bluuebunny/crossref_metadata_2025 huggingface dataset:
Botulinum Toxin Accessory Proteins: Are They Just an Accessory?
Authors: Avelar Rui
Published: June 2024

BACKGROUND

Botulinum neurotoxins produced by Clostridium botulinum consist of a complex of a core neurotoxin protein and one or more nontoxin accessory proteins. The accessory proteins are generally thought to protect the neurotoxin from the gastric environment in botulism poisoning, dissociating away upon absorption. Other than their questionable immunogenicity, they are rarely mentioned in botulinum toxin therapy.

OBJECTIVE

To review evidence that accessory proteins potentially play a role in neurotoxin activity.

RESULTS

Evidence suggests that the accessory proteins do not dissociate from the neurotoxin complex and enhance neurotoxin activity. Complexed type A botulinum toxin has dramatically higher endopeptidase activity than noncomplexed neurotoxin. A primary accessory protein, hemagglutinin-33, exhibits this same effect on both type A and type E core neurotoxin proteins, the latter not natively having this accessory protein. A clinical study using an objective computer assessment assay has shown a correlation between type A complex size and glabellar strain reduction, which reflects increasing clinical efficacy. Finally, a systematic review found no correlation between type A complex size and neutralizing antibody formation.

CONCLUSION

Accessory proteins may play a role in the efficacy of botulinum toxin and could remain complexed to the neurotoxin for longer than previously reported.
Network pharmacology and bioinformatics analysis identify potential therapeutic effects of berberine on colon cancer complicated with radiation enteritis
Authors: Yan Ziqiao , Yu Hongyang , Zhang Liangliang , Liao Zebin , Ge Xiangwei , Wang Yuguo , Tian Peiyu , Ni Zhexin , Dou Yongqi , Gao Yue
Published: June 2024

Objective:

Patients with colon adenocarcinoma (COAD) who undergo radiation therapy develop radiation enteritis (RE). The predictive value of RE in COAD is yet to be established. Berberine, an active compound derived from the traditional Chinese medicinal plant, Coptis chinensis, has notable anti-inflammatory properties and offers protection to the intestinal mucosa. This study aimed to evaluate the possible therapeutic effect and mechanism of berberine as a treatment for COAD complicated with RE (COAD&RE).

Methods:

Relevant genetic features of diverse COAD&RE populations were analyzed using bioinformatics and the Cox proportional hazards regression model. The therapeutic targets of berberine were predicted using network pharmacology and molecular docking. In vivo and in vitro experiments were conducted to validate the core genes identified using molecular docking.

Results:

RE has a certain impact on the prognosis of COAD and berberine may play an important role in the treatment of COAD&RE. In addition, we identified five core therapeutic targets of berberine by network pharmacology and molecular docking: CCND1, MYC, AR, LEP, and CYP19A1. In vivo experiments showed that berberine increased short-term survival rate, body weight, and intestinal epithelial cell recovery in mice after radiation. In an in vitro study, berberine promoted the proliferation of human intestinal epithelial cells and enhanced the radiosensitivity of HT29 cells after radiation, and the relative mRNA expression levels of CCND1 and MYC closely correlated with these effects.

Conclusions:

This study predicted the potential therapeutic effects of berberine on COAD&RE and verified the relevant mechanisms, which may provide insights and suggestions for the clinical treatment of COAD&RE.
Dorsal Penile Artery Avulsion After Collagenase Clostridium histolyticum (Xiaflex) for Peyronie’s Disease: A Case Report
Authors: Goradia Rajvi , Skokan Alexander J. , Hehemann Marah C.
Published: June 2024

Collagenase Clostridium histolyticum (CCH) is frequently used as first-line therapy for patients with Peyronie’s disease. It was United States Food and Drug Administration approved in 2013 and since then, has been widely accepted as a safe and effective treatment option with most adverse effects being minor and amenable to conservative management. We report an unusual and previously unreported complication after CCH (Xiaflex) injection: avulsion of a dorsal penile artery, which required surgical exploration and ligation. This article seeks to inform urologists about an unexpected complication that should be considered in the differential diagnosis for severe penile hematoma after CCH injection and discusses our strategy for surgical management.
Fatal Presentation of Susac Syndrome in a Congenitally Deaf Patient With a Cochlear Implant
Authors: Richter John E. , Rourk Katelyn S. , Stewart Michael W. , Raymond Mallory J.
Published: June 2024

Objective

To report a fatal case of Susac syndrome in a congenitally deaf patient with a cochlear implant and a history of migraines, emphasizing the diagnostic challenges in patients with preexisting conditions.

Patient

A 33-year-old male with congenital hearing loss, a cochlear implant, and chronic migraines who presented with mild subacute auditory disturbance and headaches that later progressed to severe encephalopathy.

Intervention

Explantation of a non–magnetic resonance imaging (MRI) compatible cochlear implant followed by MRI, fundoscopy, and the administration of immunosuppressive medications.

Main Outcome Measures

Diagnosis was confirmed by characteristic MRI appearance and the presence of a hemi-retinal artery occlusion.

Results

After weeks of immunosuppressive treatment, the patient died of a global cerebral ischemic event of unknown origin.

