bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk of HIV Acquisition Among Men Who Have Sex With Men Infected With Bacterial Sexually Transmitted Infections: A Systematic Review and Meta-Analysis
Authors: Malekinejad Mohsen , Barker Erin K. , Merai Rikita , Lyles Cynthia M. , Bernstein Kyle T. , Sipe Theresa Ann , DeLuca Julia B. , Ridpath Alison D. , Gift Thomas L. , Tailor Amrita , Kahn James G.
Published: March 2021

Background

Men who have sex with men (MSM) who have bacterial sexually transmitted infections (STIs) are at increased risk for HIV infection. We enhanced and updated past summary risk estimates.

Methods

We systematically reviewed (PROSPERO No. CRD42018084299) peer-reviewed studies assessing the risk of HIV infection among MSM attributable to Chlamydia trachomatis (CT), Mycoplasma genitalium (MG), Neisseria gonorrhoeae (NG), Treponema pallidum (TP), and/or Trichomonas vaginalis (TV). We searched 3 databases through December 2017. We excluded studies with self-reported data or simultaneous STI and HIV assessment. We conducted dual screening and data extraction, meta-analytically pooled risk ratios (RRs), and assessed potential risk of bias.

Results

We included 26 studies yielding 39 RR (k) for HIV acquisition due to one of TP, NG, or CT. We did not identify eligible data for MG or TV, or for HIV transmission. HIV acquisition risk increased among MSM infected with TP (k = 21; RR, 2.68, 95% confidence interval [CI], 2.00–3.58), NG (k = 11; RR, 2.38; 95% CI, 1.56–3.61), and CT (k = 7; RR, 1.99; 95% CI, 1.59–2.48). Subanalysis RRs for all 3 pathogens were ≥1.66 and remained statistically significant across geography and methodological characteristics. Pooled RR increased for data with the lowest risk of bias for NG (k = 3; RR, 5.49; 95% CI, 1.11–27.05) and TP (k = 4; RR, 4.32; 95% CI, 2.20–8.51). We observed mostly moderate to high heterogeneity and moderate to high risk of bias.

Conclusions

Men who have sex with men infected with TP, NG, or CT have twice or greater risk of HIV acquisition, although uncertainties exist because of data heterogeneity and risk of bias.
The Availability of HIV and Sexually Transmitted Infection Testing and Treatment Services at Crisis Pregnancy Centers in the United States
Authors: Swartzendruber Andrea , Solsman Amy , Lambert Danielle N.
Published: March 2021

Background

Crisis pregnancy centers (CPCs) are nonprofit organizations that aim to prevent abortion and promote sexual abstinence before marriage only often using misinformation and deceptive tactics. We sought to describe the availability of HIV and sexually transmitted infection (STI) testing, treatment, and referral services at CPCs in the United States.

Methods

We used CPC Map, an online geocoded directory, to identify US CPCs. From December 2018 to August 2019, we assessed HIV/STI services advertised on CPC Web sites and used a standard script to call CPCs about the availability of services. Referrals were not requested but recorded.

Results

Of 2400 CPCs (96.3%) with accessible Web sites, 507 (21.1%) advertised STI testing, 291 (12.1%) STI treatment, and 114 (4.8%) HIV testing. Of 2467 (99.0%) CPCs reached by telephone, 552 (22.4%) offered STI testing, 377 (15.3%) STI treatment, and 208 (8.4%) HIV testing. At centers where services were unavailable, 795 (41.5%) proactively referred for STI testing, 170 (8.1%) for STI treatment, and 170 (7.5%) for HIV-related services. Nearly one-quarter (22.8%) of centers that offered STI testing did not offer treatment or provide a referral.

Conclusions

A minority but substantial number of CPCs advertised and offered HIV/STI services. People at risk for pregnancy who seek CPC services likely have outstanding need for HIV/STI services.
Recurrent Bacterial Vaginosis: An Unmet Therapeutic Challenge. Experience With a Combination Pharmacotherapy Long-Term Suppressive Regimen
Authors: Surapaneni Sarvani , Akins Robert , Sobel Jack D.
Published: March 2021

Background

Recurrence of bacterial vaginosis (RBV) is a major challenge to effective therapy. Women experiencing intractable and frequent recurrences are ill-served by available treatment options, such as both antimicrobial and use of probiotics.

Methods

One hundred five women with RBV failing all recommended regimens seen in the clinic were prescribed combination oral nitroimidazole 500 mg twice a day for 7 days and simultaneous boric acid 600 mg daily per vagina therapy for 30 days; thereafter, they were prescribed twice-weekly vaginal metronidazole gel for 5 months in an attempt to prevent recurrence and followed by a 6-month observation period. Results reflect standard of clinic care in this uncontrolled retrospective cohort analysis.

Results

An initial regimen of nitroimidazole and simultaneous but prolonged vaginal boric acid achieved a satisfactory response (BV cure ≤2 Amsel criteria) in 92 of 93 available patients. Thereafter, a maintenance metronidazole gel prevented symptomatic BV recurrence in 69.6% of compliant patients at 6-month follow-up. Long-term cure at a 12-month follow-up was demonstrated in almost 69% of women reaching the 6-month observation phase. Vaginal candidiasis frequently complicated prolonged antibiotic prophylaxis requiring frequent antifungal rescue or prophylaxis. Frequent loss to follow-up in this long-term study influenced efficacy evaluation.

