The lncRNA APOLO interacts with the transcription factor WRKY42 to trigger root hair cell expansion in response to cold

Plant long noncoding RNAs (lncRNAs) have emerged as important regulators of chromatin dynamics, impacting on transcriptional programs leading to different developmental outputs. The lncRNA AUXIN-REGULATED PROMOTER LOOP (APOLO) directly recognizes multiple independent loci across the Arabidopsis genome and modulates their three-dimensional chromatin conformation, leading to transcriptional shifts. Here, we show that APOLO recognizes the locus encoding the root hair (RH) master regulator ROOT HAIR DEFECTIVE 6 (RHD6) and controls RHD6 transcriptional activity, leading to cold-enhanced RH elongation through the consequent activation of the transcription factor gene RHD6-like RSL4. Furthermore, we demonstrate that APOLO interacts with the transcription factor WRKY42 and modulates its binding to the RHD6 promoter. WRKY42 is required for the activation of RHD6 by low temperatures and WRKY42 deregulation impairs cold-induced RH expansion. Collectively, our results indicate that a novel ribonucleoprotein complex with APOLO and WRKY42 forms a regulatory hub to activate RHD6 by shaping its epigenetic environment and integrate signals governing RH growth and development.

Molecular Basis of Root Nodule Symbiosis between Bradyrhizobium and 'Crack-Entry' Legume Groundnut (Arachis hypogaea L.)

Nitrogen is one of the essential plant nutrients and a major factor limiting crop productivity. To meet the requirements of sustainable agriculture, there is a need to maximize biological nitrogen fixation in different crop species. Legumes are able to establish root nodule symbiosis (RNS) with nitrogen-fixing soil bacteria which are collectively called rhizobia. This mutualistic association is highly specific, and each rhizobia species/strain interacts with only a specific group of legumes, and vice versa. Nodulation involves multiple phases of interactions ranging from initial bacterial attachment and infection establishment to late nodule development, characterized by a complex molecular signalling between plants and rhizobia. Characteristically, legumes like groundnut display a bacterial invasion strategy popularly known as "crack-entry'' mechanism, which is reported approximately in 25% of all legumes. This article accommodates critical discussions on the bacterial infection mode, dynamics of nodulation, components of symbiotic signalling pathway, and also the effects of abiotic stresses and phytohormone homeostasis related to the root nodule symbiosis of groundnut and Bradyrhizobium. These parameters can help to understand how groundnut RNS is programmed to recognize and establish symbiotic relationships with rhizobia, adjusting gene expression in response to various regulations. This review further attempts to emphasize the current understanding of advancements regarding RNS research in the groundnut and speculates on prospective improvement possibilities in addition to ways for expanding it to other crops towards achieving sustainable agriculture and overcoming environmental challenges.

Evolution of the Small Family of Alternative Splicing Modulators Nuclear Speckle RNA-binding Proteins in Plants

RNA-Binding Protein 1 (RBP1) was first identified as a protein partner of the long noncoding RNA (lncRNA) ENOD40 in Medicago truncatula, involved in symbiotic nodule development. RBP1 is localized in nuclear speckles and can be relocalized to the cytoplasm by the interaction with ENOD40. The two closest homologs to RBP1 in Arabidopsis thaliana were called Nuclear Speckle RNA-binding proteins (NSRs) and characterized as alternative splicing modulators of specific mRNAs. They can recognize in vivo the lncRNA ALTERNATIVE SPLICING COMPETITOR (ASCO) among other lncRNAs, regulating lateral root formation. Here, we performed a phylogenetic analysis of NSR/RBP proteins tracking the roots of the family to the Embryophytes. Strikingly, eudicots faced a reductive trend of NSR/RBP proteins in comparison with other groups of flowering plants. In Medicago truncatula and Lotus japonicus, their expression profile during nodulation and in specific regions of the symbiotic nodule was compared to that of the lncRNA ENOD40, as well as to changes in alternative splicing. This hinted at distinct and specific roles of each member during nodulation, likely modulating the population of alternatively spliced transcripts. Our results establish the basis to guide future exploration of NSR/RBP function in alternative splicing regulation in different developmental contexts along the plant lineage.

