A Model for the Development of the Rhizobial and Arbuscular Mycorrhizal Symbioses in Legumes and Its Use to Understand the Roles of Ethylene in the Establishment of these two Symbioses

We propose a model depicting the development of nodulation and arbuscular mycorrhizae. Both processes are dissected into many steps, using Pisum sativum L. nodulation mutants as a guideline. For nodulation, we distinguish two main developmental programs, one epidermal and one cortical. Whereas Nod factors alone affect the cortical program, bacteria are required to trigger the epidermal events. We propose that the two programs of the rhizobial symbiosis evolved separately and that, over time, they came to function together. The distinction between these two programs does not exist for arbuscular mycorrhizae development despite events occurring in both root tissues. Mutations that affect both symbioses are restricted to the epidermal program. We propose here sites of action and potential roles for ethylene during the formation of the two symbioses with a specific hypothesis for nodule organogenesis. Assuming the epidermis does not make ethylene, the microsymbionts probably first encounter a regulatory level of ethylene at the epidermis–outermost cortical cell layer interface. Depending on the hormone concentrations there, infection will either progress or be blocked. In the former case, ethylene affects the cortex cytoskeleton, allowing reorganization that facilitates infection; in the latter case, ethylene acts on several enzymes that interfere with infection thread growth, causing it to abort. Throughout this review, the difficulty of generalizing the roles of ethylene is emphasized and numerous examples are given to demonstrate the diversity that exists in plants

Is home-based monitoring of ovulution to time frozen embryo transfer a cost-effective alternative for hospital-based monitoring of ovulation? Study protocol of the multicentre, non-inferiority Antarctica-2 randomised controlled trial

STUDY QUESTION: The objective of this trial is to compare the effectiveness and costs of true natural cycle (true NC-) frozen embryo transfer (FET) using urinary LH tests to modified NC-FET using repeated ultrasound monitoring and ovulation trigger to time FET in the NC. Secondary outcomes are the cancellation rates of FET (ovulation before hCG or no dominant follicle, no ovulation by LH urine test, poor embryo survival), pregnancy outcomes (miscarriage rate, clinical pregnancy rates, multiple ongoing pregnancy rates, live birth rates, costs) and neonatal outcomes (including gestational age, birthweight and sex, congenital abnormalities or diseases of babies born). WHAT IS KNOWN ALREADY: FET is at the heart of modern IVF. To allow implantation of the thawed embryo, the endometrium must be prepared either by exogenous oestrogen and progesterone supplementation (artificial cycle (AC)-FET) or by using the NC to produce endogenous oestradiol before and progesterone after ovulation to time the transfer of the thawed embryo (NC-FET). During an NC-FET, women visit the hospital repeatedly and receive an ovulation trigger to time FET (i.e. modified (m)NC-FET or hospital-based monitoring). From the woman’s point of view, a more natural approach using home-based monitoring of the ovulation with LH urine tests to allow a natural ovulation to time FET may be desired (true NC-FET or home-based monitoring). STUDY DESIGN, SIZE, DURATION: This is a multicentre, non-inferiority prospective randomised controlled trial design. Consenting women will undergo one FET cycle using either true NC-FET or mNC-FET based on randomisation. PARTICIPANTS/MATERIALS, SETTING, METHODS: Based on our sample size calculation, the study group will consist of 1464 women between 18 and 45 years old who are scheduled for FET. Women with anovulatory cycles, women who need ovulation induction and women with a contra indication for pregnancy will be excluded. The primary outcome is ongoing pregnancy. Secondary outcomes are cancellation rates of FET, pregnancy outcomes (including miscarriage rate, clinical pregnancy, multiple pregnancy rate and live birth rate). Costs will be estimated by counting resource use and calculating unit prices. STUDY FUNDING/COMPETING INTEREST(S): The study received a grant from the Dutch Organisation for Health Research and Development (ZonMw 843002807; www.zonmw.nl). ZonMw has no role in the design of the study, collection, analysis, and interpretation of data or writing of the manuscript. F.B. reports personal fees from member of the external advisory board for Merck Serono, grants from Research support grant Merck Serono, outside the submitted work. A.E.P.C. reports and Unrestricted grant of Ferring B.V. to the Center for Reproductive medicine, no personal fee. Author up-to-date on Hyperthecosis. Congress meetings 2019 with Ferring B.V. and Theramex B.V. M.G. reports Department research and educational grants from Guerbet, Merck and Ferring (location VUMC) outside the submitted work. E.R.G. reports personal fees from Titus Health Care, outside the submitted work. C.B.L. reports grants from Ferring, grants from Merck, from Guerbet, outside the submitted work. The other authors have none to declare. TRIAL REGISTRATION NUMBER: Dutch Trial Register (Trial NL6414 (NTR6590), https://www.trialregister.nl/). TRIAL REGISTRATION DATE: 23 July 2017 DATE OF FIRST PATIENT’S ENROLMENT: 10 April 201