Conclusions

For patients with preexisting sensorineural hearing loss and cochlear implants, Susac syndrome poses a diagnostic challenge. Auditory disturbances in the absence of cochlear implant failure should prompt further evaluation for visual disturbances and encephalopathy. MRI and fundoscopy should be performed to detect other features of the disease.
Resonance Frequency Analysis Identifies Implant- and Host-Related Factors Associated With Bone-Anchored Hearing Implant Stability
Authors: Bezdjian Aren , Mikolajewicz Nicholas , Denton Carolyn , Bouchard Alice , Rummler Maximilian , Gludovatz Bernd , Shin Mihee , Zimmermann Elizabeth , Salameh Samer , Daniel Sam J. , Willie Bettina M.
Published: June 2024

Hypothesis

Resonance frequency analysis (RFA) is a reliable, noninvasive method to assess the stability of bone-anchored hearing implants (BAHIs), although surgical-, implant-, and host-related factors can affect its outcome.

Background

BAHI plays an important role in restoring hearing function. However, implant- and host-related factors contribute to premature implant extrusion. To mitigate this, noninvasive methods to assess implant stability, along with a better understanding of factors contributing to BAHI failure, are needed.

Methods

We evaluated the utility of RFA to quantify implant stability in sawbone (bone mimicking material), 29 human cadaveric samples, and a prospective cohort of 29 pediatric and 27 adult participants, and identified factors associated with implant stability. To validate the use of RFA in BAHI, we compared RFA-derived implant stability quotient (ISQ) estimates to peak loads obtained from mechanical push-out testing.

Results

ISQ and peak loads were significantly correlated (Spearman rho = 0.48, p = 0.0088), and ISQ reliably predicted peak load up to 1 kN. We then showed that in cadaveric samples, abutment length, internal table bone volume, and donor age were significantly associated with implant stability. We validated findings in our prospective patient cohort and showed that minimally invasive Ponto surgery (MIPS; versus linear incision), longer implantation durations (>16 wk), older age (>25 yr), and shorter abutment lengths (≤10 mm) were associated with better implant stability. Finally, we characterized the short-term reproducibility of ISQ measurements in sawbone and patient implants.

Conclusions

Together, our findings support the use of ISQ as a measure of implant stability and emphasize important considerations that impact implant stability, including surgical method, implant duration, age, and abutment lengths.
Immediate Facial Nerve Palsy Secondary to Otological Surgery: A Systematic Review and Narrative Synthesis
Authors: Patel Sanjay , Walters Ben , Kim Valerie , Walijee Hussein
Published: June 2024

Objectives

Iatrogenic facial nerve palsy following otological surgery is a devastating complication that results in adverse aesthetic and functional outcomes. This study aims to review studies that have reported cases of immediate facial nerve palsy to learn why and where injuries occurred and to assess outcomes following management.

Databases Reviewed

MEDLINE, Embase, Cochrane CENTRAL, and Pubmed up to June 20, 2023.

Methods

Clinical studies of immediate facial nerve palsies following middle ear and cochlear implantation surgery were included. Risk of bias was examined using the Brazzelli risk of bias tool. Due to the inconsistency in reporting of outcomes, we were unable to perform a meta-analysis.

Results

Of 234 studies identified, 11 met the inclusion criteria. The most common causes of injury were excessive drilling, use of sharp hooks to remove disease, or disorientation of the surgeon secondary to bleeding or inflammation. Variable usage of preoperative computed tomography (CT) imaging and intraoperative facial nerve monitoring was reported. The tympanic segment was the most common site of injury. A variety of surgical techniques were employed to approach the facial nerve injury including facial nerve decompression, direct closure, and repair using an autologous nerve graft.

Conclusions

Otological surgeons should consider utilizing preoperative CT imaging to establish a three-dimensional mental image of key landmarks and anatomical variations before embarking on surgery. Intraoperative FN monitoring enables safe practice. Despite these measures, complex disease processes and hostile intraoperative conditions can present difficulty. Multiple treatment options are available to treat the underlying injury.
Performance of Manchester Acute Coronary Syndromes decision rules in acute coronary syndrome: a systematic review and meta-analysis
Authors: Roshdi Dizaji Shayan , Ahmadzadeh Koohyar , Zarei Hamed , Miri Reza , Yousefifard Mahmoud
Published: June 2024

Multiple decision-aiding models are available to help physicians identify acute coronary syndrome (ACS) and accelerate the decision-making process in emergency departments (EDs). This study evaluated the diagnostic performance of the Manchester Acute Coronary Syndrome (MACS) rule and its derivations, enhancing the evidence for their clinical use. A systematic review and meta-analysis was performed. Medline, Embase, Scopus, and Web of Science were searched from inception until October 2023 for studies including adult ED patients with suspected cardiac chest pain and inconclusive findings requiring ACS risk-stratification. The predictive value of MACS, Troponin-only MACS (T-MACS), or History and Electrocardiogram-only MACS (HE-MACS) decision aids for diagnosing acute myocardial infarction (AMI) and 30-day major adverse cardiac outcomes (MACEs) among patients admitted to ED with chest pain suspected of ACS. Overall sensitivity and specificity were synthesized using the ‘Diagma’ package in STATA statistical software. Applicability and risk of bias assessment were performed using the QUADAS-2 tool. For AMI detection, MACS has a sensitivity of 99% [confidence interval (CI): 97–100], specificity of 19% (CI: 10–32), and AUC of 0.816 (CI: 0.720–0.885). T-MACS shows a sensitivity of 98% (CI: 98–99), specificity of 35% (CI: 29–42), and AUC of 0.859 (CI: 0.824–0.887). HE-MACS exhibits a sensitivity of 99% (CI: 98–100), specificity of 9% (CI: 3–21), and AUC of 0.787 (CI: 0.647–0.882). For MACE detection, MACS demonstrates a sensitivity of 98% (CI: 94–100), specificity of 22% (CI: 10–42), and AUC of 0.804 (CI: 0.659–0.897). T-MACS displays a sensitivity of 96% (CI: 94–98), specificity of 36% (CI: 30–43), and AUC of 0.792 (CI: 0.748–0.830). HE-MACS maintains a sensitivity of 99% (CI: 97–99), specificity of 10% (CI 6–16), and AUC of 0.713 (CI: 0.625–0.787). Of all the MACS models, T-MACS displayed the highest overall accuracy due to its high sensitivity and significantly superior specificity. T-MACS exhibits very good diagnostic performance in predicting both AMI and MACE. This makes it a highly promising tool for managing patients with acute chest pain.
Parents’ Experiences of Communicating With Children About Their Diagnosis of Nonterminal Cancer and Its Related Issues
Authors: Du Yiran , Huang Xiaoyan , Xie Run , Gu Ying , Zhu Daqian , Wang Hongsheng
Published: June 2024

