N-Myristoyltransferase Inhibition causes Mitochondrial Iron Overload and Parthanatos in TIM17A-dependent Aggressive Lung Carcinoma.

Myristoylation is a type of protein acylation by which the fatty acid myristate is added to the N-terminus of target proteins, a process mediated by N-myristoyltransferases. Myristoylation is emerging as a promising cancer therapeutic target, however the molecular determinants of sensitivity to N-myristoyltransferase inhibition or the mechanism by which it induces cancer cell death are not completely understood. We report that N-myristoyltransferases are a novel therapeutic target in lung carcinoma cells with LKB1 and/or KEAP1 mutations in a KRAS mutant background. Inhibition of myristoylation decreases cell viability in vitro and tumor growth in vivo. Inhibition of myristoylation causes mitochondrial ferrous iron overload, oxidative stress, elevated protein poly (ADP)-ribosylation and death by parthanatos. Furthermore, NMT inhibitors sensitized lung carcinoma cells to platinum-based chemotherapy. Unexpectedly, the mitochondrial transporter Translocase of Inner Mitochondrial Membrane 17 homologue A (TIM17A) is a critical target of myristoylation inhibitors in these cells. TIM17A silencing recapitulated the effects of NMT inhibition at inducing mitochondrial ferrous iron overload and parthanatos. Furthermore, sensitivity of lung carcinoma cells to myristoylation inhibition correlated with their dependency on TIM17A. This study reveals the unexpected connection between protein myristoylation, the mitochondrial import machinery, and iron homeostasis. It also uncovers myristoylation inhibitors as novel inducers of parthanatos in cancer, and the novel axis N-myristoyltransferase-TIM17A as a potential therapeutic target in highly aggressive lung carcinomas.

A stargate mechanism of Microviridae genome delivery unveiled by cryogenic electron tomography.

Single-stranded DNA bacteriophages of the Microviridae family are major components of the global virosphere. Microviruses are highly abundant in aquatic ecosystems and are prominent members of the mammalian gut microbiome, where their diversity has been linked to various chronic health disorders. Despite the clear importance of microviruses, little is known about the molecular mechanism of host infection. Here, we have characterized an exceptionally large microvirus, Ebor, and provide crucial insights into long-standing mechanistic questions. Cryogenic electron microscopy of Ebor revealed a capsid with trimeric protrusions that recognise lipopolysaccharides on the host surface. Cryogenic electron tomography of the host cell colonized with virus particles demonstrated that the virus initially attaches to the cell via five such protrusions, located at the corners of a single pentamer. This interaction triggers a stargate mechanism of capsid opening along the 5-fold symmetry axis, enabling delivery of the virus genome. Despite variations in specific virus-host interactions among different Microviridae family viruses, structural data indicate that the stargate mechanism of infection is universally employed by all members of the family. Startlingly, our data reveal a mechanistic link for the opening of relatively small capsids made out of a single jelly-roll fold with the structurally unrelated giant viruses.

Patient Satisfaction with Nonopioid Postoperative Analgesia in Head and Neck Surgery: A Prospective Randomized Trial.

OBJECTIVE: To evaluate patients' satisfaction with opioid versus opioid-sparing postoperative analgesia in patients undergoing outpatient head and neck surgery. STUDY DESIGN: Prospective randomized trial. SETTING: Tertiary care academic hospital. METHODS: Adult patients undergoing outpatient head and neck surgery were randomly assigned to 1 of 3 analgesic regimens. First- and second-line medications were the following by group (1) Hydrocodone-acetaminophen with ibuprofen, (2) ibuprofen with hydrocodone-acetaminophen, and (3) ibuprofen with acetaminophen. Preoperative counseling was provided to patients regarding expected pain and proper medication use. Postoperative questionnaires were administered to assess satisfaction. RESULTS: One hundred three patients were enrolled in the study (mean age, 56.5 years; women, 75 [73%]). The mean satisfaction score with the pain regimen assigned was similar between the 3 groups (scale 0-10, [7.7, 8.3, 8.5, P = .46]). A similar percentage of patients in each group reported that surgery was more painful than anticipated (25%, 32%, 26%, P = .978), and a similar percentage of patients reported willingness to utilize the same analgesic regimen following future surgeries (75%, 83%, 76%, P = .682). Additional questions evaluating the side effect profile, maximum and minimum pain scores, and difficulty of recovery were not statistically different between the 3 groups. CONCLUSION: In the postoperative population for outpatient head and neck surgeries, there was no significant difference in patient satisfaction and pain control between the opioid and nonopioid arms. Providers should discuss opioid-sparing regimens preoperatively with patients and describe them as effective in providing adequate pain control without a significant impact on patient's perception of care.