The 2023 Orthopedic Research Society's international consensus meeting on musculoskeletal infection: Summary from the in vitro section

Antimicrobial strategies for musculoskeletal infections are typically first developed with in vitro models. The In Vitro Section of the 2023 Orthopedic Research Society Musculoskeletal Infection international consensus meeting (ICM) probed our state of knowledge of in vitro systems with respect to bacteria and biofilm phenotype, standards, in vitro activity, and the ability to predict in vivo efficacy. A subset of ICM delegates performed systematic reviews on 15 questions and made recommendations and assessment of the level of evidence that were then voted on by 72 ICM delegates. Here, we report recommendations and rationale from the reviews and the results of the internet vote. Only two questions received a ≥90% consensus vote, emphasizing the disparate approaches and lack of established consensus for in vitro modeling and interpretation of results. Comments on knowledge gaps and the need for further research on these critical MSKI questions are included

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Methodologies for <i>in vitro</i> and <i>in vivo</i> evaluation of efficacy of antifungal and antibiofilm agents and surface coatings against fungal biofilms.

Unlike superficial fungal infections of the skin and nails, which are the most common fungal diseases in humans, invasive fungal infections carry high morbidity and mortality, particularly those associated with biofilm formation on indwelling medical devices. Therapeutic management of these complex diseases is often complicated by the rise in resistance to the commonly used antifungal agents. Therefore, the availability of accurate susceptibility testing methods for determining antifungal resistance, as well as discovery of novel antifungal and antibiofilm agents, are key priorities in medical mycology research. To direct advancements in this field, here we present an overview of the methods currently available for determining (i) the susceptibility or resistance of fungal isolates or biofilms to antifungal or antibiofilm compounds and compound combinations; (ii) the &lt;i&gt;in vivo&lt;/i&gt; efficacy of antifungal and antibiofilm compounds and compound combinations; and (iii) the &lt;i&gt;in vitro&lt;/i&gt; and &lt;i&gt;in vivo&lt;/i&gt; performance of anti-infective coatings and materials to prevent fungal biofilm-based infections

Facilitators and barriers for home-based monitoring to time frozen embryo transfers in IVF among women and healthcare providers

