in those with cone-shaped devices (Celect), the inclination of the IVC filter >15° was significantly associated with difficult withdrawal.

The RecD2 helicase balances RecA activities

DNA helicases of the RecD2 family are ubiquitous. Bacillus subtilis RecD2 in association with the single-stranded binding protein SsbA may contribute to replication fork progression, but its detailed action remains unknown. In this work, we explore the role of RecD2 during DNA replication and its interaction with the RecA recombinase. RecD2 inhibits replication restart, but this effect is not observed in the absence of SsbA. RecD2 slightly affects replication elongation. RecA inhibits leading and lagging strand synthesis, and RecD2, which physically interacts with RecA, counteracts this negative effect. In vivo results show that recD2 inactivation promotes RecA–ssDNA accumulation at low mitomycin C levels, and that RecA threads persist for a longer time after induction of DNA damage. In vitro, RecD2 modulates RecA-mediated DNA strand-exchange and catalyzes branch migration. These findings contribute to our understanding of how RecD2 may contribute to overcome a replicative stress, removing RecA from the ssDNA and, thus, it may act as a negative modulator of RecA filament growth.

P–781 Birthweight is not affected by freezing process. Results from a quasi-experimental study using the Oocyte Donation Model

Study question

Is the freezing process responsible to increase the birthweight or the incidence of Large for Gestational Age (LGA) in Frozen Embryo Transfers (FET)?

Summary answer

Neither the birthweight nor the LGA incidence were different in embryos that underwent the freezing-thawing process.

What is known already

Freezing-thawing constitutes one of the processes with a potential impact on the health of the newborn. Data coming from register-based studies and metaanalisis have found an increase in birthweight with a higher incidence of LGA in newborns coming from FET. This is a matter of concern since epigenetic alterations have been suggested to explain this finding casting doubts on future health during childhood and adulthood. Clarifying the safety of cryotechniques should be a priority taken into account that at present frozen embryo transfers outnumber fresh embryo transfers in IVF clinics.

Study design, size, duration

This retrospective cohort study evaluated 670 women oocyte recipients who underwent fresh (367 cycles) or frozen embryo transfer (303 cycles) at Instituto Bernabeu between July 2017 and March 2019. All recipients were prepared with substitutive cycle and received single blastocyst embryo transfers on day five. All of them at the same culture medium, resulting in a singleton live birth.

Participants/materials, setting, methods

1637 patients were assessed for eligibility but 967 were excluded. The sample size has been calculated accepting an alpha risk of 5% and a beta risk of 20%. A sample size of 266 patients (133 per group) is required to detect a minimum mean difference of 275 grams with a standard deviation of 800 grams. Pearsońs Chi-square test (univariate) and binary logistic regression (multivariate for confounding factors) were used to analyze association between variables.

Main results and the role of chance

Maternal age (42.21 ± 4.45; 42.79 ± 3.83 p = 0.519), BMI (23.34 ± 3.69; 24.99 ± 15.52; p = 0.060), maternal parity (Nulliparous 81.5%; 85.5%; Multiparous 18.5%; 14.5% p = 0.177), gestational diabetes (4.9%; 4.3% p = 0.854), preeclampsia (2.7%; 5.6% p = 0.074), hypertensive disorders (3.3%; 2.3% p = 0.494), maternal smoking (10.8%; 13.0% p = 0.475), gestational age (38.96 ± 1.97; 38.77 ± 2.15; p = 0.207) and liveborn gender (Female 44.5%; 48.8%; Male 55.5%; 51.2%p=0.276) do not present statistically significant differences between fresh or frozen groups, respectively.

However endometrial thickness was statistically signiticantly different in both groups (8.83mm ± 1.73 fresh; 8.57mm ± 1.59 frozen p = 0.035)

The mean birthweight did not present statistically significant differences (3239.21 ± 550.43 fresh; 3224.56 ± 570.83 frozen p = 0.211). There were also no differences regarding macrosomy (7.1% fresh; 6.3% frozen p = 0.317), LGA (6.0% fresh; 6.7% frozen p = 0.866), pre-term birth (10.9% fresh; 9.0% frozen p = 0.988), very pre-term birth (0.8% fresh; 1.3% frozen p = 0.999), and extremely pre-term birth (0% fresh; 1.0% frozen p = 0.998).

There were statistically significant differences regarding underweight (10.0% fresh; 7.0% frozen p = 0.020), but there were no differences in very low weight (0.6 fresh; 1.1% frozen p = 0.972) and SGA (1.9% fresh; 0.7% frozen p = 0.432).

