The Division Defect of a Bacillus subtilis minD noc Double Mutant Can Be Suppressed by Spx-Dependent and Spx-Independent Mechanisms.

During growth, bacteria increase in size and divide. Division is initiated by the formation of the Z-ring, a ring-like cytoskeletal structure formed by treadmilling protofilaments of the tubulin homolog FtsZ. FtsZ localization is thought to be controlled by the Min and Noc systems, and here we explore why cell division fails at high temperature when the Min and Noc systems are simultaneously mutated. Microfluidic analysis of a minD noc double mutant indicated that FtsZ formed proto-Z-rings at periodic interchromosome locations but that the rings failed to mature and become functional. Extragenic suppressor analysis indicated that a variety of mutations restored high temperature growth to the minD noc double mutant, and while many were likely pleiotropic, others implicated the proteolysis of the transcription factor Spx. Further analysis indicated that a Spx-dependent pathway activated the expression of ZapA, a protein that primarily compensates for the absence of Noc. In addition, an Spx-independent pathway reduced the length of the cytokinetic period, perhaps by increasing divisome activity. Finally, we provide evidence of an as-yet-unidentified protein that is activated by Spx and governs the frequency of polar division and minicell formation. IMPORTANCE Bacteria must properly position the location of the cell division machinery in order to grow, divide, and ensure each daughter cell receives one copy of the chromosome. In Bacillus subtilis, cell division site selection depends on the Min and Noc systems, and while neither is individually essential, cells fail to grow at high temperature when both are mutated. Here, we show that cell division fails in the absence of Min and Noc, due not to a defect in FtsZ localization but rather to a failure in the maturation of the cell division machinery. Suppressor mutations that restored growth were selected, and while some activated the expression of ZapA via the Spx stress response pathway, others appeared to directly enhance divisome activity.

The phosphatidic acid pathway enzyme PlsX plays both catalytic and channeling roles in bacterial phospholipid synthesis.

PlsX is the first enzyme in the pathway that produces phosphatidic acid in Gram-positive bacteria. It makes acylphosphate from acyl-acyl carrier protein (acyl-ACP) and is also involved in coordinating phospholipid and fatty acid biosyntheses. PlsX is a peripheral membrane enzyme in Bacillus subtilis, but how it associates with the membrane remains largely unknown. In the present study, using fluorescence microscopy, liposome sedimentation, differential scanning calorimetry, and acyltransferase assays, we determined that PlsX binds directly to lipid bilayers and identified its membrane anchoring moiety, consisting of a hydrophobic loop located at the tip of two amphipathic dimerization helices. To establish the role of the membrane association of PlsX in acylphosphate synthesis and in the flux through the phosphatidic acid pathway, we then created mutations and gene fusions that prevent PlsX's interaction with the membrane. Interestingly, phospholipid synthesis was severely hampered in cells in which PlsX was detached from the membrane, and results from metabolic labeling indicated that these cells accumulated free fatty acids. Because the same mutations did not affect PlsX transacylase activity, we conclude that membrane association is required for the proper delivery of PlsX's product to PlsY, the next enzyme in the phosphatidic acid pathway. We conclude that PlsX plays a dual role in phospholipid synthesis, acting both as a catalyst and as a chaperone protein that mediates substrate channeling into the pathway.

The tug of war between Al3+ and Na+ for order-disorder transitions in lipid-A membranes.

Cations play a critical role in the stability and morphology of lipid-A aggregates by neutralizing, hydrating and cross-linking these glycolipid molecules. Monophosphorylated lipid-A is the major immunostimulatory principle in commercially available adjuvants containing Al3+ such as adjuvant system 04 (AS04). The antagonist/agonist immunomodulatory properties of lipid-A are associated with chemical variations (e.g. the number of acyl chains and phosphate groups) and their aggregate arrangements (e.g. lamellar, nonlamellar or mixed). Therefore, the identification of the active form of lipid-A can provide valuable guidance in the development of vaccine adjuvants capable of boosting the immune system with decreased reactogenicity. Although the effect of mono and divalent cations on the structural polymorphism and endotoxicity of LPS has been previously investigated, much less is known about the effect of trivalent cations. We have investigated the effect of NaCl and AlCl3 salt solutions on the structural dynamics and stability of mono and diphosphorylated lipid-A membranes via atomistic MD simulations. The Al3+ ion exerts two major effects on the structural dynamics of lipid-A membranes. It acts as an efficient cross-linker of mono or diphosphorylated lipid-A molecules, thus stabilizing the lamellar arrangement of these glycolipids. It also alters the lipid-A packing and membrane fluidity, inducing disorder → order structural transitions of the membrane. This effect is promptly reversed upon the addition of NaCl solution, which promotes a nearly threefold increase in the amount of water in the carbohydrate moiety of the Al3+-containing lipid-A membranes. The exchange dynamics and residence times of cation-coordinated water molecules in these membranes provide insights into the molecular mechanism for the Na+-induced transition from a densely packed ordered phase to a disordered one. Al3+ counter-ions favor ordered lamellar aggregates, which has been previously associated with the lack of endotoxic activity and cytokine-inducing action. The resulting microscopic understanding of the structure and dynamics of lipid-A aggregates in the presence of Al3+ and Na+ salts can provide valuable guidance in the development of vaccine adjuvants capable of boosting the immune system with decreased reactogenicity.

