A High-Quality Blue Whale Genome, Segmental Duplications, and Historical Demography.

The blue whale, Balaenoptera musculus, is the largest animal known to have ever existed, making it an important case study in longevity and resistance to cancer. To further this and other blue whale-related research, we report a reference-quality, long-read-based genome assembly of this fascinating species. We assembled the genome from PacBio long reads and utilized Illumina/10×, optical maps, and Hi-C data for scaffolding, polishing, and manual curation. We also provided long read RNA-seq data to facilitate the annotation of the assembly by NCBI and Ensembl. Additionally, we annotated both haplotypes using TOGA and measured the genome size by flow cytometry. We then compared the blue whale genome with other cetaceans and artiodactyls, including vaquita (Phocoena sinus), the world's smallest cetacean, to investigate blue whale's unique biological traits. We found a dramatic amplification of several genes in the blue whale genome resulting from a recent burst in segmental duplications, though the possible connection between this amplification and giant body size requires further study. We also discovered sites in the insulin-like growth factor-1 gene correlated with body size in cetaceans. Finally, using our assembly to examine the heterozygosity and historical demography of Pacific and Atlantic blue whale populations, we found that the genomes of both populations are highly heterozygous and that their genetic isolation dates to the last interglacial period. Taken together, these results indicate how a high-quality, annotated blue whale genome will serve as an important resource for biology, evolution, and conservation research.

Prognostic value of genomic mutation signature associated with immune microenvironment in southern Chinese patients with esophageal squamous cell carcinoma.

The genomic landscape of esophageal squamous cell cancer (ESCC), as well as its impact on the regulation of immune microenvironment, is not well understood. Thus, tumor samples from 92 patients were collected from two centers and subjected to targeted-gene sequencing. We identified frequently mutated genes, including TP53, KMT2C, KMT2D, LRP1B, and FAT1. The most frequent mutation sites were ALOX12B (c.1565C > T), SLX4 (c.2786C > T), LRIG1 (c.746A > G), and SPEN (c.6915_6917del) (6.5%). Pathway analysis revealed dysregulation of cell cycle regulation, epigenetic regulation, PI3K/AKT signaling, and NOTCH signaling. A 17-mutated gene-related risk model was constructed using random survival forest analysis and showed significant prognostic value in both our cohort and the validation cohort. Based on the Estimation of Stromal and Immune cells in Malignant Tumor tissues using Expression (ESTIMATE) algorithm, the Tumor Immune Dysfunction and Exclusion (TIDE) algorithm, and the MCPcounter algorithm, we found that the risk score calculated by the risk model was significantly correlated with stimulatory immune checkpoints (TNFSF4, ITGB2, CXCL10, CXCL9, and BTN3A1; p < 0.05). Additionally, it was significantly associated with markers that are important in predicting response to immunotherapy (CD274, IFNG, and TAMM2; p < 0.05). Furthermore, the results of immunofluorescence double staining showed that patients with high risk scores had a significantly higher level of M2 macrophage than those with low risk scores (p < 0.05). In conclusion, our study provides insights into the genomic landscape of ESCC and highlights the prognostic value of a genomic mutation signature associated with the immune microenvironment in southern Chinese patients with ESCC.

Oligo-residual disease in PD-1/PD-L1 inhibitor-treated metastatic non-small cell lung cancer: incidence, pattern of failure, and clinical value of local consolidative therapy.

OBJECTIVES: To investigate the feasibility and potential clinical value of local consolidative therapy (LCT) in PD-1/PD-L1 inhibitor-treated metastatic non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: PD-1/PD-L1 inhibitor-treated metastatic NSCLC patients with measurable disease in three academic centers were screened and those with adequate follow-up were included. Oligo-residual disease (ORD) was defined as residual tumors limited to three organs and five lesions evaluated at the best response among patients with partial response or stable disease after PD-1/PD-L1 inhibitors. Oligometastatic and multiple-metastatic disease (OMD/MMD) were similarly classified at baseline. Locoregional interventions, administered after effective treatment of PD-1/PD-L1 inhibitors and before initial disease progression, were defined as LCT. Patterns of initial progressive disease (PD) were classified as involving only residual sites (RP), only new sites (NP), or a combination of both (BP). RESULTS: Among the 698 patients included, ORD was documented in 73 (47.1%) of 155 patients with baseline OMD and 60 (11.0%) of 543 patients with baseline MMD. With a median follow-up of 31.0 (range, 6.0-53.0) months, 108 patients with ORD developed initial PD, with RP, NP, and BP occurring in 51 (47%), 23 (21.3%), and 34 (31.5%), respectively. Among the 133 patients with ORD, those receiving LCT (n = 43) had longer progression-free survival (HR = 0.58, 95% CI 0.40-0.85, p = 0.01) and overall survival (HR = 0.49, 95% CI 0.30-0.79, p < 0.0001). CONCLUSION: ORD occurs with a clinically relevant frequency among PD-1/PD-L1 inhibitor-treated metastatic NSCLC patients and LCT may provide extra survival benefits in those with ORD.

