Radiological Hypertrophic Olivary Degeneration Following Posterior Fossa Tumor Surgery.

INTRODUCTION: Hypertrophic olivary degeneration is a rare form of transsynaptic degeneration, caused by injury to the Dentato-rubro-olivary pathway (DROP). Radiologically this manifests as T2 hyperintensity, with or without enlargement of the inferior olivary nucleus (ION). The purpose of the study was to evaluate the incidence, associated imaging characteristics, potential etiologies, latency period, and temporal progression of HOD in patients undergoing surgical resection of posterior fossa tumors (PFTs). MATERIALS AND METHODS: A retrospective analysis of patients with PFTs and post-surgical MRI scans was conducted. HOD was diagnosed based on ION signal abnormalities and size changes. Demographics, tumor characteristics, time to HOD onset, involved DROP components, and clinical symptoms were recorded. RESULTS: HOD was seen in 40 (6.2%) patients following PFT surgery. 26 patients were aged 17 or less while the rest were older than 17 years. Medulloblastoma was the most frequently diagnosed tumor type (n=25), followed by pilocytic astrocytoma (n=8), ependymoma (n=6), and high grade glioma (n=1). No statistical association was found between the development of HOD and tumor grade (p=0.882). Ataxia was the most commonly reported clinical symptom (n=15). The time elapsed between surgery and the diagnosis of HOD varied, with median intervals of 1 month, 5 months, and 37 months for different stages. Dentate nucleus was the most commonly affected component of the DROP (n=36). CONCLUSION: HOD is a frequently overlooked postoperative complication following PFT resection. Increased recognition of HOD by neuroradiologists is essential for timely diagnosis and avoidance of unnecessary diagnostic procedures.

Identification and Characterization of Innate Immunity in Actinidia melanandra in Response to Pseudomonas syringae pv. actinidiae.

Pseudomonas syringae pv. actinidiae biovar 3 (Psa3) has decimated kiwifruit orchards growing susceptible kiwifruit Actinidia chinensis varieties. Effector loss has occurred recently in Psa3 isolates from resistant kiwifruit germplasm, resulting in strains capable of partially overcoming resistance present in kiwiberry vines (Actinidia arguta, Actinidia polygama, and Actinidia melanandra). Diploid male A. melanandra recognises several effectors, sharing recognition of at least one avirulence effector (HopAW1a) with previously studied tetraploid kiwiberry vines. Sequencing and assembly of the A. melanandra genome enabled the characterisation of the transcriptomic response of this non-host to wild-type and genetic mutants of Psa3. A. melanandra appears to mount a classic effector-triggered immunity (ETI) response to wildtype Psa3 V-13, as expected. Surprisingly, the type III secretion (T3SS) system-lacking Psa3 V-13 ∆hrcC strain did not appear to trigger pattern-triggered immunity (PTI) despite lacking the ability to deliver immunity-suppressing effectors. Contrasting the A. melanandra responses to an effectorless Psa3 V-13 ∆33E strain and to Psa3 V-13 ∆hrcC suggested that PTI triggered by Psa3 V-13 was based on the recognition of the T3SS itself. The characterisation of both ETI and PTI branches of innate immunity responses within A. melanandra further enables breeding for durable resistance in future kiwifruit cultivars.

Stimulus duration encoding occurs early in the moth olfactory pathway.

Pheromones convey rich ethological information and guide insects' search behavior. Insects navigating in turbulent environments are tasked with the challenge of coding the temporal structure of an odor plume, obliging recognition of the onset and offset of whiffs of odor. The coding mechanisms that shape odor offset recognition remain elusive. We designed a device to deliver sharp pheromone pulses and simultaneously measured the response dynamics from pheromone-tuned olfactory receptor neurons (ORNs) in male moths and Drosophila. We show that concentration-invariant stimulus duration encoding is implemented in moth ORNs by spike frequency adaptation at two time scales. A linear-nonlinear model fully captures the underlying neural computations and offers an insight into their biophysical mechanisms. Drosophila use pheromone cis-vaccenyl acetate (cVA) only for very short distance communication and are not faced with the need to encode the statistics of the cVA plume. Their cVA-sensitive ORNs are indeed unable to encode odor-off events. Expression of moth pheromone receptors in Drosophila cVA-sensitive ORNs indicates that stimulus-offset coding is receptor independent. In moth ORNs, stimulus-offset coding breaks down for short ( < 200 ms) whiffs. This physiological constraint matches the behavioral latency of switching from the upwind surge to crosswind cast flight upon losing contact with the pheromone.