Variability Between Full-Length Lateral Radiographs and Standard Short Knee Radiographs When Evaluating Posterior Tibial Slope in Revision ACL Patients.

Background: Increased posterior tibial slope (PTS) has been identified as a risk factor for failure after anterior cruciate ligament (ACL) reconstruction. Correction of PTS may improve outcomes after revision ACL reconstruction. There are conflicting reports demonstrating the measurement of the PTS on standard short knee (SSK) radiographs versus full-length lateral (FLL) radiographs including the entire tibia. Purpose/Hypothesis: To compare PTS measurements between SSK and FLL radiographs in patients who failed primary ACL reconstruction. It was hypothesized that there would be high variability between the SSK and FLL radiographic measurements. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: The medial and lateral PTS were measured on the SSK and FLL radiographs of 33 patients with failed primary ACL reconstructions. All measurements were performed by 2 trained independent observers (A.A.M., J.S.), and inter- and intraobserver reliability were calculated using the intraclass correlation coefficient (ICC). Measurements recorded by the observer with the higher intraobserver ICC were used for comparison of the PTS on SSK versus FLL radiographs. Results: Both the inter- and the intraobserver reliability values of the PTS measurements were excellent. There was a significant difference in mean PTS on the medial plateau as measured on the SSK and FLL radiographs (11.2°± 5.3° vs 12.5°± 4.6°; P = .03), with the FLL radiographs demonstrating higher PTS. There was also a significant difference in the mean PTS on the lateral plateau as measured on SSK versus FLL radiographs (10.7°± 4.3° vs 12.2°± 4°, respectively; P = .01), with the FLL radiographs demonstrating higher PTS. Notably, 66.67% of the absolute measurements for PTS on the medial plateau differed by ≥2°, with variability as high as 8.5°. Conclusion: Results indicated that FLL and SSK radiographs are not interchangeable measurements for PTS associated with failed ACL reconstruction. Because FLL radiographs demonstrate less variability than SSK radiographs, we recommend obtaining them to evaluate these complex patients.

Risk Factors and Outcomes Associated with Gaps in Care in Children with Congenital Heart Disease.

Adults with congenital heart disease (CHD) benefit from cardiology follow-up at recommended intervals of ≤ 2 years. However, benefit for children is less clear given limited studies and unclear current guidelines. We hypothesize there are identifiable risks for gaps in cardiology follow-up in children with CHD and that gaps in follow-up are associated with differences in healthcare utilization. Our cohort included children < 10 years old with CHD and a healthcare encounter from 2008 to 2013 at one of four North Carolina (NC) hospitals. We assessed associations between cardiology follow-up and demographics, lesion severity, healthcare access, and educational isolation (EI). We compared healthcare utilization based on follow-up. Overall, 60.4% of 6,969 children received cardiology follow-up within 2 years of initial encounter, including 53.1%, 58.1%, and 79.0% of those with valve, shunt, and severe lesions, respectively. Factors associated with gaps in care included increased drive time to a cardiology clinic (Hazard Ratio (HR) 0.92/15-min increase), EI (HR 0.94/0.2-unit increase), lesion severity (HR 0.48 for shunt/valve vs severe), and older age (HR 0.95/month if < 1 year old and 0.94/year if > 1 year old; p < 0.05). Children with a care gap subsequently had more emergency department (ED) visits (Rate Ratio (RR) 1.59) and fewer inpatient encounters and procedures (RR 0.51, 0.35; p < 0.05). We found novel factors associated with gaps in care for cardiology follow-up in children with CHD and altered health care utilization with a gap. Our findings demonstrate a need to mitigate healthcare barriers and generate clear cardiology follow-up guidelines for children with CHD.

Induction of genetic variability of maize genotypes through radiation revealed mutants resistant to maize streak disease.