Conclusions

In the absence of new antimicrobials or proven probiotic regimens, women with RBV may benefit from a prolonged drug-intensive antimicrobial regimen incorporating antibiofilm activity until newer measures are available. Additional randomized, control studies are needed.
Medicaid Expansion and Rates of Reportable Sexually Transmitted Infections in the United States: A County-Level Analysis
Authors: Rietmeijer Cornelis A. , Hauschild Benjamin C. , Burnside Helen C. , Wendel Karen A.
Published: March 2021

Chlamydia, gonorrhea, and primary/secondary syphilis rates in 2018 were significantly higher in counties located in states without Medicaid expansion compared with those with Medicaid expansion. For sexually transmitted infections combined, 59.9% of counties without Medicaid expansion were in the highest 2 sexually transmitted infection rate quartiles compared with 42.2% of counties with Medicaid expansion (P < 0.0001).
The Impact of the COVID-19 Pandemic on Sexually Transmitted Infection/Human Immunodeficiency Virus Testing Among Adolescents in a Large Pediatric Primary Care Network
Authors: Bonett Stephen , Petsis Danielle , Dowshen Nadia , Bauermeister José , Wood Sarah M.
Published: March 2021

Disruptions in sexually transmitted infection (STI) testing infrastructure during the COVID-19 pandemic threaten to impact STI service delivery for adolescents. Within a large pediatric primary care network, we compared STI testing encounters between the pandemic period and an analogous prepandemic period. The STI test counts decreased and test positivity increased during the pandemic period.
Intestinal Fatty Acid Binding Protein Levels in Pediatric Celiac Patients in Transition From Active Disease to Clinical and Serological Remission
Authors: Hoofien Assaf , Guz-Mark Anat , Zevit Noam , Tsadok Perets Tsachi , Assa Amit , Layfer Olga , Matar Manar , Nachmias-Friedler Vered , Silbermintz Ari , Shamir Raanan
Published: March 2021

Objectives:

Celiac disease (CD) is increasingly diagnosed without endoscopy. As such, the need for accurate serological markers to aid in the diagnosis and follow-up of CD has increased. Intestinal fatty acid binding protein (I-FABP) is a cytosolic protein present in enterocytes, whose blood levels reflect mucosal damage in a reliable and quantifiable way. The aim of this study was to compare I-FABP levels in newly diagnosed patients with CD and to examine changes in levels following 6 months of gluten-free diet (GFD).

Methods:

A prospective observational case control study of pediatric patients diagnosed with CD, with measurements of tissue transglutaminase IgA (TTG-IgA) and I-FABP levels at diagnosis and after 6 months of gluten free diet were compared to a control group of nonceliac patients.

Results:

This study included 35 patients and 32 controls. The CD group had higher I-FABP levels at diagnosis compared with the control group (median 641.7 pg/mL versus 334 pg/mL; P < 0.05). I-FABP levels significantly differed between patients presenting with TTG-IgA level 3–10 times the upper limit of normal (ULN) compared with those presenting with values >10 times ULN (median 432.2 pg/mL versus 796.2 pg/mL; P < 0.05). Patients with CD had a significant decrease in median I-FABP levels after 6 months of GFD (median 268.2 pg/mL), paralleling a decrease in TTG-IgA and GFD adherence.

Conclusions:

I-FABP levels are increased in patients with CD at diagnosis compared with controls and decrease significantly while patients adhere to GFD.
Placental Invasion into the Small Bowel Intestine Through a Myomectomy Scar: A Case Report With Literature Review
Authors: Saleh Mohamed M. , Mallmann Michael R. , Essakly Ahlem , Drebber Uta , Kleinert Robert , Kütting Fabian , Bratke Grischa , Müller Annette M.
Published: March 2021

Although extremely rare, uterine damage after hysteroscopic myomectomy sets the precondition for various life-threatening placental attachment disorders like placenta percreta (PP) or scar pregnancy. Due to vast clinical similarities, these terms are often used interchangeably. We report a case of a 47-yr-old patient at 27 wk + 4 d of gestation who presented with rectal bleeding. Clinical history revealed a previous uterine posterior wall myomectomy. The patient received intensive diagnostic work-up including sonography and magnetic resonance imaging. Under the suspicion of a bleeding Meckel diverticulum, an emergency laparotomy was performed. Intraoperatively it was observed that the placental tissue infiltrated the small bowel intestine at the location of the previous myomectomy. The adjacent intestine and the infiltrating placenta were surgically removed. The placenta could be easily detached from the uterus, which is why no hysterectomy was performed. Retrospectively, no radiologic or clinical hints of PP or scar pregnancy were evident before the surgery. Moreover, the pathologic work-up carried out afterwards proved no histopathologic evidence for PP. Our case underlines several clinical and pathologic difficulties. First, invasive placenta disorders including infiltration of intestinal organs have to be considered even after minor surgical interventions such as myomectomy. Second, clinical presentation is extremely variable and sometimes misleading, depending on the localization and the type of invasion. Our case underlines the importance of histopathologic work-up for distinguishing between various placenta attachment disorders such as PP and scar pregnancy. Given the large overlap in clinical presentation, pathophysiology and definition, we propose that the current definitions for PP and scar pregnancy have to be carefully reevaluated and broadened.
Mucinous Epithelium in Endometrial Curetting Leading to Diagnostic Conundrum: A Case Report
Authors: Gupta Garima , Hussain Fuad , Bagwan Izhar N.
Published: March 2021

Mucinous differentiation of the endometrium can occur in a spectrum of changes ranging from benign (metaplasia) to malignant (adenocarcinomas with mucinous differentiation). A rarer differential which is usually not considered is a teratoma. We present a case of a 55-yr-old woman with history of irregular perimenopausal bleeding. Endometrial curetting revealed proliferative mucinous epithelium on histology raising a possibility of low-grade epithelial mucinous malignancy. Hysterectomy was performed and histologic examination revealed a diagnosis of uterine mature teratoma. Mature cystic teratoma of the lower uterine segment is very rare and presence of just one element such as mucinous epithelium can lead to a misdiagnosis of carcinoma on biopsy or curetting.
Comparing 2 Appointment Scheduling Policies Using Discrete-Event Simulation
Authors: Abdoli Mohsen , Bahadori Mohammadkarim , Ravangard Ramin , Babaei Mansour , Aminjarahi Mohammad
Published: March 2021

Background and Objectives:

Two of the most important policies for dealing with the negative effects of high rates of no-show patients and appointment cancellations include double-booking and walk-in admission policies. This study aimed to compare these policies to identify their differences and their effects as well as the best circumstances for using each one.