A Cost-Utility Analysis of the Use of -125 mm Hg Closed-incision Negative Pressure Therapy in Oncoplastic Breast Surgery.

Background: Closed-incision negative pressure therapy (ciNPT) decreases the rate of wound complications in oncoplastic breast surgery (OBS) but at a fiscal cost. Our aim was to examine the cost-utility of ciNPT in OBS. Methods: A literature review was performed to obtain the probabilities and outcomes for the treatment of unilateral breast cancer with OBS with ciNPT versus without. Reported utility scores in the literature were used to calculate quality-adjusted life years (QALYs) for each health state. A decision analysis tree was constructed with rollback analysis to determine the more cost-effective strategy. An incremental cost-utility ratio was calculated. Sensitivity analyses were performed. Results: OBS with ciNPT is associated with a higher clinical effectiveness (QALY) of 33.43 compared to without (33.42), and relative cost increase of $667.89. The resulting incremental cost-utility ratio of $57432.93/QALY favored ciNPT. In one-way sensitivity analysis, ciNPT was the more cost-effective strategy if the cost of ciNPT was less than $1347.02 or if the probability of wound dehiscence without was greater than 8.2%. Monte Carlo analysis showed a confidence of 75.39% that surgery with ciNPT is more cost effective. Conclusion: Despite the added cost, surgery with ciNPT is cost-effective. This finding is a direct result of decreased overall wound complications with ciNPT.

Spinal Diffuse Midline Glioma H3 K27M-Altered: Report of a Rare Tumor with Extracranial Skeletal Metastases and Review of Literature.

Diffuse midline glioma, H3 K27-altered is a rare and aggressive pediatric brain tumor with a grim prognosis. Diffuse midline glioma is characterized by specific molecular alterations, including H3 K27 mutations, and involves deep midline structures such as the brainstem, cerebellum, spinal cord, and thalamus. These tumors present with a classic triad of symptoms and have limited surgical options due to their challenging locations. Extra-neural metastases are an unusual occurrence in diffuse midline glioma and have been rarely described. Here we report a 17-year-old girl with spinal diffuse midline glioma, H3 K27M-mutant, who presented with multiple metastatic osseous lesions confirmed on biopsy of the thoracic vertebral lesion. Due to the rapid disease progression, the patient was recommended palliative therapy. Extra-neural metastases in diffuse midline glioma are rare, with only 16 reported patients, and no standard therapy exists. An accurate and early diagnosis is necessary to develop a personalized plan of treatment. Further research is needed to gain insights into the molecular pathology of diffuse midline glioma, H3 K27-altered, and improve the quality of life and the outcome of patients with this deadly disease.

Validation testing of OUTPATSAT-35RT questionnaire to assess satisfaction in patients on outpatient radiotherapy in a large Indian cohort.

BACKGROUND: This study reports the psychometric properties of OUTPASAT-35RT questionnaire from a large Indian cancer cohort treated with ambulatory radiotherapy (RT) at a tertiary-care comprehensive cancer center. MATERIALS AND METHODS: Adults with a pathologically proven diagnosis of cancer undergoing fractionated RT (≥10 fractions) with the ability to read and understand English, Hindi, or Marathi were accrued after written informed consent. Patients were administered a language-appropriate version of OUTPATSAT-35RT along with European Organization for Research and Treatment of Cancer (EORTC) generic quality-of-life questionnaire (QLQ-C30) at conclusion of RT (±3 days). Psychometric properties of OUTPATSAT-35RT were analyzed. RESULTS: A total of 314 patients were accrued between 2018 and 2020. A negligible floor effect (<2%) but a high ceiling effect (>15%) was observed for OUTPATSAT-35RT. Multi-trait analysis revealed satisfactory validity and reliability of the questionnaire. Pearson's correlation coefficient (PCC) of individual item score with own scale was >0.4 suggesting good convergent validity. Discriminant validity was satisfactory as the PCC with its own scale/own domain was greater than with other scales of the same domain and other domains of OUTPATSAT-35RT, respectively. Correlation of scales of OUTPATSAT-35RT with scales of QLQ-C30 demonstrated acceptable divergent validity (all values of PCC <0.3). Cronbach's alpha was >0.7 suggesting good internal consistency. Test-retest reliability was good with intra-class coefficient being >0.7. Economic status was the only socio-demographic factor correlating significantly with OUTPATSAT-35RT scores; satisfaction of patients with the delivery of care increased with increasing family income. CONCLUSION: The psychometric properties of OUTPATSAT-35RT were found to be acceptable and satisfactory during validation testing in a large Indian cohort.

