ED50 of remimazolam combined with different doses butorphanol for first trimester artificial abortion.

Introduction: Remimazolam (RMZ) is a novel intravenous sedative drug of ultra-short benzodiazepine. The optimal dose of RMZ plus butorphanol for sedation during first trimester artificial abortion is unknown. Therefore, the present study aimed to evaluate the median effective dose (ED50) of RMZ combined with different doses of butorphanol on the sedative effect for first-trimester artificial abortion. Methods: Sixty-one female patients were randomly assigned to Group B10 (31 patients) and Group B15 (30 patients). RMZ was administered 5 min after IV butorphanol at doses of 10 µg/kg (Group B10) and 15 µg/kg (Group B15). Cervical dilatation at the time of using a cervical dilating rod, if the patient has body movement and affects the gynecologist's operation, we define it as "Ineffective." Therefore, the dose of RMZ was increased in the next patient. Otherwise, it was defined as "Effective," and the dose of RMZ was reduced in the next patient. According to the pre-experiment, the first dose of RMZ in the first patient was 0.35 mg/kg, and the adjacent geometric dose ratio was 0.9. The centered isotonic regression was performed to determine the ED50 of RMZ. The total RMZ dose administered, recovery time, and anesthesia-related adverse events were all recorded. Results: The ED50 (90% CI) of RMZ was 0.263 (0.215-0.310) mg/kg in Group B10, and 0.224 (0.191-0.261) mg/kg in Group B15, respectively. The recovery time in Group B10 was significantly shorter than in Group B15 (9.8 ± 2.3 vs. 12.5 ± 3.6 min, p ≤ 0.001). There was no significant difference in the incidence rate of all anesthesia-related adverse events between the two groups (p > 0.05). Conclusion: The ED50 of RMZ combined with a 10 µg/kg or 15 µg/kg dose of butorphanol was 0.263 and 0.224 mg/kg during painless first trimester artificial abortion. However, RMZ combined with a 10 µg/kg dose of butorphanol seems to have a shorter recovery time. Clinical trial registration: https://www.chictr.org.cn/bin/project/edit?pid=166623.

Incorporation of Multiple ß2-Hydroxy Acids into a Protein In Vivo Using an Orthogonal Aminoacyl-tRNA Synthetase.

The programmed synthesis of sequence-defined biomaterials whose monomer backbones diverge from those of canonical α-amino acids represents the next frontier in protein and biomaterial evolution. Such next-generation molecules provide otherwise nonexistent opportunities to develop improved biologic therapies, bioremediation tools, and biodegradable plastic-like materials. One monomer family of particular interest for biomaterials includes ß-hydroxy acids. Many natural products contain isolated ß-hydroxy acid monomers, and polymers of ß-hydroxy acids (ß-esters) are found in polyhydroxyalkanoate (PHA) polyesters under development as bioplastics and drug encapsulation/delivery systems. Here we report that ß2-hydroxy acids possessing both (R) and (S) absolute configuration are substrates for pyrrolysyl-tRNA synthetase (PylRS) enzymes in vitro and that (S)-ß2-hydroxy acids are substrates in cellulo. Using the orthogonal MaPylRS/MatRNAPyl synthetase/tRNA pair, in conjunction with wild-type E. coli ribosomes and EF-Tu, we report the cellular synthesis of model proteins containing two (S)-ß2-hydroxy acid residues at internal positions. Metadynamics simulations provide a rationale for the observed preference for the (S)-ß2-hydroxy acid and provide mechanistic insights that inform future engineering efforts. As far as we know, this finding represents the first example of an orthogonal synthetase that acylates tRNA with a ß2-hydroxy acid substrate and the first example of a protein hetero-oligomer containing multiple expanded-backbone monomers produced in cellulo.

Prediction of ventilator weaning failure in postoperative cardiac surgery patients using vasoactive-ventilation-renal score and nomogram analysis.