[Acromioclavicular instability: arthroscopic and mini-open combined treatment]

INTRODUCTION

The surgical treatment of acromioclavicular dislocation remains controversial. We describe herein a combined two-stage technique that includes an arthroscopic approach followed by a mini-invasive approach.

MATERIAL AND METHODS

41 patients with acromioclavicular dislocation grades III, IV and V. Acute and chronic lesions and revision surgeries were included during the follow-up. Patients with other shoulder conditions were excluded. Mean age was 28.6 years. Patients were assessed preoperatively with the UCLA and Constant scores, and the pain visual analog scale. The 6- and 12-month postoperative evaluation included X-rays to assess coronal and axial stability, coracoclavicular ossifications, signs of acromioclavicular arthrosis and/or distal clavicular osteolysis.

RESULTS

The Constant scores were as follows: 41.3 preoperatively; 89.4 at 6 months; 92.3 at 12 months. The UCLA scores were as follows: 21.7 preoperatively; 29.1 at 6 months; 31.4 at 12 months. The VAS scores were 8.4, 2.3 and 1.2, for the same periods respectively. Two cases had repeated injury due to trauma and one case was dissatisfied with the cosmetic appearance of the scar. The X-ray assessment showed two cases of loss of stability and one case of distal clavicular osteolysis.

CONCLUSION

The combination of two reduction methods, a synthetic one and a biological one allows for a solid anatomical reconstruction that is stable in the coronal and axial planes and good medium-term results.

Self-assembled monolayers of thiolates on metals: a review article on sulfur-metal chemistry and surface structures

A review article on fundamental aspects of thiolate self-assembled monolayers (SAMs) on the (111) and (100) surfaces of the Cu and Ni groups is presented.

Interaction among Arachis hypogaea L. (peanut) and beneficial soil microorganisms: how much is it known?

The leguminous crop Arachis hypogaea L. (peanut) is originally from South America and then was disseminated to tropical and subtropical regions. The dissemination of the crop resulted in peanut plants establishing a symbiotic nitrogen-fixing relationship with a wide diversity of indigenous soil bacteria. We present in this review, advances on the molecular basis for the crack-entry infection process involved in the peanut-rhizobia interaction, the diversity of rhizobial and fungal antagonistic bacteria associated with peanut plants, the effect of abiotic and biotic stresses on this interaction and the response of peanut to inoculation.

Characterization of Staphylococcus aureus strains isolated from humans in Argentina

Humans are a natural reservoir of Staphylococcus aureus and asymptomatic colonization is far more common than infection. The aim of this work was to characterize genotypically 68 S. aureus strains isolated from nasal swabs of healthy people and from human clinical infections. A total of fourteen (20%) strains were susceptible to all the antimicrobials tested. The strains isolated from nasal swabs showed the lowest percentages of resistance. Resistance to one or more than one antibiotics tested was detected in 83% and 70% of the S. aureus strains isolated from clinical infections and nasal swabs, respectively. All of the 68 S. aureus strains were subject to RAPD-PCR analysis. Cluster A-I grouped 42 (87%) clinical infection strains and cluster A-II grouped 13 (65%) strains isolated from nasal swabs suggesting a genetic relationship among S. aureus strains. Cluster A-II grouped 65% of the S. aureus strains associated with the anterior nares, suggesting that these strains may be adapted to this site. Furthermore, five RAPD profiles isolated from nasal swabs, belonged to clusters B to F, were similar to strains isolated from clinical infection, suggesting that they might have a high propensity to cause disease. The results of the present study allow a characterization of S. aureus strains isolated from humans and shows that some S. aureus genotypes from nasal swabs are similar to the genotypes obtained from clinical infections, suggesting that clinical isolates may be originated from human normal flora.