Limitations, reasons for caution

Despite a quasi-experimental design, the synchronization in fresh embryo transfer drove to a longer preparation with a thicker endometrium. It’s not possible to rule-out the influence in the results of this parameter.

Wider implications of the findings: As a hypothesis, the increase in birthweight and/or an abnormal placentation in FET could be explained by the endometrial preparation more than the freezing process. Studies must be planned in the future to explore the possibility of changes in the birthweight between embryos transferred in natural vs artificial endometrial preparations.

Trial registration number

Not applicable

Nucleoid-associated Rok differentially affects chromosomal transformation on Bacillus subtilis recombination-deficient cells

Rok, a Bacillus subtilis nucleoid-associated protein (NAP), negatively regulates competence development and silences xenogeneic genes. We show that rok inactivation increases rpoB482 natural intraspecies chromosomal transformation (CT) and plasmid transformation to a different extent. In ΔaddAB, ΔrecO, recF15, ΔrecU, ΔruvAB or rec⁺ cells intraspecies CT significantly increases, but the ΔrecD2 mutation reduces, and the ΔrecX, ΔradA or ΔdprA mutation further decreases CT in the Δrok context when compared to rok⁺ cells. These observations support the idea that rok inactivation, by altering the topology of the recipient DNA, differentially affects the integration of homologous DNA in rec-deficient strains, and in minor extent the competent subpopulation size. The impairment of other NAP (Hbsu or LrpC) also increased intra- and interspecies CT (nonself-DNA, ~8% nucleotide sequence divergence) in rec⁺ cells, but differentially reduced both types of CTs in certain rec-deficient strains. We describe that rok inactivation significantly stimulates intra and interspecies CT but differentially reduces them in transformation-deficient cells, perhaps by altering the nucleoid architecture. We extend the observation to other NAPs (Hbsu, LrpC).

Polyhydroxyalkanoates production from fermented domestic wastewater using phototrophic mixed cultures

Phototrophic mixed cultures (PMC) have been found to be a promising technology to produce polyhydroxyalkanoates (PHA), however, work performed thus far has focussed mainly on the use of synthetic feedstocks and operational conditions that differ from those expectable in full-scale processes. The goals of this work were to study, for the first time, the capability of PMCs to produce PHA using real fermented domestic wastewater as feedstock under mixing/light/temperature conditions that are naturally found in outdoor open systems. Various operational strategies were evaluated in this study to increase PHA productivity, namely the poly(3-hydroxybutyric-co-3-hydroxyvaleric) copolymer (PHBV) by PMC systems. Two lab-scale photobioreactors were operated in parallel, with transient illumination (12 h light/12 h dark) and subjected to feedstock fluctuations under two culture selection strategies that best suit the oxidative conditions of high rate algal ponds (HRAPs) which are commonly applied in wastewater treatment plants (WWTP). Under a permanent carbon feast regime (selection strategy 1), the PMC became highly enriched in phototrophic purple bacteria (PPB), and two complementary conditions that can improve the selection of PHA accumulating bacteria were discovered: phosphate cycling, where 20% PHA/VSS (86HB:14HV in a C-mol basis) with a light phase productivity of 0.23 g PHA/L•d_light phase was attained; and transitioning from selection under low organic loading rate (OLR) to high OLR where 17.6% PHA/VSS (60HB:40HV in C base) with a light phase productivity of 0.18 g PHA/L•d_light phase was achieved. Under a feast and famine regime (selection strategy 2), a PMC consortium of microalgae and PPB was obtained, and a multiple pulse feeding strategy during the first hours of the light phase in the selector reactor led to a 26.1% PHA/VSS (36HB:64HV in C base) content, with a productivity of 0.26 g PHA/L•d_light phase and 0.52 g PHA/L•d_feast phase. An accumulation test under higher light intensity led to 30.8% PHA/VSS (85HB:15HV on a C-mol basis) with a productivity of 2.67 g PHA/L•d, along the 8 h of accumulation.

[Poor results and complications in the use of focused shockwaves and radial pressure waves in musculoskeletal pathology]

The application of focused shockwaves and radial pressure waves in musculoskeletal pathology has had a great development in the last decade. Although most of the publications have highlighted their safety and efficacy, poor results and complications can occur. This review analyzes the main causes of its poor results, adverse effects, and complications, emphasizing their prevention.

