Systems Biology

Analysis of Intestinal and Nasopharyngeal Microbiota of Children with Meningococcemia in Pediatric Intensive Care Unit: INMACS-PICU Study

Wed, 2023-06-28 06:00

Diagnostics (Basel). 2023 Jun 6;13(12):1984. doi: 10.3390/diagnostics13121984.

ABSTRACT

Microbiota composition might play a role in the pathophysiology and course of sepsis, and understanding its dynamics is of clinical interest. Invasive meningococcal disease (IMD) is an important cause of community-acquired serious infection, and there is no information regarding microbiota composition in children with meningococcemia. In this study, we aimed to evaluate the intestinal and nasopharyngeal microbiota composition of children with IMD. Materials and Methods: In this prospective, multi-center study, 10 children with meningococcemia and 10 age-matched healthy controls were included. Nasopharyngeal and fecal samples were obtained at admission to the intensive care unit and on the tenth day of their hospital stay. The V3 and V4 regions of the 16S rRNA gene were amplified following the 16S Metagenomic Sequencing Library Preparation. Results: Regarding the alpha diversity on the day of admission and on the tenth day at the PICU, the Shannon index was significantly lower in the IMD group compared to the control group (p = 0.002 at admission and p = 0.001, on the tenth day of PICU). A statistical difference in the stool samples was found between the IMD group at Day 0 vs. the controls in the results of the Bray-Curtis and Jaccard analyses (p = 0.005 and p = 0.001, respectively). There were differences in the intestinal microbiota composition between the children with IMD at admission and Day 10 and the healthy controls. Regarding the nasopharyngeal microbiota analysis, in the children with IMD at admission, at the genus level, Neisseria was significantly more abundant compared to the healthy children (p < 0.001). In the children with IMD at Day 10, genera Moraxella and Neisseria were decreased compared to the healthy children. In the children with IMD on Day 0, for paired samples, Moraxella, Neisseria, and Haemophilus were significantly more abundant compared to the children with IMD at Day 10. In the children with IMD at Day 10, the Moraxella and Neisseria genera were decreased, and 20 different genera were more abundant compared to Day 0. Conclusions: We first found alterations in the intestinal and nasopharyngeal microbiota composition in the children with IMD. The infection itself or the other care interventions also caused changes to the microbiota composition during the follow-up period. Understanding the interaction of microbiota with pathogens, e.g., N. meningitidis, could give us the opportunity to understand the disease's dynamics.

PMID:37370879 | DOI:10.3390/diagnostics13121984

Categories: Literature Watch

Reduction of Tumor Growth with RNA-Targeting Treatment of the NAB2-STAT6 Fusion Transcript in Solitary Fibrous Tumor Models

Wed, 2023-06-28 06:00

Cancers (Basel). 2023 Jun 9;15(12):3127. doi: 10.3390/cancers15123127.

ABSTRACT

Solitary fibrous tumor (SFT) is a rare soft-tissue sarcoma. This nonhereditary cancer is the result of an environmental intrachromosomal gene fusion between NAB2 and STAT6 on chromosome 12, which fuses the activation domain of STAT6 with the repression domain of NAB2. Currently there is not an approved chemotherapy regimen for SFTs. The best response on available pharmaceuticals is a partial response or stable disease for several months. The purpose of this study is to investigate the potential of RNA-based therapies for the treatment of SFTs. Specifically, in vitro SFT cell models were engineered to harbor the characteristic NAB2-STAT6 fusion using the CRISPR/SpCas9 system. Cell migration as well as multiple cancer-related signaling pathways were increased in the engineered cells as compared to the fusion-absent parent cells. The SFT cell models were then used for evaluating the targeting efficacies of NAB2-STAT6 fusion-specific antisense oligonucleotides (ASOs) and CRISPR/CasRx systems. Our results showed that fusion specific ASO treatments caused a 58% reduction in expression of fusion transcripts and a 22% reduction in cell proliferation after 72 h in vitro. Similarly, the AAV2-mediated CRISPR/CasRx system led to a 59% reduction in fusion transcript expressions in vitro, and a 55% reduction in xenograft growth after 29 days ex vivo.