Methods:

The main approach used in this study was discrete-event simulation using the Arena software application. Moreover, the average waiting time (considering patients' lateness) and the number of missed patients (considering no-show and cancelled patients) were accounted for in the performance evaluation criteria for both of the selected policies.

Results:

When the patients' arrival rate was high, the double-booking system resulted in higher productivity, while when it was low, the walk-in admission policy was the best policy for patient admission. The successful appointment rates of the current system, the walk-in admission system, and the double-booking system were 61.18%, 89.45%, and 93.24%, respectively.

Conclusions:

Although both double-booking and walk-in policies reduced the negative effects of cancelled and no-show patients, they had significantly different results in different situations. In general, there is no best system for appointment scheduling, and the choice of the superior system depends on the demand rate and its fluctuations.
Quality Improvement of Bowel Preparation for Screening Colonoscopies: A Study of Hospital Team Resource Management in Taiwan
Authors: Chung Chen-Shuan , Lin Chih-Ming , Chen Ming-Shu
Published: March 2021

Background and Objectives:

This study aimed to investigate the impact of patient education using a medical team resource management (TRM) method on the adequacy of bowel preparation.

Methods:

The study setting was a single hospital in northern Taiwan, and a total of 2104 (884 female, 1220 male) healthy subjects who underwent a health checkup colonoscopy screening were enrolled before and after the application of the TRM program intervention. The efficacy of the TRM intervention and the factors affecting bowel preparation were estimated using multivariate logistic regression.

Results:

The prevalence of adequate bowel preparation improved significantly from the preintervention period to the postintervention and validation periods, which had prevalence of 79.0%, 81.3%, and 84.0%, respectively. Using the preintervention period prevalence as a reference, the adjusted odds ratios (aORs) for adequate bowel preparation in the postintervention and validation periods were 2.199 (95% confidence interval [CI]: 1.538-3.142) and 2.035 (1.525-2.716), respectively. Men had a lower probability of adequate cleansing than women (aOR = 0.757; 95% CI = 0.598-0.957), and purgative containing polyethylene glycol had a lower probability of adequate cleansing than purgative containing sodium phosphate (aOR = 0.366; 95% CI: 0.277-0.483).

Conclusions:

Bowel preparation quality for colonoscopy could be improved by enhancing patient education via TRM, and we suggest that effective quality improvement schemes should be proposed for health-screening programs.
FDG PET/CT in 3 Cases of Hypertrophic Pachymeningitis Associated With Antineutrophil Cytoplasmic Antibody–Associated Vasculitis
Authors: Zhang Jian , Li Yuhan , Dong Aisheng , Zhu Yuzhao
Published: March 2021

Hypertrophic pachymeningitis associated with antineutrophil cytoplasmic antibody–associated vasculitis is a rare dural inflammatory disorder. We describe MRI and FDG PET/CT findings in 3 cases of hypertrophic pachymeningitis associated with antineutrophil cytoplasmic antibody–associated vasculitis. Enhanced brain MRI of the 3 cases showed linear enhancement of the thickened dura matter involving the skull base, tentorium, and/or convexity. On FDG PET/CT, the thickened dura matter showed diffusely increased FDG uptake with SUVmax ranging from 5.8 to 11.3. Familiarity with these MRI and FDG PET/CT findings is helpful for correct diagnosis and treatment.
18F-FDG PET/CT in Infective Endocarditis on Papillary Muscles
Authors: Fang Na , Zeng Lei , Jin Fei , Lin Shuai , Wang Yan-li
Published: March 2021

Infective endocarditis is a serious, potentially life-threatening condition. The valve leaflets and annulus are the most commonly affected sites, but involvement of the papillary muscles is extremely rare. We present the case of a 69-year-old woman who had infective endocarditis only involving the papillary muscle on 18F-FDG PET/CT.
Axillary Lymph Nodes Hypermetabolism After BNT162b2 mRNA COVID-19 Vaccination in Cancer Patients Undergoing 18F-FDG PET/CT
Authors: Bernstine Hanna , Priss Miriam , Anati Tamer , Turko Olga , Gorenberg Miguel , Steinmetz Adam Peter , Groshar David
Published: March 2021

Purpose

Recognition of the pattern of FDG uptake in hypermetabolic axillary lymph nodes (HALs) and association with recent messenger RNA (mRNA) vaccination are important to prevent patient anxiety and further needless examinations or costly biopsies in cancer patients.

Materials and Methods

This study was a retrospective cohort study in a single tertiary care institution. We investigate the occurrence and pattern of HAL on FDG PET/CT scans from 650 consecutive cancer patients with recent BNT162b2 mRNA COVID-19 vaccination.

