bluuebunny/crossref_metadata_2025 huggingface dataset:
Role, Management, and Outcome of Free Flap Reconstruction for Acute Full-Thickness Burns in Hands
Authors: Ziegler Benjamin , Hundeshagen Gabriel , Will Patrick A. , Bickert Berthold , Kneser Ulrich , Hirche Christoph
Published: May 2020

Introduction

Severe thermal trauma to the hand can result in major impairment and reduced function due to defective healing or even extremity loss. Full-thickness injuries frequently incur exposure of tendons or bone and require an early and stable coverage with soft tissue transplants to allow for rapid induction of exercise and to preserve structures and hand function. Free tissue transfer to the hand after thermal trauma is a rare indication, and safety, management, and outcome of free flap surgery for severe acute burn injuries to the hand remains underreported.

Methods

Patients with primary reconstructions of full-thickness burn injuries to the hand undergoing microsurgical free tissue transfer surgery were retrospectively assessed in a period from 2013 to 2016. Salvage strategy of the extremity, postoperative complications, length of hospital stay, and primary reconstructive result were quantified and analyzed. Functional outcome measures (range of motion and grip strength) were assessed during clinical follow-up examinations.

Results

During the investigated period, 13 patients were identified undergoing reconstruction of 14 hands via free flap transplantation after severe burn injury in the acute phase. Nine anteriolateral thigh flaps (64%), 3 latissimus dorsi flaps (18%), 1 serratus anterior flap, and 1 tensor fasciae lata flap (7%) were performed. In all cases, salvage of the affected extremity was achieved, although 1 flap (7%) was lost during the early postoperative period requiring secondary reconstruction via pedicled groin flap. Further complications were venous thrombosis (n = 2; 14%) and hematoma (n = 2; 14%). Mean length of hospital stay was 51 days. Functional outcome during follow-up examination after an average of 9.3 months was inhomogeneous depending on the pattern of injury and ranged from complete recovery to nearly entire loss of hand function.

Conclusions

Free flap transfer can be a mandatory and valuable tool to cover full-thickness burn injuries of the hand early in the clinical course of thermal trauma and may provide extremity salvage by favorable means of reconstruction to achieve acceptable functional outcomes, in the most severe cases. Although microsurgical failure rates in burn patients are slightly higher than in free flap transfer to the upper extremity in general, it can be performed with reasonable risk-to-benefit ratio.
SECg Staging System: A New Approach to the Management of Arteriovenous Malformations of the Head and Neck
Authors: Colletti Giacomo , Biglioli Federico , Ierardi Anna Maria , Dessy Margherita , Tombris Stavros , Mattassi Raul , Stillo Francesco , Dionisio Ambra , Rozell-Shannon Linda , Carrafiello Gianpaolo , Waner Milton
Published: May 2020

Objectives:

Arteriovenous malformations (AVM) are the most troublesome vascular malformations to deal with. They tend to behave like low-grade malignancies with infiltrative and disruptive growth. Crucially, the clinical course of an AVM that has been improperly managed is usually characterized by a recurrence that is much more aggressive than the original disease. As in oncology, a comprehensive staging system is highly desirable and is to date lacking in the literature. The authors present a new comprehensive staging system.

Methods:

A multicentric multidisciplinary team of experts in the field of vascular anomalies has created this new staging system. The SECg staging system defines the local extension of the disease (S1–S4), the vascular architecture of the malformation (E1, E2, E3), the severity of the symptoms (C0–C3) and the presence or absence of growth of the AVM (g+, g−).

Results:

This staging system allows to address all the aspects of AVMs and, more importantly, to help building an appropriate, individualized treatment plan for affected patients. After being staged an AVM can be defined as (a) healable, (b) healable with predicted sequelae, or (c) unhealable. Then, the SECg system allows to outline (a) absolute indications, (b) relative indications, and (c) no indications for treatment. The purpose of the treatment (radical, palliative) is furthermore taken into consideration.

Conclusions:

This multicentric, the SECg staging system that this multidisciplinary group of Authors has defined allows for a comprehensive staging of the disease which in turn has enabled to outline an algorithm to properly manage AVMs.
Modified Medial and Lateral Platysmaplasty
Authors: Choi Jeongho , Hwang Kun
Published: May 2020

In our previous anatomic study, the authors could pull the platysma effectively in the medial direction, lateral direction, or both the medial and lateral directions. In this paper, the authors analyzed the results of our series of modified medial and lateral platysmaplasties, in which the technique was based on Hamra's platysmaplasty, modified in light of Feldman's corset platysmaplasty and Mendelson's concepts.

In medial platysmaplasty, subcutaneous dissection was performed from the mandibular border to 2 or 3 finger breadths above the xiphoid process. Lateral platysmaplasty required only peri-lobular subcutaneous dissection for exposing and anchoring the lateral border of the platysma to the preauricular platysma auricular fascia (PAF). Lateral dissection does not go beyond the occipital hairline. During dissection, the zygomatic retaining ligaments were detached and repositioned and anchored to the lateral side of the PAF using 4–0 sutures. One hundred sixty-eight patients underwent platysmaplasty (87 medial platysmaplasty, 76 lateral platysmaplasty, 3 isolated neck lift).