Multi-gigaelectronvolt acceleration of positrons in a self-loaded plasma wakefield.

Electrical breakdown sets a limit on the kinetic energy that particles in a conventional radio-frequency accelerator can reach. New accelerator concepts must be developed to achieve higher energies and to make future particle colliders more compact and affordable. The plasma wakefield accelerator (PWFA) embodies one such concept, in which the electric field of a plasma wake excited by a bunch of charged particles (such as electrons) is used to accelerate a trailing bunch of particles. To apply plasma acceleration to electron-positron colliders, it is imperative that both the electrons and their antimatter counterpart, the positrons, are efficiently accelerated at high fields using plasmas. Although substantial progress has recently been reported on high-field, high-efficiency acceleration of electrons in a PWFA powered by an electron bunch, such an electron-driven wake is unsuitable for the acceleration and focusing of a positron bunch. Here we demonstrate a new regime of PWFAs where particles in the front of a single positron bunch transfer their energy to a substantial number of those in the rear of the same bunch by exciting a wakefield in the plasma. In the process, the accelerating field is altered--'self-loaded'--so that about a billion positrons gain five gigaelectronvolts of energy with a narrow energy spread over a distance of just 1.3 metres. They extract about 30 per cent of the wake's energy and form a spectrally distinct bunch with a root-mean-square energy spread as low as 1.8 per cent. This ability to transfer energy efficiently from the front to the rear within a single positron bunch makes the PWFA scheme very attractive as an energy booster to an electron-positron collider.

Inoculation with the endophytic bacterium Herbaspirillum seropedicae promotes growth, nutrient uptake and photosynthetic efficiency in rice.

MAIN CONCLUSION: Higher vacuolar proton pump activity may increase plant energy and nutrient use efficiency and provide the nexus between plant inoculation with Herbaspirillum seropedicae and growth promotion. Global change and growing human population are exhausting arable land and resources, including water and fertilizers. We present inoculation with the endophytic plant-growth promoting bacterium (PGPB) Herbaspirillum seropedicae as a strategy for promoting growth, nutrient uptake and photosynthetic efficiency in rice (Oryza sativa L.). Because plant nutrient acquisition is coordinated with photosynthesis and the plant carbon status, we hypothesize that inoculation with H. seropedicae will stimulate proton (H+) pumps, increasing plant growth nutrient uptake and photosynthetic efficiency at low nutrient levels. Plants were inoculated and grown in pots with sterile soil for 90 days. Herbaspirillum seropedicae endophytic colonization was successful and, as hypothesized, inoculation (1) stimulated root vacuolar H+ pumps (vacuolar H+-ATPase and vacuolar H+-PPase), and (2) increased plant growth, nutrient contents and photosynthetic efficiency. The results showed that inoculation with the endophytic bacterium H. seropedicae can promote plant growth, nutrient uptake and photosynthetic efficiency, which will likely result in a more efficient use of resources (nutrients and water) and higher production of nutrient-rich food at reduced economic and environmental costs.

SuAVE: A Tool for Analyzing Curvature-Dependent Properties in Chemical Interfaces.