STUDY QUESTION: What are the facilitators and barriers concerning the implementation of home-based monitoring for natural cycle frozen embryo transfer (NC-FET) from the perspectives of patients and healthcare providers in the Netherlands? SUMMARY ANSWER: The most important facilitator was optimal pregnancy chance for both the patients and healthcare providers, and the most important barriers were the risk of missing an ovulation for the patients and laboratory capacity for the healthcare providers. WHAT IS KNOWN ALREADY: The share of FET cycles in IVF treatments is increasing and, therefore, it is important to optimize protocols for FET. Monitoring of ovulation, which is used in NC-FET, can be hospital-based (ultrasounds and ovulation triggering) or home-based (LH urine tests). Home-based monitoring has the advantage of being the most natural protocol for FET and provides the feeling of empowerment and discretion for patients. A systematic approach for the implementation of home-based monitoring has to start with an exploration of the perspectives of all stakeholders. STUDY DESIGN SIZE DURATION: Stakeholders (patients and healthcare providers) involved in the implementation process in the Netherlands participated in the present study. Patients were represented by the Dutch Patient Organisation for Couples with Fertility Problems (FREYA) and healthcare providers were represented by gynaecologists and their society (The Netherlands Society of Obstetrics and Gynaecology), embryologists and their society (The Dutch Federation of Clinical Embryology) as well as fertility doctors. A panel of experts hypothesized on barriers and facilitators for the implementation of home-based monitoring during the proposal phase of the Antarctica-2 randomized controlled trial (RCT). PARTICIPANTS/MATERIALS SETTING METHODS: All stakeholders were represented during the study. Two different questionnaires were developed in order to investigate facilitators and barriers for the patients and for healthcare providers. The facilitators and barriers were ranked on a scale of 1-10 with 10 being the most important. Based on our power analysis, we aimed for a minimum of 300 completed questionnaires for the patients and a minimum of 90 completed questionnaires for the healthcare providers. Facilitators and barriers were analysed using frequencies, mean (SD) and ranking. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 311 patients filled out the questionnaire of whom 86.8% underwent FET previously. The most important facilitator for the patients was to implement the strategy with the highest chance of pregnancy (mean 9.7; 95% CI 9.6-9.7) and the most important barrier was risk of missing ovulation (mean 8.4; 95% CI 8.2-8.6). A total of 96 healthcare providers filled out the questionnaire. According to healthcare providers, patients would accept the strategy when it causes less interference with their work and private life (mean 7.5; 95% CI 7.1-8.0) and has a low risk of missing the ovulation (mean 7.6; 95% CI 7.1-8.0). The most important facilitator for the implementation of home-based monitoring for healthcare providers was optimizing cumulative pregnancy rates (mean 8.1; 95% CI 7.7-8.4) and the most important barrier was the lack of laboratory capacity and flexibility (mean 6.4; 95% CI 5.8-7.0). LIMITATIONS REASONS FOR CAUTION: Facilitators and barriers were selected based on expert opinion. Currently, there are no validated questionnaires that aim to assess facilitators and barriers for the implementation of treatments in fertility care. WIDER IMPLICATIONS OF THE FINDINGS: During our study, we gained insight into barriers and facilitators for the implementation of home-based monitoring of NC-FET at an early phase. Early sharing and discussion of the results of this study with all stakeholders involved should stimulate a fast incorporation in guidelines, especially as key professionals in guideline development took part in this study. Also, based on our results, we can advise guideline developers to add tools to the guideline that may help overcome the implementation barriers. STUDY FUNDING/COMPETING INTERESTS: The Antarctica-2 RCT is supported by a grant from the Netherlands Organisation for Health Research and Development (ZonMw 843002807). No authors have any competing interests to declare. TRIAL REGISTRATION NUMBER: Trial NL6414 (NTR6590)

Obstetric and neonatal outcomes after natural versus artificial cycle frozen embryo transfer and the role of luteal phase support: a systematic review and meta-analysis

BACKGROUND: The number of frozen embryo transfers (FET) has increased dramatically over the past decade. Based on current evidence, there is no difference in pregnancy rates when natural cycle FET (NC-FET) is compared to artificial cycle FET (AC-FET) in subfertile women. However, NC-FET seems to be associated with lower risk of adverse obstetric and neonatal outcomes compared with AC-FET cycles. Currently, there is no consensus about whether NC-FET needs to be combined with luteal phase support (LPS) or not. The question of how to prepare the endometrium for FET has now gained even more importance and taken the dimension of safety into account as it should not simply be reduced to the basic question of effectiveness. OBJECTIVE AND RATIONALE: The objective of this project was to determine whether NC-FET, with or without LPS, decreases the risk of adverse obstetric and neonatal outcomes compared with AC-FET. SEARCH METHODS: A systematic review and meta-analysis was carried out. A literature search was performed using the following databases: CINAHL, EMBASE, and MEDLINE from inception to 10 October 2022. Observational studies, including cohort studies, and registries comparing obstetric and neonatal outcomes between singleton pregnancies after NC-FET and those after AC-FET were sought. Risk of bias was assessed using the ROBINS-I tool. The quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation approach. We calculated pooled odds ratios (ORs), pooled risk differences (RDs), pooled adjusted ORs, and prevalence estimates with 95% CI using a random effect model, while heterogeneity was assessed by the I2. OUTCOMES: The conducted search identified 2436 studies, 890 duplicates were removed and 1546 studies were screened. Thirty studies (NC-FET n = 56 445; AC-FET n = 57 231) were included, 19 of which used LPS in NC-FET. Birthweight was lower following NC-FET versus AC-FET (mean difference 26.35 g; 95% CI 11.61-41.08, I2 = 63%). Furthermore NC-FET compared to AC-FET resulted in a lower risk of large for gestational age (OR 0.88, 95% 0.83-0.94, I2 = 54%), macrosomia (OR 0.81; 95% CI 0.71-0.93, I2 = 68%), low birthweight (OR 0.81, 95% CI 0.77-0.85, I2 = 41%), early pregnancy loss (OR 0.73; 95% CI 0.61-0.86, I2 = 70%), preterm birth (OR 0.80; 95% CI 0.75-0.85, I2 = 20%), very preterm birth (OR 0.66, 95% CI 0.53-0.84, I2 = 0%), hypertensive disorders of pregnancy (OR 0.60, 95% CI 0.50-0.65, I2 = 61%), pre-eclampsia (OR 0.50; 95% CI 0.42-0.60, I2 = 44%), placenta previa (OR 0.84, 95% CI 0.73-0.97, I2 = 0%), and postpartum hemorrhage (OR 0.43; 95% CI 0.38-0.48, I2 = 53%). Stratified analyses on LPS use in NC-FET suggested that, compared to AC-FET, NC-FET with LPS decreased preterm birth risk, while NC-FET without LPS did not (OR 0.75, 95% CI 0.70-0.81). LPS use did not modify the other outcomes. Heterogeneity varied from low to high, while quality of the evidence was very low to moderate. WIDER IMPLICATIONS: This study confirms that NC-FET decreases the risk of adverse obstetric and neonatal outcomes compared with AC-FET. We estimate that for each adverse outcome, use of NC-FET may prevent 4 to 22 cases per 1000 women. Consequently, NC-FET should be the preferred treatment in women with ovulatory cycles undergoing FET. Based on very low quality of evidence, the risk of preterm birth be decreased when LPS is used in NC-FET compared to AC-FET. However, because of many uncertainties-the major being the debate about efficacy of the use of LPS-future research is needed on efficacy and safety of LPS and no recommendation can be made about the use of LPS