The follow-up period ranged from 1 month to 156 months. In general, medial platysmaplasty was more efficacious than simple lateral pulling back for various conditions involving neck deformities, especially midline bands and severe submental fullness with skin laxity. The complications were 1 case of neuropraxia of the cervical branch (0.6%), 3 cases of hematoma (1.8%), 2 cases of seroma (1.2%), and 2 cases of submental depression (1.2%). All patients had temporary paresthesia around the periauricular area, but fully recovered by 6 months.

Using this modified medial and lateral platysmaplasty, we obtained satisfactory results with low complications.
Pediatric Otoplasty: Does Surgical Specialty Training Affect Safety and Rates of Adverse Perioperative Events?
Authors: Kalmar Christopher L. , Patel Vijay A. , Humphries Laura S. , Zimmerman Carrie E. , Vu Giap H. , Swanson Jordan W. , Taylor Jesse A.
Published: May 2020

Background:

Otoplasty remains an overlapping clinical domain of plastic surgery and otolaryngology. The purpose of this study is to objectively analyze the safety of otoplasty and determine if there are any risk factors, such as surgical training, associated with increased patient morbidity.

Methods:

Retrospective cohort study was conducted of otoplasty procedures performed in North America by plastic surgeons and otolaryngologists between 2012 and 2017 using the American College of Surgeons National Surgical Quality Improvement Program Pediatric dataset. Statistical analysis was performed to analyze the relationships between comorbidities, congenital malformations, and postoperative complications.

Results:

There were 777 otoplasty procedures performed during the study period. Median age at time of surgery was 8.3 years (95% CI 7.9–8.7 years). Plastic surgeons performed 75.8% (n = 589) procedures and otolaryngologists performed 23.4% (n = 182). No significant (P = 0.952) difference in the occurrence of postoperative complications between surgical specialties was appreciated despite the fact that operative time was significantly longer in procedures performed by otolaryngologists (121 minutes versus 94 minutes, P < 0.001). Overall, 1.3% (n = 10 of 777) children experienced a complication, with the most common complication being superficial surgical site infection, occurring in 0.9% (n = 7 of 777) patients. There was no association of comorbidities (P all > 0.324) or congenital malformations (P all > 0.382) contributing to postoperative complications. Reoperation (0.8%, n = 6 of 777) and readmission (0.4%, n = 3 of 777) were uncommon; nevertheless, these adverse events were significantly associated with multiple inherent patient risk factors on multivariate regression.

Conclusions:

Otoplasty is a relatively safe surgical procedure with similarly low complication and readmission rates when performed by plastic surgeons and otolaryngologists. Surgical site infection remains the most prevalent complication after otoplasty. Readmission and reoperation after otoplasty were significantly correlated to prematurity, structural pulmonary abnormality, alimentary tract disease, and seizure disorder.
Metabolomic Profiling for Diagnosis and Prognostication in Surgery: A Scoping Review
Authors: Khan Tabassum A. , Loftus Tyler J. , Filiberto Amanda C. , Ozrazgat-Baslanti Tezcan , Ruppert Matthew M. , Bandyopadhyay Sabyasachi , Laiakis Evagelia C. , Arnaoutakis Dean J. , Bihorac Azra
Published: June 2020

Objective:

This review assimilates and critically evaluates available literature regarding the use of metabolomic profiling in surgical decision-making.

Background:

Metabolomic profiling is performed by nuclear magnetic resonance spectroscopy or mass spectrometry of biofluids and tissues to quantify biomarkers (ie, sugars, amino acids, and lipids), producing diagnostic and prognostic information that has been applied among patients with cardiovascular disease, inflammatory bowel disease, cancer, and solid organ transplants.

Methods:

PubMed was searched from 1995 to 2019 to identify studies investigating metabolomic profiling of surgical patients. Articles were included and assimilated into relevant categories per PRISMA-ScR guidelines. Results were summarized with descriptive analytical methods.

Results:

Forty-seven studies were included, most of which were retrospective studies with small sample sizes using various combinations of analytic techniques and types of biofluids and tissues. Results suggest that metabolomic profiling has the potential to effectively screen for surgical diseases, suggest diagnoses, and predict outcomes such as postoperative complications and disease recurrence. Major barriers to clinical adoption include a lack of high-level evidence from prospective studies, heterogeneity in study design regarding tissue and biofluid procurement and analytical methods, and the absence of large, multicenter metabolome databases to facilitate systematic investigation of the efficacy, reproducibility, and generalizability of metabolomic profiling diagnoses and prognoses.

Conclusions:

Metabolomic profiling research would benefit from standardization of study design and analytic approaches. As technologies improve and knowledge garnered from research accumulates, metabolomic profiling has the potential to provide personalized diagnostic and prognostic information to support surgical decision-making from preoperative to postdischarge phases of care.
MegaLMM: Mega-scale linear mixed models for genomic predictions with thousands of traits
Authors: Runcie Daniel E , Qu Jiayi , Cheng Hao , Crawford Lorin
Published: May 2020

Large-scale phenotype data can enhance the power of genomic prediction in plant and animal breeding, as well as human genetics. However, the statistical foundation of multi-trait genomic prediction is based on the multivariate linear mixed effect model, a tool notorious for its fragility when applied to more than a handful of traits. We presentMegaLMM, a statistical framework and associated software package for mixed model analyses of a virtually unlimited number of traits. Using three examples with real plant data, we show thatMegaLMMcan leverage thousands of traits at once to significantly improve genetic value prediction accuracy.
Sex hormones underlying 17a-Estradiol effects on neuroinflammation
Authors: Debarba Lucas K. , Jayarathne Hashan , Miller Richard A. , Garratt Michael , Sadagurski Marianna
Published: May 2020