Recombination proteins differently control the acquisition of homeologous DNA during Bacillus subtilis natural chromosomal transformation

Natural chromosomal transformation (CT) plays a major role in prokaryote evolution, yet factors that govern the integration of DNA from related species remain poorly understood. We show that in naturally competent Bacillus subtilis cells the acquisition of homeologous sequences is governed by sequence divergence (SD). Integration initiates in a minimal efficient processing segment via homology-directed CT, and its frequency decreases log-linearly with increased SD up to 15%. Beyond this and up to 23% SD the interspecies boundaries prevail, the CT frequency marginally decreases, and short (<10-nucleotides) segments are integrated via homology-facilitated micro-homologous integration. Both mechanisms are RecA dependent. We identify the other recombination proteins required for the acquisition of homeologous DNA. The absence of AddAB, RecF, RecO, RuvAB or RecU, crucial for repair-by-recombination, did not affect CT. However, dprA, radA, recJ, recX or recD2 inactivation strongly decreased intraspecies and interspecies CT. Interspecies CT was not detected beyond ~8% SD in ΔdprA, ~10% in ΔrecJ, ΔradA, ΔrecX and ~14% in ΔrecD2 cells. We propose that DprA, RecX, RadA/Sms, RecJ and RecD2 accessory proteins are important for the generation of genetic diversity. Together with RecA, they facilitate gene acquisition from bacteria of related species.

Reversible regulation of conjugation of Bacillus subtilis plasmid pLS20 by the quorum sensing peptide responsive anti-repressor RappLS20

Quorum sensing plays crucial roles in bacterial communication including in the process of conjugation, which has large economical and health-related impacts by spreading antibiotic resistance. The conjugative Bacillus subtilis plasmid pLS20 uses quorum sensing to determine when to activate the conjugation genes. The main conjugation promoter, Pc, is by default repressed by a regulator RcopLS20 involving DNA looping. A plasmid-encoded signalling peptide, Phr*pLS20, inactivates the anti-repressor of RcopLS20, named RappLS20, which belongs to the large group of RRNPP family of regulatory proteins. Here we show that DNA looping occurs through interactions between two RcopLS20 tetramers, each bound to an operator site. We determined the relative promoter strengths for all the promoters involved in synthesizing the regulatory proteins of the conjugation genes, and constructed an in vivo system uncoupling these regulatory genes to show that RappLS20 is sufficient for activating conjugation in vivo. We also show that RappLS20 actively detaches RcopLS20 from DNA by preferentially acting on the RcopLS20 molecules involved in DNA looping, resulting in sequestration but not inactivation of RcopLS20. Finally, results presented here in combination with our previous results show that activation of conjugation inhibits competence and competence development inhibits conjugation, indicating that both processes are mutually exclusive.

COVID-19 and rhinology, from the consultation room to the operating theatre

The purpose of this article is to give rhinologists advice on how to adapt their standard practice during the COVID-19 pandemic. The main goal of these recommendations is to protect healthcare workers against COVID-19 while continuing to provide emergency care so as to prevent loss of chance for patients. We reviewed our recommendations concerning consultations, medical prescriptions and surgical activity in rhinology.

Bacillus subtilis RarA Acts as a Positive RecA Accessory Protein

Ubiquitous RarA AAA+ ATPases play crucial roles in the cellular response to blocked replication forks in pro- and eukaryotes. Here, we provide evidence that absence of RarA reduced the viability of ΔrecA, ΔrecO, and recF15 cells during unperturbed growth. The rarA gene was epistatic to recO and recF genes in response to H2O2- or MMS-induced DNA damage. Conversely, the inactivation of rarA partially suppressed the HR defect of mutants lacking end-resection (ΔaddAB, ΔrecJ, ΔrecQ, ΔrecS) or branch migration (ΔruvAB, ΔrecG, ΔradA) activity. RarA contributes to RecA thread formation, that are thought to be the active forms of RecA during homology search. The absence of RarA reduced RecA accumulation, and the formation of visible RecA threads in vivo upon DNA damage. When ΔrarA was combined with mutations in genuine RecA accessory genes, RecA accumulation was further reduced in ΔrarA ΔrecU and ΔrarA ΔrecX double mutant cells, and was blocked in ΔrarA recF15 cells. These results suggest that RarA contributes to the assembly of RecA nucleoprotein filaments onto single-stranded DNA, and possibly antagonizes RecA filament disassembly.