Curvature is an intrinsic feature of biological membranes underlying vital cellular processes such as endocytosis, membrane fusion-fission, trafficking, and remodeling. The continuous expansion of the spatiotemporal scales accessible to computational simulations nowadays makes possible quasi-atomistic molecular dynamics simulations of these processes. In despite of that, computation of the shapes and curvatures associated with the dynamics of biological membranes remains challenging. For this reason, the effect of curvature is often neglected in the analysis of quantities essential for the accurate description of membrane properties (e.g., area and volume per lipid, density profiles, membrane thickness). We propose an algorithm for surface assessment via grid evaluation (SuAVE) that relies on the application of a radial base function to interpolate points scattered across an interface of any shape. This enables the representation of the chemical interface as fully differentiable so that related geometrical properties can be calculated through the straightforward employment of well-established differential geometry techniques. Hence, the effect of different types or degrees of curvature can be accurately taken into account in the calculations of structural properties of any interfaces regardless of chemical composition, asymmetry, and level of atom coarseness. The main functionalities implemented in SuAVE are featured for a number of tetraacylated and hexaacylated Lipid-A membranes of distinct curvatures and a surfactant micelle. We show that the properties calculated for moderately to highly curved membranes differ significantly between curvature-dependent and -independent algorithms. The SuAVE software is freely available from www.biomatsite.net/suave-software .

High-efficiency acceleration of an electron beam in a plasma wakefield accelerator.

High-efficiency acceleration of charged particle beams at high gradients of energy gain per unit length is necessary to achieve an affordable and compact high-energy collider. The plasma wakefield accelerator is one concept being developed for this purpose. In plasma wakefield acceleration, a charge-density wake with high accelerating fields is driven by the passage of an ultra-relativistic bunch of charged particles (the drive bunch) through a plasma. If a second bunch of relativistic electrons (the trailing bunch) with sufficient charge follows in the wake of the drive bunch at an appropriate distance, it can be efficiently accelerated to high energy. Previous experiments using just a single 42-gigaelectronvolt drive bunch have accelerated electrons with a continuous energy spectrum and a maximum energy of up to 85 gigaelectronvolts from the tail of the same bunch in less than a metre of plasma. However, the total charge of these accelerated electrons was insufficient to extract a substantial amount of energy from the wake. Here we report high-efficiency acceleration of a discrete trailing bunch of electrons that contains sufficient charge to extract a substantial amount of energy from the high-gradient, nonlinear plasma wakefield accelerator. Specifically, we show the acceleration of about 74 picocoulombs of charge contained in the core of the trailing bunch in an accelerating gradient of about 4.4 gigavolts per metre. These core particles gain about 1.6 gigaelectronvolts of energy per particle, with a final energy spread as low as 0.7 per cent (2.0 per cent on average), and an energy-transfer efficiency from the wake to the bunch that can exceed 30 per cent (17.7 per cent on average). This acceleration of a distinct bunch of electrons containing a substantial charge and having a small energy spread with both a high accelerating gradient and a high energy-transfer efficiency represents a milestone in the development of plasma wakefield acceleration into a compact and affordable accelerator technology.

Out of Sight, Out of Mind: The Effect of the Equilibration Protocol on the Structural Ensembles of Charged Glycolipid Bilayers.

Molecular dynamics (MD) simulations represent an essential tool in the toolbox of modern chemistry, enabling the prediction of experimental observables for a variety of chemical systems and processes and majorly impacting the study of biological membranes. However, the chemical diversity of complex lipids beyond phospholipids brings new challenges to well-established protocols used in MD simulations of soft matter and requires continuous assessment to ensure simulation reproducibility and minimize unphysical behavior. Lipopolysaccharides (LPS) are highly charged glycolipids whose aggregation in a lamellar arrangement requires the binding of numerous cations to oppositely charged groups deep inside the membrane. The delicate balance between the fully hydrated carbohydrate region and the smaller hydrophobic core makes LPS membranes very sensitive to the choice of equilibration protocol. In this work, we show that the protocol successfully used to equilibrate phospholipid bilayers when applied to complex lipopolysaccharide membranes occasionally leads to a small expansion of the simulation box very early in the equilibration phase. Although the use of a barostat algorithm controls the system dimension and particle distances according to the target pressure, fluctuation in the fleeting pressure occasionally enables a few water molecules to trickle into the hydrophobic region of the membrane, with spurious solvent buildup. We show that this effect stems from the initial steps of NPT equilibration, where initial pressure can be fairly high. This can be solved with the use of a stepwise-thermalization NVT/NPT protocol, as demonstrated for atomistic MD simulations of LPS/DPPE and lipid-A membranes in the presence of different salts using an extension of the GROMOS forcefield within the GROMACS software. This equilibration protocol should be standard procedure for the generation of consistent structural ensembles of charged glycolipids starting from atomic coordinates not previously pre-equilibrated. Although different ways to deal with this issue can be envisioned, we investigated one alternative that could be readily available in major MD engines with general users in mind.