17-α-estradiol (17aE2) treatment extends lifespan in male mice and can reduce neuroinflammatory responses in the hypothalamus of 12-month-old males. Although 17aE2 improves longevity in males, female mice are unaffected, suggesting a sexually dimorphic pattern of lifespan regulation. We tested whether the sex-specific effects of 17aE2 on neuroinflammatory responses are mediated by sex hormones and whether hypothalamic changes extend to other brain regions in old age. Manipulating sex hormone levels through gonadectomy, we show that sex-specific effects of 17aE2 on age-associated gliosis are brain region-specific and are partially dependent on gonadal hormone production. 17aE2 treatment started at 4 months of age protected 25-month-old males from hypothalamic inflammation. Castration prior to 17aE2 exposure reduced the effect of 17aE2 on hypothalamic astrogliosis. By contrast, sex-specific changes in microgliosis with 17aE2 were not significantly affected by castration in males. While 17aE2 treatment had no effect of hypothalamic astrocytes or microglia in intact females, ovariectomy significantly increased the occurrence of hypothalamic gliosis evaluated in 25-month-old females, which was partially reduced by 17aE2. In the hippocampus, both male and female gonadally-derived hormones influenced the severity of gliosis and the responsiveness to 17aE2 in a regiondependent manner. The male-specific effects of 17aE2 correlate with changes in hypothalamic ERα expression, highlighting a receptor through which 17aE2 could act. The results of this study demonstrate that neuroinflammatory responses to 17aE2 are partially controlled by the presence of sex-specific gonads. Interactions between sex-steroids and neuroinflammation could, therefore, influence late-life health and disease onset, leading to sexual dimorphism in aging.
Understanding the genetics of important traits in quality protein maize (Zea maysL.) by Line × Tester analysis
Authors: Bharti Baudh , Dubey R.B. , Kumar Arun , Pal Lalit , Kaushik Prashant
Published: May 2020

Maize (Zea maysL.) is among the top ten most valuable crops and livestock products. Maize demand and production are continuously rising. The nutritionally rich quality proteins maize (QPM) has almost two times as much lysine as well as tryptophan, amino acids which then the conventional maize varieties. In this study, genetics of important traits in quality protein maize were determined using a Line by Tester matting design. The 45 hybrids were obtained via Line by Tester crossing of 15 lines and 3 testers. The parents and their hybrids were evaluated under two environments. A significant amount of variation was recorded for most of the traits studied. Parental genotypes L2, L6, T2, L8, L7 and L14, exhibited negative and considerable general combining ability (GCA) effects for days to flowering and maturity. L7 × T2, L13 × T3, L10 × T1, L1 × T1, L9 × T2, L5 × T1, L12 × T2, L11 × T3, L10 × T3, L14 × T1 and L6 × T1 were identified with suitable yield and component traits. Crosses L5 × T1, L3 × T1, L12 × T2, L7 × T3, L1 × T2 and L13 × T1 were identified for quality traits. Heterosis over the mid parent crosses L13 × T1 showed highest negative and significant followed by L6 × T1, L12 × T2, L14 × T2 and L2 × T1 for days to 50 per cent tasselling. A significant correlation for the lysine content was determined between F1 mean and specific combining ability (SCA) effects. Overall, this work provides the useful insights into the genetics of important agronomical and biochemical traits of quality protein maize.
Flexibility of the neck-linker during docking is pivotal for function of bi-directional kinesin
Authors: Goldstein-Levitin Alina , Allhuzaeel Kanary , Pandey Himanshu , Gheber Larisa
Published: May 2020

The role of the neck-linker (NL) element in regulating the functions of bi-directional kinesins is unknown. We report that replacing the NL of the bi-directional kinesin-5 Cin8 with sequences from plus-end directed kinesins produces non-functional Cin8 with defective spindle localization and abolished minus-end directionality and microtubule-crosslinking in vitro. Mutation of a single glycine in the NL of Cin8 to asparagine (proposed to serve as an N-latch that stabilizes the docked conformation of the NL in the plus-end directed kinesins) causes defects in the functions of Cin8. Strikingly, in a non-functional Cin8 containing the NL of the plus-end directed kinesin-5 Eg5, a single mutation of the N-latch asparagine back to glycine rescues the in vivo and in vitro defects. Since such replacement eliminates stabilizing interactions between the docked NL and the motor domain, we conclude that flexibility of NL during docking is pivotal for the function of bi-directional kinesin motors.
A giant leap in sequence space reveals the intracellular complexities of evolving a new function
Authors: Hall Kelsi R. , Robins Katherine J. , Rich Michelle H. , Calcott Mark J. , Copp Janine N. , Williams Elsie M. , Little Rory F. , Schwörer Ralf , Evans Gary B. , Patrick Wayne M. , Ackerley David F.
Published: May 2020