Viral SPP1 DNA is infectious in naturally competent Bacillus subtilis cells: inter- and intramolecular recombination pathways

A proteolyzed bacteriophage (phage) might release its DNA into the environment. Here, we define the recombination functions required to resurrect an infective lytic phage from inactive environmental viral DNA in naturally competent Bacillus subtilis cells. Using phage SPP1 DNA, a model that accounts for the obtained data is proposed (i) the DNA uptake apparatus takes up environmental SPP1 DNA, fragments it, and incorporates into the cytosol different linear single-stranded (ss) DNA molecules shorter than genome-length; (ii) the SsbA-DprA mediator loads RecA onto any fragmented linear SPP1 ssDNA, but negative modulators (RecX and RecU) promote a net RecA disassembly from these ssDNAs not homologous to the host genome; (iii) single strand annealing (SSA) proteins, DprA and RecO, anneal the SsbA- or SsbB-coated complementary strands, yielding tailed SPP1 duplex intermediates; (iv) RecA polymerized on these tailed intermediates invades a homologous region in another incomplete molecule, and in concert with RecD2 helicase, reconstitutes a complete linear phage genome with redundant regions at the ends of the molecule; and (v) DprA, RecO or viral G35P SSA, may catalyze the annealing of these terminally redundant regions, alone or with the help of an exonuclease, to produce a circular unit-length duplex viral genome ready to initiate replication.

Bacillus subtilis RecA interacts with and loads RadA/Sms to unwind recombination intermediates during natural chromosomal transformation

During natural transformation Bacillus subtilis RecA, polymerized onto the incoming single-stranded (ss) DNA, catalyses DNA strand invasion resulting in a displacement loop (D-loop) intermediate. A null radA mutation impairs chromosomal transformation, and RadA/Sms unwinds forked DNA in the 5′→3′ direction. We show that in the absence of RadA/Sms competent cells require the RecG translocase for natural chromosomal transformation. RadA/Sms tetracysteine motif (C13A and C13R) variants, which fail to interact with RecA, are also deficient in plasmid transformation, but this defect is suppressed by inactivating recA. The RadA/Sms C13A and C13R variants bind ssDNA, and this interaction stimulates their ATPase activity. Wild-type (wt) RadA/Sms interacts with and inhibits the ATPase activity of RecA, but RadA/Sms C13A fails to do it. RadA/Sms and its variants, C13A and C13R, bound to the 5′-tail of a DNA substrate, unwind DNA in the 5′→3′ direction. RecA interacts with and loads wt RadA/Sms to promote unwinding of a non-cognate 3′-tailed or 5′-fork DNA substrate, but RadA/Sms C13A or C13R fail to do it. We propose that wt RadA/Sms interaction with RecA is crucial to recruit the former onto D-loop DNA, and both proteins in concert catalyse D-loop extension to favour integration of ssDNA during chromosomal transformation.

Measurement of the Length of the Integrated Donor DNA during Bacillus subtilis Natural Chromosomal Transformation

For natural transformation to occur, bacterial cells must first develop a programmed physiological state called competence. Competence in Bacillus subtilis, which occurs only in a fraction of cells, is a transient stress response that allows cells to take up DNA from the environment. During natural chromosomal transformation, the internalized linear single-stranded (ss) DNA recombines with the identical (homologous) or partially identical (homeologous) sequence of the resident duplex. The length of the integrated DNA, which can be measured, depends on the percentage of sequence divergence between the donor (internalized) and the recipient (chromosomal) DNAs. The following protocol describes how to induce the development of competence in B. subtilis cells, how to transform them with donor DNAs representing different percentages of sequence divergence compared with the recipient chromosomal DNA, how to calculate the chromosomal transformation efficiency for each of them, and how to amplify the chromosomal DNA from the transformants in order to measure the length in base pairs (bp) of the integrated donor DNA.