Results

Between December 20, 2020, and February 8, 2021, 650 patients (351 female patients [54%]; mean age, 68.9 years) had recent mRNA COVID-19 vaccination and an FDG PET/CT scan. HALs were found in 57 (14.5%) of 394 patients (95% confidence interval [CI], 10.9%–18.7%) 12.3 ± 5.9 (1–22) days after dose 1 and in 111 (43.3%) of 256 patients (95% CI, 35.3%–52.2%; P < 0.0001) after 7.5 ± 5.4 (1–22) days after dose 2. There was no difference between dose 1 and dose 2 concerning SUVmax (3.7 ± 1.8 [1.3–11.3] and 4.5 ± 3.9 [1.4–26.3], P = 0.13, respectively), SUVmean (2.1 ± 1.0 [0.7–6.5] and 2.7 ± 2.4 [0.8–17], P = 0.08, respectively), and reactogenicity volume (2.7 ± 2.3 [0.2–11.6] cm3 and 2.7 ± 2.4 [0.2–15.5] cm3, P = 0.98, respectively). There was no difference in number and in size of positive lymph nodes between dose 1 and dose 2: 3.2 ± 2.2 (1–10) and 3.7 ± 2.4 (1–12) (P = 0.18), and 1.4 ± 0.4 cm (0.7–2.5 cm) and 1.5 ± 0.4 cm (0.6–3.2 cm) (P = 0.75), respectively.

Conclusions

A cluster pattern of hypermetabolic ipsilateral small axillary lymph nodes is common after mRNA COVID-19 vaccination, mainly after the second injection.
The Challenges of Dyad Practice in Simulation Training of Basic Open Surgical Skills—A Mixed-Method Study
Authors: Zetner Diana B. , Konge Lars , Fabrin Anja , Christensen John B. , Thinggaard Ebbe
Published: March 2021

Introduction

Simulation training at home improves access to training, but motivation can be difficult to maintain. Dyad training could keep trainees motivated. This study aimed to examine the effect of self-regulated training of basic surgical skills in pairs versus individually.

Methods

One hundred one medical doctors were included in this prospective, mixed-method, simulation-based study. Participants were randomized to train individually or in pairs during a 6-week course in open surgical skills, consisting of didactic instructions and self-directed training at home. Trainees kept a training log and filled in a questionnaire. Skills were tested before and after the course. Tests were rated by an expert using the Objective Structured Assessment of Technical Skills Global Rating Scale.

Results

Ninety-seven doctors completed the study. We found no differences in test score between dyad and individual trainees. Dyad trainees compared with individual trainees improved by 7.23 points (intercept estimate) versus 6.94 points, respectively (P = 0.881). Dyad trainees trained less frequently [7.3 times (intercept estimate) vs. 12.1 times, P < 0.001, but for longer intervals compared with individual trainees (68 minutes vs. 38 minutes)]. Dyad trainees reported benefits such as having a sparring partner, receiving feedback, corrections, increased motivation, having fun, and more structured training sessions. However, the coordination of training sessions was difficult.

Conclusions

No differences were found between dyad trainees and individual trainees in improvement of surgical skills. Off-site dyad training led to fewer, but longer training sessions, which may have negatively impacted the effectiveness of training. Dyad trainees perceived dyad training beneficial.
Evolution of a Simulation Faculty Development Program in a Low-Resource Setting
Authors: Seethamraju Rajasri R. , Stone Kimberly P. , Shepherd Michael
Published: March 2021

Summary Statement

The PediSTARS Faculty Development Program is a novel approach for simulation faculty training with an aim to increase the pool of trained simulation faculty in India and neighboring countries that could then facilitate simulation-based training, both at their own workplaces and in the PediSTARS simulation-based workshops that provide training in pediatric and neonatal emergencies. This commentary describes the evolution of the faculty development program, the initial process, the feedback obtained, the changes undertaken, the progress made to date, and the challenges ahead. There is also an emphasis on the key generalizable principles that can be applicable to other low-resource settings.
World Society of Emergency Surgery-American Association for the Surgery of Trauma Guidelines for management of Clostridioides (Clostridium) difficile infection in surgical patients: An executive summary
Authors: Sartelli Massimo , Ansaloni Luca , Biffl Walter A. , Coccolini Federico , De Simone Belinda , Leppaniemi Ari , Kluger Yoram , Tolonen Matti , Moore Ernest E. , Catena Fausto
Published: March 2021

In the last three decades, the dramatic worldwide increase in incidence and severity of Clostridioides difficile infection (CDI) (formerly Clostridium difficile infection) has made CDI a global public health challenge. Surgery is a known risk factor for development of CDI yet surgery is also a treatment option in severe cases of CDI. The World Society of Emergency Surgery guidelines for management of CDI in surgical patients were published in 2015. In 2019, the guidelines were revised and updated according to the grading of recommendations assessment, development and evaluation methodology. This executive summary is intended to consolidate knowledge on the management of CDI focusing on aspects that a general and emergency surgeon should know about the prevention and the management of CDI, by providing a practical and concise version of the original guidelines.
Addition of neurological status to pediatric adjusted shock index to predict early mortality in trauma: A pediatric Trauma Quality Improvement Program analysis
Authors: Lammers Daniel T. , Marenco Christopher W. , Morte Kaitlin R. , Conner Jeffrey R. , Horton John D. , Barlow Meade , Martin Matthew J. , Bingham Jason R. , Eckert Matthew J. , Escobar Mauricio A.
Published: March 2021

INTRODUCTION

Pediatric adjusted shock index (SIPA) has demonstrated the ability to prospectively identify children at the highest risk for early mortality. The addition of neurological status to shock index has shown promise as a reliable triage tool in adult trauma populations. This study sought to assess the utility of combining SIPA with Glasgow Coma Scale (GCS) for predicting early trauma-related outcomes.