Selection for a promiscuous enzyme activity provides substantial opportunity for competition between endogenous and new substrates to influence the evolutionary trajectory, an aspect that has generally been overlooked in laboratory directed evolution studies. We evolved theEscherichia colinitro/quinone reductase NfsA to detoxify chloramphenicol by randomising eight active site residues simultaneously and interrogating ∼250,000,000 reconfigured NfsA variants. Analysis of every possible evolutionary intermediate of the two best chloramphenicol reductases revealed complex epistatic interactions that restrict each hypothetical trajectory. In both cases, improved chloramphenicol detoxification was only possible after one essential substitution had eliminated activity with endogenous quinone substrates. Unlike the predominantly weak trade-offs seen in previous experimental studies, this substrate incompatibility suggests endogenous metabolites have considerable potential to shape evolutionary outcomes. Unselected prodrug-converting activities were mostly unaffected, which emphasises the importance of negative selection to effect enzyme specialisation, and offers an application for the evolved genes as dual-purpose selectable/counter-selectable markers.
The orchestrated cellular and molecular responses of the kidney to endotoxin define the sepsis timeline
Authors: Janosevic Danielle , Myslinski Jered , McCarthy Thomas , Zollman Amy , Syed Farooq , Xuei Xiaoling , Gao Hongyu , Liu Yunlong , Collins Kimberly S. , Cheng Ying-Hua , Winfree Seth , El-Achkar Tarek M. , Maier Bernhard , Ferreira Ricardo Melo , Eadon Michael T. , Hato Takashi , Dagher Pierre C.
Published: May 2020

Clinical sepsis is a highly dynamic state that progresses at variable rates and has life-threatening consequences. Staging patients along the sepsis timeline requires a thorough knowledge of the evolution of cellular and molecular events at the tissue level. Here, we investigated the kidney, an organ central to the pathophysiology of sepsis. Single cell RNA sequencing revealed the involvement of various cell populations in injury and repair to be temporally organized and highly orchestrated. We identified key changes in gene expression that altered cellular functions and can explain features of clinical sepsis. These changes converged towards a remarkable global cell-cell communication failure and organ shutdown at a well-defined point in the sepsis timeline. Importantly, this time point was also a transition towards the emergence of recovery pathways. This rigorous spatial and temporal definition of murine sepsis will uncover precise biomarkers and targets that can help stage and treat human sepsis.
Diploid male gametes circumvent hybrid sterility between Asian and African rice species
Authors: Kuniyoshi Daichi , Masuda Itaru , Kanaoka Yoshitaka , Shimazaki-Kishi Yuki , Okamoto Yoshihiro , Yasui Hideshi , Yamamoto Toshio , Nagaki Kiyotaka , Hoshino Yoichiro , Koide Yohei , Takamure Itsuro , Kishima Yuji
Published: May 2020

In F1hybrids ofOryza sativa(Asian rice) andO. glaberrima(African rice), heterozygosity leads to a complete gamete abortion because of allelic conflict at each of the 13hybrid sterility(HS) loci. We systematically produced 19 plants from the F1hybrids of both the rice species by the anther culture (AC) method. Five of the 19 interspecific hybrid plants were fertile and able to produce seeds. Unlike ordinal doubled haploid plants resulting from AC, these regenerated plants showed various ploidy levels (diploid to pentaploid) and different zygosities (completely homozygous, completely heterozygous, and a combination). These properties were attributable to meiotic anomalies in the interspecific hybrid F1plants. Examination of the genetic structures of the regenerated plants suggested meiotic non-reduction took place in the interspecific hybrid F1plants. The centromeric regions in the regenerated plants revealed that the abnormal first and/or second divisions of meiosis, namely the first division restitution (FDR) and/or second division restitution (SDR), had occurred in the interspecific hybrid. Immunohistochemical observations also verified these phenomena. FDR and SDR occurrences at meiosis might strongly lead to the formation of diploid microspores. The results demonstrated that meiotic anomalies functioned as a reproductive barrier occurred before theHSgenes acted in gamete of the interspecific hybrid. Although such meiotic anomalies are detrimental to pollen development, the early rescue of microspores carrying the diploid gamete resulted in the fertile regenerated plants. The five fertile plants carrying tetraploid genomes with heterozygous alleles of theHSloci produced fertile diploid pollens, implying that the diploid gametes circumvented the allelic conflicts at theHSloci. We also proposed how diploid male gametes avoid HS with the killer-protector model.
CAR T cell entry into tumor islets is a two-step process dependent on IFNγ and ICAM-1
Authors: Kantari-Mimoun Chahrazade , Barrin Sarah , Haghiri Sandrine , Gervais Claire , Mittelstaet Joerg , Mockel-Tenbrinck Nadine , Kinkhabwala Ali , Damotte Diane , Lupo Audrey , Sibony Mathilde , Alifano Marco , Vimeux Lene , Dondi Elisabetta , Bercovici Nadège , Trautmann Alain , Kaiser Andrew , Donnadieu Emmanuel
Published: May 2020

Adoptive transfer of T cells expressing chimeric antigen receptors (CARs) has shown remarkable clinical efficacy against advanced B cell malignancies but not yet against solid tumors. Here, we used fluorescent imaging microscopy andex vivoassays to compare the early functional responses (migration, Ca2+and cytotoxicity) of CD20 and EGFR CAR T cells upon contact with malignant B and carcinoma cells. Our results indicate that CD20 CAR T cells rapidly form productive ICAM-1-dependent conjugates with their targets. By comparison, EGFR CAR T cells only interact at first with a subset of carcinoma cells located at the periphery of tumor islets. After this initial peripheral activation, EGFR CAR T cells progressively infiltrate the center of tumor cell regions. The analysis of this two-step entry process shows that activated CAR T cells trigger the upregulation of ICAM-1 on tumor cells in an IFNγ-dependent pathway. The blockade of ICAM-1/LFA-1 interactions prevents CAR T cell recruitment into tumor islets. The requirement for IFNγ and ICAM-1 to enable CAR T cell entry into tumor islets is of significance for improving CAR T strategy in solid tumors.
R-type voltage-gated Ca2+channels mediate A-type K+current regulation of synaptic input in hippocampal dendrites
Authors: Murphy Jonathan G. , Gutzmann Jakob J. , Lin Lin , Hu Jiahua , Petralia Ronald S. , Wang Ya-Xian , Hoffman Dax A.
Published: May 2020