Background

Many children experience serious symptoms when they are diagnosed with and treated for cancer. Through appropriate parent-child communication, parents were able to identify children’s physical and psychological problems, adjust their behavior, and help them cope with the disease.

Objective

This study aimed to systematically search for and integrate evidence from qualitative studies on communication between parents and children with nonterminal cancer from parents’ perspectives.

Methods

A thorough systematic review and metasynthesis of qualitative studies were conducted. Articles were searched from PubMed/MEDLINE, EMBASE, Web of Science, CINAHL, PsycINFO, and PsycArticles from the database inception to November 6, 2022. After screening and quality appraisal, 14 articles were finally included in the metasynthesis.

Results

Three themes and 11 subthemes were identified: (1) communication content, including diagnosis, treatment, health management, health risk, and emotion; (2) factors influencing communication, including ages of children, parents’ experience of communication, parents’ awareness of protection, and culture; and (3) children’s responses, including acceptance and resistance.

Conclusions

This systematic review found that parents were influenced by various factors during the decision-making process of parent-child communication about childhood cancer and its related issues. Parents tended to adjust their communication content and style to protect their children.

Implications for Practice

Future research should be conducted to explore children’s experiences of communicating with their parents and analyze the similarities and differences between the communication needs of parents and children. Healthcare professionals should provide professional communication guidance to facilitate the parent-child relationship and improve the mental health of both children and their parents.
Perinatal Care for Persons with Dissociative Disorders
Authors: Dindinger Rebeccah A. , Manzo Laura L. , Manupule Susannah E. , Harp Solène Lehuédé
Published: June 2024

Caring for persons with mental health diagnoses can be daunting, especially when the conditions are rare, and there is little evidence to guide nursing practice. There is minimal information about caring for persons with dissociative disorders beyond the behavioral health literature, much less as in obstetric context. Women are more likely to experience dissociative disorders and post-traumatic stress disorders than men. Severe maternal morbidity is significantly more common in women with a history of stress and trauma-related conditions, highlighting the importance of providing guidance for clinicians caring for them. It is imperative that nurses caring for women who may dissociate understand the complexities of the disorders and advocate for early, interdisciplinary care. Dissociative disorders, including dissociative identity disorder, post-traumatic stress disorder with dissociation, dissociative amnesia, depersonalization-derealization disorder, other specified dissociative disorders, and the care of pregnant persons with these conditions are presented.
Trends in Gender Authorship of Abstract Presentations at Plastic Surgery the Meeting
Authors: Stewart Sara J. , Jabori Sinan K. , Pandya Shivani , Alawadi Salman , Szewczyk Joanne , Samaha Yasmina , Lessard Anne-Sophie , Singh Devinder , Danker Sara
Published: June 2024

Current literature fails to examine gender differences of authors presenting abstracts at national plastic surgery meetings. This study aims to assess the ratio of female to male abstract presentations at Plastic Surgery The Meeting (PSTM).

The gender of all abstract presenters from PSTM between 2010 and 2020 was recorded. The primary outcome variable was authorship (first, second, or last). Trends in gender authorship were assessed via Cochran-Armitage trend tests. Chi-square was utilized to evaluate the association between author gender and presentation type and author gender and subspecialty.

Between 2010 and 2020, 3653 abstracts were presented (oral = 3035, 83.1%; poster = 618, 16.9%) with 19,328 (5175 females, 26.8%) authors. Of these, 34.5%, 32.0%, and 18.6% of first, second, and last authors were female, respectively. The total proportion of female authors increased from 153 (20.4%) in 2010 to 1065 (33.1%) by 2020. The proportion of female first, second, and last authors increased from 21.8% to 44.8%, 24.0% to 45.3%, and 14.3% to 22.1%, respectively, and demonstrated a positive linear trend (P < 0.001). The proportion of female first authors in aesthetics (23.9%) was lower than that for breast (41.8%), cranio/maxillofacial/head & neck (38.5%), practice management (43.3%), and research/technology (39.4%) (P < 0.001).

Our study demonstrates a significant increase in female representation as first, second, and last authors in abstract presentations at PSTM within the last decade, although the absolute prevalence remains low.
Can Lymph Node Involvement in Unilateral Wilms Tumor be Predicted by Preoperatively known Data in Combination with Intraoperative Findings?
Authors: Meier Clemens-Magnus , Furtwängler Rhoikos , Welter Nils , Mergen Marvin , Wagenpfeil Stefan , von Schweinitz Dietrich , Stein Raimund , Kager Leo , Schenk Jens-Peter , Vokuhl Christian , Kroiss-Benninger Sabine , Melchior Patrick , Warmann Steven W. , Fuchs Jörg , Graf Norbert
Published: June 2024

Objective:

This study aimed to identify parameters that allow the estimation of tumor-infiltrated lymph nodes (LN) after pretreatment for unilateral Wilms tumor (WT).