Synthesis, biophysical and functional studies of two BP100 analogues modified by a hydrophobic chain and a cyclic peptide.

Antimicrobial peptides (AMPs) work as a primary defense against pathogenic microorganisms. BP100, (KKLFKKILKYL-NH2), a rationally designed short, highly cationic AMP, acts against many bacteria, displaying low toxicity to eukaryotic cells. Previously we found that its mechanism of action depends on membrane surface charge and on peptide-to-lipid ratio. Here we present the synthesis of two BP100 analogs: BP100­alanyl­hexadecyl­1­amine (BP100-Ala-NH-C16H33) and cyclo(1­4)­d­Cys1, Ile2, Leu3, Cys4-BP100 (Cyclo(1­4)­cILC-BP100). We examined their binding to large unilamellar vesicles (LUV), conformational and functional properties, and compared with those of BP100. The analogs bound to membranes with higher affinity and a lesser dependence on electrostatic forces than BP100. In the presence of LUV, BP100 and BP100-Ala-NH-C16H33 acquired α-helical conformation, while Cyclo(1­4)­cILC-BP100) was partly α-helical and partly ß-turn. Taking in conjunction: 1. particle sizes and zeta potential, 2. effects on lipid flip-flop, 3. leakage of LUVs internal contents, and 4. optical microscopy of giant unilamellar vesicles, we concluded that at high concentrations, all three peptides acted by a carpet mechanism, while at low concentrations the peptides acted by disorganizing the lipid bilayer, probably causing membrane thinning. The higher activity and lesser membrane surface charge dependence of the analogs was probably due to their greater hydrophobicity. The MIC values of both analogs towards Gram-positive and Gram-negative bacteria were similar to those of BP100 but both analogues were more hemolytic. Confocal microscopy showed Gram-positive B. subtilis killing with concomitant extensive membrane damage suggestive of lipid clustering, or peptide-lipid aggregation. These results were in agreement with those found in model membranes.

The stringent response plays a key role in Bacillus subtilis survival of fatty acid starvation.

The stringent response is a universal adaptive mechanism to protect bacteria from nutritional and environmental stresses. The role of the stringent response during lipid starvation has been studied only in Gram-negative bacteria. Here, we report that the stringent response also plays a crucial role in the adaptation of the model Gram-positive Bacillus subtilis to fatty acid starvation. B. subtilis lacking all three (p)ppGpp-synthetases (RelBs , RelP and RelQ) or bearing a RelBs variant that no longer synthesizes (p)ppGpp suffer extreme loss of viability on lipid starvation. Loss of viability is paralleled by perturbation of membrane integrity and function, with collapse of membrane potential as the likely cause of death. Although no increment of (p)ppGpp could be detected in lipid starved B. subtilis, we observed a substantial increase in the GTP/ATP ratio of strains incapable of synthesizing (p)ppGpp. Artificially lowering GTP with decoyinine rescued viability of such strains, confirming observations that low intracellular GTP is important for survival of nutritional stresses. Altogether, our results show that activation of the stringent response by lipid starvation is a broadly conserved response of bacteria and that a key role of (p)ppGpp is to couple biosynthetic processes that become detrimental if uncoordinated.

Measurement of Transverse Wakefields Induced by a Misaligned Positron Bunch in a Hollow Channel Plasma Accelerator.

Hollow channel plasma wakefield acceleration is a proposed method to provide high acceleration gradients for electrons and positrons alike: a key to future lepton colliders. However, beams which are misaligned from the channel axis induce strong transverse wakefields, deflecting beams and reducing the collider luminosity. This undesirable consequence sets a tight constraint on the alignment accuracy of the beam propagating through the channel. Direct measurements of beam misalignment-induced transverse wakefields are therefore essential for designing mitigation strategies. We present the first quantitative measurements of transverse wakefields in a hollow plasma channel, induced by an off-axis 20 GeV positron bunch, and measured with another 20 GeV lower charge trailing positron probe bunch. The measurements are largely consistent with theory.

Association of magnetotactic multicellular prokaryotes with Pseudoalteromonas species in a natural lagoon environment.