Transcriptional upregulation of MMP-9 gene under hyperglycemic conditions in AGS cells: Role of AP-1 transcription factor.

Gastric cancer and diabetes are two complex and interrelated diseases having significant impact on global health. Hyperglycemic condition notably exacerbates cancer by promoting inflammation, angiogenesis, and metastasis. Elevated glucose levels can also upregulate the expression of specific matrix metalloproteinases (MMPs), especially MMP-9, which is associated with cancer cell migration and invasion. However, the molecular mechanism behind such upregulation remains unexplored. In the present study, we have identified the mechanism for hyperglycemia-induced transcriptional activation of MMP-9, in gastric adenocarcinoma (AGS) cells. Using various tools like luciferase-reporter assays with promoter deletion constructs, siRNAs, pharmacological inhibitors, and nuclear translocation experiments, we have identified that the transcriptional activation of MMP-9 under hyperglycemic conditions is predominantly governed by the MAPK pathway, via formation of the AP-1 heterodimer. The p65 NF-κB signaling pathway, although activated, plays no significant role in regulating hyperglycemia-induced MMP-9 expression. Chromatin immunoprecipitation studies indicate that the distal AP-1 binding site is responsible for hyperglycemia-induced MMP-9 transcription; whereas the proximal one accounts for both hyperglycemia-induced and basal MMP-9 transcription. Therefore, binding of AP-1 at both the proximal and distal binding sites on the MMP-9 promoter region is required for hyperglycemia-induced MMP-9 expression. Overall, our study unveils a novel mechanism of MMP-9 transcription under hyperglycemic conditions and also suggests that inhibiting the binding of the AP-1 heterodimer with its distal binding site can potentially reduce the complications developed during gastric cancer-hyperglycemia co-morbidity. A drug designed specifically to inhibit this interaction may prevent hyperglycemia-induced tumor aggressiveness to a considerable extent by impeding MMP-9 transcription.

Is Oncoplastic Surgery Safe in High-Risk Breast Cancer Phenotypes?

BACKGROUND: Oncoplastic surgery (OPS) has increased in popularity over the recent years. It is a form of breast conservation surgery allowing for larger partial mastectomy (PM) resections followed by either volume displacement or volume replacement reconstruction techniques. However, there is a lack of evidence on the effectiveness and safety of OPS with radiotherapy (OPS + RT) in high-risk breast cancer phenotypes, such as triple negative breast cancer (TNBC) and HER2 positive (HER2+) patients. Our aim was to compare the breast cancer-specific survival (BCSS) and postoperative surgical complications in OPS + RT compared to PM alone with radiation (PM + RT) and total mastectomy (MTX) without radiotherapy (MTX-RT). METHODS: Patient data were analyzed from the Surveillance, Epidemiology, and End Results (SEER) cancer registries from January 1, 2012 to December 31, 2020. Patients were stratified according to the type of surgery. Cox regression analysis was performed to assess prognostic factors of BCSS. RESULTS: A total of 24 621 patients with high-risk breast cancer phenotypes were identified, 180 underwent OPS + RT; 13 402, PM + RT; and 11 039 MTX-RT. OPS + RT was more frequently performed in younger (mean age of 65.53 years, SD: 9.29, p < 0.001), non-Hispanic White (90.5% vs. 77.7% vs. 76.3%) and single women (17.9% vs. 12.1% vs. 13.3%). MTX-RT was usually performed in patients with high histological grade, TNBC, and higher stages. Overall complication rates were higher in the MTX-RT, compared to OPS + RT and PM + RT, 2%, 1.1%, and 0.7%, respectively, p < 0.001. Rates of hematoma and surgical site infections were higher in the MTX-RT group. With a median follow-up of 46 months, OPS + RT had better BCSS rates at 5 years compared to PM + RT and MTX-RT (97.1% vs. 94.7% vs. 89.8%, p < 0.001). MTX-RT was found to be an independent prognostic factor of worse BCSS compared to OPS + RT (hazard ratio [HR] = 2.584; 95% confidence interval [CI]: 1.005-7.171), while PM + RT had no difference compared to OPS + RT (HR = 1.670, 95% CI: 0.624-4.469). CONCLUSIONS: OPS is a safe breast surgical option in patients with HER2+ and TNBC. Patients with high-risk phenotypes who underwent OPS + RT and have similar BCSS and complication rates compared to standard breast surgical options. As such, OPS should be considered as an option whenever breast conservation surgery is being discussed.