Summary Background Data:

Complete tumor resection with removal of regional LN is always necessary. Positive LNs require local irradiation influencing benefits in case of NSS in long-term follow-up. Clinical and tumor-related data available at the time of surgery in combination with intraoperative findings (IAF) were used to estimate the LN status during surgery.

Methods:

Altogether, 2115 patients with unilateral WT were prospectively enrolled in SIOP-93-01 / GPOH and SIOP-2001 / GPOH over a period of 30 years (1993–2023). LN infiltration by tumor was calculated for age, sex, metastases at diagnosis, tumor volume (TV), TV shrinkage, and intraoperative findings (IAF) using logistic regression models.

Results:

Age ≥48 months (P<0.001, OR 2.17, CI 1.57 – 3.00), TV at diagnosis ≥300 (P<0.001, OR 3.72, CI 2.37 – 5.85), metastasis at diagnosis (P<0.001, OR 6.21, CI 4.47 – 8.62) and IAF (>1: P<0.001, OR 3.54, CI 2.13 – 5.88) correlated with positive LNs. TV shrinkage was not predictive of positive LN. Three flow charts were developed based on age, TV at diagnosis, metastasis, and IAF. These flowcharts defined risks between 0% and 41.5% for LN infiltration by tumor.

Conclusions:

The combination of age, TV at diagnosis, and metastasis with IAF allows the estimation of the frequency of positive LNs, which may help surgeons deciding about NSS.
Decoding frontotemporal and cell-type-specific vulnerabilities to neuropsychiatric disorders and psychoactive drugs
Authors: Ji Jiatong , Chao Honglu , Chen Huimei , Liao Jun , Shi Wenqian , Ye Yangfan , Wang Tian , You Yongping , Liu Ning , Ji Jing , Petretto Enrico
Published: June 2024

Frontotemporal lobe abnormalities are linked to neuropsychiatric disorders and cognition, but the role of cellular heterogeneity between temporal lobe (TL) and frontal lobe (FL) in the vulnerability to genetic risk factors remains to be elucidated. We integrated single-nucleus transcriptome analysis in ‘fresh’ human FL and TL with genetic susceptibility, gene dysregulation in neuropsychiatric disease and psychoactive drug response data. We show how intrinsic differences between TL and FL contribute to the vulnerability of specific cell types to both genetic risk factors and psychoactive drugs. Neuronal populations, specifically PVALB neurons, were most highly vulnerable to genetic risk factors for psychiatric disease. These psychiatric disease-associated genes were mostly upregulated in the TL, and dysregulated in the brain of patients with obsessive-compulsive disorder, bipolar disorder and schizophrenia. Among these genes, GRIN2A and SLC12A5, implicated in schizophrenia and bipolar disorder, were significantly upregulated in TL PVALB neurons and in psychiatric disease patients’ brain. PVALB neurons from the TL were twofold more vulnerable to psychoactive drugs than to genetic risk factors, showing the influence and specificity of frontotemporal lobe differences on cell vulnerabilities. These studies provide a cell type resolved map of the impact of brain regional differences on cell type vulnerabilities in neuropsychiatric disorders.
Three distinct conductance states in polycyclic aromatic hydrocarbon derivatives
Authors: Ismael Ali K. , Mohaymen Taha Taha Abdel , Al-Jobory Alaa
Published: June 2024

Tight-binding model (TBM) and density functional theory (DFT) calculations were employed. Both simulations have demonstrated that the electrical conductance for eight polycyclic aromatic hydrocarbons (PAHs) can be modulated by varying the number of aromatic rings (NAR) within the aromatic derivatives. TBM simulations reveal three distinct conductance states: low, medium and high for the studied PAH derivatives. The three distinct conductance states suggested by TBM are supported by DFT transmission curves, where the low conductance evidenced by
T
(
E
) = 0, for benzene, naphthalene, pyrene and anthracene. While azulene and anthanthrene exhibit a medium conductance as
T
(
E
) = 1, and tetracene and dibenzocoronene possess a high conductance with
T
(
E
) = 2. Low, medium and high values were elucidated according to the energy gap
E
g
and
E
g
gaps are strongly dependent on the NAR in the PAH derivatives. This study also suggests that any PAH molecules are a conductor if
E
g
< 0.20 eV. A linear relationship between the conductance and NAR (
G 
∝ NAR) was found and conductance follows the order
G
(benzene, 1 NAR) <
G
(anthanthrene, 4 NAR) <
G
(dibenzocoronene, 9 NAR). The proposed study suggests a relevant step towards the practical application of molecular electronics and future device application.
Fine-scale genetic structure and phenotypic divergence of a passerine bird population inhabiting a continuous Mediterranean woodland
Authors: Garrido-Bautista Jorge , Comas Mar , Jowers Michael J. , Smith Steve , Penn Dustin J. , Bakkali Mohammed , Moreno-Rueda Gregorio
Published: June 2024