NGS-based Tissue-Blood TMB Comparison and Blood-TMB Monitoring in Stage-III Non-Small Cell Lung Cancer Treated with Concurrent Chemoradiotherapy.

In this study, we analyzed the blood-based TMB (b-TMB) and its dynamic changes in patients with locally advanced non-small cell lung cancer (LA-NSCLC) who received concurrent chemoradiotherapy. Baseline tissue and blood TMB from 15 patients showed a strong positive correlation (Pearson correlation = 0.937), and nearly all mutations were markedly reduced in the later course of treatment, indicating a treatment-related response. This study suggests that in patients with LA-NSCLC, b-TMB is a reliable biomarker, and its dynamic monitoring can help distinguish patients who might benefit most from the consolidated immunotherapy.

Diastereoselective Synthesis of Less Accessible Fluorine-Containing Acyclic Tetrasubstituted Stereocenters via Electrophilic Fluorination of ß,ß-Disubstituted Metalloenamines.

A stereocontrolled protocol was developed to construct less accessible fluorine-containing acyclic tetrasubstituted stereocenters bearing two sterically and electronically similar alkyl groups at the α-position of carbonyls. In this process, tBuOK-promoted stereospecific α-deprotonation of α,α-disubstituted N-tert-butanesulfinyl ketimines or NH deprotonation of ß,ß-disubstituted enesulfinamides generates geometry-defined multisubstituted metalloenamines, followed by stereoselective electrophilic fluorination with the N-fluoro ammonium salt of quinine, affording the acyclic α-fluorinated ketimines with excellent diastereoselectivities.

Enhancing biological signals and detection rates in single-cell RNA-seq experiments with cDNA library equalization.

Considerable effort has been devoted to refining experimental protocols to reduce levels of technical variability and artifacts in single-cell RNA-sequencing data (scRNA-seq). We here present evidence that equalizing the concentration of cDNA libraries prior to pooling, a step not consistently performed in single-cell experiments, improves gene detection rates, enhances biological signals, and reduces technical artifacts in scRNA-seq data. To evaluate the effect of equalization on various protocols, we developed Scaffold, a simulation framework that models each step of an scRNA-seq experiment. Numerical experiments demonstrate that equalization reduces variation in sequencing depth and gene-specific expression variability. We then performed a set of experiments in vitro with and without the equalization step and found that equalization increases the number of genes that are detected in every cell by 17-31%, improves discovery of biologically relevant genes, and reduces nuisance signals associated with cell cycle. Further support is provided in an analysis of publicly available data.

Noncovalent Association Thermodynamics of Turn-On Fluorescent Probes with Human Serum Albumin: Dual-Concentration Ratio Method.

Efficient quantification of the affinity of a drug and the targeted protein is critical for strategic drug design. Among the various molecules, turn-on fluorescent probes are the most promising signal transducers to reveal the binding strength and site-specificity of designed drugs. However, the conventional method of measuring the binding ability of turn-on fluorescent probes by using the fractional occupancy under the law of mass action is time-consuming and a massive sample is required. Here, we report a new method, called dual-concentration ratio method, for quantifying the binding affinity of fluorescent probes and human serum albumin (HSA). Temperature-dependent fluorescence intensity ratios of a one-to-one complex (L ⋅ HSA) for a turn-on fluorescent probe (L), e. g., ThT (thioflavin T) or DG (dansylglycine), with HSA at two different values of [L]0 /[HSA]0 under the constraint [HSA]0 >[L]0 were collected. The van't Hoff analysis on these association constants further resulted in the thermodynamic properties. Since only two samples at different [L]0 /[HSA]0 are required without the need of [L]0 /[HSA]0 at a wide range, the dual-concentration ratio method is an easy way to greatly reduce the amounts of fluorescent probes and proteins, as well as the acquisition time.