PMID:37370737 | DOI:10.3390/cancers15123127

Categories: Literature Watch

Automated Classification of Lung Cancer Subtypes Using Deep Learning and CT-Scan Based Radiomic Analysis

Wed, 2023-06-28 06:00

Bioengineering (Basel). 2023 Jun 6;10(6):690. doi: 10.3390/bioengineering10060690.

ABSTRACT

Artificial intelligence and emerging data science techniques are being leveraged to interpret medical image scans. Traditional image analysis relies on visual interpretation by a trained radiologist, which is time-consuming and can, to some degree, be subjective. The development of reliable, automated diagnostic tools is a key goal of radiomics, a fast-growing research field which combines medical imaging with personalized medicine. Radiomic studies have demonstrated potential for accurate lung cancer diagnoses and prognostications. The practice of delineating the tumor region of interest, known as segmentation, is a key bottleneck in the development of generalized classification models. In this study, the incremental multiple resolution residual network (iMRRN), a publicly available and trained deep learning segmentation model, was applied to automatically segment CT images collected from 355 lung cancer patients included in the dataset "Lung-PET-CT-Dx", obtained from The Cancer Imaging Archive (TCIA), an open-access source for radiological images. We report a failure rate of 4.35% when using the iMRRN to segment tumor lesions within plain CT images in the lung cancer CT dataset. Seven classification algorithms were trained on the extracted radiomic features and tested for their ability to classify different lung cancer subtypes. Over-sampling was used to handle unbalanced data. Chi-square tests revealed the higher order texture features to be the most predictive when classifying lung cancers by subtype. The support vector machine showed the highest accuracy, 92.7% (0.97 AUC), when classifying three histological subtypes of lung cancer: adenocarcinoma, small cell carcinoma, and squamous cell carcinoma. The results demonstrate the potential of AI-based computer-aided diagnostic tools to automatically diagnose subtypes of lung cancer by coupling deep learning image segmentation with supervised classification. Our study demonstrated the integrated application of existing AI techniques in the non-invasive and effective diagnosis of lung cancer subtypes, and also shed light on several practical issues concerning the application of AI in biomedicine.

PMID:37370621 | DOI:10.3390/bioengineering10060690

Categories: Literature Watch

Circadian clocks are modulated by compartmentalized oscillating translation

Tue, 2023-06-27 06:00

Cell. 2023 Jun 20:S0092-8674(23)00599-8. doi: 10.1016/j.cell.2023.05.045. Online ahead of print.

ABSTRACT

Terrestrial organisms developed circadian rhythms for adaptation to Earth's quasi-24-h rotation. Achieving precise rhythms requires diurnal oscillation of fundamental biological processes, such as rhythmic shifts in the cellular translational landscape; however, regulatory mechanisms underlying rhythmic translation remain elusive. Here, we identified mammalian ATXN2 and ATXN2L as cooperating master regulators of rhythmic translation, through oscillating phase separation in the suprachiasmatic nucleus along circadian cycles. The spatiotemporal oscillating condensates facilitate sequential initiation of multiple cycling processes, from mRNA processing to protein translation, for selective genes including core clock genes. Depleting ATXN2 or 2L induces opposite alterations to the circadian period, whereas the absence of both disrupts translational activation cycles and weakens circadian rhythmicity in mice. Such cellular defect can be rescued by wild type, but not phase-separation-defective ATXN2. Together, we revealed that oscillating translation is regulated by spatiotemporal condensation of two master regulators to achieve precise circadian rhythm in mammals.

PMID:37369203 | DOI:10.1016/j.cell.2023.05.045

Categories: Literature Watch

Clinical Nomogram Using Novel Computed Tomography-Based Radiomics Predicts Survival in Patients With Non-Small-Cell Lung Cancer Treated With Stereotactic Body Radiation Therapy

Tue, 2023-06-27 06:00

JCO Clin Cancer Inform. 2023 Jun;7:e2200173. doi: 10.1200/CCI.22.00173.

ABSTRACT

PURPOSE: Improved survival prediction and risk stratification in non-small-cell lung cancer (NSCLC) would lead to better prognosis counseling, adjuvant therapy selection, and clinical trial design. We propose the persistent homology (PHOM) score, the radiomic quantification of solid tumor topology, as a solution.