Protocol for aerial trapping and analyses of candidate pheromone compounds released by moths via gas chromatography-mass spectrometry.

Detection of pheromones is pivotal to chemical ecology and agronomy; however, analytic detection of the volatile pheromone components from odorized air is highly challenging. Here, we introduce a protocol for the detection of airborne pheromones from female moths, which are key models for chemosensory studies. We describe a step-by-step guide from pheromone collection to quantitative estimation of pheromone components. We also detail procedures for gas chromatography-mass spectrometry (GC-MS) analysis. This protocol has potential applications beyond chemosensory research, particularly in environmental chemistry. For complete details on the use and execution of this protocol, please refer to Ghosh et al.1.

Carbon emissions from the 2023 Canadian wildfires.

The 2023 Canadian forest fires have been extreme in scale and intensity with more than seven times the average annual area burned compared to the previous four decades1. Here, we quantify the carbon emissions from these fires from May to September 2023 on the basis of inverse modelling of satellite carbon monoxide observations. We find that the magnitude of the carbon emissions is 647 TgC (570-727 TgC), comparable to the annual fossil fuel emissions of large nations, with only India, China and the USA releasing more carbon per year2. We find that widespread hot-dry weather was a principal driver of fire spread, with 2023 being the warmest and driest year since at least 19803. Although temperatures were extreme relative to the historical record, climate projections indicate that these temperatures are likely to be typical during the 2050s, even under a moderate climate mitigation scenario (shared socioeconomic pathway, SSP 2-4.5)4. Such conditions are likely to drive increased fire activity and suppress carbon uptake by Canadian forests, adding to concerns about the long-term durability of these forests as a carbon sink5-8.

Magnetic Resonance Imaging Features of Sporadic Optic Chiasmatic-Hypothalamic Gliomas and Correlation with Histopathology and BRAF Gene Alterations.

OBJECTIVE: Sporadic optic chiasmatic-hypothalamic gliomas (OCHGs), though histologically low-grade tumors, manifest as aggressive neoplasms radiologically, leading to difficulty in diagnosis. Molecular alterations of the BRAF gene are detectable in a majority of sporadic OCHGs. The purpose of our study was to elucidate the characteristic imaging features of sporadic OCHGs and to investigate whether imaging phenotypes could potentially correlate with specific BRAF gene alterations associated with these tumors. METHODS: We retrospectively reviewed baseline magnetic resonance (MR) images and medical records of 26 patients with histopathologically proven sporadic OCHGs. MR imaging (MRI) features were systematically evaluated. Statistical analysis was performed to determine whether there was a significant association between imaging findings and BRAF molecular alterations. RESULTS: Twenty-two cases (84.6%) presented with solid-cystic masses, while four (15.4%) presented with purely solid lesions. In all 26 cases, the solid component revealed central necrosis; there was minimal necrosis in 11 cases (42.3%), moderate in 8 (30.7%), and marked in 7 (26.9%). The presence of multiple cysts (>4) and minimal necrosis showed a significant association with BRAFV600E mutation (P < 0.005). Marked necrosis in the solid component significantly correlated with BRAF wild genotype (P < 0.001). The presence of a single peripheral cyst significantly correlated with BRAF fusion (P = 0.04). CONCLUSION: Sporadic OCHGs have a distinctive appearance on imaging. The solid-cystic composition coupled with varying degrees of central necrosis are clues to the radiological diagnosis of this entity and can facilitate early recognition in clinical practice. Imaging could potentially serve as a non-invasive predictor of the BRAF alteration status, thereby serving as a prognostic marker and guiding personalized management.