Real-Time Observation for Dynamic Oscillation during Self-Assembly and Clearance of Aß42.

The dynamic oscillation implicated in structural heterogeneity during the self-assembly of amyloid peptide 1-42 (Aß42) may play a crucial role in eliciting cellular responses. We developed a real-time monitoring platform to observe an oscillatory non-equilibrium interaction that dominated the Aß42 clearance by neuronal cells during interplay with an oscillator (lipopolysaccharide, LPS). Molecular dynamics studies indicated that the electrostatic and hydrophobic segments of LPS involved in the temporary heteromolecular association and slightly decelerated the intrinsic thermally-induced protein dynamics of Aß42. A bait-specific intervention strategy could temporarily slow down the self-propagation of Aß42 to extend the lifetime of autonomous oscillation and augment Aß42 clearance of neuronal cells. The lifetime increment of oscillation shows a bait concentration-dependent manner to reflect the non-equilibrium binding strength. This relationship may serve as a predictor for Alzheimer's disease drug discovery.

Critical Role of Trichloramine Interaction with Dichloramine for N-Nitrosamine Formation during Breakpoint Chlorination.

Breakpoint chlorination is prevalent in drinking water and potable reuse water treatment. Breakpoint chlorination enhances the formation of N-nitrosamines through reactions that form nitrosating agents. The most recent study suggests that nitroxyl (HNO) can react with free chlorine (HOCl) to form the nitrosyl chloride (ClNO) nitrosating agent but has not experimentally verified its importance in breakpoint chlorination. This study first assessed the formation of N-nitrosamines from model N-chloro-alkylamine precursors when they were added to a mixture of HOCl and HNO-derived nitrosating agents generated by chlorinating hydroxyurea. Results demonstrated negligible N-nitrosamine formation. Instead, we observed that the interaction of NCl3 with NHCl2 (total Cl2/total N molar ratio = 2.4-3:1) produced an intermediate capable of nitrosating N-chloro-alkylamines to N-nitrosamines at yields 8-fold higher to those observed in NHCl2 treatment alone, within a very short timescale (<3 min). We examined the stoichiometry of the reaction of NCl3 with NHCl2 using a UV-spectrum-based approach. Nitrosyl chloride was proposed as the key intermediate, likely formed alongside the reformation of NHCl2. Further isotopic experiments, byproduct measurements, and kinetic modeling supported the hypotheses. Modeling indicated that the reaction of NCl3 with NHCl2 explained ∼75% of NDMA formation during breakpoint chlorination. Because NCl3 is mainly derived from the reaction of HOCl with NHCl2, controlling NHCl2 (e.g., with additional treatment) is critical for minimizing nitrosamine formation in waters where breakpoint chlorination occurs.

Ronin is essential for embryogenesis and the pluripotency of mouse embryonic stem cells.

Pluripotency is a unique biological state that allows cells to differentiate into any tissue type. Here we describe a candidate pluripotency factor, Ronin, that possesses a THAP domain, which is associated with sequence-specific DNA binding and epigenetic silencing of gene expression. Ronin is expressed primarily during the earliest stages of murine embryonic development, and its deficiency in mice produces periimplantational lethality and defects in the inner cell mass. Conditional knockout of Ronin prevents the growth of ES cells while forced expression of Ronin allows ES cells to proliferate without differentiation under conditions that normally do not promote self-renewal. Ectopic expression also partly compensates for the effects of Oct4 knockdown. We demonstrate that Ronin binds directly to HCF-1, a key transcriptional regulator. Our findings identify Ronin as an essential factor underlying embryogenesis and ES cell pluripotency. Its association with HCF-1 suggests an epigenetic mechanism of gene repression in pluripotent cells.

In situ and real-time vibrational spectroscopic characterizations of the photodegradation of nitrite in the presence of methanediol.