MATERIALS AND METHODS: Patients diagnosed with stage I or II NSCLC primarily treated with stereotactic body radiation therapy (SBRT) were selected (N = 554). The PHOM score was calculated for each patient's pretreatment computed tomography scan (October 2008-November 2019). PHOM score, age, sex, stage, Karnofsky Performance Status, Charlson Comorbidity Index, and post-SBRT chemotherapy were predictors in the Cox proportional hazards models for OS and cancer-specific survival. Patients were split into high- and low-PHOM score groups and compared using Kaplan-Meier curves for overall survival (OS) and cumulative incidence curves for cause-specific death. Finally, we generated a validated nomogram to predict OS, which is publicly available at Eashwarsoma.Shinyapps.

RESULTS: PHOM score was a significant predictor for OS (hazard ratio [HR], 1.17; 95% CI, 1.07 to 1.28) and was the only significant predictor for cancer-specific survival (1.31; 95% CI, 1.11 to 1.56) in the multivariable Cox model. The median survival for the high-PHOM group was 29.2 months (95% CI, 23.6 to 34.3), which was significantly worse compared with the low-PHOM group (45.4 months; 95% CI, 40.1 to 51.8; P < .001). The high-PHOM group had a significantly greater chance of cancer-specific death at post-treatment month 65 (0.244; 95% CI, 0.192 to 0.296) compared with the low-PHOM group (0.171; 95% CI, 0.123 to 0.218; P = .029).

CONCLUSION: The PHOM score is associated with cancer-specific survival and predictive of OS. Our developed nomogram can be used to inform clinical prognosis and assist in making post-SBRT treatment considerations.

PMID:37369090 | DOI:10.1200/CCI.22.00173

Categories: Literature Watch

Effects of Glyphosate on Female Reproductive Output in the Marine Polychaete Worm <em>Ophryotrocha diadema</em>

Tue, 2023-06-27 06:00

Toxics. 2023 Jun 2;11(6):501. doi: 10.3390/toxics11060501.

ABSTRACT

Glyphosate is a broad-spectrum herbicide widely employed in agriculture. Exposure to this genotoxic and endocrine-disrupting compound has adverse effects on terrestrial and aquatic organisms and on humans as well. Here, we explored the effects of glyphosate on female reproductive output and somatic growth rate in the marine polychaete worm, Ophryotrocha diadema. Adult focal individuals were exposed to different concentrations of pure glyphosate (0.0, 0.125 0.250, 0.500, 1.000 µg/mL) administered once a week for 3 weeks. Toxic effects and mortalities were observed at the three higher concentrations, whereas only a decrease in growth rate was noted after exposure to 0.125 µg/mL, which did not affect female allocation. An area of focus in future studies should be the effects of contaminants, their metabolites, and ecologically relevant human-driven stressors in the context of global warming.

PMID:37368601 | DOI:10.3390/toxics11060501

Categories: Literature Watch

Comparing the Efficacy of Myo-Inositol Plus α-Lactalbumin vs. Myo-Inositol Alone on Reproductive and Metabolic Disturbances of Polycystic Ovary Syndrome

Tue, 2023-06-27 06:00

Metabolites. 2023 May 31;13(6):717. doi: 10.3390/metabo13060717.

ABSTRACT

Despite the beneficial effect of myo-inositol on metabolic, hormonal, and reproductive parameters of polycystic ovary syndrome (PCOS) patients, 28% to 38% could be resistant to this treatment. The combination with the milk protein α-lactalbumin can be a useful therapeutic approach to overcome inositol resistance and achieve ovulation in these women. This open-label prospective study aimed to compare the effects of supplementing myo-inositol plus α-lactalbumin vs myo-inositol alone on reproductive and metabolic abnormalities in PCOS. A total of 50 anovulatory women with a PCOS diagnosis were randomly assigned to receive myo-inositol alone or a combination of myo-inositol and α-lactalbumin for three months. Anthropometric measures, hormonal levels, and menstrual cycle duration were collected at baseline and after treatment. The therapy with myo-inositol plus α-lactalbumin improved both ovulation rate and menstrual cycle duration more than myo-inositol alone. The body weight was significantly reduced in women receiving myo-inositol plus α-lactalbumin, while patients in the myo-inositol group experienced no change. In addition, the improvement of hyperandrogenism was more prominent in patients treated with myo-inositol plus α-lactalbumin. The benefits of associating myo-inositol and α-lactalbumin clearly make this combination a true edge in the management of PCOS.