The absence of genetic variability among crop genotypes is an impediment to breeding progress, hence mutagenesis could serve as a useful tool to create genetic variation to obtain desirable traits of interest. In this study, four maize genotypes, Obatampa, Dapango, Pann 54 and Honampa which were susceptible to maize streak disease (MSD) were acutely irradiated at 254.3 Gy, using a cobalt 60 (60Co) at a rate of 300 Gy/hr. The irradiated seeds were planted with their parental controls at streak disease highly endemic environment. Field trials for the selected maize genotypes were conducted from the M1 to M4 generations to screen for MSD resistance and improved grain yield. Sixteen putative mutants and four individual parental controls were selected across the four maize genotypes at the end of the M4 generation based on disease severity score and yield indices. Detailed morphological screening and field evaluation of putative mutants showing improved plant architecture, increased grain yield and resistance to maize streak disease were tagged and selected. Obatanpa-induced-genotype was the best mutant identified with a grain yield of 6.8 t ha-1. Data on days to 50% flowering indicated that all 16 putative mutants were maturing plants.

Surgery for nonlocalizing hyperparathyroidism in high volume center.

BACKGROUND: Patients with nonlocalizing hyperparathyroidism pose a significant challenge to surgeons when undergoing neck exploration for parathyroidectomy. METHODS: We evaluated 536 patients that had parathyroidectomy for primary hyperparathyroidism (PHPT) from 2005 to 2018 at a single tertiary academic center, and 155 (29%) had standard nonlocalizing preoperative imaging (negative ultrasound and sestamibi scans). RESULTS: There were a total of 102 (66%) non-ectopic single adenomas in the nonlocalizing group and 325 (85%) single adenomas in the localizing group. There was no significant difference (p = 0.09) in adenoma quadrant between localizing and nonlocalizing single adenomas, but the most common location in both groups was right inferior. Patients with nonlocalizing scans were more likely to have double adenomas (21% vs. 9%, p < 0.001), ectopic glands (10% vs. 5%, p = 0.052), and multi-gland disease (13% vs. 8%, p = 0.002). CONCLUSION: Nonlocalizing PHPT patients experienced similar cure and complication rates as localizing PHPT, but required more bilateral explorations and increased operative time.

Quantitative Aggregation of Microbiome Sequencing Data Provides Insights into the Associations between the Skin Microbiome and Psoriasis.

Although prior studies have reported distinct skin microbiome profiles associated with psoriasis, differences in methods and analyses limit generalizable conclusions. Individual studies have actually reported conflicting findings; for example, Propionibacterium and Staphylococcus have been significantly associated with both psoriatic lesions and healthy skin. Qualitative reviews have attempted to summarize this body of work, but there is great variability across the studies' findings and methods. To better unify these data, we created a meta-analysis of all publicly available datasets by utilizing a uniform bioinformatics pipeline and reference database to investigate associations of the skin microbiome in psoriasis. A total of 977 skin swab samples (341 lesional, 295 nonlesional, and 341 healthy) from 6 studies were analyzed. The aggregated analysis revealed a higher relative abundance of microorganisms, including Staphylococcus aureus and Corynebacterium simulans, among others, from patients with psoriasis than those from healthy swab samples; in addition, Cutibacterium acnes, Lawsonella unclassified, and S warneri were significantly higher in healthy samples. Furthermore, comparison of functional pathways predicted from 16S gene markers showed that L-ornithine biosynthesis and L-histidine biosynthesis were lower in psoriatic lesions than in healthy controls. Taken together, this meta-analysis allows for a more generalizable association between the skin microbiome and psoriasis.

Myocardial Oedema as a Consequence of Viral Infection and Persistence-A Narrative Review with Focus on COVID-19 and Post COVID Sequelae.

Microvascular integrity is a critical factor in myocardial fluid homeostasis. The subtle equilibrium between capillary filtration and lymphatic fluid removal is disturbed during pathological processes leading to inflammation, but also in hypoxia or due to alterations in vascular perfusion and coagulability. The degradation of the glycocalyx as the main component of the endothelial filtration barrier as well as pericyte disintegration results in the accumulation of interstitial and intracellular water. Moreover, lymphatic dysfunction evokes an increase in metabolic waste products, cytokines and inflammatory cells in the interstitial space contributing to myocardial oedema formation. This leads to myocardial stiffness and impaired contractility, eventually resulting in cardiomyocyte apoptosis, myocardial remodelling and fibrosis. The following article reviews pathophysiological inflammatory processes leading to myocardial oedema including myocarditis, ischaemia-reperfusion injury and viral infections with a special focus on the pathomechanisms evoked by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In addition, clinical implications including potential long-term effects due to viral persistence (long COVID), as well as treatment options, are discussed.