Shatavarin-IV, a steroidal saponin from Asparagus racemosus, inhibits cell cycle progression and epithelial-to-mesenchymal transition in AGS cells under hyperglycemic conditions.

Gastric cancer (GC)-diabetes co-morbidity is nowadays growing into a rising concern. However, no separate treatment procedures have been outlined for such patients. Phytochemicals and their derivatives can therefore be used as therapeutics as they have greater effectiveness, reduced toxicity, and a reduced likelihood of developing multi-drug resistance in cancer treatments. The present study intended to assess the therapeutic efficacy of Shatavarin-IV - a major steroidal saponin from the roots of Asparagus racemosus, in human gastric adenocarcinoma cell line under hyperglycemic conditions and explore its mechanism of action in controlling GC progression. For the present study, AGS cells were incubated in high glucose-containing media and the effects of Shatavarin-IV therein have been evaluated. Cell proliferation, confocal microscopic imaging, flow-cytometric analysis for cell cycle and apoptosis, immunoblotting, zymography, reverse zymography, wound-healing, colony formation, and invasion assays were performed. Shatavarin-IV has a prominent effect on AGS cell proliferation; with IC50 of 2.463 µ M under hyperglycemic conditions. Shatavarin-IV induces cell cycle arrest at the G0/G1 phase, thereby preventing hyperglycemia-induced excessive cell proliferation that later on leads to apoptotic cell death at 36 h of incubation. Shatavarin-IV further inhibits the migratory and invasive potential of AGS cells by altering the expression patterns of different EMT markers. It also inhibits MMP-9 while promoting TIMP-1 activity and expression; thereby regulating ECM turnover. This is the first report demonstrating the therapeutic efficacy of Shatavarin-IV against AGS cells grown in hyperglycemic conditions, implicating new insights into the treatment paradigm of patients with GC-diabetes co-morbidity.

Recent advances in managing obstructive sleep apnea.

Obstructive sleep apnea (OSA) is a rapidly increasing global concern. If it remains untreated, it can lead to cardiovascular, metabolic, and psychiatric complications and may result in premature death. The efficient and effective management of OSA can have a beneficial effect and help reduce the financial burden on the health sector. There has been constant development in OSA management, and numerous options are available. The mainstay of therapy is still the conventional measures and behavioral modifications. However, in cases of failure of these modalities, surgical therapy is the only option. Numerous studies have shown that proper management of OSA has beneficial effects with good long-term outcomes.

A Translation-Independent Directed Evolution Strategy to Engineer Aminoacyl-tRNA Synthetases.

Using directed evolution, aminoacyl-tRNA synthetases (aaRSs) have been engineered to incorporate numerous noncanonical amino acids (ncAAs). Until now, the selection of such novel aaRS mutants has relied on the expression of a selectable reporter protein. However, such translation-dependent selections are incompatible with exotic monomers that are suboptimal substrates for the ribosome. A two-step solution is needed to overcome this limitation: (A) engineering an aaRS to charge the exotic monomer, without ribosomal translation; (B) subsequent engineering of the ribosome to accept the resulting acyl-tRNA for translation. Here, we report a platform for aaRS engineering that directly selects tRNA-acylation without ribosomal translation (START). In START, each distinct aaRS mutant is correlated to a cognate tRNA containing a unique sequence barcode. Acylation by an active aaRS mutant protects the corresponding barcode-containing tRNAs from oxidative treatment designed to damage the 3'-terminus of the uncharged tRNAs. Sequencing of these surviving barcode-containing tRNAs is then used to reveal the identity of the aaRS mutants that acylated the correlated tRNA sequences. The efficacy of START was demonstrated by identifying novel mutants of the Methanomethylophilus alvus pyrrolysyl-tRNA synthetase from a naïve library that enables incorporation of ncAAs into proteins in living cells.