Nitrite (NO2-) is one of the common salts in aqueous aerosols, and its photolytic products, nitric oxide (NO) and hydroxyl radical (OH), have potential for use in the oxidation of organic matter, such as dissolved formaldehyde, methanediol (CH2(OH)2), which is regarded as the precursor of atmospheric formic acid. In this work, the simulation of UVA irradiation in an aqueous mixture of NaNO2/CH2(OH)2 was carried out via continuous exposure with a 365 nm LED lamp, and the reaction evolutions were probed by in situ and real-time infrared and Raman spectroscopy, which provided multiplexity in the identification of the relevant species and the corresponding reaction evolution. Although performing infrared absorption measurements in aqueous solution seemed impracticable due to the strong interference of water, the multiplexity of the vibrational bands of parents and products in the non-interfered infrared regimes and the conjunction with Raman spectroscopy still make it possible to perform in situ and real-time characterization of the photolytic reaction in the aqueous phase, supplementary to chromatographic approaches. During the 365 nm irradiation, NO2- and CH2(OH)2 gradually decreased, concomitant with the formation of nitrous oxide (N2O) and formate (HCOO-) in the early period and carbonate (CO32-) in the late period, as revealed by the vibrational spectra. The losses or the gains of the aforementioned species increased with increases in the concentration of CH2(OH)2 and the irradiation flux of the 365 nm UV light. The ionic product HCOO- was also confirmed by ion chromatography, but oxalate (C2O42-) was absent in the vibrational spectra and ion chromatogram. The reaction mechanism is reasonably proposed on the basis of the evolutions of the aforementioned species and the predicted thermodynamic favorableness.

The perks of doing housework: Longitudinal associations with survival and underlying mechanisms.

BACKGROUND: Although the majority of existing literature has suggested positive effects of housework on older adults' health and survival rate, the underlying mechanisms of such effects remain unclear. To address potential mechanisms, the present study examined the association between older adults' housework engagement and days of survival across 14 years and tested three potential mediation pathways in this association. METHODS: Four thousand Hong Kong older adults (50% female; aged between 65 and 98 years) participated in a longitudinal study in which they reported initial housework engagement and health status across three domains (cognitive functioning, physical health, and mental health) at the baseline, and the numbers of days they survived over the subsequent 14-year period were recorded. Linear regression, Cox proportional hazard, and parallel mediation analyses were performed to examine the relationship between housework engagement and days survived, and the mediating effects of these three health factors. RESULTS: The results showed a positive association between housework engagement and days survived after controlling for demographic variables (age, sex, education, marital status, subjective social status, and living alone). Physical health and mental health, but not cognitive functioning, partially mediated the relationship between housework engagement and days survived. The findings suggest that doing housework may contribute to longer survival by improving older adults' physical and mental health. CONCLUSION: The current study confirms positive relations of housework with health and mortality among Hong Kong older adults. As the first study examining the relationships and mediation pathways between doing housework and survival in later life, the findings advance our understanding of the mechanisms underlying the positive association between housework and mortality and provide insights for future daily-life health-promotion interventions for older adults.

Clinical Study of Glutamine Combined with Early Enteral Nutrition Support on Nutritional Status of Gastric Cancer Patients Undergoing Neoadjuvant Chemotherapy.

Objective: To explore the clinical study of glutamine combined with early enteral nutrition support on the nutritional status of gastric cancer patients undergoing neoadjuvant chemotherapy. Methods: Divided into control and observation groups, a control group received routine enteral nutrition, while the observation group received an additional 0.5 g/kg/d of glutamine. The researchers measured nutritional indicators, immunoglobulins, T lymphocyte subsets, and stress indexes such as fasting blood sugar and C-reactive protein throughout the study. Results: Before nutritional support, there was no significant difference in the HGB, TP, and ALB levels. During nutritional support, however, the observation group began registering significantly higher levels of HGB, TP, and ALB, suggesting that glutamine intervention can improve the nutritional status of patients. Throughout the study, the CD4+ level showed a consistent increase in the observation group. The levels of IgA and IgG in the observation group also grew significantly higher. Both groups had higher blood glucose levels before nutritional support. However, on day 8 and day 15, the levels decreased. The observation group had significantly lower fasting blood glucose (FBG) levels than the control group. By day 15, the FBG levels in the observation group were close to normal. The CRP level showed a consistent decrease in the observation group compared to the control group on day 8 and day 15. Glutamine intervention appears to improve the stress capacity of gastric cancer patients undergoing neoadjuvant chemotherapy. Overall, the findings suggest that glutamine intervention in enteral nutrition can significantly improve immune function, nutritional status, and stress capacity in gastric cancer patients undergoing neoadjuvant chemotherapy and appears to be more effective than conventional enteral nutrition. Conclusion: The combination of glutamine and early enteral nutrition support can significantly improve gastric cancer patients undergoing neoadjuvant chemotherapy's nutritional status and immune function levels. It is a safe and reliable enteral nutrition support method worthy of clinical promotion.