Clinical significance of prostate cancer identified by transperineal standard template biopsy in men with nonsuspicious multiparametric magnetic resonance imaging.

OBJECTIVE: Multiparametric magnetic resonance imaging (mpMRI) of the prostate has excellent sensitivity in detecting clinically significant prostate cancer (csCaP). However, whether a negative mpMRI in patients with a clinical suspicion of CaP can omit a confirmatory biopsy remains less understood and without consensus. Transperineal (TP) standard template biopsy (SBx) provides an effective approach to CaP detection. Our aim is to provide a comprehensive understanding of the CaP characteristics detected through TP SBx that are systematically overlooked by mpMRI. METHODS: We conducted a retrospective analysis of all men who underwent prebiopsy mpMRI and subsequent a 20-core TP SBx at our hospital from September 2019 to February 2021. Patients with suspicious mpMRI received a combined TP SBx and targeted biopsy (TBx) (suspicious group), while those without suspicious (negative) mpMRI and who proceeded to biopsy, received TP SBx only (nonsuspicious group). A negative mpMRI was defined as the absence of suspicious findings and/or the presence of low-risk areas with a PI-RADS score of ≤2. Subsequently, we compared and evaluated the clinical and biopsy characteristics between these 2 groups. RESULTS: We identified 301 men in suspicious group and 215 men in nonsuspicious group. The overall CaP detection rate and csCaP detection rate by TP SBx were 74.1%, 38.9% for suspicious group and 43.3%, 14.9% for nonsuspicious group, respectively. csCaP NPV of mpMRI was 85.1% with a csCaP prevalence 28.9%. The greatest percentage of cancer involvement (GPC) in biopsy core from nonsuspicious group was significantly lower than those of suspicious group (40% vs. 50%, p = 0.005), In multivariate logistic analysis, only PSAD > 0.15 ng/ml/cc was identified as an independent and significant predictor of csCaP in nonsuspicious group. CONCLUSION: Within our cohort, false-negative rates of mpMRI for csCaP are substantial, reaching 15%. Nonsuspicious cases may contain a large volume tumor since the high GPC of SBx. For cases with nonsuspicious imaging and higher PSAD, a confirmatory biopsy may be necessary due to the increased risk of missed csCaP by mpMRI.

Pelvic tilt affects superolateral coverage, but not superomedial coverage of the femoral head following periacetabular osteotomy.

BACKGROUND: Pelvic tilt is an important sagittal parameter that varies greatly among individuals. The objective of this study was to quantify the effect of pelvic tilt on femoral head coverage and range of motion in a dysplastic population following periacetabular osteotomy. METHODS: Twenty-three dysplastic hips from 19 patients (17 female, 2 male) were included in this study. Three-dimensional models were reconstructed using pre-operative CT images, and patient-specific neutral pelvic tilt was obtained on an anteroposterior X-ray. Following a simulated periacetabular osteotomy, the pelvic tilt was changed from -15° to +15°, and the effects on femoral head coverage and hip range of motion was quantified using a customized MATLAB program. FINDINGS: Pelvic tilt did not significantly affect total femoral head coverage (P > 0.2). However, a 15° anterior tilt from neutral resulted in a 17.72 ± 9.45% increase in anterolateral coverage and a 23.96 ± 7.48% decrease in posterolateral coverage (P < 0.0001), as well as an 18.2 ± 8.4° loss of internal rotation at 90° of hip flexion. Contrarily, posterior pelvic tilt led to a 26.79 ± 9.04% reduction in anterolateral coverage (P < 0.0001) and an 18.02 ± 9.57% increase in posterolateral coverage (P < 0.0001), and the maximum internal rotation increased 11.8 ± 3.7°. INTERPRETATION: While pelvic tilt did not affect total femoral head coverage, it had a significant impact on the distribution of coverage within the superolateral region of the femoral head. Anterior pelvic tilt led to increased anterolateral coverage, but also had a negative impact on hip range of motion. An optimal surgical plan should achieve adequate coverage while not significantly limiting the patient's mobility.

Regulatory and Interacting Partners of PDLIM7 in Thyroid Cancer.