The transient K+current (IA) carried by pore forming Kv4.2 subunits regulates the propagation of synaptic input, dendritic excitability, and synaptic plasticity in CA1 pyramidal neuron dendrites of the hippocampus. We report that the Ca2+channel subunit Cav2.3 regulates IAin this cell type. We first identified Cav2.3 as a Kv4.2 interacting protein in a proteomic screen and we confirmed Cav2.3-Kv4.2 complex association using multiple techniques. Functionally, Cav2.3 Ca2+-entry increases Kv4.2-mediated whole-cell current due to an increase in Kv4.2 surface expression. Using pharmacology and Cav2.3 knockout mice, Cav2.3 was found to promote whole-cell IAand the increasing gradient of IAin the apical dendrite distal to the neuronal soma. Furthermore, the loss of Cav2.3 function leads to enhancement of synaptic currents and spine Ca2+influx. These results present Cav2.3 and Kv4.2 as integral constituents of an ion channel complex that impacts synaptic function in the hippocampus.
Ir56d-dependent fatty acid responses inDrosophilauncovers taste discrimination between different classes of fatty acids
Authors: Brown Elizabeth B. , Shah Kreesha D. , Palermo Justin , Dey Manali , Dahanukar Anupama , Keene Alex C.
Published: May 2020

Chemosensory systems are critical for evaluating the caloric value and potential toxicity of food prior to ingestion. While animals can discriminate between 1000’s of odors, much less is known about the discriminative capabilities of taste systems. Fats and sugars represent calorically potent and innately attractive food sources that contribute to hedonic feeding. Despite the differences in nutritional value between fats and sugars, the ability of the taste system to discriminate between different rewarding tastants is thought to be limited. InDrosophila, sweet taste neurons expressing the Ionotropic Receptor 56d (IR56d) are required for reflexive behavioral responses to the medium-chain fatty acid, hexanoic acid. Further, we have found that flies can discriminate between a fatty acid and a sugar in aversive memory assays, establishing a foundation to investigate the capacity of theDrosophilagustatory system to differentiate between various appetitive tastants. Here, we tested whether flies can discriminate between different classes of fatty acids using an aversive memory assay. Our results indicate that flies are able to discriminate medium-chain fatty acids from both short- and long-chain fatty acids, but not from other medium-chain fatty acids. Characterization of hexanoic acid-sensitiveIonotropic receptor 56d(Ir56d) neurons reveals broad responsive to short-, medium-, and long-chain fatty acids, suggesting selectivity is unlikely to occur through activation of distinct sensory neuron populations. However, genetic deletion ofIR56dselectively disrupts response to medium chain fatty acids, but not short and long chain fatty acids. These findings reveal Ir56d is selectively required for fatty acid taste, and discrimination of fatty acids occurs through differential receptor activation within shared populations of neurons. These findings uncover a capacity for the taste system to encode tastant identity within a taste category.
Observations of the Effect of Scopolamine on Hippocampal CA1 Place Cell and Network Properties in Freely Moving Mice Using Miniscope Imaging
Authors: Sun Dechuan , Unnithan Ranjith Rajasekharan , French Chris
Published: May 2020

The hippocampus and associated cholinergic inputs regulate spatial memory in rodents. Muscarinic blockade with scopolamine results in cognition deficits usually attributed to impaired memory encoding, but effects on memory retrieval are controversial. Here, we simultaneously recorded hundreds of neurons in mouse hippocampal CA1 using calcium imaging with a miniatured fluorescent microscope to study place cell and ensemble neuronal properties in a linear track environment. We found decoding accuracy and ensemble stability were significantly reduced after the administration of scopolamine. Several other parameters including theCa2+event rate, number of total cells and place cells observed, spatial information content were affected including a small increase in running speed. This study enhances the understanding of cholinergic blockade on spatial memory impairment.
Expansion of SARS-CoV-2-specific Antibody-secreting Cells and Generation of Neutralizing Antibodies in Hospitalized COVID-19 Patients
Authors: Varnaitė Renata , García Marina , Glans Hedvig , Maleki Kimia T. , Sandberg John Tyler , Tynell Janne , Christ Wanda , Lagerqvist Nina , Asgeirsson Hilmir , Ljunggren Hans-Gustaf , Ahlén Gustaf , Frelin Lars , Sällberg Matti , Blom Kim , Klingström Jonas , Gredmark-Russ Sara
Published: May 2020