Surface Exclusion Revisited: Function Related to Differential Expression of the Surface Exclusion System of Bacillus subtilis Plasmid pLS20

During conjugation a genetic element is transferred from a bacterial donor to a recipient cell via a connecting channel. It is the major route responsible for the spread of antibiotic resistance. Conjugative elements can contain exclusion system(s) that inhibit its transfer to a cell already harboring the element. Our limited knowledge on exclusion systems is mainly based on plasmids of Gram-negative bacteria. Here we studied the conjugative plasmid pLS20 of the Gram-positive Bacillus subtilis. We demonstrate that pLS20 contains an exclusion system and identified the single gene responsible for exclusion, named sespLS20 , which is embedded in the conjugation operon. SespLS20 is the founding member of a novel family of surface exclusion proteins encoded by conjugative elements of Gram-positive origin. We show that the extent of surface exclusion correlates with the level of sespLS20 expression, and that sespLS20 is expressed at basal low-levels in all donor cells but becomes highly expressed in conjugating cells. Accordingly, the transfer of pLS20 from a conjugation-primed donor cell to an un-primed or conjugation-primed donor is inhibited moderately and very efficiently, respectively. The consequences of this differential regulation, which appears to be a conserved feature of surface exclusion systems of Gram-positive and Gram-negative origin, are discussed.

Novel regulatory mechanism of establishment genes of conjugative plasmids

The principal route for dissemination of antibiotic resistance genes is conjugation by which a conjugative DNA element is transferred from a donor to a recipient cell. Conjugative elements contain genes that are important for their establishment in the new host, for instance by counteracting the host defense mechanisms acting against incoming foreign DNA. Little is known about these establishment genes and how they are regulated. Here, we deciphered the regulation mechanism of possible establishment genes of plasmid p576 from the Gram-positive bacterium Bacillus pumilus. Unlike the ssDNA promoters described for some conjugative plasmids, the four promoters of these p576 genes are repressed by a repressor protein, which we named Reg576. Reg576 also regulates its own expression. After transfer of the DNA, these genes are de-repressed for a period of time until sufficient Reg576 is synthesized to repress the promoters again. Complementary in vivo and in vitro analyses showed that different operator configurations in the promoter regions of these genes lead to different responses to Reg576. Each operator is bound with extreme cooperativity by two Reg576-dimers. The X-ray structure revealed that Reg576 has a Ribbon-Helix-Helix core and provided important insights into the high cooperativity of DNA recognition.

Predictive capacity of prodromal symptoms in first-episode psychosis of recent onset

BACKGROUND

Both the nature and number of a wide range of prodromal symptoms have been related to the severity and type of psychopathology in the psychotic phase. However, at present there is an incomplete picture focused mainly on the positive pre-psychotic dimension.

AIM

To characterize the prodromal phase retrospectively, examining the number and nature of prodromal symptoms as well as their relationship with psychopathology at the onset of first-episode psychosis.

METHODS

Retrospective study of 79 patients experiencing a first-episode psychosis of less than 1 year from the onset of full-blown psychosis. All patients were evaluated with a comprehensive battery of instruments including socio-demographic and clinical questionnaire, IRAOS interview, PANSS, stressful life events scale (PERI) and WAIS/WISC (vocabulary subtest). Bivariate associations and multiple regression analysis were performed.

RESULTS

Regression models revealed that several prodromal dimensions of IRAOS (delusions, affect, language, behaviour and non-hallucinatory disturbances of perception) predicted the onset of psychosis, with positive (22.4% of the variance) and disorganized (25.6% of the variance) dimensions being the most widely explained.

CONCLUSION

In addition to attenuated positive symptoms, other symptoms such as affective, behavioural and language disturbances should also be considered in the definitions criteria of at-high-risk people.

Bacillus subtilis RadA/Sms contributes to chromosomal transformation and DNA repair in concert with RecA and circumvents replicative stress in concert with DisA

Bacillus subtilis radA is epistatic to disA and recA genes in response to methyl methane sulfonate- and 4-nitroquinoline-1-oxide-induced DNA damage. We show that ΔradA cells were sensitive to mitomycin C- and H₂O₂-induced damage and impaired in natural chromosomal transformation, whereas cells lacking DisA were not. RadA/Sms mutants in the conserved H1 (K104A and K104R) or KNRFG (K255A and K255R) motifs fail to rescue the sensitivity of ΔradA in response to the four different DNA damaging agents. A RadA/Sms H1 or KNRFG mutation impairs both chromosomal and plasmid transformation, but the latter defect was suppressed by inactivating RecA. RadA/Sms K255A, K255R and wild type RadA/Sms reduced the diadenylate cyclase activity of DisA, whereas RadA/Sms K104A and K104R blocked it. Single-stranded and Holliday junction DNA are preferentially bound over double-stranded DNA by RadA/Sms and its variants. Moreover, RadA/Sms ATPase activity was neither stimulated by a variety of DNA substrates nor by DisA. RadA/Sms possesses a 5´→3´ DNA helicase activity. The RadA/Sms mutants neither hydrolyze ATP nor unwind DNA. Thus, we propose that RadA/Sms has two activities: to modulate DisA and to promote RecA-mediated DNA strand exchange. Both activities are required to coordinate responses to replicative stress and genetic recombination.