Enigma protein, encoded by the PDLIM7 gene, is overexpressed in thyroid cancer in a stage-dependent manner, suggesting a potential involvement in the initiation and progression of thyroid cancer. The Enigma interacts with several cellular pathways, including PI3K/AKT, MDM2, and BMP-1. The Enigma is regulated by microRNAs. Specifically, we showed that the Enigma protein upregulation corresponds to the downregulation of Let-7 family genes. There is limited research on the interactions and regulation of the Enigma with other proteins/genes in thyroid cancer tissues, indicating a gap in current knowledge. Our aim is to establish the Enigma as a biomarker. We also aim to study the interacting partners of the Enigma signaling pathways and their probable miRNA regulation in thyroid cancer progression. Using Western blotting, densitometric analysis, immunoprecipitation (IP), and reverse IP, we detected the protein expression and protein-protein interactions in the corresponding papillary thyroid carcinomas (PTCs). Utilizing real-time qPCR assay and Pearson's correlation test, we highlighted the correlation between PDLIM7 and Let-7g gene expression in the same tissues. The results showed the differential upregulations of the Enigma protein in different stages of PTCs compared to benign tissues along with AKT, VDR, BMP-1, and MDM2 proteins. Loss of DBP was observed in a subset of PTCs. Strong interactions of the Enigma with PI3K/AKT and MDM2 were noted, along with a weaker BMP-1 interaction. Pearson's correlation coefficient analysis between PDLIM7 and let-7g gene expression was significant (p < 0.05); however, there was a weak inverse correlation (r = -0.27). The study suggests the potential utility of the PDLIM7-qPCR assay as a biomarker for thyroid cancer. The Enigma's interactions with key signaling pathways may provide valuable insights into the development of thyroid cancer. The study contributes to understanding the molecular mechanisms involving the Enigma protein in thyroid cancer and highlights its potential as a biomarker.

Jorvik: A membrane-containing phage that will likely found a new family within Vinavirales.

Although membrane-containing dsDNA bacterial viruses are some of the most prevalent predators in aquatic environments, we know little about how they function due to their intractability in the laboratory. Here, we have identified and thoroughly characterized a new type of membrane-containing bacteriophage, Jorvik, that infects the freshwater mixotrophic model bacterium Rhodobacter capsulatus. Jorvik is extremely virulent, can persist in the host integrated into the RuBisCo operon and encodes two experimentally verified cell wall hydrolases. Jorvik-like prophages are abundant in the genomes of Alphaproteobacteria, are distantly related to known viruses of the class Tectiliviricetes, and we propose they should be classified as a new family. Crucially, we demonstrate how widely used phage manipulation methods should be adjusted to prevent loss of virus infectivity. Our thorough characterization of environmental phage Jorvik provides important experimental insights about phage diversity and interactions in microbial communities that are often unexplored in common metagenomic analyses.

Plasticity of root hair and rhizosheath traits and their relationship to phosphorus uptake in sorghum.

Sorghum is an essential crop for resilient and adaptive responses to climate change. The root systems of crop plants significantly contribute to the tolerance of abiotic stresses. There is little information on sorghum genotypes' root systems and plasticity to external P supply. In this paper, we investigated the variations in root systems, as well as the responses, trait relationships, and plasticity of two sorghum genotypes (Naga Red and Naga White), popularly grown in Ghana, to five external P concentrations ([P]ext): 0, 100, 200, 300, and 400 mg P kg-1 soil. Sorghum plants were grown in greenhouse pots and harvested for root trait measurements at the five-leaf and growing point differentiation (GPD) developmental stages. The plants were responsive to [P]ext and formed rhizosheaths. The two genotypes showed similar characteristics for most of the traits measured but differed significantly in total and lateral root lengths in favor of the red genotype. For example, at the five-leaf growth stage, the lateral root length of the red and white genotypes was 22.8 and 16.2 cm, respectively, but 124 and 88.9 cm, at the GPD stage. The responses and plasticity of the root system traits, including rhizosheath, to [P]ext were more prominent, positive, and linear at the five-leaf stage than at the GPD growth stage. At the five-leaf growth stage, total root length increased by about 2.5-fold with increasing [P]ext compared to the unamended soil. At the GPD stage, however, total root length decreased by about 1.83-fold as [P]ext increased compared to the unamended soil. Specific rhizosheath weight correlated with RHD, albeit weakly, and together explained up to 59% of the variation in tissue P. Root hair density was more responsive to P supply than root hair length and showed a similar total and lateral root length pattern. Most desirable responses to P occurred at a rate of 200-300 mg P kg-1 soil. It is concluded that sorghum would form rhizosheath, and [P]ext could be critical for the early vigorous growth of sorghum's responsive root and shoot traits. Beyond the early days of development, additional P application might be necessary to sustain the responses and plasticity observed during the early growth period, but this requires further investigation, potentially under field conditions.