Genetic differentiation between populations inhabiting ecologically different habitats might appear because of limited dispersal and gene flow, which may lead to patterns of phenotypic divergence and local adaptation. In this study, we use dispersal, genotypic (24 microsatellite loci) and phenotypic (body size and clutch size) data to analyse patterns of genetic structuring and phenotypic divergence in a blue tit (
Cyanistes caeruleus
) population inhabiting a continuous and heterogeneous woodland along a valley. The two slopes of the valley differ in their forest formations and environmental conditions. Findings showed that most blue tits reproduced within their natal slope. Accordingly, microsatellite analyses revealed that populations of blue tits established in the two slopes show subtle genetic differentiation. The two genetic populations diverged in clutch size, exceeding the level of differentiation expected based on genetic drift, hence suggesting divergent selection (or other processes promoting divergence) on this life-history trait. Our findings reveal that restricted dispersal and spatial heterogeneity may lead to genetic differentiation among bird populations at a surprisingly small scale. In this respect, it is worth highlighting that such differentiation occurs for an organism with high dispersal capacity and within a continuous woodland. Moreover, we show that small-scale ecological differences, together with limited gene flow, can result in selection favouring different phenotypes even within the same continuum population.
Body-size-dependent effects of landscape-level resource energetics on pollinator abundance in woodland remnants
Authors: Pille Arnold Juliana , Tylianakis Jason M. , Murphy Mark V. , Cawthray Gregory R. , Webber Bruce L. , Didham Raphael K.
Published: June 2024

Land use change alters floral resource availability, thereby contributing to declines in important pollinators. However, the severity of land use impact varies by species, influenced by factors such as dispersal ability and resource specialization, both of which can correlate with body size. Here. we test whether floral resource availability in the surrounding landscape (the ‘matrix’) influences bee species’ abundance in isolated remnant woodlands, and whether this effect varies with body size. We sampled quantitative flower-visitation networks within woodland remnants and quantified floral energy resources (nectar and pollen calories) available to each bee species both within the woodland and the matrix. Bee abundance in woodland increased with floral energy resources in the surrounding matrix, with strongest effects on larger-bodied species. Our findings suggest important but size-dependent effects of declining matrix floral resources on the persistence of bees in remnant woodlands, highlighting the need to incorporate landscape-level floral resources in conservation planning for pollinators in threatened natural habitats.
Phase synchronization between culture and climate forcing
Authors: Timmermann Axel , Wasay Abdul , Raia Pasquale
Published: June 2024

Over the history of humankind, cultural innovations have helped improve survival and adaptation to environmental stress. This has led to an overall increase in human population size, which in turn further contributed to cumulative cultural learning. During the Anthropocene, or arguably even earlier, this positive sociodemographic feedback has caused a strong decline in important resources that, coupled with projected future transgression of planetary boundaries, may potentially reverse the long-term trend in population growth. Here, we present a simple consumer/resource model that captures the coupled dynamics of stochastic cultural learning and transmission, population growth and resource depletion in a changing environment. The idealized stochastic mathematical model simulates boom/bust cycles between low-population subsistence, high-density resource exploitation and subsequent population decline. For slow resource recovery time scales and in the absence of climate forcing, the model predicts a long-term global population collapse. Including a simplified periodic climate forcing, we find that cultural innovation and population growth can couple with climatic forcing via nonlinear phase synchronization. We discuss the relevance of this finding in the context of cultural innovation, the anthropological record and long-term future resilience of our own predatory species.
Barcoded SARS-CoV-2 viruses define the impact of time and route of transmission on the transmission bottleneck in a Syrian hamster model
Authors: Trende Reed , Darling Tamarand L. , Gan Tianyu , Wang David , Boon Adrianus C.M.
Published: June 2024

The transmission bottleneck, defined as the number of viruses that transmit from one host to infect another, is an important determinant of the rate of virus evolution and the level of immunity required to protect against virus transmission. Despite its importance, SARS-CoV-2’s transmission bottleneck remains poorly characterized, in part due to a lack of quantitative measurement tools. To address this, we adapted a SARS-CoV-2 reverse genetics system to generate a pool of >200 isogenic SARS-CoV-2 viruses harboring specific 6-nucleotide barcodes inserted in ORF10, a non-translated ORF. We directly inoculated donor Syrian hamsters intranasally with this barcoded virus pool and exposed a paired naïve contact hamster to each donor. Following exposure, the nasal turbinates, trachea, and lungs were collected, viral titers were measured, and the number of barcodes in each tissue were enumerated to quantify the transmission bottleneck. The duration and route (airborne, direct contact, and fomite) of exposure were varied to assess their impact on the transmission bottleneck. In airborne-exposed hamsters, the transmission bottleneck increased with longer exposure durations. We found that direct contact exposure produced the largest transmission bottleneck (average 27 BCs), followed by airborne exposure (average 16 BCs) then fomite exposure (average 8 BCs). Interestingly, we detected unique BCs in both the upper and lower respiratory tract of contact animals from all routes of exposure, suggesting that SARS-CoV-2 can directly infect hamster lungs. Altogether, these findings highlight the utility of barcoded viruses as tools to rigorously study virus transmission. In the future, barcoded SARS-CoV-2 will strengthen studies of immune factors that influence virus transmission.
Factors Affecting Integration of an Early Warning System for Antimalarial Drug Resistance within a Routine Surveillance System in a Pre-elimination Setting in Sub-Saharan Africa
Authors: Kagoro Frank M. , Allen Elizabeth , Raman Jaishree , Mabuza Aaron , Magagula Ray , Kok Gerdalize , Malatje Gillian , Guerin Philippe J , Dhorda Mehul , Maude Richard J , Barnes Karen I
Published: June 2024

1.