PMID:37367875 | DOI:10.3390/metabo13060717

Categories: Literature Watch

Coccidioidomycosis Granulomas Informed by Other Diseases: Advancements, Gaps, and Challenges

Tue, 2023-06-27 06:00

J Fungi (Basel). 2023 Jun 9;9(6):650. doi: 10.3390/jof9060650.

ABSTRACT

Valley fever is a respiratory disease caused by a soil fungus, Coccidioides, that is inhaled upon soil disruption. One mechanism by which the host immune system attempts to control and eliminate Coccidioides is through granuloma formation. However, very little is known about granulomas during Coccidioides infection. Granulomas were first identified in tuberculosis (TB) lungs as early as 1679, and yet many gaps in our understanding of granuloma formation, maintenance, and regulation remain. Granulomas are best defined in TB, providing clues that may be leveraged to understand Coccidioides infections. Granulomas also form during several other infectious and spontaneous diseases including sarcoidosis, chronic granulomatous disease (CGD), and others. This review explores our current understanding of granulomas, as well as potential mechanisms, and applies this knowledge to unraveling coccidioidomycosis granulomas.

PMID:37367586 | DOI:10.3390/jof9060650

Categories: Literature Watch

Parasitoid Wasp <em>Acerophagus papayae</em>: A Promising Solution for the Control of Papaya Mealybug <em>Paracoccus marginatus</em> in Cassava Fields in Vietnam

Tue, 2023-06-27 06:00

Insects. 2023 Jun 6;14(6):528. doi: 10.3390/insects14060528.

ABSTRACT

Cassava is a valuable export commodity crop that is often attacked by pests, causing economic losses for this crop. The papaya mealybug Paracoccus marginatus has become a major pest of cassava in Vietnam. The parasitoid wasp Acerophagus papayae has been demonstrated to be the most efficient parasitoid wasp for controlling P. marginatus in many regions. We observed the occurrence of A. papayae in Vietnam, studied the biological characteristics of A. papayae, and investigated its parasitic activity on P. marginatus. The results showed that A. papayae occurred more frequently than Anagyrus loecki, another known parasitoid of P. marginatus. The lifespan of A. papayae was approximately 16 days. In the absence of hosts, a 50% honey solution was an essential diet to increase the longevity of both female and male of A. papayae. The second instar of P. marginatus was a suitable host stage for parasitism by A. papayae. Female A. papayae laid approximately 60.8 eggs within 17 days, mostly during the first 6 to 7 days. These findings suggest that A. papayae has the potential to control P. marginatus, and could inform the development of more effective pest management strategies for cassava crops in Vietnam and other regions affected by this pest.

PMID:37367346 | DOI:10.3390/insects14060528

Categories: Literature Watch

Behavioural Repeatability and Behavioural Syndrome in the Dung Beetle <em>Copris umbilicatus</em> (Coleoptera, Scarabaeidae)

Tue, 2023-06-27 06:00

Insects. 2023 Jun 6;14(6):529. doi: 10.3390/insects14060529.

ABSTRACT

Although personality studies have primarily focused on vertebrates, the evidence showing invertebrates to be capable of displaying personalities has been steadily growing in recent years. In this study, we investigated the behavioural repeatability (repetition of a behaviour over time) and behavioural syndromes (a set of correlated behaviours) in Copris umbilicatus, which is a dung beetle species showing complex sub-social behaviour. We analysed three behaviours (activity, thanatosis and distress call emission) by measuring seven distinct behavioural traits (i.e., three activity-, one thanatosis- and three distress call-related traits). We found moderate to high levels of individual repeatability in all behavioural traits considered. The duration of thanatosis was inversely correlated with two activity traits, hinting a behavioural syndrome for thanatosis and activity, with bolder individuals exhibiting shorter thanatosis and higher locomotor activity in contrast with fearful individuals, which display longer thanatosis and poor locomotor activity. No relationships were found between the behavioural traits and body size or sex. Results of the principal component analysis (PCA) suggested personality differences among individuals. Dung beetles provide an impressive variety of ecosystem services. Since the provision of these services may depend on the personalities represented in local populations and communities, studies on the ecology of personality in dung beetles should be encouraged in future research.