Prevalence of Occult Central Lymph Node Metastasis by Tumor Size in Papillary Thyroid Carcinoma: A Systematic Review and Meta-Analysis.

BACKGROUND: While papillary thyroid carcinoma (PTC) is associated with high occult central neck metastasis (CNM) rates, prophylactic central neck dissection (pCND) is controversial. This meta-analysis aims to look at the occult CNM rate according to tumor size. METHODS: A literature search was conducted in PubMed from inception to April 2023. Inclusion criteria were primary studies that determined occult CNM rates in cN0 PTC by tumor size. Heterogeneity, influential case diagnostics, and proportion data were evaluated with Cochran's Q-test, Baujat plots and Forest plots, respectively. RESULTS: Fifty-two studies were included in this meta-analysis. The findings demonstrated an occult CNM rate of 30.3% for tumors ≤ 5 mm, 32.7% for tumors ≤ 1 cm, 46.0% for tumors between 1 and 2 cm, 43.1% for tumors between 2 and 4 cm, and 61.2% for tumors > 4 cm. The heterogeneity of each study group was high, though no publication bias was noted. While there was a trend towards increased occult CNM rates with larger tumors, comparisons between different size cutoffs varied in significance. CONCLUSION: This comprehensive review affirms that occult CNM is high and that an ipsilateral pCND can be justified in all PTC patients for accurate differentiation between Stage I and Stage II disease and its clinical implications.

Structure of HK97 small terminase:DNA complex unveils a novel DNA binding mechanism by a circular protein.

DNA recognition is critical for assembly of double-stranded DNA viruses, in particular for the initiation of packaging the viral genome into the capsid. DNA packaging has been extensively studied for three archetypal bacteriophage systems: cos, pac and phi29. We identified the minimal site within the cos region of bacteriophage HK97 specifically recognised by the small terminase and determined a cryoEM structure for the small terminase:DNA complex. This nonameric circular protein utilizes a previously unknown mechanism of DNA binding. While DNA threads through the central tunnel, unexpectedly, DNA-recognition is generated at its exit by a substructure formed by the N- and C-terminal segments of two adjacent protomers of the terminase which are unstructured in the absence of DNA. Such interaction ensures continuous engagement of the small terminase with DNA, allowing sliding along DNA while simultaneously checking the DNA sequence. This mechanism allows locating and instigating packaging initiation and termination precisely at the cos site.

Insights into a viral motor: the structure of the HK97 packaging termination assembly.

Double-stranded DNA viruses utilise machinery, made of terminase proteins, to package viral DNA into the capsid. For cos bacteriophage, a defined signal, recognised by small terminase, flanks each genome unit. Here we present the first structural data for a cos virus DNA packaging motor, assembled from the bacteriophage HK97 terminase proteins, procapsids encompassing the portal protein, and DNA containing a cos site. The cryo-EM structure is consistent with the packaging termination state adopted after DNA cleavage, with DNA density within the large terminase assembly ending abruptly at the portal protein entrance. Retention of the large terminase complex after cleavage of the short DNA substrate suggests that motor dissociation from the capsid requires headful pressure, in common with pac viruses. Interestingly, the clip domain of the 12-subunit portal protein does not adhere to C12 symmetry, indicating asymmetry induced by binding of the large terminase/DNA. The motor assembly is also highly asymmetric, showing a ring of 5 large terminase monomers, tilted against the portal. Variable degrees of extension between N- and C-terminal domains of individual subunits suggest a mechanism of DNA translocation driven by inter-domain contraction and relaxation.

Implementation of Bedaquiline, Pretomanid, and Linezolid in the United States: Experience Using a Novel All-Oral Treatment Regimen for Treatment of Rifampin-Resistant or Rifampin-Intolerant Tuberculosis Disease.