To address the current threat of antimalarial resistance, countries need innovative solutions for timely and informed decision-making. Integrating molecular resistance marker surveillance into routine malaria surveillance in pre-elimination contexts offers a potential early warning mechanism to identify resistance signals and target areas for further investigation, including therapeutic efficacy studies. However, there is limited evidence on what influences the performance of such a system in resource-limited settings.

From March 2018 to February 2020, a sequential mixed-methods study was conducted in primary healthcare facilities in a South African pre-elimination setting to explore factors influencing the flow, quality and linkage of malaria case notification and antimalarial molecular resistance marker data. Using a process-oriented framework, we undertook monthly and quarterly data linkage and consistency analysis at different levels of the health system, as well as a survey, focus group discussions and interviews to identify potential barriers to, and enhancers of, the roll-out and uptake of this integrated information system.

Over two years, 4,787 confirmed malaria cases were notified from 42 primary healthcare facilities in the Nkomazi sub-district, Mpumalanga, South Africa. Of the notified cases, 78.5% (n=3,758) were investigated, and 55.1% (n=2,636) were successfully linked to theirPlasmodium falciparummolecular resistance marker profiles. Five tangible processes—malaria case detection and notification, sample collection, case investigation, analysis and reporting—were identified within the process-oriented logic model. Workload, training, ease of use, supervision, leadership, and resources were recognized as cross-cutting influencers affecting the program’s performance.

Approaching malaria elimination, linking molecular markers of antimalarial resistance to routine malaria surveillance is feasible. However, cross-cutting barriers inherent in the healthcare system can determine its success in a resource-limited setting.
Runaway resorption of microcracks contributes to age-related hip-fracture patients
Authors: Gray Marena , Boughton Oliver , Wiles Crispin , Reinhard Christina , Vo Nghia T. , Atwood Robert , Stavri Richard , Cobb Justin P. , Hansen Ulrich , Abel Richard L.
Published: June 2024

Microdefects, including microcracks and resorption trenches, may be important contributors to bone fragility. 3D microdefect morphology was imaged using synchrotron micro-CT to develop a classification system for investigating the relationship with bone mechanics and hip-fractures.

Femoral heads from ageing hip-fracture patients (n=5, 74-82 years) were compared to ageing non-fracture controls (n=5, 72-84 years). Two trabecular cores were prepared from the chiasma; one was imaged using synchrotron micro-CT to measure microdefects and one was mechanically tested to measure tensile strength. Morphological and mechanical data were compared and correlated using Mann Whitney U test and Pearson’s rank correlation.

Microdefects varied and were classified into four categories based on shape and measurable parameters. Hip-fracture donors exhibited significantly higher density of all microdefects (p<0.05). Microdefect volume was strongly negatively correlated with ultimate tensile strength (p<0.05) and stiffness (p<0.05).

Microdefects might contribute to loss of bone strength and fragility fracture via runaway resorption. Microcracks could promote focussed osteoclastic resorption and the formation of resorption pits which create stress risers leading to the re-formation of microcracks under continued load. CT-based classification methods should be used to explore the complex interaction between microdefects, metabolism, and bone fracture mechanics.
Convergent genetic adaptation in human tumors developed under systemic hypoxia and in populations living at high altitudes
Authors: Arenillas Carlota , Ruiz-Cantador José , Celada Lucía , Calsina Bruna , García-Galea Eduardo , Datta Debayan , Fasani Roberta , Moreno-Cárdenas Ana Belén , Alba-Linares Juan José , Miranda Berta , Martínez-Montes Ángel M. , Álvarez-Escolá Cristina , Lecumberri Beatriz , González García Elvira Ana , Flores Shahida K. , Esquivel Emmanuel , Ding Yanli , Regojo Zapata Rita Maria , Pozo-Kreilinger Jose Juan , Iglesias Carmela , Dwight Trisha , Muir Christopher , Alday Amelia Oleaga , Garrido-Lestache Rodríguez-Monte Maria Elvira , Del Cerro Maria Jesús , Martínez-Bendayán Isaac , Lourenço Delmar M. , Pereira Maria Adelaide A. , Burnichon Nelly , Buffet Alexandre , Broberg Craig , Dickson Paxton , Fraga Mario Fernandez , Llorente Pendás José Luis , Soriano Joaquín Rueda , Fuentes Francisco Buendía , Toledo Sergio P.A. , Clifton-Bligh Roderick , Dienstmann Rodrigo , Capdevila Jaume , Gimenez-Roqueplo Anne-Paule , Favier Judith , Weghorn Donate , Nuciforo Paolo , Young William , Opotowsky Alexander R. , Vaidya Anand , Bancos Irina , Robledo Mercedes , Casteràs Anna , Dos-Subirà Laura , Chiara María Dolores , Adameyko Igor , Dahia Patricia L.M. , Toledo Rodrigo A.
Published: June 2024