Oncoplastic Surgery Outcomes in the Older Breast Cancer Population: A Matched-Cohort Comparison Study.

BACKGROUND: Oncoplastic breast surgery (OBS) is a form of breast conservation surgery (BCS) that involves a partial mastectomy followed by immediate volume displacement or volume replacement surgical techniques. To date, there are few studies evaluating OBS in older patients. Therefore, we sought to determine if outcomes differed between patients 65 years and older versus younger patients who underwent oncoplastic surgical procedures. METHODS: A retrospective chart review was performed for all oncoplastic breast operations within a single health system from 2015 to 2021. Patients were stratified by age, with patients 65 years and older (OBS65+) identified and then matched with younger patients (OBS <65) based on BMI. Primary outcomes were positive margin rates and overall complication rates; secondary outcomes were locoregional recurrence (LR), distant recurrence (DR), disease-free survival (DFS), overall survival (OS), and long-term breast asymmetry. RESULTS: A total of 217 patients underwent OBS over the 6-year period, with 22% being OBS65+. Preoperatively, older patients experienced higher American Anesthesia (ASA) scores, Charlson Co-morbidity index (CCI) scores, and higher rates of diabetes mellitus, hypertension, and grade 3 breast ptosis. Despite this, no significant differences were found between primary or secondary outcomes compared to younger patients undergoing the same procedures. CONCLUSIONS: Oncoplastic breast reconstruction is a safe option in patients 65 years and older, with overall similar recurrence rates, positive margin rates, and survival when compared to younger patients. Although the older cohort of patients had greater preoperative risk, there was no difference in overall surgical complication rates or outcomes. Supporting the argument that all oncoplastic breast reconstruction techniques should be offered to eligible patients, irrespective of age.

Chemical approaches to probe and engineer AAV vectors.

Adeno-associated virus (AAV) has emerged as the most promising vector for in vivo human gene therapy, with several therapeutic approvals in the last few years and countless more under development. Underlying this remarkable success are several attractive features that AAV offers, including lack of pathogenicity, low immunogenicity, long-term gene expression without genomic integration, the ability to infect both dividing and non-dividing cells, etc. However, the commonly used wild-type AAV capsids in therapeutic development present significant challenges, including inadequate tissue specificity and the need for large doses to attain therapeutic effectiveness, raising safety concerns. Additionally, significant preexisting adaptive immunity against most natural capsids, and the development of such anti-capsid immunity after the first treatment, represent major challenges. Strategies to engineer the AAV capsid are critically needed to address these challenges and unlock the full promise of AAV gene therapy. Chemical modification of the AAV capsid has recently emerged as a powerful new approach to engineer its properties. Unlike genetic strategies, which can be more disruptive to the delicate capsid assembly and packaging processes, "late-stage" chemical modification of the assembled capsid-whether at natural amino acid residues or site-specifically installed noncanonical amino acid residues-often enables a versatile approach to introducing new properties to the capsid. This review summarizes the significant recent progress in AAV capsid engineering strategies, with a particular focus on chemical modifications in advancing the next generation of AAV-based gene therapies.

Directed Evolution of a Bacterial Leucyl tRNA in Mammalian Cells for Enhanced Noncanonical Amino Acid Mutagenesis.

The Escherichia coli leucyl-tRNA synthetase (EcLeuRS)/tRNAEcLeu pair has been engineered to genetically encode a structurally diverse group of enabling noncanonical amino acids (ncAAs) in eukaryotes, including those with bioconjugation handles, environment-sensitive fluorophores, photocaged amino acids, and native post-translational modifications. However, the scope of this toolbox in mammalian cells is limited by the poor activity of tRNAEcLeu. Here, we overcome this limitation by evolving tRNAEcLeu directly in mammalian cells by using a virus-assisted selection scheme. This directed evolution platform was optimized for higher throughput such that the entire acceptor stem of tRNAEcLeu could be simultaneously engineered, which resulted in the identification of several variants with remarkably improved efficiency for incorporating a wide range of ncAAs. The advantage of the evolved leucyl tRNAs was demonstrated by expressing ncAA mutants in mammalian cells that were challenging to express before using the wild-type tRNAEcLeu, by creating viral vectors that facilitated ncAA mutagenesis at a significantly lower dose and by creating more efficient mammalian cell lines stably expressing the ncAA-incorporation machinery.