Hesperetin ameliorates ischemia/hypoxia-induced myocardium injury via inhibition of oxidative stress, apoptosis, and regulation of Ca2+ homeostasis.

Ischemia/hypoxia (I/H)-induced myocardial injury has a large burden worldwide. Hesperetin (HSP) has a cardioprotective effect, but the molecular mechanism underlying this is not clearly established. Here, we focused on the protective mechanisms of HSP against I/H-induced myocardium injury. H9c2 cardiomyocytes were challenged with CoCl2 for 22 h to imitate hypoxia after treatment groups received HSP for 4 h. The viability of H9c2 cardiomyocytes was evaluated, and cardiac function indices, reactive oxygen species, apoptosis, mitochondrial membrane potential (MMP), and intracellular Ca2+ concentration ([Ca2+ ]i ) were measured. L-type Ca2+ current (ICa-L ), myocardial contraction, and Ca2+ transients in isolated ventricular myocytes were also recorded. We found that HSP significantly increased the cell viability, and MMP while significantly decreasing cardiac impairment, oxidative stress, apoptosis, and [Ca2+ ]i caused by CoCl2 . Furthermore, HSP markedly attenuated ICa-L , myocardial contraction, and Ca2+ transients in a concentration-dependent manner. Our findings suggest a protective mechanism of HSP on I/H-induced myocardium injury by restoring oxidative balance, inhibiting apoptosis, improving mitochondrial function, and reducing Ca2+ influx via L-type Ca2+ channels (LTCCs). These data provide a new direction for HSP applied research as a LTCC inhibitor against I/H-induced myocardium injury.

Inadvertent perioperative hypothermia and surgical site infections after liver resection.

BACKGROUND: In the overall surgical population, inadvertent perioperative hypothermia has been associated with an increased incidence of surgical site infection (SSI). However, recent clinical trials did not validate this notion. This study aimed to investigate the potential correlation between inadvertent perioperative hypothermia and SSIs following liver resection. METHODS: This retrospective cohort study included all consecutive patients who underwent liver resection between January 2019 and December 2021 at the First Affiliated Hospital, Zhejiang University School of Medicine. Perioperative temperature managements were implemented for all patients included in the analysis. Estimated propensity score matching (PSM) was performed to reduce the baseline imbalances between the normothermia and hypothermia groups. Before and after PSM, univariate analyses were performed to evaluate the correlation between hypothermia and SSI. Multivariate regression analysis was performed to determine whether hypothermia was an independent risk factor for postoperative transfusion and major complications. Subgroup analyses were performed for diabetes mellitus, age > 65 years, and major liver resection. RESULTS: Among 4000 patients, 2206 had hypothermia (55.2%), of which 150 developed SSI (6.8%). PSM yielded 1434 individuals in each group. After PSM, the hypothermia and normothermia groups demonstrated similar incidence rates of SSI (6.3% vs. 7.0%, P = 0.453), postoperative transfusion (13.3% vs. 13.7%, P = 0.743), and major complications (9.0% vs. 10.1%, P = 0.309). Univariate regression analysis revealed no significant effects of hypothermia on the incidence of SSI in the group with the highest hypothermia exposure [odds ratio (OR) = 1.25, 95% confidence interval (CI): 0.84-1.87, P = 0.266], the group with moderate exposure (OR = 1.00, 95% CI: 0.65-1.53, P = 0.999), or the group with the lowest exposure (OR = 1.11, 95% CI: 0.73-1.65, P = 0.628). The subgroup analysis revealed similar results. Regarding liver function, patients in the hypothermia group demonstrated lower γ-glutamyl transpeptidase (37 vs. 43 U/L, P = 0.001) and alkaline phosphatase (69 vs. 72 U/L, P = 0.016). However, patients in the hypothermia group exhibited prolonged activated partial thromboplastin time (29.2 vs. 28.6 s, P < 0.01). CONCLUSIONS: In our study of patients undergoing liver resection, we found no significant association between mild perioperative hypothermia and SSI. It might be due to the perioperative temperature managements, especially active warming measures, which limited the impact of perioperative hypothermia on the occurrence of SSI.

Rapid changes in chromatin structure during dedifferentiation of primary hepatocytes in vitro.