Magnetotactic bacteria, for the most part, are free-living, motile, unicellular prokaryotes that inhabit almost all marine and freshwater environments. One notable exception to the unicellular mode, however, are the magnetotactic multicellular prokaryotes. These morphologically unique prokaryotes (e.g., Candidatus Magnetoglobus multicellularis) are motile aggregates of 20-40 genetically identical, Gram-negative cells organised as a sphere (or ovoid in shape) and only motile as a unit. No specific close physical association between magnetotactic bacteria and non-magnetotactic microorganisms has ever been reported. Here, using culture-independent approaches, we show an unusual association between the spherical magnetotactic multicellular prokaryote Ca. Magnetoglobus multicellularis and Pseudoalteromonas species in environmental sediment and water samples collected from the Araruama Lagoon in Brazil. Cells of Pseudoalteromonas species were observed to be physically attached to the surface and, notably, even in the intercellular space of these spherical magnetotactic multicellular prokaryotes. An attempt to correlate the frequency of association between Pseudoalteromonas and magnetotactic multicellular prokaryotes with sediment depth was made but only a slight decrease in the number of Pseudoalteromonas cells per magnetotactic multicellular prokaryote was observed with increasing depth. Similar observations were made with magnetotactic multicellular prokaryotes from another Brazilian Lagoon (Rodrigo de Freitas) and the putative symbiont/parasite was detected. Although our results suggest some sort of specificity in the relationship between these prokaryotes, the precise nature of this association remains unclear.

Clinical and hematological data to group different chronic kidney disease patients: A practical approach to establish different groups of patients.

BACKGROUND: Chronic kidney disease (CKD) is the convergent point of several pathological processes, and its evolution is insidious and characterized by a progressive and irreversible loss of kidney function. This impaired function induces the accumulation of uremic toxins and individuals with terminal CKD often have altered physiological responses, including a persistent state of immuno-suppression and development of diseases. A better characterization and stratification of these patients with CKD in different immuno-compromised groups would contribute to more effective and personalized treatments. The focus of this study was to use two parameters to stratify patients with CKD into four separate groups that are representative of different immunological status. METHODS: Patients with CKD were chosen randomly and stratified into four separate groups according to the period of time receiving dialysis treatment and leukocyte blood counts. The amount of apoptotic CD4 T cells were measured in each group of patients, and clinical/hematological parameters were correlated by multivariate analysis with each group. RESULTS: Observations reveal that one of the four groups of patients with CKD (group 3) had more apoptotic CD4 T cells than the other group; this group also had an increased malnutrition inflammation score (MIS), an elevated Kt/V, and a higher incidence of smoking. CONCLUSION: A simple two-parameter-based stratification strategy could be used to design effective immunological therapies that differentiate the degrees of immuno-suppression across groups of patients with CKD.

FtsZ filament capping by MciZ, a developmental regulator of bacterial division.

Cytoskeletal structures are dynamically remodeled with the aid of regulatory proteins. FtsZ (filamentation temperature-sensitive Z) is the bacterial homolog of tubulin that polymerizes into rings localized to cell-division sites, and the constriction of these rings drives cytokinesis. Here we investigate the mechanism by which the Bacillus subtilis cell-division inhibitor, MciZ (mother cell inhibitor of FtsZ), blocks assembly of FtsZ. The X-ray crystal structure reveals that MciZ binds to the C-terminal polymerization interface of FtsZ, the equivalent of the minus end of tubulin. Using in vivo and in vitro assays and microscopy, we show that MciZ, at substoichiometric levels to FtsZ, causes shortening of protofilaments and blocks the assembly of higher-order FtsZ structures. The findings demonstrate an unanticipated capping-based regulatory mechanism for FtsZ.

Revisiting the cell biology of the acyl-ACP:phosphate transacylase PlsX suggests that the phospholipid synthesis and cell division machineries are not coupled in Bacillus subtilis.

PlsX is a central enzyme of phospholipid synthesis in bacteria, converting acyl-ACP to acyl-phosphate on the pathway to phosphatidic acid formation. PlsX has received attention because it plays a key role in the coordination of fatty acid and phospholipid synthesis. Recently, PlsX was also suggested to coordinate membrane synthesis with cell division in Bacillus subtilis. Here, we have re-investigated the cell biology of PlsX and determined that the enzyme is uniformly distributed on the membrane of most cells, but occasionally appears as membrane foci as well. Foci and homogenous patterns seem freely interconvertible but the prevalence of the uniform staining suggests that PlsX does not need to localize to specific sites to function correctly. We also investigated the relationship between PlsX and the divisome. In contrast to previous observations, PlsX's foci showed no obvious periodicity of localization and did not colocalize with the divisome. Furthermore, depletion of PlsX did not affect cell division if phospholipid synthesis is maintained by an alternative enzyme. These results suggest that coordination between division and membrane synthesis may not require physical or functional interactions between the divisome and phospholipid synthesis enzymes.