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in late 2019 and has since become a global pandemic. Pathogen-specific antibodies are typically a major predictor of protective immunity, yet B cell and antibody responses during COVID-19 are not fully understood. Here, we analyzed antibody-secreting cell (ASC) and antibody responses in twenty hospitalized COVID-19 patients. The patients exhibited typical symptoms of COVID-19, and presented with reduced lymphocyte numbers and increased T cell and B cell activation. Importantly, we detected an expansion of SARS-CoV-2 nucleocapsid protein-specific ASCs in all twenty COVID-19 patients using a multicolor FluoroSpot assay. Out of the 20 patients, 16 had developed SARS-CoV-2-neutralizing antibodies by the time of inclusion in the study. SARS-CoV-2-specific IgA, IgG and IgM antibody levels positively correlated with SARS-CoV-2-neutralizing antibody titers, suggesting that SARS-CoV-2-specific antibody levels may reflect the titers of neutralizing antibodies in COVID-19 patients during the acute phase of infection. Lastly, we showed that interleukin 6 (IL-6) and C-reactive protein (CRP) concentrations were higher in serum of patients who were hospitalized for longer, supporting the recent observations that IL-6 and CRP could be used to predict COVID-19 severity. Altogether, this study constitutes a detailed description of clinical and immunological parameters in twenty COVID-19 patients, with a focus on B cell and antibody responses, and provides tools to study immune responses to SARS-CoV-2 infection and vaccination.
Robust estimates of cuticle conductance on stomatous leaf surfaces during the light induction of photosynthesis
Authors: Tominaga Jun , Stinziano Joseph R. , Hanson David T.
Published: May 2020

Cuticle conductance (gcw) can bias calculations of intercellular CO2concentration inside the leaf (Ci) when stomatal conductance (gsw) is small.

We examined how the light induction of photosynthesis impacts calculations by directly measuringCialong with standard gas exchange in sunflower and tobacco leaves.

When photosynthesis was induced from dark to saturating light (1200 μmol m−2s−1PAR) the calculatedCiwas significantly larger than measuredCiand the difference decreased asgswincreased. This difference could lead to over-estimation of rubisco deactivation by limited CO2supply during early induction of photosynthesis. However, only small differences inCiwere observed during the induction from shade (50 μmol m−2s−1PAR) becausegswwas sufficiently large. The induction from dark also allowed robust estimations ofgcwwhen combined with directCimeasurements. Thesegcwestimates succeeded in correcting the calculation, suggesting that the cuticle was the major source of error.

Despite a technical restriction to amphi-stomatous leaves, the presented technique has a potential to provide insights into the cuticle conductance on intact stomatous leaf surfaces.
Lapatinib protects against epileptic seizures via halting glutathione peroxidase 4-dependent ferroptosis
Authors: Jia Jining , Li Qin , Sun Qianyi , Yang Nan , Chen Kangni , Yin Xixi , Zhou Honghao , Mao Xiaoyuan
Published: May 2020

Background and Purpose

Repetitive epileptic seizures trigger massive neuronal death. Therefore, neuroprotection plays a role in preventing neuronal death and inversely suppresses seizure generation. Additionally, some studies have shown ferroptosis, featured by lipid peroxidation (a dominant form of oxidative stress in the brain), is of paramount importance in epileptic seizures. Lapatinib can play a first-line anti-tumor role by targeting oxidative stress and a recent work illustrates the improvement of encephalomyelitis in rodent models after lapatinib treatment. We hypothesize whether lapatinib can protect against ferroptosis in epileptic seizures via regulating lipid peroxidation.

Experimental Approach

The epileptic behavior of the mice was recorded after intracranial injection of KA. Western blot and RT-qPCR were used to detect the protein expression of 4-hydroxynonenal (4-HNE) and glutathione peroxidase 4 (GPX4) and the mRNA expression of prostaglandin endoperoxide synthase 2 (PTGS2) in vivo and in vitro. The level of lipid reactive oxygen species (lipid ROS) in cells pretreated with lapatinib was analyzed by flow cytometry.

Key Results

Lapatinib remarkably prevented KA-induced epileptic seizures in mice and ferroptosis was involved in the neuroprotection of lapatinib. Compared with the model group, western blot showed that lapatinib significantly upregulated the levels of GPX4. In the ferroptotic cell death model, lapatinib exerted neuroprotection via up-regulating GPX4. Treatment with Ras-selective lethal small molecule 3 (RSL3), a selective GPX4 inhibitor abrogated its anti-ferroptotic potential.

Conclusions and Implications

These results illustrated that lapatinib has neuroprotective potential against KA-triggered epileptic seizures via suppressing GPX4-dependent ferroptosis.

What is already known

Activation of ferroptosis occurs in epileptic seizures.

What this study adds

Lapatinib protects brain against epileptic seizures via blocking ferroptosis.

GPX4-dependent ferroptosis is involved in the neuroprotection of lapatinib.

What is the clinical significance

Inhibition of ferroptosis by lapatinib represents a potential neuroprotective strategy for epileptic patients.
Interleukin-6 trans-signaling is a candidate mechanism to drive progression of human DCCs during periods of clinical latency
Authors: Werner-Klein Melanie , Grujovic Ana , Irlbeck Christoph , Obradovic Milan , Hoffmann Martin , Koerkel-Qu Huiqin , Lu Xin , Treitschke Steffi , Köstler Cäcilia , Botteron Catherine , Weidele Kathrin , Werno Christian , Polzer Bernhard , Kirsch Stefan , Guzvic Miodrag , Warfsmann Jens , Honarnejad Kamran , Czyz Zbigniew , Blochberger Isabell , Grunewald Sandra , Schneider Elisabeth , Haunschild Gundula , Patwary Nina , Guetter Severin , Huber Sandra , Buchholz Stefan , Rümmele Petra , Heine Norbert , Rose-John Stefan , Klein Christoph A.
Published: May 2020