PMID:37367344 | DOI:10.3390/insects14060529

Categories: Literature Watch

A Review on Digestive System of <em>Rhynchophorus ferrugineus</em> as Potential Target to Develop Control Strategies

Tue, 2023-06-27 06:00

Insects. 2023 May 31;14(6):506. doi: 10.3390/insects14060506.

ABSTRACT

Rhynchophorus ferrugineus, commonly known as red palm weevil (RPW), is a high-risk insect pest that has become a threat to many important palm species. There are several dominant factors that lead to the successful infestation of RPW, including its stealthy lifestyle, highly chitinized mouthpart, and high fecundity rate. Due to that, millions of dollars of losses have been suffered by many countries invaded by RPW. Several methods have been designed to control its invasion, including the usage of insecticides, but many cause resistance and environmental pollution. Therefore, an environmentally friendly insecticide that targets specific systems or pathways in RPW is urgently needed. One of the potential targets is the digestive system of RPW, as it is the major interface between the insect and its plant host. The related knowledge of RPW's digestive system, such as the anatomy, microflora, transcriptomic analysis, and proteomic analysis, is important to understand its effects on RPW's survival. Several data from different omics regarding the digestive systems of RPW have been published in separate reports. Some of the potential targets have been reported to be inhibited by certain potential insecticides, while other targets have not yet been tested with any inhibitors. Hence, this review may lead to a better understanding on managing infestations of RPW using the system biology approach for its digestive system.

PMID:37367322 | DOI:10.3390/insects14060506

Categories: Literature Watch

Gene Co-Expression Network Analysis Reveals Key Regulatory Genes in <em>Metisa plana</em> Hormone Pathways

Tue, 2023-06-27 06:00

Insects. 2023 May 30;14(6):503. doi: 10.3390/insects14060503.

ABSTRACT

Metisa plana Walker (Lepidoptera: Psychidae) is a major oil palm pest species distributed across Southeast Asia. M. plana outbreaks are regarded as serious ongoing threats to the oil palm industry due to their ability to significantly reduce fruit yield and subsequent productivity. Currently, conventional pesticide overuses may harm non-target organisms and severely pollute the environment. This study aims to identify key regulatory genes involved in hormone pathways during the third instar larvae stage of M. plana gene co-expression network analysis. A weighted gene co-expression network analysis (WGCNA) was conducted on the M. plana transcriptomes to construct a gene co-expression network. The transcriptome datasets were obtained from different development stages of M. plana, i.e., egg, third instar larvae, pupa, and adult. The network was clustered using the DPClusO algorithm and validated using Fisher's exact test and receiver operating characteristic (ROC) analysis. The clustering analysis was performed on the network and 20 potential regulatory genes (such as MTA1-like, Nub, Grn, and Usp) were identified from ten top-most significant clusters. Pathway enrichment analysis was performed to identify hormone signalling pathways and these pathways were identified, i.e., hormone-mediated signalling, steroid hormone-mediated signalling, and intracellular steroid hormone receptor signalling as well as six regulatory genes Hnf4, Hr4, MED14, Usp, Tai, and Trr. These key regulatory genes have a potential as important targets in future upstream applications and validation studies in the development of biorational pesticides against M. plana and the RNA interference (RNAi) gene silencing method.

PMID:37367319 | DOI:10.3390/insects14060503

Categories: Literature Watch

Broad Sarbecovirus Neutralizing Antibodies Obtained by Computational Design and Synthetic Library Screening

Tue, 2023-06-27 06:00

J Virol. 2023 Jun 27:e0061023. doi: 10.1128/jvi.00610-23. Online ahead of print.