METHODS

Retrospective review of the 2017 Trauma Quality Improvement Program Database was performed for all severely injured patients younger than 18 years old. Pediatric adjusted shock index and reverse SIPA × GCS (rSIG) were calculated. Age-specific cutoff values were derived for reverse shock index multiplied by GCS (rSIG) and compared with their SIPA counterparts for early mortality assessment using area under the receiver operating characteristic curve analyses.

RESULTS

A total of 10,389 pediatric patients with an average age of 11.4 years, 67% male, average Injury Severity Score of 24.1, and 4% sustaining a major penetrating injury were included in the analysis. The overall mortality was 9.3%. Furthermore, 32.1% of patients displayed an elevated SIPA score, while only 27.5% displayed a positive rSIG. On area under the receiver operating characteristic curve analysis, rSIG was found to be superior to SIPA as a predictor for in hospital mortality with values of 0.854 versus 0.628, respectively.

CONCLUSION

Reverse shock index multiplied by GCS more readily predicted in hospital mortality for pediatric trauma patients when compared with SIPA. These findings suggest that neurological status should be an important factor during initial patient assessment. Further study to assess the applicability of rSIG for expanded trauma-related outcomes in pediatric trauma is necessary.

LEVEL OF EVIDENCE

Prognostic study, level IV.
An ERK5-KLF2 signalling module regulates early embryonic gene expression dynamics and stem cell rejuvenation
Authors: Brown Helen A. , Williams Charles A.C. , Zhou Houjiang , Rios-Szwed Diana , Fernandez-Alonso Rosalia , Mansoor Saria , McMulkin Liam , Toth Rachel , Gourlay Robert , Peltier Julien , Dieguez-Martinez Nora , Trost Matthias , Lizcano Jose M. , Stavridis Marios P. , Findlay Greg M.
Published: March 2021

The ERK5 MAP kinase signalling pathway drives transcription of naïve pluripotency genes in mouse Embryonic Stem Cells (mESCs). However, how ERK5 impacts on other aspects of mESC biology has not been investigated. Here, we employ quantitative proteomic profiling to identify proteins whose expression is regulated by the ERK5 pathway in mESCs. This reveals a function for ERK5 signalling in regulating dynamically expressed early embryonic 2-cell stage (2C) genes including the mESC rejuvenation factor ZSCAN4. ERK5-dependent ZSCAN4 induction in mESCs increases telomere length, a key rejuvenative process required for prolonged culture. Mechanistically, ERK5 promotes ZSCAN4 and 2C gene expression via transcription of the KLF2 pluripotency transcription factor. Surprisingly, ERK5 also directly phosphorylates KLF2 to drive ubiquitin-dependent degradation, encoding negative-feedback regulation of 2C gene expression. In summary, our data identify a regulatory module whereby ERK5 kinase and transcriptional activities bi-directionally control KLF2 levels to pattern dynamic 2C gene transcription and mESC rejuvenation.
Correlative Organelle Microscopy: fluorescence guided volume electron microscopy of intracellular processes
Authors: Loginov Sergey , Fermie Job , Fokkema Jantina , Agronskaia Alexandra V. , de Heus Cilia , Blab Gerhard A. , Klumperman Judith , Gerritsen Hans C. , Liv Nalan
Published: March 2021

Intracellular processes depend on a strict spatial and temporal organization of proteins and organelles. Directly linking molecular to nanoscale ultrastructural information is therefore crucial to understand cellular physiology. Volume or 3-dimensional (3D) correlative light and electron microscopy (volume-CLEM) holds unique potential to explore cellular physiology at high-resolution ultrastructural detail across cell volumes. Application of volume-CLEM is however hampered by limitations in throughput and 3D correlation efficiency. Addressing these limitations, we here describe a novel pipeline for volume-CLEM that provides high-precision (<100nm) registration between 3D fluorescence microscopy (FM) and 3D electron microscopy (EM) data sets with significantly increased throughput. Using multi-modal fiducial nanoparticles that remain fluorescent in epoxy resins and a 3D confocal fluorescence microscope integrated in a Focused Ion Beam Scanning Electron Microscope (FIB.SEM), our approach uses FM to target extremely small volumes of even single organelles for imaging in volume-EM, and obviates the need for post correlation of big 3D datasets. We extend our targeted volume-CLEM approach to include live-cell imaging, adding information on the motility of intracellular membranes selected for volume-CLEM. We demonstrate the power of our approach by targeted imaging of rare and transient contact sites between endoplasmic reticulum (ER) and lysosomes within hours rather than days. Our data suggest that extensive ER-lysosome and mitochondria-lysosome interactions restrict lysosome motility, highlighting the unique capabilities of our integrated CLEM pipeline for linking molecular dynamic data to high-resolution ultrastructural detail in 3D.

Significance

We have developed a correlative imaging pipeline to(i)correlate 3D-FM to volume-EM data with high precision, directly bridging the FM and EM resolutions(ii)achieve high-throughput volume-CLEM by targeted EM imaging of a single organelle sized region-of-interest, pre-identified by FM(iii)link live-cell fluorescence imaging of cultured mammalian cells to high-throughput volume-CLEM(iv)quantitatively study structure-function relations at subcellular scale(v)link rare (e.g. membrane contact sites) and transient (e.g. organelle interactions) cellular events to 3D ultrastructure.