In Vitro 3D Staphylococcus aureus Abscess Communities Induce Bone Marrow Cells to Expand into Myeloid-Derived Suppressor Cells.

Staphylococcus aureus is the main causative pathogen of subcutaneous, bone, and implant-related infections, forming structures known as staphylococcal abscess communities (SACs) within tissues that also contain immunosuppressive myeloid-derived suppressor cells (MDSCs). Although both SACs and MDSCs are present in chronic S. aureus infections, it remains unknown whether SACs directly trigger MDSC expansion. To investigate this, a previously developed 3D in vitro SAC model was co-cultured with murine and human bone marrow cells. Subsequently, it was shown that SAC-exposed human CD11blow/- myeloid cells or SAC-exposed murine CD11b+ Gr-1+ cells were immunosuppressive mainly by reducing absolute CD4+ and CD8α+ T cell numbers, as shown in T cell proliferation assays and with flow cytometry. Monocytic MDSCs from mice with an S. aureus bone infection also strongly reduced CD4+ and CD8α+ T cell numbers. Using protein biomarker analysis and an immunoassay, we detected in SAC-bone marrow co-cultures high levels of GM-CSF, IL-6, VEGF, IL-1β, TNFα, IL-10, and TGF-β. Furthermore, SAC-exposed neutrophils expressed Arg-1 and SAC-exposed monocytes expressed Arg-1 and iNOS, as shown via immunofluorescent stains. Overall, this study showed that SACs cause MDSC expansion from bone marrow cells and identified possible mediators to target as an additional strategy for treating chronic S. aureus infections

Three-Dimensional In Vitro Staphylococcus aureus Abscess Communities Display Antibiotic Tolerance and Protection from Neutrophil Clearance

Staphylococcus aureus is a prominent human pathogen in bone and soft-tissue infections. Pathophysiology involves abscess formation, which consists of central staphylococcal abscess communities (SACs), surrounded by a fibrin pseudocapsule and infiltrating immune cells. Protection against the ingress of immune cells such as neutrophils, or tolerance to antibiotics, remains largely unknown for SACs and is limited by the lack of availability of in vitro models. We describe a three-dimensional in vitro model of SACs grown in a human plasma-supplemented collagen gel. The in vitro SACs reached their maximum size by 24 h and elaborated a fibrin pseudocapsule, as confirmed by electron and immunofluorescence microscopy. The in vitro SACs tolerated 100× the MIC of gentamicin alone and in combination with rifampin, while planktonic controls and mechanically dispersed SACs were efficiently killed. To simulate a host response, SACs were exposed to differentiated PLB-985 neutrophil-like (dPLB) cells and to primary human neutrophils at an early stage of SAC formation or after maturation at 24 h. Both cell types were unable to clear mature in vitro SACs, but dPLB cells prevented SAC growth upon early exposure before pseudocapsule maturation. Neutrophil exposure after plasmin pretreatment of the SACs resulted in a significant decrease in the number of bacteria within the SACs. The in vitro SAC model mimics key in vivo features, offers a new tool to study host-pathogen interactions and drug efficacy assessment, and has revealed the functionality of the S. aureus pseudocapsule in protecting the bacteria from host phagocytic responses and antibiotics