ABSTRACT

Members of the Sarbecovirus subgenus of Coronaviridae have twice caused deadly threats to humans. There is increasing concern about the rapid mutation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has evolved into multiple generations of epidemic variants in 3 years. Broad neutralizing antibodies are of great importance for pandemic preparedness against SARS-CoV-2 variants and divergent zoonotic sarbecoviruses. Here, we analyzed the structural conservation of the receptor-binding domain (RBD) from representative sarbecoviruses and chose S2H97, a previously reported RBD antibody with ideal breadth and resistance to escape, as a template for computational design to enhance the neutralization activity and spectrum. A total of 35 designs were purified for evaluation. The neutralizing activity of a large proportion of these designs against multiple variants was increased from several to hundreds of times. Molecular dynamics simulation suggested that extra interface contacts and enhanced intermolecular interactions between the RBD and the designed antibodies are established. After light and heavy chain reconstitution, AI-1028, with five complementarity determining regions optimized, showed the best neutralizing activity across all tested sarbecoviruses, including SARS-CoV, multiple SARS-CoV-2 variants, and bat-derived viruses. AI-1028 recognized the same cryptic RBD epitope as the parental prototype antibody. In addition to computational design, chemically synthesized nanobody libraries are also a precious resource for rapid antibody development. By applying distinct RBDs as baits for reciprocal screening, we identified two novel nanobodies with broad activities. These findings provide potential pan-sarbecovirus neutralizing drugs and highlight new pathways to rapidly optimize therapeutic candidates when novel SARS-CoV-2 escape variants or new zoonotic coronaviruses emerge. IMPORTANCE The subgenus Sarbecovirus includes human SARS-CoV, SARS-CoV-2, and hundreds of genetically related bat viruses. The continuous evolution of SARS-CoV-2 has led to the striking evasion of neutralizing antibody (NAb) drugs and convalescent plasma. Antibodies with broad activity across sarbecoviruses would be helpful to combat current SARS-CoV-2 mutations and longer term animal virus spillovers. The study of pan-sarbecovirus NAbs described here is significant for the following reasons. First, we established a structure-based computational pipeline to design and optimize NAbs to obtain more potent and broader neutralizing activity across multiple sarbecoviruses. Second, we screened and identified nanobodies from a highly diversified synthetic library with a broad neutralizing spectrum using an elaborate screening strategy. These methodologies provide guidance for the rapid development of antibody therapeutics against emerging pathogens with highly variable characteristics.

PMID:37367229 | DOI:10.1128/jvi.00610-23

Categories: Literature Watch

The CUL4B-based E3 ubiquitin ligase regulates mitosis and brain development by recruiting phospho-specific DCAFs

Tue, 2023-06-27 06:00

EMBO J. 2023 Jun 27:e112847. doi: 10.15252/embj.2022112847. Online ahead of print.

ABSTRACT

The paralogs CUL4A and CUL4B assemble cullin-RING E3 ubiquitin ligase (CRL) complexes regulating multiple chromatin-associated cellular functions. Although they are structurally similar, we found that the unique N-terminal extension of CUL4B is heavily phosphorylated during mitosis, and the phosphorylation pattern is perturbed in the CUL4B-P50L mutation causing X-linked intellectual disability (XLID). Phenotypic characterization and mutational analysis revealed that CUL4B phosphorylation is required for efficient progression through mitosis, controlling spindle positioning and cortical tension. While CUL4B phosphorylation triggers chromatin exclusion, it promotes binding to actin regulators and to two previously unrecognized CUL4B-specific substrate receptors (DCAFs), LIS1 and WDR1. Indeed, co-immunoprecipitation experiments and biochemical analysis revealed that LIS1 and WDR1 interact with DDB1, and their binding is enhanced by the phosphorylated N-terminal domain of CUL4B. Finally, a human forebrain organoid model demonstrated that CUL4B is required to develop stable ventricular structures that correlate with onset of forebrain differentiation. Together, our study uncovers previously unrecognized DCAFs relevant for mitosis and brain development that specifically bind CUL4B, but not the CUL4B-P50L patient mutant, by a phosphorylation-dependent mechanism.