Complications of central venous catheters in patients with haemophilia and inhibitors

We report our clinical experience with central venous catheters (CVCs) in 15 patients with haemophilia who, in total, had 34 catheters inserted. Eighteen devices were Hickman, six were Port-A-Cath and 10 were nontunnelled catheters (one Quinton, seven antecubital, one jugular and one subclavian vein access). All patients had factor VIII/IX inhibitors at the time of insertion. The mean age at operation was 8.8 years (range 16 months-39 years). Eight of the 15 patients (26/34 implanted catheters, 76%) presented some kind of complication. Pericatheter bleeding during the postoperative period affected a total of seven CVCs (7/34, 20%) in six patients, which required substitutive treatment for several days. Infection was reported in 15 of the CVCs (15/34, 44%), and four of these (4/15, 26%) had more than one episode, with a mean of 1.4 infection episodes per catheter (21/15). The infection rate was 0.2 infections per 1000 patient days or 0.1 per 1000 catheter days. Despite the usefulness of CVCs in haemophilic patients, the high incidence of complications requires careful assessment of the type of device as well as continuous surveillance.

[Refractory hypotension sustained during general anesthesia due to chronic treatment with angiotensin-converting enzyme inhibitors]

Perioperative management of angiotensin-converting enzyme inhibitors (ACEI) is controversial because of associated hypertensive episodes during induction and maintenance of anesthesia. A 71-year-old woman with a non-functioning thyroid node was scheduled for thyroid lobectomy. Her medical history included high blood pressure and she was being chronically treated with ACEI, which were taken until the morning of surgery. After induction of anesthesia, arterial hypotension refractory to crystalloid therapy developed and worsened in spite of administration of a gelatin-type colloid (Gelafundina). The patient did not respond to ephedrine or dopamine and required stabilization with adrenalin in continuous perfusion for 12 hours. Later evolution was satisfactory and recovery took place without sequelae. We discuss the anesthetic implications of chronic ACEI treatment and possible hemodynamic repercussions of associated administration with gelatin-type solutions or human albumin.

Oestrogen and progesterone receptors in the human vagina during the menstrual cycle, pregnancy and postmenopause

Oestrogen receptor (ER) and progesterone receptor (PR) concentrations were measured by enzyme immunoassays in human vaginal tissues. There were no significant differences in either case between the follicular and luteal phases, or in ER concentrations between regularly cycling and postmenopausal women. ER levels were significantly lower in pregnant than in non-pregnant women. PR levels were significantly lower in both postmenopausal and pregnant women than in regularly cycling women. A positive correlation between ER and PR was found in pregnant women and there were correlations between ER and both oestradiol and prolactin in postmenopausal women. This is the first study to compare both ER and PR in the human vagina during the menstrual cycle, pregnancy and postmenopause.

Revascularization of the lower limb through arterial bypass with "in-situ" saphenous vein

Thirty three femoropopliteal and infrapopliteal artery bypass grafts with in-situ saphenous vein as a conduit, operated and followed during 42 months are described. This method involved the use of microscissors and valvulotome (Leather) and of a modified valve cutter (Hall) to render the vein insufficient through the intraluminal incision of its valves, transversally to the cusps axis. Arteriovenous fistulae were detected intraoperatively visually and by angiography, and ligated. The operative indications were rest pain; ischemic ulcers and distal gangrene in 79% of cases, and invalidating claudication in the rest. The vein utilization rate was 97%. The cumulative patency rate for all grafts was 97% at 3 months, 82% at one year, 78% at two years and 75% at three and a half years. At 42 months, 4 of 18 femoropopliteal bypass grafts had occluded, with a cumulative patency rate of 78%. In the same period, 4 of 15 tibial or peroneal bypasses had occluded, with a patency rate of 72%. The data presented suggests that in Chile this technique should be preferentially adopted to revascularize the lower extremity, particularly in distal artery bypass grafts, due to the superior capacity of the in-situ saphenous vein to remain patent in low-flow states with poor outflow tracts.