BACKGROUND: Rifampin-resistant tuberculosis is a leading cause of morbidity worldwide; only one-third of persons start treatment, and outcomes are often inadequate. Several trials demonstrate 90% efficacy using an all-oral, 6-month regimen of bedaquiline, pretomanid, and linezolid (BPaL), but significant toxicity occurred using 1200-mg linezolid. After US Food and Drug Administration approval in 2019, some US clinicians rapidly implemented BPaL using an initial 600-mg linezolid dose adjusted by serum drug concentrations and clinical monitoring. METHODS: Data from US patients treated with BPaL between 14 October 2019 and 30 April 2022 were compiled and analyzed by the BPaL Implementation Group (BIG), including baseline examination and laboratory, electrocardiographic, and clinical monitoring throughout treatment and follow-up. Linezolid dosing and clinical management was provider driven, and most patients had linezolid adjusted by therapeutic drug monitoring. RESULTS: Of 70 patients starting BPaL, 2 changed to rifampin-based therapy, 68 (97.1%) completed BPaL, and 2 of the 68 (2.9%) experienced relapse after completion. Using an initial 600-mg linezolid dose daily adjusted by therapeutic drug monitoring and careful clinical and laboratory monitoring for adverse effects, supportive care, and expert consultation throughout BPaL treatment, 3 patients (4.4%) with hematologic toxicity and 4 (5.9%) with neurotoxicity required a change in linezolid dose or frequency. The median BPaL duration was 6 months. CONCLUSIONS: BPaL has transformed treatment for rifampin-resistant or intolerant tuberculosis. In this cohort, effective treatment required less than half the duration recommended in 2019 US guidelines for drug-resistant tuberculosis. Use of individualized linezolid dosing and monitoring likely enhanced safety and treatment completion. The BIG cohort demonstrates that early implementation of new tuberculosis treatments in the United States is feasible.

Fluoroquinolone-resistant latent tuberculosis infection: A literature review and case series of 5 patients treated with linezolid monotherapy.

Latent tuberculosis infection (LTBI) constitutes an important public health problem because of risk of progression to TB disease. Effective treatment of multi-drug resistant (MDR) LTBI would prevent progression to MDR TB disease, which would improve patient and public health outcomes. The majority of MDR LTBI treatment studies have focused on the use of fluoroquinolone-based antibiotic regimens. Options for and experience in the treatment of fluoroquinolone-resistant MDR LTBI are limited in the published literature and not comprehensively addressed in current guidelines. In this review, we share our experience with the treatment of fluoroquinolone-resistant MDR LTBI with linezolid. We discuss treatment options for MDR TB that provide context for predicting effective MDR LTBI treatment, with a focus on the microbiologic and pharmacokinetic properties of linezolid that support its use. We then summarize the evidence for treatment of MDR LTBI. Finally, we present our experiences treating fluoroquinolone-resistant MDR LTBI with linezolid with an emphasis on dosing considerations to optimize efficacy and minimize potential toxicities.

Structural atlas of a human gut crassvirus.

CrAssphage and related viruses of the order Crassvirales (hereafter referred to as crassviruses) were originally discovered by cross-assembly of metagenomic sequences. They are the most abundant viruses in the human gut, are found in the majority of individual gut viromes, and account for up to 95% of the viral sequences in some individuals1-4. Crassviruses are likely to have major roles in shaping the composition and functionality of the human microbiome, but the structures and roles of most of the virally encoded proteins are unknown, with only generic predictions resulting from bioinformatic analyses4,5. Here we present a cryo-electron microscopy reconstruction of Bacteroides intestinalis virus ΦcrAss0016, providing the structural basis for the functional assignment of most of its virion proteins. The muzzle protein forms an assembly about 1 MDa in size at the end of the tail and exhibits a previously unknown fold that we designate the 'crass fold', that is likely to serve as a gatekeeper that controls the ejection of cargos. In addition to packing the approximately 103 kb of virus DNA, the ΦcrAss001 virion has extensive storage space for virally encoded cargo proteins in the capsid and, unusually, within the tail. One of the cargo proteins is present in both the capsid and the tail, suggesting a general mechanism for protein ejection, which involves partial unfolding of proteins during their extrusion through the tail. These findings provide a structural basis for understanding the mechanisms of assembly and infection of these highly abundant crassviruses.