PMID:37365982 | DOI:10.15252/embj.2022112847

Categories: Literature Watch

How honey bees make fast and accurate decisions

Tue, 2023-06-27 06:00

Elife. 2023 Jun 27;12:e86176. doi: 10.7554/eLife.86176.

ABSTRACT

Honey bee ecology demands they make both rapid and accurate assessments of which flowers are most likely to offer them nectar or pollen. To understand the mechanisms of honey bee decision-making, we examined their speed and accuracy of both flower acceptance and rejection decisions. We used a controlled flight arena that varied both the likelihood of a stimulus offering reward and punishment and the quality of evidence for stimuli. We found that the sophistication of honey bee decision-making rivalled that reported for primates. Their decisions were sensitive to both the quality and reliability of evidence. Acceptance responses had higher accuracy than rejection responses and were more sensitive to changes in available evidence and reward likelihood. Fast acceptances were more likely to be correct than slower acceptances; a phenomenon also seen in primates and indicative that the evidence threshold for a decision changes dynamically with sampling time. To investigate the minimally sufficient circuitry required for these decision-making capacities, we developed a novel model of decision-making. Our model can be mapped to known pathways in the insect brain and is neurobiologically plausible. Our model proposes a system for robust autonomous decision-making with potential application in robotics.

PMID:37365884 | DOI:10.7554/eLife.86176

Categories: Literature Watch

Karst spring microbiome: Diversity, core taxa, and community response to pathogens and antibiotic resistance gene contamination

Mon, 2023-06-26 06:00

Sci Total Environ. 2023 Jun 24:165133. doi: 10.1016/j.scitotenv.2023.165133. Online ahead of print.

ABSTRACT

Karst aquifers are important water resources for drinking water supplies worldwide. Although they are susceptible to anthropogenic contamination due to their high permeability, there is a lack of detailed knowledge on the stable core microbiome and how contamination may affect these communities. In this study, eight karst springs (distributed across three different regions in Romania) were sampled seasonally for one year. The core microbiota was analysed by 16S rRNA gene amplicon sequencing. To identify bacteria carrying antibiotic resistance genes and mobile genetic elements, an innovative method was applied, consisting of high-throughput antibiotic resistance gene quantification performed on potential pathogen colonies cultivated on Compact Dry™ plates. A taxonomically stable bacterial community consisting of Pseudomonadota, Bacteroidota, and Actinomycetota was revealed. Core analysis reaffirmed these results and revealed primarily freshwater-dwelling, psychrophilic/psychrotolerant species affiliated to Rhodoferax, Flavobacterium, and Pseudomonas genera. Both sequencing and cultivation methods indicated that more than half of the springs were contaminated with faecal bacteria and pathogens. These samples contained high levels of sulfonamide, macrolide, lincosamide and streptogramins B, and trimethoprim resistance genes spread primarily by transposase and insertion sequences. Differential abundance analysis found Synergistota, Mycoplasmatota, and Chlamydiota as suitable candidates for pollution monitoring in karst springs. This is the first study highlighting the applicability of a combined approach based on high-throughput SmartChip™ antibiotic resistance gene quantification and Compact Dry™ pathogen cultivation for estimating microbial contaminants in karst springs and other challenging low biomass environments.

PMID:37364839 | DOI:10.1016/j.scitotenv.2023.165133

Categories: Literature Watch

PickYOLO: Fast deep learning particle detector for annotation of cryo electron tomograms

Mon, 2023-06-26 06:00

J Struct Biol. 2023 Jun 24:107990. doi: 10.1016/j.jsb.2023.107990. Online ahead of print.

ABSTRACT

Particle localization (picking) in digital tomograms is a laborious and time-intensive step in cryogenic electron tomography (cryoET) analysis often requiring considerable user involvement, thus becoming a bottleneck for automated cryoET subtomogram averaging (STA) pipelines. In this paper, we introduce a deep learning framework called PickYOLO to tackle this problem. PickYOLO is a super-fast, universal particle detector based on the deep-learning real-time object recognition system YOLO (You Only Look Once), and tested on single particles, filamentous structures, and membrane-embedded particles. After training with the centre coordinates of a few hundred representative particles, the network automatically detects additional particles with high yield and reliability at a rate of 0.24-3.75 seconds per tomogram. PickYOLO can automatically detect number of particles comparable to those manually selected by experienced microscopists. This makes PickYOLO a valuable tool to substantially reduce the time and manual effort needed to analyse cryoET data for STA, greatly aiding in high-resolution cryoET structure determination.