The targeted volume-CLEM pipeline provides a unique prospect for multi-modal correlative intracellular analysis combining dynamic interaction (live-cell imaging), functional state (live-cell imaging), molecular localization (FM), and 3D-ultrastructure (FIB.SEM) at nanometer scale.
Type 2 innate immunity regulates hair follicle homeostasis to controlDemodexpathosymbionts
Authors: Ricardo-Gonzalez Roberto R. , Kotas Maya E. , Tenvooren Iliana , Marquez Diana M. , Fassett Marlys S. , Lee Jinwoo , Daniel Scott G. , Bittinger Kyle , Díaz Roberto Efraín , Fraser James S. , Ansel K. Mark , Spitzer Matthew H. , Liang Hong-Erh , Locksley Richard M.
Published: March 2021

Allergic skin diseases are common, but basal roles for type 2 immunity in cutaneous homeostasis are incompletely understood. Here, we show that skin group 2 innate lymphoid cells (ILC2s) are the predominant resident cells that secretes IL-13, which attenuates epithelial cell proliferation during anagen throughout the hair follicle (HF), including in HF stem cells. Although HF are normal in the absence of type 2 immunity, colonization with the commensal mite,Demodex musculi,results in epithelial proliferation and aberrant hair follicle morphology accompanied by loss of stable commensalism with massive infestation and expansion of inflammatory ILC2s and other immune cells. Topical anti-parasitic agents, but not broad-spectrum antibiotics, reversed the phenotype. CommensalDemodexcolonization of mammalian hair follicles is ubiquitous, including in humans, revealing an unanticipated role for ILC2s and type 2 immunity for skin homeostasis in the normal environment.

One Sentence Summary

Dynamic regulation of skin physiology by Type 2 innate immunity regulates healthy commensalism by parasiticDemodexmites.
Staphylococcus aureusα-toxin induces acid sphingomyelinase release from a human endothelial cell line
Authors: Krones David , Rühling Marcel , Becker Katrin Anne , Kunz Tobias C. , Sehl Carolin , Paprotka Kerstin , Gulbins Erich , Fraunholz Martin
Published: March 2021

Staphylococcus aureus(S. aureus) is well known to express a plethora of toxins of which the pore-forming hemolysin A (α-toxin) is the best-studied cytolysin. Pore-forming toxins (PFT) permeabilize host membranes during infection thereby causing concentration-dependent effects in host cell membranes ranging from disordered ion fluxes to cytolysis. Host cells possess defense mechanisms against PFT attack, resulting in endocytosis of the breached membrane area and delivery of repair vesicles to the insulted plasma membrane as well as a concurrent release of membrane repair enzymes. Since PFTs from several pathogens have been shown to recruit membrane repair components, we here investigated whether staphylococcal α-toxin is able to induce these mechanisms in endothelial cells. We show thatS. aureusα-toxin induced increase in cytosolic Ca2+in endothelial cells, which was accompanied by p38 MAPK phosphorylation. Toxin challenge led to increased endocytosis of an extracellular fluid phase marker as well as increased externalization of LAMP1-positive membranes suggesting that peripheral lysosomes are recruited to the insulted plasma membrane. We further observed that thereby the lysosomal protein acid sphingomyelinase (ASM) was released into the cell culture medium. Thus, our results show that staphylococcal α-toxin triggers mechanisms in endothelial cells, which have been implicated in membrane repair after damage of other cell types by different toxins.
DecipheringBrassicaplant defence responses to cabbage white butterfly egg-associated molecular patterns
Authors: Caarls Lotte , Bassetti Niccoló , van Doesburg Femke , Verbaarschot Patrick , van Loon Joop J.A. , Schranz M. Eric , Fatouros Nina E.
Published: March 2021

Brassicaplants activate a strong hypersensitive response (HR)-like necrosis underneath eggs of cabbage white butterflies, but their molecular response to eggs is poorly understood. Here, we developed a method to generate egg wash to identify potential insect egg-associated molecular patterns (EAMPs) inducing HR-like necrosis. We found that egg wash, containing compounds fromPieriseggs, induced a similar response as eggs. We show that wash of hatched eggs, of egg glue, and of accessory reproductive glands (ARG) that produce this glue, also induced HR-like necrosis, whereas removal of the glue from eggs resulted in a reduced response. Eggs ofPierisbutterflies induced callose deposition, production of reactive oxygen species and cell death inB. nigraandB. rapaleaf tissue, also in plants that did not express HR-like necrosis. Finally, only washes fromPieriseggs induced defence genes and ethylene production, whereas egg wash of a generalist moth did not. Our results indicate that EAMPs are in the egg glue and that the response inB. nigrais specific toPierisspecies. Our study expands knowledge on theBrassica-Pieris-egg interaction, and paves the way for identification of EAMPs inPierisegg glue and corresponding receptor inBrassicaspp.
Innate immune signaling in trophoblast and decidua organoids defines differential antiviral defenses at the maternal-fetal interface
Authors: Yang Liheng , Semmes Eleanor C. , Ovies Cristian , Megli Christina , Permar Sallie , Gilner Jennifer B. , Coyne Carolyn B.
Published: March 2021