Training Program for Cardiology Residents to Perform Focused Cardiac Ultrasound Examination with Portable Device.

INTRODUCTION: Training requirements for general cardiologists without echocardiographic expertise to perform focused cardiac ultrasound (FCU) with portable devices have not yet been defined. The objective of this study was to evaluate a training program to instruct cardiology residents to perform FCU with a hand-carried device (HCD) in different clinical settings. METHODS: Twelve cardiology residents were subjected to a 50-question test, 4 lectures on basic echocardiography and imaging interpretation, the supervised interpretation of 50 echocardiograms and performance of 30 exams using HCD. After this period, they repeated the written test and were administered a practical test comprising 30 exams each (360 patients) in different clinical settings. They reported on 15 parameters and a final diagnosis; their findings were compared to the HCD exam of a specialist in echocardiography. RESULTS: The proportion of correct answers on the theoretical test was higher after training (86%) than before (51%; P = 0.001). The agreement was substantial among the 15 parameters analyzed (kappa ranging from 0.615 to 0.891; P < 0.001). The percentage of correct interpretation was lower for abnormal (75%) than normal (95%) items, for valve abnormalities (85%) compared to other items (92%) and for graded scale (87%) than for dichotomous (95%) items (P < 0.0001, for all). For the final diagnoses, the kappa value was higher than 0.941 (P < 0.001; 95% CI [0.914, 0.955]). CONCLUSION: The training proposed enabled residents to perform FCU with HCD, and their findings were in good agreement with those of a cardiologist specialized in echocardiography.

Beam loading by distributed injection of electrons in a plasma wakefield accelerator.

We show through experiments and supporting simulations that propagation of a highly relativistic and dense electron bunch through a plasma can lead to distributed injection of electrons, which depletes the accelerating field, i.e., beam loads the wake. The source of the injected electrons is ionization of the second electron of rubidium (Rb II) within the wake. This injection of excess charge is large enough to severely beam load the wake, and thereby reduce the transformer ratio T. The reduction of the average T with increasing beam loading is quantified for the first time by measuring the ratio of peak energy gain and loss of electrons while changing the beam emittance. Simulations show that beam loading by Rb II electrons contributes to the reduction of the peak accelerating field from its weakly loaded value of 43 GV/m to a strongly loaded value of 26 GV/m.

Laparoscopic surgery for endometriosis.