PMID:37364763 | DOI:10.1016/j.jsb.2023.107990

Categories: Literature Watch

Alkaline soil primes the recovery from drought in Populus nigra plants through physiological and chemical adjustments

Mon, 2023-06-26 06:00

Plant Physiol Biochem. 2023 Jun 21;201:107838. doi: 10.1016/j.plaphy.2023.107838. Online ahead of print.

ABSTRACT

Perennial plants are frequently exposed to severe and prolonged drought, and when the balance between water transport and transpirational demand is compromised trees are in danger of embolism formation. To maintain the physiological balance, plants can rely on mechanisms to quickly recover the lost xylem hydraulic capacity and reduce the prolonged impact on photosynthetic activity upon rehydration. Among factors helpful for plants to sustain acclimation and adaptation responses to drought and promote recovery, maintaining an optimal nutritional status is crucial for plant survival. This study aimed to investigate the physiological and biochemical responses under drought and recovery of Populus nigra plants grown in soil with impaired nutrient bioavailability obtained by adding calcium oxide (CaO) to the substrate. Although the CaO treatment did not affect plant growth, in well-watered conditions, treated poplars displayed an impaired inorganic ions profile in tissues. Under drought, although CaO-treated and untreated plants showed similar physiological responses, the former closed the stomata earlier. During water stress relief, the CaO-treated poplars exhibited a faster stomatal opening and a higher capacity to restore xylem hydraulic conductivity compared to not-treated plants, probably due to the higher osmolyte accumulation during drought. The content of some inorganic ions (e.g, Ca2+ and Cl-) was also higher in the xylem sap collected from stressed CaO-treated plants, thus contributing to increase the osmotic gradient necessary for the recovery. Taken together, our results suggest that CaO treatment promotes a faster and more efficient plant recovery after drought due to a modulation of ions homeostasis.

PMID:37364510 | DOI:10.1016/j.plaphy.2023.107838

Categories: Literature Watch

Microscopy-Based Tracking and Quantification Methods to Study Phagosome Resolution

Mon, 2023-06-26 06:00

Methods Mol Biol. 2023;2692:221-235. doi: 10.1007/978-1-0716-3338-0_15.

ABSTRACT

Phagosome resolution is a newly defined, terminal stage in the process of phagocytosis. During this phase, phagolysosomes are fragmented into smaller vesicles, which we called phagosome-derived vesicles (PDVs). PDVs gradually accumulate within macrophages, while the phagosomes diminish in size until the organelles are no longer detectable. Although PDVs share the same maturation markers as phagolysosomes, they are heterogeneous in size and very dynamic, which makes PDVs difficult to track. Thus, to analyze PDV populations in cells, we developed methods to differentiate PDVs from the phagosomes in which they were derived and further assess their characteristics. In this chapter, we describe two microscopy-based methods that can be used to quantify different aspects of phagosome resolution: volumetric analysis of phagosome shrinkage and PDV accumulation and co-occurrence analysis of various membrane markers with PDVs.

PMID:37365471 | DOI:10.1007/978-1-0716-3338-0_15

Categories: Literature Watch

Filamentous Bacteria as Targets to Study Phagocytosis

Mon, 2023-06-26 06:00

Methods Mol Biol. 2023;2692:91-107. doi: 10.1007/978-1-0716-3338-0_7.

ABSTRACT

Filamentous targets are internalized via phagocytic cups that last for several minutes before closing to form a phagosome. This characteristic offers the possibility to study key events in phagocytosis with greater spatial and temporal resolution than is possible to achieve using spherical particles, for which the transition from a phagocytic cup to an enclosed phagosome occurs within a few seconds after particle attachment. In this chapter, we provide methodologies to prepare filamentous bacteria and describe how they can be used as targets to study different aspects of phagocytosis.

PMID:37365463 | DOI:10.1007/978-1-0716-3338-0_7

Categories: Literature Watch

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