EPAS1HIF2αis the primary gene implicated in systemic hypoxia adaptation. Conversely, aberrantly activatedEPAS1HIF2αacts as a tumor driver against which anti-tumor therapeutics are proven effective. We elucidated connections between adaptation to systemic hypoxia in high-altitude populations, such as Tibetans and Sherpas, and human tumors. Similar to the accelerated adaptability observed in high-altitude populations via genetic introgression, tumors from patients with hypoxia since birth exhibited impaired DNA repair and increased mutation burden. As in high-altitude dwellers,EPAS1HIF2αgenetic variants were positively selected within sympathetic tumors developed under hypoxia, with a consistently high frequency of 90%. Bulk and single-cell RNA sequencing followed byin vitrostudies have shown that hypoxia andEPAS1HIF2αgain-of-function tumor mutations induceCOX4i2expression and impair mitochondrial respiration, indicating that decreased cellular oxygen consumption may confer a proliferative advantage in hypoxia. Analyzing medical data from a patient cohort with hypoxia since birth who developed/did not develop tumors revealed tissue-specific and time-dependent tumorigenic effects of systemic hypoxia, which is limited to oxygen-sensitive and responsive cells, particularly during the postnatal period. This study supports connections between theEPAS1HIF2αgenetic adaptation in human tumors developed under systemic hypoxia to populations living in high altitudes. The genetic adaptations in populations to different stressors can be explored further to understand tumorigenesis and tumor evolution.
Mitochondrial defects and metabolic vulnerabilities in Lynch syndrome-associated MSH2-deficient endometrial cancer
Authors: Bowen Mikayla Borthwick , Melendez Brenda , Zhang Qian , Moreno Diana , Peralta Leah , Chan Wai Kin , Jeter Collene , Tan Lin , Zal M. Anna , Lorenzi Philip L. , Dunner Kenneth , Yang Richard K , Broaddus Russell R. , Celestino Joseph , Gokul Nisha , Whitley Elizabeth , Schmandt Rosemarie , Lu Karen , Kim Hyun-Eui , Yates Melinda S.
Published: June 2024

Lynch syndrome (LS) is defined by inherited mutations in DNA mismatch repair genes, includingMSH2,and carries 60% lifetime risk of developing endometrial cancer (EC). Beyond hypermutability, specific mechanisms for LS-associated endometrial carcinogenesis are not well understood. Here, we assessed the effects of MSH2 loss on EC pathogenesis using a novel mouse model (PR-CreMsh2flox/flox, abbreviated Msh2KO), primary cell lines established from this model, human tissues, and human EC cell lines with isogenic MSH2 knockdown. Beginning at eight months of age, 30% of Msh2KO mice exhibited endometrial atypical hyperplasia (AH), a precancerous lesion. At 12 to 16 months of age, 47% of Msh2KO mice exhibited either AH or ECs with histologic features similar to human LS-related ECs. Transcriptomic profiling of EC from Msh2KO mice revealed a transcriptomic signature for mitochondrial dysfunction. Studiesin vitroandin vivorevealed mitochondrial dysfunction based upon two mechanisms: marked mitochondrial content reduction, along with pronounced disruptions to the integrity of retained mitochondria. Human LS-related ECs also exhibited mitochondrial content reduction compared with non-LS-related ECs. Functional studies revealed metabolic reprogramming of MSH2-deficient EC cellsin vitro, including reduced oxidative phosphorylation and increased susceptibility to glycolysis suppression. We are the first to identify mitochondrial dysfunction and metabolic disruption as a consequence of MSH2 deficiency-related EC. Mitochondrial and metabolic aberrations should be evaluated as novel biomarkers for endometrial carcinogenesis or risk stratification and could serve as targets for cancer interception in women with LS.

Significance

This is the first study to report mitochondrial dysfunction contributing to MSH2-deficient endometrial cancer development, identifying a noncanonical pathway for MSH2 deficient carcinogenesis, which also imparts vulnerability to metabolic targeting.
Immune Checkpoint Blockade Delays Cancer and Extends Survival in Murine DNA Polymerase Mutator Syndromes
Authors: Sawant Akshada , Shi Fuqian , Lopes Eduardo Cararo , Hu Zhixian , Abdelfattah Somer , Baul Jennele , Powers Jesse , Hinrichs Christian S. , Rabinowitz Joshua D. , Chan Chang S. , Lattime Edmund C. , Ganesan Shridar , White Eileen
Published: June 2024

Mutations in polymerasesPold1andPoleexonuclease domains in humans are associated with increased cancer incidence, elevated tumor mutation burden (TMB) and response to immune checkpoint blockade (ICB). Although ICB is approved for treatment of several cancers, not all tumors with elevated TMB respond. Here we generatedPold1andPoleproofreading mutator mice and show that ICB treatment of mice with high TMB tumors did not improve survival as only a subset of tumors responded. Similarly, introducing the mutator alleles into mice with Kras/p53 lung cancer did not improve survival, however, passaging mutator tumor cellsin vitrowithout immune editing caused rejection in immune-competent hosts, demonstrating the efficiency by which cells with antigenic mutations are eliminated. Finally, ICB treatment of mutator mice earlier, before observable tumors delayed cancer onset, improved survival, and selected for tumors without aneuploidy, suggesting the use of ICB in individuals at high risk for cancer prevention.

Highlights

Germline somatic and conditionalPold1andPoleexonuclease domain mutations in mice produce a mutator phenotype.

Spontaneous cancers arise in mutator mice that have genomic features comparable to human tumors with these mutations.

ICB treatment of mutator mice with tumors did not improve survival as only a subset of tumors respond.

Introduction of the mutator alleles into an autochthonous mouse lung cancer model also did not produce immunogenic tumors, whereas passaging mutator tumor cellsin vitrocaused immune rejection indicating efficient selection against antigenic mutationsin vivo.

Prophylactic ICB treatment delayed cancer onset, improved survival, and selected for tumors with no aneuploidy.