Infections at the maternal-fetal interface can directly harm the fetus and induce complications that adversely impact pregnancy outcomes. Innate immune signaling by both fetal-derived placental trophoblasts and the maternal decidua must provide antimicrobial defenses at this critical interface without compromising its integrity. Here, we developed matched trophoblast and decidua organoids from human placentas to define the relative contributions of these cells to antiviral defenses at the maternal-fetal interface. We demonstrate that trophoblast and decidua organoids basally secrete distinct immunomodulatory factors, including the constitutive release of the antiviral type III interferon IFN- λ2 from trophoblast organoids, and differentially respond to viral infections through the induction of organoid-specific factors. Lastly, we define the differential susceptibility of trophoblast and decidua organoids to human cytomegalovirus (HCMV) and the transcriptional and immunological responses of these organoids to HCMV infection. Our findings establish matched trophoblast and decidua organoids as ex vivo models to study vertically transmitted infections and highlight differences in innate immune signaling by fetal-derived trophoblasts and the maternal decidua.
Interactions and information: Exploring task allocation in ant colonies using network analysis
Authors: Swain Anshuman , Williams Sara D. , Di Felice Louisa J. , Hobson Elizabeth A.
Published: March 2021

In animal societies, individuals may take on different roles to fulfil their own needs and the needs of their groups. Ant colonies display high levels of organisational complexity, with ants fulfilling different roles at different timescales (what is known astask allocation). Factors affecting task allocation can be at the individual level (e.g., physiology), or at the group level (e.g., the network of interactions). We focus on group level processes by exploring the relationship between interaction networks, task allocation and task switching using a previously published dataset (Mersch et al., 2013) tracking the behaviour of sixCamponotus fellahcolonies over 41 days. In our new analyses, our goal was to better explain the noisy process of task switching beyond simple age polyethism. First, we investigated the architecture of interaction networks using node (individual) level network measures and their relation to the individual’s task – foraging, cleaning or nursing – and whether or not the ant switched tasks. We then explored how noisy information propagation was among ants, as a function of the colony composition (how many ants carried out which tasks), through the information-theoretic metric ofEffective Information. Our results show that interaction history was tied to task allocation: ants who switched to a task are more likely to have interacted with other ants carrying out that task. The degree to which interactions related to task allocation, as well as the noise in those interactions, depended on which groups of ants were interacting. Overall, we showed that colony cohesion was stable even as ant-level network measures varied more for ants when they switched functional groups; thus, ant colonies maintained a high level of information flow as determined by network analysis, and ant functional groups played different roles in maintaining colony cohesion through varied information flows.

Highlights

We analysed the interaction networks of sixCamponotus fellahcolonies

We tested how centrality and information flow were tied to task switching

Node-level network metrics and the information theoretic measure ofEffective Informationexplained differences among functional groups

Interactions were correlated with task switching, but the strength of the correlation differed across functional groups
HPMCP-coated microcapsules containing the Ctx(Ile21)-Ha antimicrobial peptide reduces the mortality rate caused by resistantSalmonellaEnteritidis in poultry
Authors: Roque Borda Cesar Augusto , Pereira Larissa Pires , Lopes Guastalli Elisabete Aparecida , Soares Nilce Maria , Mac-Lean Priscilla Ayleen Bustos , D’Alessandro Salgado Douglas , Meneguin Andréia Bagliotti , Chorilli Marlus , Vicente Eduardo Festozo
Published: March 2021

The constant use of synthetic antibiotics as growth promoters can cause great bacterial resistance in chicks. Consequently, the use of these drugs has been restricted in different countries. Antimicrobial peptides have gained relevance in recent years due to their minimal capacity for bacterial resistance and does not generate toxic residues that harm the environment and human health. In this work, Ctx(Ile21)-Ha antimicrobial peptide was employed, due to its previously reported largely antimicrobial potential, to evaluate its application effect in laying chicks challenged withSalmonellaEnteritidis, resistant to nalidixic acid and spectinomycin. For this, Ctx(Ile21)-Ha was synthesized, microencapsulated and coated with hypromellose phthalate (HPMCP) to be release in the intestine. Two different doses (3.2 and 6.4 µg of Ctx(Ile21)-Ha per kg of isoproteic and isoenergetic poultry feed) were included in the chicks’ food and administered for 28 days. Antimicrobial activity, effect and response as treatment were evaluated. Statistical results were analyzed in detail and indicate that the formulated Ctx(Ile21)-Ha peptide had a positive and significant effect in relation to the reduction of chick mortality. There was a significant difference in laying chick weight between the control and microencapsulation treatment groups as a function of time. Therefore, the microencapsulated Ctx(Ile21)-Ha antimicrobial peptide may be an interesting and promising option in the substitution of conventional antibiotics.
Invertebrate methylomes provide insight into mechanisms of environmental tolerance and reveal methodological biases
Authors: Trigg Shelly A. , Venkataraman Yaamini R. , Gavery Mackenzie R. , Roberts Steven B. , Bhattacharya Debashish , Downey-Wall Alan , Eirin-Lopez Jose M. , Johnson Kevin M. , Lotterhos Katie E. , Puritz Jonathan B. , Putnam Hollie M.
Published: March 2021

There is a growing focus on the role of DNA methylation in the ability of marine invertebrates to rapidly respond to changing environmental factors and anthropogenic impacts. However, genome-wide DNA methylation studies in non-model organisms are currently hampered by limited understanding of methodological biases. Here we compare three methods for quantifying DNA methylation at single base-pair resolution — Whole Genome Bisulfite Sequencing (WGBS), Reduced Representation Bisulfite Sequencing (RRBS), and Methyl-CpG Binding Domain Bisulfite Sequencing (MBDBS) — using multiple individuals from two reef-building coral species with contrasting environmental sensitivity. All methods reveal substantially greater methylation inMontipora capitata(11.4%) than the more sensitivePocillopora acuta(2.9%). The majority of CpG methylation in both species occurs in gene bodies and flanking regions. In both species, MBDBS has the greatest capacity for detecting CpGs in coding regions at our sequencing depth, however MBDBS may be influenced by intra-sample methylation heterogeneity. RRBS yields robust information for specific loci albeit without enrichment of any particular genome feature and with significantly reduced genome coverage. Relative genome size strongly influences the number and location of CpGs detected by each method when sequencing depth is limited, illuminating nuances in cross-species comparisons. As genome-wide methylation differences, supported by data across bisulfite sequencing methods, may contribute to environmental sensitivity phenotypes in critical marine invertebrate taxa, these data provide a genomic resource for investigating the functional role of DNA methylation in environmental tolerance.
Self-organization of a doubly asynchronous irregular network state for spikes and bursts
Authors: Vercruysse Filip , Naud Richard , Sprekeler Henning
Published: March 2021