Bacillus subtilis MutS Modulates RecA-Mediated DNA Strand Exchange Between Divergent DNA Sequences

The efficiency of horizontal gene transfer, which contributes to acquisition and spread of antibiotic resistance and pathogenicity traits, depends on nucleotide sequence and different mismatch-repair (MMR) proteins participate in this process. To study how MutL and MutS MMR proteins regulate recombination across species boundaries, we have studied natural chromosomal transformation with DNA up to ∼23% sequence divergence. We show that Bacillus subtilis natural chromosomal transformation decreased logarithmically with increased sequence divergence up to 15% in wild type (wt) cells or in cells lacking MutS2 or mismatch repair proteins (MutL, MutS or both). Beyond 15% sequence divergence, the chromosomal transformation efficiency is ∼100-fold higher in ΔmutS and ΔmutSL than in ΔmutS2 or wt cells. In the first phase of the biphasic curve (up to 15% sequence divergence), RecA-catalyzed DNA strand exchange contributes to the delineation of species, and in the second phase, homology-facilitated illegitimate recombination might aid in the restoration of inactivated genes. To understand how MutS modulates the integration process, we monitored DNA strand exchange reactions using a circular single-stranded DNA and a linear double-stranded DNA substrate with an internal 77-bp region with ∼16% or ∼54% sequence divergence in an otherwise homologous substrate. The former substrate delayed, whereas the latter halted RecA-mediated strand exchange. Interestingly, MutS addition overcame the heterologous barrier. We propose that MutS assists DNA strand exchange by facilitating RecA disassembly, and indirectly re-engagement with the homologous 5′-end of the linear duplex. Our data supports the idea that MutS modulates bidirectional RecA-mediated integration of divergent sequences and this is important for speciation.

Transoral robotic surgery of the tongue base for obstructive sleep apnea: Preliminary results

INTRODUCTION

Obstructive sleep apnea syndrome (OSAS) is a major public health issue. Robotic tongue-base reduction surgery is being developed, but needs assessment. The present study reports clinical and polygraphic results at 6 months' follow-up.

METHOD

Single-center prospective study of 8 patients undergoing transoral robotic surgery (TORS) for severe OSAS.

RESULTS

Mean age was 47 years. M/F sex ratio was 5:3. Initial body-mass index ranged from 18 to 35kg/m². Mean Epworth score was 12. Mean preoperative apnea-hypopnea index (AHI) was 47 (range, 36-60). At 6 months, only 1 patient did not meet usual success criteria (AHI<20 with>50% decrease); 2 patients had residual AHI between 10 and 20; the other 5 had non-significant event rates.

CONCLUSION

TORS tongue-base reduction showed promising results, which need confirmation on long-term multicenter studies.

RecA Regulation by RecU and DprA During Bacillus subtilis Natural Plasmid Transformation

Natural plasmid transformation plays an important role in the dissemination of antibiotic resistance genes in bacteria. During this process, Bacillus subtilis RecA physically interacts with RecU, RecX, and DprA. These three proteins are required for plasmid transformation, but RecA is not. In vitro, DprA recruits RecA onto SsbA-coated single-stranded (ss) DNA, whereas RecX inhibits RecA filament formation, leading to net filament disassembly. We show that a null recA (ΔrecA) mutation suppresses the plasmid transformation defect of competent ΔrecU cells, and that RecU is essential for both chromosomal and plasmid transformation in the ΔrecX context. RecU inhibits RecA filament growth and facilitates RecA disassembly from preformed filaments. Increasing SsbA concentrations additively contributes to RecU-mediated inhibition of RecA filament extension. DprA is necessary and sufficient to counteract the negative effect of both RecU and SsbA on RecA filament growth onto ssDNA. DprA-SsbA activates RecA to catalyze DNA strand exchange in the presence of RecU, but this effect was not observed if RecU was added prior to RecA. We propose that DprA contributes to RecA filament growth onto any internalized SsbA-coated ssDNA. When the ssDNA is homologous to the recipient, DprA antagonizes the inhibitory effect of RecU on RecA filament growth and helps RecA to catalyze chromosomal transformation. On the contrary, RecU promotes RecA filament disassembly from a heterologous (plasmid) ssDNA, overcoming an unsuccessful homology search and favoring plasmid transformation. The DprA–DprA interaction may promote strand annealing upon binding to the complementary plasmid strands and facilitating thereby plasmid transformation rather than through a mediation of RecA filament growth.