Graphical Abstract
Epstein-Barr virus induced 3 attributes to TLR7-mediated splenomegaly and bicytopenia
Authors: Iseki Masanori , Sakamoto Yuma , Takezaki Daiki , Matsuda Yoshihiro , Inoue Mariko , Morizane Shin , Mukai Tomoyuki
Published: June 2024

Epstein-Barr virus induced 3 (EBI3) is a gene induced by stimulation of toll-like receptors (TLRs) and functions as a component of a heterodimer cytokine IL-27. IL-27 regulates both innate and acquired immune responses; however, their functionin vivois still largely unknown. Splenomegaly, an enlargement of the spleen, is known to be induced by chronic infectious diseases, including infectious mononucleosis due to EB virus infection. Repeated treatment of imiquimod (IMQ; a TLR7 agonist) has been reported to induce splenomegaly and cytopenia due to increased splenic function. Although immune cell activation is speculated to be involved in the pathogenesis of chronic infection-mediated splenomegaly, the detailed molecular mechanism is unknown. Here, we demonstrated that IMQ induced marked splenomegaly and severe bicytopenia (anemia and thrombocytopenia) in the wild-type mice. Myeloid cells, not lymphoid cells, were increased in the enlarged spleen. Extramedullary hematopoiesis was observed in the enlarged spleen of the IMQ-treated mice. RNA-seq analysis revealed that type I interferon (IFN)-related genes were upregulated in the spleen and peripheral blood in IMQ-treated mice.Ebi3deficiency partially retrieved these IMQ-induced pathological changes. We found thatIl27as well asEbi3genes were elevated by IMQ in the spleen and peripheral blood. Further, IL-27 stimulation upregulated type I IFN-related genes in bone marrow-derived macrophage culture in the absence of type I IFN. Collectively, EBI3 contributes to TLR7-induced splenomegaly and bicytopenia, presumably via IL-27.
Structural and biochemical analysis of ligand binding in yeast Niemann-Pick type C1-related protein
Authors: Nel Lynette , Thaysen Katja , Jamecna Denisa , Olesen Esben , Szomek Maria , Langer Julia , Frain Kelly May , Höglinger Doris , Wüstner Daniel , Pedersen Bjørn P.
Published: June 2024

In eukaryotes, integration of sterols into the vacuolar/lysosomal membrane is critically dependent on the Niemann-Pick type C (NPC) system. The system consists of an integral membrane protein, called NCR1 in yeast, and NPC2, a luminal soluble protein that transfers sterols to the N-terminal domain (NTD) of NCR1 before membrane integration. Both proteins have been implicated in sterol homeostasis of yeast and humans. Here, we investigate sterol and lipid binding of the NCR1/NPC2 transport system and determine crystal structures of the sterol-binding NTD. The NTD binds both ergosterol and cholesterol, with nearly identical conformations of the binding pocket. Apart from sterols, the NTD can also bind fluorescent analogs of phosphatidylinositol, phosphatidylcholine and phosphatidylserine as well as sphingosine and ceramide. We confirm the multi-lipid scope of the NCR1/NPC2 system using photo-crosslinkable and clickable lipid analogs, namely pac-cholesterol, pac-sphingosine and pac-ceramide. Finally, we reconstitute the transfer of pac-sphingosine from NPC2 to the NTDin vitro. Collectively, our results support that the yeast NPC system can work as versatile machinery for vacuolar homeostasis of structurally diverse lipids, besides ergosterol.

Summary blurb

Results of X-ray crystallography and binding assays with different lipids expand our knowledge of the substrate scope of the Niemann-Pick type C1-related proteins NCR1 and NPC2 in yeast.

GRAPHICAL ABSTRACT
Kinetic landscape of single virus-like particles highlights the efficacy of SARS-Cov-2 internalization
Authors: Atemin Aleksandar , Ivanova Aneliya , Peppel Wiley , Stamatov Rumen , Gallegos Rodrigo , Durden Haley , Uzunova Sonya , Vershinin Michael D. , Saffarian Saveez , Stoynov Stoyno S.
Published: June 2024

The efficiency of virus internalization into target cells is a major determinant of infectivity. SARS-CoV-2 internalization occurs via S-protein-mediated cell binding followed either by direct fusion with the plasma membrane or endocytosis and subsequent fusion with the endosomal membrane. Despite the crucial role of virus internalization, the precise kinetics of the processes involved remains elusive. We developed a pipeline, which combines live-cell microscopy and advanced image analysis, for measuring the rates of multiple internalization-associated molecular events of single SARS-CoV-2-virus-like particles (VLPs), including endosome ingression, pH change, and nucleocapsid release. Our live-cell imaging experiments demonstrate that only a few minutes after binding to the plasma membrane, VLPs ingress into Rab5-negative endosomes via Dynamin-dependent scission. Less than two minutes later, the pH of VLPs drops below 5 followed by an increase in VLP speed, yet these two events are not interrelated. Nucleocapsid release from the VLPs occurs with similar kinetics to the pH drop, suggesting that VLP fusion occurs during endosome acidification. Neither Omicron mutations nor abrogation of the S protein polybasic cleavage site altered the rate of VLP internalization events, indicating that they do not affect these processes. Finally, we observe that VLP internalization occurs two to three times faster in VeroE6 than in A549 cells, which may contribute to the greater susceptibility of the former cell line to SARS-CoV-2 infection. Taken together, our precise measurements of the kinetics of VLP internalization-associated processes shed light on their contribution to the effectiveness of SARS-CoV-2 propagation in cells. Time-lapse videos of the studied internalization events can be accessed in the dedicatedCOVIDynamics database.