BACKGROUND: Endometriosis is the presence of endometrial glands or stroma in sites other than the uterine cavity and is associated with pain and subfertility. Surgical interventions aim to remove visible areas of endometriosis and restore the anatomy. OBJECTIVES: To assess the effectiveness and safety of laparoscopic surgery in the treatment of painful symptoms and subfertility associated with endometriosis. SEARCH METHODS: This review has drawn on the search strategy developed by the Cochrane Menstrual Disorders and Subfertility Group including searching CENTRAL, MEDLINE, EMBASE, PsycINFO, and trial registries from inception to July 2013. SELECTION CRITERIA: Randomised controlled trials (RCTs) were selected in which the effectiveness and safety of laparoscopic surgery used to treat pain or subfertility associated with endometriosis was compared with any other laparoscopic or robotic intervention, holistic or medical treatment or diagnostic laparoscopy only. DATA COLLECTION AND ANALYSIS: Selection of studies, assessment of trial quality and extraction of relevant data were performed independently by two review authors with disagreements resolved by a third review author. The quality of evidence was evaluated using GRADE methods. MAIN RESULTS: Ten RCTs were included in the review. The studies randomised 973 participants experiencing pain or subfertility associated with endometriosis. Five RCTs compared laparoscopic ablation or excision versus diagnostic laparoscopy only. Two RCTs compared laparoscopic excision versus diagnostic laparoscopy only. Two RCTs compared laparoscopic excision versus ablation. One RCT compared laparoscopic ablation versus diagnostic laparoscopy and injectable gonadotropin-releasing hormone analogue (GnRHa) (goserelin) with add-back therapy. Common limitations in the primary studies included lack of clearly-described blinding, failure to fully describe methods of randomisation and allocation concealment, and risk of attrition bias.Laparoscopic surgery was associated with decreased overall pain (measured as 'pain better or improved') compared with diagnostic laparoscopy, both at six months (odds ratio (OR) 6.58, 95% CI 3.31 to 13.10, 3 RCTs, 171 participants, I(2) = 0%, moderate quality evidence) and at 12 months (OR 10.00, 95% CI 3.21 to 31.17, 1 RCT, 69 participants, low quality evidence). Compared with diagnostic laparoscopy, laparoscopic surgery was also associated with an increased live birth or ongoing pregnancy rate (OR 1.94, 95% CI 1.20 to 3.16, P = 0.007, 2 RCTs, 382 participants, I(2) = 0%, moderate quality evidence) and increased clinical pregnancy rate (OR 1.89, 95% CI 1.25 to 2.86, P = 0.003, 3 RCTs, 528 participants, I(2) = 0%, moderate quality evidence). Two studies collected data on adverse events (including infection, vascular and visceral injury and conversion to laparotomy) and reported no events in either arm. Other studies did not report this outcome. The similar effect of laparoscopic surgery and diagnostic laparotomy on the rate of miscarriage per pregnancy was imprecise (OR 0.94, 95% CI 0.35 to 2.54, 2 studies, 112 women, moderate quality evidence).When laparoscopic ablation was compared with diagnostic laparoscopy plus medical therapy (GnRHa plus add-back therapy), more women in the ablation group reported that they were pain free at 12 months (OR 5.63, 95% CI 1.18 to 26.85, 1 RCT, 35 participants, low quality evidence).The difference between laparoscopic ablation and laparoscopic excision in the proportion of women reporting overall pain relief at 12 months on a VAS 0 to 10 pain scale was 0 (95% CI -1.22 to 1.22, P = 1.00, 1 RCT, 103 participants, low quality evidence). AUTHORS' CONCLUSIONS: There is moderate quality evidence that laparoscopic surgery to treat mild and moderate endometriosis reduces overall pain and increases live birth or ongoing pregnancy rates. There is low quality evidence that laparoscopic excision and ablation were similarly effective in relieving pain, although there was only one relevant study. More research is needed considering severe endometriosis, different types of pain associated with endometriosis (for example dysmenorrhoea (pain with menstruation)) and comparing laparoscopic interventions with holistic and medical interventions. There was insufficient evidence on adverse events to allow any conclusions to be drawn regarding safety.

Simplified single plane echocardiography is comparable to conventional biplane two-dimensional echocardiography in the evaluation of left atrial volume: a study validated by three-dimensional echocardiography in 143 individuals.

The left atrial volume index (LAVI) is a biomarker of diastolic dysfunction and a predictor of cardiovascular events. Three-dimensional echocardiography (3DE) is highly accurate for LAVI measurements but is not widely available. Furthermore, biplane two-dimensional echocardiography (B2DE) may occasionally not be feasible due to a suboptimal two-chamber apical view. Simplified single plane two-dimensional echocardiography (S2DE) could overcome these limitations. We aimed to compare the reliability of S2DE with other validated echocardiographic methods in the measurement of the LAVI. We examined 143 individuals (54 ± 13 years old; 112 with heart disease and 31 healthy volunteers; all with sinus rhythm, with a wide range of LAVI). The results for all the individuals were compared with B2DE-derived LAVIs and validated using 3DE. The LAVIs, as determined using S2DE (32.7 ± 13.1 mL/m(2)), B2DE (31.9 ± 12.7 mL/m(2)), and 3DE (33.1 ± 13.4 mL/m(2)), were not significantly different from each other (P = 0.85). The S2DE-derived LAVIs correlated significantly with those obtained using both B2DE (r = 0.98; P < 0.001) and 3DE (r = 0.93; P < 0.001). The mean difference between the S2DE and B2DE measurements was <1.0 mL/m(2). Using the American Society of Echocardiography criteria for grading LAVI enlargement (normal, mild, moderate, severe), we observed an excellent agreement between the S2DE- and B2DE-derived classifications (κ = 0.89; P < 0.001). S2DE is a simple, rapid, and reliable method for LAVI measurement that may expand the use of this important biomarker in routine echocardiographic practice.