Transnasal Endoscopic Sphenopalatine Artery Ligation Compared With Embolization for Intractable Epistaxis: A Long-term Analysis

Background Transnasal endoscopic sphenopalatine artery ligation (TESPAL) and selective embolization both provide excellent treatment success rate in the management of intractable epistaxis. Few long-term studies comparing these approaches have been previously published. Recommendations often present these techniques as alternatives, but there is no clear consensus. Objective The purpose of this study was to evaluate and compare the clinical efficacy of sphenopalatine artery ligation versus embolization to control intractable epistaxis. Methods We performed a retrospective study including all patients referred to our tertiary medical center for severe epistaxis and treated by surgical ligation and/or embolization. The patients were classified into 2 groups: those who underwent TESPAL only and those who underwent endovascular embolization only. We evaluate and compare long-term clinical outcomes after surgical ligation or embolization for the control of intractable epistaxis in terms of effectiveness (recurrence rate) and safety (complication rate). Results Forty-one procedures of supraselective embolization and 39 procedures of surgical ligation for intractable epistaxis are reported and analyzed. No significant difference was observed between the groups in terms of demographic factors, comorbidities, or average length of hospital stay. The 1-year success rate was similar (75%) in both groups. Complications (minor and/or major) occurred in 34% cases in the embolization group and in 18% in the surgical group ( P = .09, ns). Bilateral embolization including facial artery was the only treatment method associated with a significant risk of complications ( P = .015). Conclusion TESPAL seems to provide a similar control rate with a decrease in the number of complications compared to selective embolization in the context of intractable epistaxis. Further studies are required.

Surge glaciers during the Little Ice Age in the Pyrenees

Historical moraine complexes and erosional features are interesting elements to discern the historical climate changes and evolution, with a complex chronologies that help us to understand the dynamics and glacier evolution during the Little Ice Age (LIA). The existence of landforms as crevasses-squeeze ridges, hummocky moraines and flutes, related to different glacier advances and retreats, allows understanding in a better way the LIA glacier evolution in the Pyrenees. The aim of this work is to show how many LIA moraine complexes have traces of fast flow ice; when the surge dynamic happened; his extent and the environmental meaning. Based on glacier landsystem analysis we have established a work hypothesis on the fast flow or surge dynamic glaciers during the LIA, with geomorphological features, as flutes and push and hummocky moraines, at least in 17 LIA glacier complexes. The analysis of morphosquences by fieldwork, photo interpretation and historical sources in 8 selected LIA moraine complexes have been compared with previous climatic reconstructions creating a hypothesis about the response of the LIA glaciers to the short time changes in temperature and moisture.The glacier cirques with fast flow features are found in the highest mountains with summits above 3000 m., mainly northern oriented (88%) and without a significant lithology. The studied complexes (Central Infierno, Eastern Infierno, Oulettes de Gaube, Monte Perdido, Marboré, La Paúl, Literola and Tempestades) show 4 morphological units: a frontal moraine system (U1); a more voluminous moraine (U2); a little push and hummocky moraines complex linking with flutes (U3); and minor arcs up valley (U4). The U3 belongs to a fast flow stage or surging and by morphostratigraphy we can point out that the surge processes were produced between 1820 and 1840, at the end of the LIA. We related it with a possible climatic response to sudden cooling and the increase of winter precipitation with melt-water availability and quick ice melting during the summer, generating hydrodynamic changes in the small glaciers and quick dynamic response.

International survey and consensus (ICON) on ambulatory surgery in rhinology

OBJECTIVES

Day-case surgery is the gold standard to several surgical procedures in Rhinology. However, few data and guidelines have been published except in the Anglo-Saxon countries and France. The aim of this survey was to propose a list of issues arising during day-case surgery in order to analyze the different constraints encountered around the world.

MATERIAL AND METHOD

It was a prospective multicenter international email survey. The method was based on the formalized expert consensus methodology. A list of 11 issues was based on literature data and was sent by e-mail to 265 key opinion leaders (KOL) who attended the IFOS congress.