Cortical pyramidal cells (PCs) have a specialized dendritic mechanism for the generation of bursts, suggesting that these events play a special role in cortical information processing.In vivo, bursts occur at a low, but consistent rate. Theory suggests that this network state increases the amount of information they convey. However, because burst activity relies on a threshold mechanism, it is rather sensitive to dendritic input levels. In spiking network models, network states in which bursts occur rarely are therefore typically not robust, but require fine-tuning. Here, we show that this issue can be solved by a homeostatic inhibitory plasticity rule in dendrite-targeting interneurons that is consistent with experimental data. The suggested learning rule can be combined with other forms of inhibitory plasticity to self-organize a network state in which both spikes and bursts occur asynchronously and irregularly at low rate. Finally, we show that this network state creates the network conditions for a recently suggested multiplexed code and thereby indeed increases the amount of information encoded in bursts.

Author summary

The language of the brain consists of sequences of action potentials. These sequences often contain bursts, short “words” consisting of a few action potentials in rapid succession. Bursts appear to play a special role in the brain. They indicate whether a stimulus was perceived or missed, and they are very effective drivers of synaptic plasticity, the neural substrate of learning. Bursts occur rarely, but consistently, a condition that is thought to maximize the amount of information they can communicate. In our article, we argue that this condition is far from self-evident, but requires very special circumstances. We show that these circumstances can be reached by homeostatic inhibitory plasticity in certain inhibitory neuron types. This may sound complicated, but basically works just like a thermostat. When bursts occur too often, inhibition goes up and suppresses them. When they are too rare, inhibition goes down and thereby increases their number. In computer simulations, we show that this simple mechanism can create circumstances akin to those in the brain, and indeed allows bursts to convey information effectively. Whether this mechanism is indeed used by the brain now remains to be tested by our experimental colleagues.
EHMT2 Controls Transcriptional Noise and the Developmental Switch after Gastrulation in the Mouse Embryo
Authors: Zeng Tie-Bo , Pierce Nicholas , Liao Ji , Singh Purnima , Zhou Wanding , Szabó Piroska E.
Published: March 2021

Embryos that carry zygotic or parental mutations inEhmt2, the gene encoding the main euchromatic histone H3K9 methyltransferase, EHMT2, exhibit variable developmental delay. We asked the question whether the delayed embryo is different transcriptionally from the normally developing embryo when they reach the same developmental stage. We collected embryos carrying a series of genetic deficiencies in theEhmt2gene and performed total RNA sequencing of somite stage-matched individual embryos. We applied novel four-way comparisons to detect differences between normal versus deficient embryos, and between 12-somite and 6-somite embryos. Importantly, we also identified developmental changes in transcription that only occur during the development of the normal embryo. We found that at the 6-somite stage, gastrulation-specific genes were not precisely turned off in theEhmt2−/−embryos, and genes involved in organ growth, connective tissue development, striated muscle development, muscle differentiation, and cartilage development were not precisely switched on in theEhmt2−/−embryos. Zygotic EHMT2 reduced transcriptional variation of developmental switch genes and at some repeat elements at the six-somite stage embryos. Maternal EHMT2-mutant embryos also displayed great transcriptional variation consistent with their variable survival, but transcription was normal in developmentally delayed parental haploinsufficient embryos, consistent with their good prospects. Global profiling of transposable elements in the embryo revealed that specific repeat classes responded to EHMT2. DNA methylation was specifically targeted by EHMT2 to LTR repeats, mostly ERVKs. Long noncoding transcripts initiated from those misregulated ‘driver’ repeats inEhmt2−/−embryos, and extended to several hundred kilobases, encompassing a multitude of additional, similarly misexpressed ‘passenger repeats.’ These findings establish EHMT2 as an important regulator of the transition between gastrulation programs and organ specification programs and of variability.
Self-Supervised Deep Learning Encodes High-Resolution Features of Protein Subcellular Localization
Authors: Kobayashi Hirofumi , Cheveralls Keith C. , Leonetti Manuel D. , Royer Loic A.
Published: March 2021

Elucidating the diversity and complexity of protein localization is essential to fully understand cellular architecture. Here, we presentcytoself, a deep-learning approach for fully self-supervised protein localization profiling and clustering.cytoselfleverages a self-supervised training scheme that does not require pre-existing knowledge, categories, or annotations. Trainingcytoselfon images of 1,311 endogenously labeled proteins from the OpenCell database reveals a highly resolved protein localization atlas that recapitulates major scales of cellular organization, from coarse classes such as nuclear, cytoplasmic and vesicular, to the subtle localization signatures of individual protein complexes. We quantitatively validatecytoself’s ability to cluster proteins into organelles and protein complex clusters using a clustering score, and show thatcytoselfattains higher scores than previous unsupervised or self-supervised approaches. Finally, to better understand the inner workings of our model, we dissect the emergent features from which our clustering is derived, interpret these features in the context of the fluorescence images, and analyze the performance contributions of the different components of our approach.