Although thousands of breast cancer cells disseminate and home to bone marrow until primary surgery, usually less than a handful will succeed in establishing manifest metastases months to years later. To identify signals that support survival or outgrowth in patients, we profiled rare bone marrow-derived disseminated cancer cells (DCCs) long before manifestation of metastasis and identified IL6/PI3K-signaling as candidate pathway for DCC activation. Surprisingly, and similar to mammary epithelial cells, DCCs lacked membranous IL6 receptor expression and mechanistic dissection revealed IL6 trans-signaling to regulate a stem-like state of mammary epithelial cells via gp130. Responsiveness to IL6 trans-signals was found to be niche-dependent as bone marrow stromal and endosteal cells down-regulated gp130 in premalignant mammary epithelial cells as opposed to vascular niche cells.PIK3CAactivation rendered cells independent from IL6 trans-signaling. Consistent with a bottleneck function of microenvironmental DCC control, we foundPIK3CAmutations highly associated with late-stage metastatic cells while being extremely rare in early DCCs. Our data suggest that the initial steps of metastasis formation are often not cancer cell-autonomous, but also depend on microenvironmental signals.
Single-lipid dynamics in phase-separated supported lipid bilayers
Authors: Woodward Xinxin , Kelly Christopher V.
Published: May 2020

Phase separation is a fundamental organizing mechanism on cellular membranes. Lipid phases have complex dependencies on the membrane composition, curvature, tension, and temperature. Single-molecule diffusion measures a key characteristic of membrane behavior and relates to the effective membrane viscosity. Lipid diffusion rates vary by up to ten-fold between liquid-disordered (Ld) and liquid-ordered (Lo) phases depending on the membrane composition, measurement technique, and the surrounding environment. This manuscript reports the lipid diffusion on phase-separated supported lipid bilayers (SLBs) with varying temperature, composition, and lipid phase. Lipid diffusion is measured by single-particle tracking (SPT) and fluorescence correlation spectroscopy (FCS) via custom data acquisition and analysis protocols that apply to diverse membranes systems. We demonstrate agreement between FCS and SPT analyses with both the single-step length distribution and the mean squared displacement of lipids with significant immobile diffusers. Traditionally, SPT is sensitive to diffuser aggregation, whereas FCS largely excludes aggregates from the reported data. Protocols are reported for identifying and culling the aggregates prior to calculating diffusion rates via SPT. With aggregate culling, all diffusion measurement methods provide consistent results. With varying membrane composition and temperature, we demonstrate the importance of the tie-line length that separates the coexisting lipid phases in predicting the differences in diffusion between the Ld and Lo phases.

HIGHLIGHTS

Lipid diffusion varies with the lipid phases, temperature, and aggregation

Aggregate culling yields consistent measurements from single-particle tracking and fluorescence correlation spectroscopy

Membrane with higher cholesterol content or at low temperature have more aggregates

A more variation in the diffusion rates occurred between the coexisting lipid phases at low temperatures and low cholesterol content
A systematic analysis of gene-gene interaction in multiple sclerosis
Authors: Slim Lotfi , Chatelain Clément , de Foucauld Hélène , Azencott Chloé-Agathe
Published: May 2020

Multiple sclerosis is a complex autoimmune disease which genetic basis has been extensively investigated through genome wide association studies. So far, the conducted studies have detected a number of loci independently associated with the disease but few have investigated the interaction between distant loci, or epistasis. In the present work, we perform a gene level epistasis analysis of multiple sclerosis GWAS from the Wellcome Trust Case Control Consortium 2. We systematically study the epistatic interactions between all pairs of genes within 19 multiple sclerosis disease maps from the MetaCore pathway database. We report 4 gene pairs with epistasis involving missense variants, and 117 gene pairs with epistasis mediated by eQTLs. Our epistasis analysis is able to retrieve known interactions linked to multiple sclerosis: direct binding interaction between GLI-I and SUFU, involved in oligodendrocyte precursor cells differentiation, and regulation of IP10 transcription by NF-κB, thus validating the potential of epistasis analysis to reveal biological interaction with relevance in a disease specific context.
Differential effects of antibiotic treatment with piperacillin/tazobactam or ceftriaxone on the murine gut microbiota
Authors: Venturini Carola , Bowring Bethany , Fajardo-Lubian Alicia , Devine Carol , Iredell Jonathan
Published: May 2020

Effective antimicrobial stewardship requires a better understanding of the impact of different antibiotics on the gut microflora. Studies in humans are confounded by large inter-individual variability and difficulty in identifying control cohorts. However, controlled murine models can provide valuable information. We examined the impact of a penicillin-like antibiotic (piperacillin/tazobactam, TZP) or a third-generation cephalosporin (ceftriaxone, CRO) on the murine gut microbiota. We analyzed gut microbiome composition by 16S-rRNA amplicon sequencing and effects on the Enterobacteriaceae by qPCR and standard microbiology. Colonization resistance to multidrug resistantEscherichia coliST131 andKlebsiella pneumoniaeST258 was also tested. Changes in microbiome composition and a significant (p<0.001) decrease in diversity occurred in all treated mice, but were more marked and longer lasting after CRO exposure with a persistent rise in Proteobacteria levels. Increases in the Enterobacteriaceae occurred in all antibiotic treated mice, but were transient and associated with direct antibiotic pressure. Co-habitation of treated and untreated mice attenuated the detrimental effect of antibiotics on treated animals, but also caused disturbance in untreated co-habitants. At the height of dysbiosis after antibiotic termination, the murine gut was highly susceptible to colonization with both multidrug resistant pathogens. The administration of a third-generation cephalosporin caused a significantly prolonged dysbiosis in the murine gut microflora, when compared to a penicillin/β-lactam inhibitor combination with comparable activity against medically important virulent bacteria. At the height of dysbiosis, both antibiotic treatments equally led to microbial imbalance associated with loss of resistance to gut colonization by antibiotic-resistant pathogens.
“Association of Poor Housing Conditions with COVID-19 Incidence and Mortality Across US Counties.”
Authors: Ahmad Khansa , Erqou Sebhat , Shah Nishant , Nazir Umair , Morrison Alan , Choudhary Gaurav , Wu Wen-Chih
Published: May 2020