Primary hepatocytes are widely used in the pharmaceutical industry to screen drug candidates for hepatotoxicity, but hepatocytes quickly dedifferentiate and lose their mature metabolic function in culture. Attempts have been made to better recapitulate the in vivo liver environment in culture, but the full spectrum of signals required to maintain hepatocyte function ex vivo remains elusive. To elucidate molecular changes that accompany, and may contribute to dedifferentiation of hepatocytes ex vivo, we performed lineage tracing and comprehensive profiling of alterations in their gene expression profiles and chromatin landscape during culture. First, using genetically tagged hepatocytes we demonstrate that expression of the fetal gene alpha-fetoprotein in cultured hepatocytes comes from cells that previously expressed the mature gene albumin, and not from a population of albumin-negative precursor cells, proving mature hepatocytes undergo true dedifferentiation in culture. Next we studied the dedifferentiation process in detail through bulk RNA-sequencing of hepatocytes cultured over an extended period. We identified three distinct phases of dedifferentiation: an early phase, where mature hepatocyte genes are rapidly downregulated in a matter of hours; a middle phase, where fetal genes are activated; and a late phase, where initially rare contaminating non-parenchymal cells proliferate, taking over the culture. Lastly, to better understand the signaling events that result in the rapid downregulation of mature genes in hepatocytes, we examined changes in chromatin accessibility in these cells during the first 24 h of culture using Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq). We find that drastic and rapid changes in chromatin accessibility occur immediately upon the start of culture. Using binding motif analysis of the areas of open chromatin sharing similar temporal profiles, we identify several candidate transcription factors potentially involved in the dedifferentiation of primary hepatocytes in culture.

Caution against simultaneous integrated boost radiotherapy for upper thoracic esophageal squamous cell carcinoma: results from a single-arm phase II trial.

PURPOSE: To explore the feasibility and safety of simultaneous integrated boost technology (SIB) with elective nodal irradiation (ENI) to the cervical and upper mediastinal lymph node (LN) regions in upper thoracic esophageal squamous cell carcinoma (ESCC). MATERIAL AND METHODS: Patients with pathologically proven unresectable upper thoracic ESCC were assigned 50.4 Gy/28 fractions (F) to the clinical target volume (encompassing the ENI area of cervical and upper mediastinal LN regions) and a boost of 63 Gy/28 F to the gross tumor volume. Chemotherapy consisted of courses of concurrent cisplatin (20 mg/m2) and docetaxel (20 mg/m2) weekly for 6 weeks. The primary endpoint was toxicity. RESULTS: Between Jan 2017 and Dec 2019, 28 patients were included. The median follow-up time for all patients was 24.6 months (range 1.9-53.5). Radiation-related acute toxicity included esophagitis, pneumonia and radiodermatitis, all of which were well managed and reversed. Late morbidity included esophageal ulcer, stenosis, fistula and pulmonary fibrosis. Grade III esophageal stenosis and fistula was seen in 11% (3/28) and 14% (4/28) patients, respectively. The cumulative incidence rate of late esophageal toxicity was 7.7%, 19.2% and 24.6% at 6, 12 and 18 months, respectively. There was significant difference of the occurrence of severe late esophageal toxicity among the different volume levels of the esophagus, and cervical and upper mediastinal LNs which received ≥ 63 Gy stratified by the tertiles (p = 0.014). CONCLUSIONS: Despite the acceptably tolerated acute toxicity of SIB in concurrent CRT with ENI to the cervical and upper mediastinal LN regions for upper thoracic ESCC, the incidence of severe late esophageal toxicity was relatively high. Cautions are provided against easy clinical application of SIB (50.4 Gy/28F to the CTV, 63 Gy/28F to the GTV) in upper thoracic ESCC. Further exploration on dose optimization is warranted.

Roles of functional lipids in bacteriorhodopsin photocycle in various delipidated purple membranes.