RESULTS

The response rate was 20% from 27 countries without statistical difference between continents concerning the score on each item. The mean age of KOL was 50±10 years. Their mean length of experience was 21±10 years. Issues in relation with technical resources and experience showed that the last time at which ambulatory surgery in the day is possible was 4:00 PM but responses varied depending the availability of technical resources. Bleeding or hematoma occurred most frequently between the third and fourth postoperative day whatever the surgical procedure. A strong agreement and consensus was obtained concerning the nasal packing, septal contention and their schedule of removal which were not a contraindication of day-case. Also 75% of participants were agreeing with a therapeutic education program to improve the performance of postoperative care and decrease readmission rates. A relative agreement without consensus were obtained for the distance between the day-case unit and home, the role of surgery duration and the impact of anticoagulant and/or antiplatelet drugs in overnight admission and readmission rates.

CONCLUSION

Practice varies widely owing to local organization constraints and the availability of a dedicated day-case unit seems to be the main limiting factor.

Bacillus subtilis RecA with DprA-SsbA antagonizes RecX function during natural transformation

Bacillus subtilis DprA and RecX proteins, which interact with RecA, are crucial for efficient chromosomal and plasmid transformation. We showed that RecA, in the rATP·Mg²⁺ bound form (RecA·ATP), could not compete with RecX, SsbA or SsbB for assembly onto single-stranded (ss)DNA, but RecA·dATP partially displaced these proteins from ssDNA. RecX promoted reversible depolymerization of preformed RecA·ATP filaments. The two-component DprA–SsbA mediator reversed the RecX negative effect on RecA filament extension, but not DprA or DprA and SsbB. In the presence of DprA–SsbA, RecX added prior to RecA·ATP inhibited DNA strand exchange, but this inhibition was reversed when RecX was added after RecA. We propose that RecA nucleation is more sensitive to RecX action than is RecA filament growth. DprA–SsbA facilitates formation of an active RecA filament that directly antagonizes the inhibitory effects of RecX. RecX and DprA enable chromosomal transformation by altering RecA filament dynamics. DprA–SsbA and RecX proteins constitute a new regulatory network of RecA function. DprA–SsbA contributes to the formation of an active RecA filament and directly antagonizes the inhibitory effects of RecX during natural transformation.

Specific immunotherapy in allergic rhinitis

Allergic rhinitis is a common condition, with significant impact on quality of life depending on severity and quality of control. Allergen-specific immunotherapy (allergen-SIT) is the only known treatment able to alter the natural course of allergic rhinitis. Although well known to allergologists, it has yet to be fully adopted by the ENT community. This review, based on the most recent meta-analyses and clinical studies, shows that SIT significantly reduces symptoms and medication requirements (nasal corticosteroids, H1-antihistamines) in allergic rhinitis. It can reduce the risk of progression to asthma and, if initiated early enough, of developing new sensitizations. Immunobiological analysis shows an altered inflammatory profile following SIT, with immune tolerance involving T-regulatory lymphocyte induction and IgG production. Sublingual SIT with drops is as effective as subcutaneous SIT and is simpler to use, with less anaphylactic risk. Standardization of trial protocols in terms of treatment response assessment and side effect grading is recommended to improve comparative studies. Sublingual SIT with tablets has recently been introduced, providing a good opportunity for ENT practitioners to adopt the SIT approach in rhinitis triggered by allergy to pollens and, in the near future, to house dust mites.

Intractable epistaxis: which arteries are responsible? An angiographic study

PURPOSE

Epistaxis constitutes a significant proportion of the Otolaryngologist's emergency workload. Optimal management differs in relation to the anatomic origin of the bleeding. The outcome of our study was to determine which artery(ies) could be considered as the cause of severe bleeding in the context of severe epistaxis.

METHODS

Fifty-five procedures of embolization preceded by angiography were reviewed. Medical records of interventionally treated patients were analysed for demographics, medical history, risk factors and clinical data. Angiographic findings were also assessed for active contrast extravasation (blush), vascular abnormality and embolised artery.

RESULTS

Previous angiography showed an active contrast extravasation in only 20 procedures. The most common bleeding source was the sphenopalatine artery (SPA) followed by anterior ethmoïdal artery (AEA) and facial artery. Majority of multiple or bilateral extravasations occured in patients with systemic factors.

CONCLUSIONS

A better understanding of the potential bleeding source might help and limit the risk of treatment failures. Our study confirms that the SPA is the most common cause of severe bleeding. We also emphasise the role of the AEA not only in traumatic context. Others arteries are rarely involved except in patients with comorbidities or frequent recurrences.