Objective

Poor housing conditions have been linked with worse health outcomes and infectious spread in communities but its relationship with incidence and mortality of COVID-19 is unknown. Therefore, we undertook this study to determine the association between poor housing condition and COVID-19 incidence and mortality in US counties.

Methods

We conducted cross-sectional analysis of county-level data from the US Centers for Disease Control, US Census Bureau and John Hopkins Coronavirus Resource Center for 3141 US counties. The exposure of interest was percentage of households with poor housing conditions (one or more of: overcrowding, high housing cost, incomplete kitchen facilities, or incomplete plumbing facilities). Outcomes were incidence rate ratios (IRR) and mortality rate ratios (MRR) of COVID-19 across US counties through 4/21/2020. Multilevel generalized linear modeling was utilized with adjustment for population density and county characteristics including demographics, income, education, prevalence of medical comorbidities, access to healthcare insurance and emergency rooms, and state-level COVID-19 test density.

Results

Across 3135 US counties, the mean percentage of households with poor housing conditions was 14.2% (range 2.7% to 60.2%). The mean (SD) incidence and mortality of COVID-19 were 255.68 (2877.03) cases and 13.90 (272.22) deaths per county, respectively. In the fully adjusted models, with each 5% increase in percent households with poor housing conditions, there was a 50% higher risk of COVID-19 incidence (IRR 1.50, 95% CI: 1.38 – 1.62) and a 42% higher risk of COVID-19 mortality (MRR 1.42, 95% CI: 1.25 – 1.61). Results remained similar using earlier timepoints (3/31/2020 and 4/10/2020).

Conclusions and Relevance

Counties with a higher percentage of households with poor housing had higher incidence of, and mortality associated with, COVID-19. These findings suggest targeted health policies to support individuals living in poor housing conditions should be considered in further efforts to mitigate adverse outcomes associated with COVID-19.
Lineage tracing of human embryonic development and foetal haematopoiesis through somatic mutations
Authors: Chapman Michael Spencer , Ranzoni Anna Maria , Myers Brynelle , Williams Nick , Coorens Tim , Mitchell Emily , Butler Timothy , Dawson Kevin J , Hooks Yvette , Moore Luiza , Nangalia Jyoti , Robinson Philip S , Hook Elizabeth , Campbell Peter J , Cvejic Ana
Published: May 2020

To date, ontogeny of the human haematopoietic system during foetal development has been characterized mainly through careful microscopic observations. Here we used whole-genome sequencing (WGS) of 511 single-cell derived haematopoietic colonies from healthy human foetuses of 8 and 18 post-conception weeks (pcw) coupled with deep targeted sequencing of tissues of known embryonic origin to reconstruct a phylogenetic tree of blood development. We found that in healthy foetuses, individual haematopoietic progenitors acquire tens of somatic mutations by 18 pcw. Using these mutations as barcodes, we timed the divergence of embryonic and extra-embryonic tissues during development and estimated the number of blood antecedents at different stages of embryonic development. Our analysis has shown that ectoderm originates from a smaller set of blood antecedents compared to endoderm and mesoderm. Finally, our data support a hypoblast origin of the extra-embryonic mesoderm and primitive blood in humans.
SYBR green one-step qRT-PCR for the detection of SARS-CoV-2 RNA in saliva
Authors: Ganguly DR , Rottet S , Yee S , Hee WY , Smith AB , Khin NC , Millar AA , Fahrer AM
Published: May 2020

We describe our efforts at developing a one-step quantitative reverse-transcription (qRT)-PCR protocol to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA directly from saliva samples, without RNA purification. We find that both heat and the presence of saliva impairs the ability to detect synthetic SARS-CoV-2 RNA. Buffer composition (for saliva dilution) was also crucial to effective PCR detection. Using the SG2 primer pair, designed by Sigma-Aldrich, we were able to detect the equivalent of 1.7×106viral copies per mL of saliva after heat inactivation; approximately equivalent to the median viral load in symptomatic patients. This would make our assay potentially useful for rapid detection of high-shedding infected individuals. We also provide a comparison of the PCR efficiency and specificity, which varied considerably, across 9 reported primer pairs for SARS-CoV-2 detection. Primer pairs SG2 and CCDC-N showed highest specificity and PCR efficiency. Finally, we provide an alternate primer pair to use as a positive control for human RNA detection in SARS-CoV-2 assays, as we found that the widely used US CDC primers (targeting humanRPP30) do not span an exon-exon junction and therefore does not provide an adequate control for the reverse transcription reaction.