Purple membrane (PM) is composed of several native lipids and the transmembrane protein bacteriorhodopsin (bR) in trimeric configuration. The delipidated PM (dPM) samples can be prepared by treating PM with CHAPS (3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate) to partially remove native lipids while maintaining bR in the trimeric configuration. By correlating the photocycle kinetics of bR and the exact lipid compositions of the various dPM samples, one can reveal the roles of native PM lipids. However, it is challenging to compare the lipid compositions of the various dPM samples quantitatively. Here, we utilize the absorbances of extracted retinal at 382 nm to normalize the concentrations of the remaining lipids in each dPM sample, which were then quantified by mass spectrometry, allowing us to compare the lipid compositions of different samples in a quantitative manner. The corresponding photocycle kinetics of bR were probed by transient difference absorption spectroscopy. We found that the removal rate of the polar lipids follows the order of BPG ≈ GlyC < S-TGD-1 ≈ PG < PGP-Me ≈ PGS. Since BPG and GlyC have more nonpolar phytanyl groups than other lipids at the hydrophobic tail, causing a higher affinity with the hydrophobic surface of bR, the corresponding removal rates are slowest. In addition, as the reaction period of PM and CHAPS increases, the residual amounts of PGS and PGP-Me significantly decrease, in concomitance with the decelerated rates of the recovery of ground state and the decay of intermediate M, and the reduced transient population of intermediate O. PGS and PGP-Me are the lipids with the highest correlation to the photocycle activity among the six polar lipids of PM. From a practical viewpoint, combining optical spectroscopy and mass spectrometry appears a promising approach to simultaneously track the functions and the concomitant active components in a given biological system.

Overall survival benefit of osimertinib and clinical value of upfront cranial local therapy in untreated EGFR-mutant nonsmall cell lung cancer with brain metastasis.

Osimertinib, as a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), showed more potent efficacy against brain metastasis (BM) in untreated EGFR-mutant nonsmall cell lung cancer (NSCLC) in the FLAURA study. However, the overall survival (OS) benefit of osimertinib and clinical value of cranial local therapy (CLT) in these patients remain undetermined. Here we conducted a retrospective study involving untreated EGFR-mutant NSCLC patients with BMs receiving first-line osimertinib or first-generation EGFR-TKIs. Upfront CLT was defined as CLT performed before disease progression to the first-line EGFR-TKIs. Pattern of treatment failure and survival outcomes were extensively investigated. Among the 367 patients enrolled, first-generation EGFR-TKI was administered in 265, osimertinib in 102 and upfront CLT performed in 140. Patients receiving osimertinib had more (P < .001) and larger BMs (P = .003) than those receiving first-generation EGFR-TKIs. After propensity score matching, osimertinib was found to prolong OS (37.7 vs 22.2 months, P = .027). Pattern of failure analyses found that 51.8% of the patients without upfront CLT developed their initial progressive disease (PD) in the brain and 59.0% of the cranial PD occurred at the original sites alone, suggesting potential clinical value of upfront CLT. Indeed, upfront stereotactic radiosurgery (SRS) and/or surgery was associated with improved OS among those receiving first-generation EGFR-TKIs (P = .019) and those receiving osimertinib (P = .041). In summary, compared to first-generation EGFR-TKIs, osimertinib is associated with improved OS in untreated EGFR-mutant NSCLC with BMs. Meanwhile, upfront SRS and/or surgery may provide extra survival benefit, which needs to be verified in future studies.

A brief report on incidence, radiographic feature and prognostic significance of brain MRI changes after anti-PD-1/PD-L1 therapy in advanced non-small cell lung cancer.

INTRODUCTION: Neurologic immune-related adverse events (nirAEs) are uncommon but potentially lethal complications of immune checkpoint inhibitor (ICI) treatment. However, the incidence, radiographic features and prognostic significance of brain magnetic resonance imaging (MRI) changes after ICI treatment remain largely unknown. METHODS: Consecutive patients with advanced non-small cell lung cancer (NSCLC) at three participating institutions receiving anti-PD-1/PD-L1 therapy from June 2017 to September 2020 were screened, and those who received brain MRI within 6 weeks before ICI initiation and at least one follow-up brain MRI after ICI treatment were included. Serial brain MRI images were independently reviewed by two experienced radiologists. RESULTS: With a median follow-up of 13.2 months, 27 (20.0%) of the 135 enrolled patients developed certain kind of brain MRI aberration. The 1-, 2- and 3-year cumulative incidence of brain MRI aberration was 17.1%, 36.3% and 52.2%, respectively. Brain MRI aberration indicative of stroke, mimicking typical white matter lesions and presenting as T2-hyperintensity suggestive of CNS vasculitis or encephalitis, was documented in 11, 9 and 4 patients, respectively. Patients with brain MRI aberration had higher clinical benefit rate (p = 0.030), longer progression-free survival (p = 0.015) and a tendency of improved overall survival (p = 0.054). CONCLUSIONS: Brain MRI aberrations developed after ICI treatment are not uncommon, and their manifestations vary a lot. Patients developing brain MRI aberrations tended to have better prognosis, which needed to be further investigated.