Native Aminoacyl-tRNA Synthetase/tRNA Pair Drives Highly Efficient Noncanonical Amino Acid Incorporation in Escherichia coli.

Site-specific noncanonical amino acid (ncAA) mutagenesis in living cells has traditionally relied on heterologous, nonsense-suppressing aminoacyl-tRNA synthetase (aaRS)/tRNA pairs that do not cross-react with their endogenous counterparts. Such heterologous pairs often perform suboptimally in a foreign host cell since they were not evolutionarily optimized to function in the foreign environment. This suboptimal performance restricts the number of ncAAs that can be simultaneously incorporated into a protein. Here, we show that the use of an endogenous aaRS/tRNA pair to drive ncAA incorporation can offer a potential solution to this limitation. To this end, we developed an engineered Escherichia coli strain (ATMY-C321), wherein the endogenous tyrosyl-tRNA synthetase (TyrRS)/tRNA pair has been functionally replaced with an archaeal counterpart, and the release factor 1 has been removed to eliminate competing termination at the UAG nonsense codons. The endogenous TyrRS/tRNACUATyr pair exhibits remarkably efficient nonsense suppression in the resulting cell, relative to established orthogonal ncAA-incorporation systems in E. coli, allowing the incorporation of an ncAA at up to 10 contiguous sites in a reporter protein. Our work highlights the limitations of orthogonal translation systems using heterologous aaRS/tRNA pairs and offers a potential alternative involving the use of endogenous pairs.

NbPTR1 confers resistance against Pseudomonas syringae pv. actinidiae in kiwifruit.

Pseudomonas syringae pv. actinidiae biovar 3 (Psa3) causes a devastating canker disease in yellow-fleshed kiwifruit (Actinidia chinensis). The effector HopZ5, which is present in all isolates of Psa3 causing global outbreaks of pandemic kiwifruit canker disease, triggers immunity in Nicotiana benthamiana and is not recognised in susceptible A. chinensis cultivars. In a search for N. benthamiana nonhost resistance genes against HopZ5, we found that the nucleotide-binding leucine-rich repeat receptor NbPTR1 recognised HopZ5. RPM1-interacting protein 4 orthologues from N. benthamiana and A. chinensis formed a complex with NbPTR1 and HopZ5 activity was able to disrupt this interaction. No functional orthologues of NbPTR1 were found in A. chinensis. NbPTR1 transformed into Psa3-susceptible A. chinensis var. chinensis 'Hort16A' plants introduced HopZ5-specific resistance against Psa3. Altogether, this study suggested that expressing NbPTR1 in Psa3-susceptible kiwifruit is a viable approach to acquiring resistance to Psa3 and it provides valuable information for engineering resistance in otherwise susceptible kiwifruit genotypes.

Perioperative cardiac risks in myasthenia gravis.

Myasthenia gravis (MG) is an autoimmune disorder that affects the neuromuscular junction. The primary pathology in MG involves the presence of autoantibodies to acetylcholine receptors (AChRs), which results in qualitative and quantitative reductions in the availability of functional AChRs. Cardiac muscles are also affected, resulting in various perioperative cardiac complications. Antistriational antibodies are commonly reported in MG cases with cardiac involvement. In the presence of thymoma, the prevalence of cardiac manifestations in patients with MG increases to approximately 10%-15%. Cardiac involvement in MG may range from asymptomatic electrocardiogram changes to ventricular tachycardia, myocarditis, conduction disorders, heart failure, and sudden death. Increased incidence of atrial fibrillation, ventricular and supraventricular extra systoles, and prolonged QTc have also been reported in patients with MG. Clinicians should consider the evaluation of autonomic dysfunction and risk of cardiovascular disease in patients with MG.