Objective: This study evaluated the predictive value of the vasoactive-ventilation-renal (VVR) score in identifying the risk of weaning failure after cardiac surgery and developing a nomogram model to help physicians improve the success rate of weaning from mechanical ventilation in adult patients undergoing postoperative cardiac surgery. Methods: Clinical data were retrospectively collected from adult patients who underwent extracorporeal circulation cardiac surgery at the First Affiliated Hospital of Nanjing Medical University between August 2022 and April 2023 and who were subsequently transferred to the Intensive Care Unit (ICU) and treated with vasoactive drugs. Patients were divided into successful and unsuccessful weaning groups based on first-attempt weaning success. Variable selection was regularized using univariate logistic regression and Least absolute shrinkage and selection operator (LASSO) regularization. Multivariate logistic regression was performed to identify predictors and a nomogram was created to predict the risk of weaning failure. Results: A total of 519 patients were included in the study. After selecting multiple stepwise variables, the VVR score before weaning, the modified Sequential Organ Failure Assessment (mSOFA) score on weaning day, and mechanical ventilation duration before weaning were determined as predictive indicators of weaning failure in adult patients after cardiac surgery. The optimal cut-off values for these indicators were 18.46 points, 4.33 points, and 20.50 h, respectively. The predictive model constructed using these three factors demonstrated good predictive performance. Conclusions: The VVR score before weaning accurately predicts the probability of weaning failure in adult patients after cardiac surgery. The weaning risk-predictive nomogram model, established based on the VVR score, mSOFA score, and mechanical ventilation duration before weaning, demonstrated robust predictive ability.

REXO2 up-regulation is positively correlated with poor prognosis and tumor immune infiltration in hepatocellular carcinoma.

BACKGROUND: As a homologous counterpart to the prokaryotic oligonuclease found in the cellular cytoplasm and mitochondrion, REXO2 assumes a pivotal role in the maintenance of mitochondrial homeostasis. Nevertheless, the precise functions and mechanisms by which REXO2 operates within the context of hepatocellular carcinoma (HCC) have hitherto remained unexamined. METHODS: The expression levels of REXO2 in HCC tissues were evaluated through the utilization of the immunohistochemical (IHC) method, and subsequently, the association between REXO2 expression and the clinicopathological characteristics of HCC patients was scrutinized employing the χ2 test. A battery of experimental assays, encompassing CCK8 viability assessment, cell colony formation, wound healing, and transwell assays, were conducted with the aim of elucidating the biological role of REXO2 within HCC cells. Complementary bioinformatics analyses were undertaken to discern potential correlations between REXO2 and immune infiltration in tumor tissues. RESULTS: Our IHC findings have unveiled a notable up-regulation of REXO2 within HCC tissues, and this heightened expression bears the status of an independent prognostic factor, portending an adverse outcome for HCC patients (P < 0.05). Upon the attenuation of REXO2 expression, a discernible reduction in the rates of proliferation, invasion and migration of HCC cells ensued (P < 0.05). Furthermore, transcriptome sequencing analysis has provided insights into the putative influence of REXO2 on the development of HCC through the modulation of TNF and NF-κB signaling pathways. Additionally, our bioinformatics analyses have demonstrated a positive correlation between REXO2 and tumor immune cell infiltration, as well as immune checkpoint CTLA-4. CONCLUSIONS: In summation, our results posit an association between the up-regulation of REXO2 and adverse prognostic outcomes, alongside the involvement of immune-related signaling pathways and tumor immune infiltration within the realm of HCC.

Stop-Codon Readthrough in Therapeutic Protein Candidates Expressed from Mammalian Cells.

Stop codon readthroughs were examined in 48 recombinant therapeutic protein candidates produced from multiple clones of Chinese hamster ovary cells, using peptide mapping with LC-MS/MS detection. We found that stop codon readthrough is a common phenomenon occurring in most of these candidates, with levels varying from below the detection limit of ∼0.001 % to ∼1 %. The readthrough propensity depends on the stop codon being used, as well as the nucleotides surrounding it. The amino acids misincorporated into the stop position can be well-predicted by a third-base wobble mismatch and a first-base U/G mismatch during codon recognition, i.e., tyrosine or glutamine insertion for the UAA and UAG stop codons, and tryptophan, cysteine or arginine insertion for the UGA stop codon. Data shown in this report demonstrate the importance of optimizing the DNA sequence near the stop codon, and the importance of detecting stop codon readthroughs during the development of a therapeutic product.

Predicting colorectal cancer risk: a novel approach using anemia and blood test markers.

Background and objectives: Colorectal cancer remains an important public health problem in the context of the COVID-19 (Corona virus disease 2019) pandemic. The decline in detection rates and delayed diagnosis of the disease necessitate the exploration of novel approaches to identify individuals with a heightened risk of developing colorectal cancer. The study aids clinicians in the rational allocation and utilization of healthcare resources, thereby benefiting patients, physicians, and the healthcare system. Methods: The present study retrospectively analyzed the clinical data of colorectal cancer cases diagnosed at the Affiliated Hospital of Guilin Medical University from September 2022 to September 2023, along with a control group. The study employed univariate and multivariate logistic regression as well as LASSO (Least absolute shrinkage and selection operator) regression to screen for predictors of colorectal cancer risk. The optimal predictors were selected based on the area under the curve (AUC) of the receiver operating characteristic (ROC) curve. These predictors were then utilized in constructing a Nomogram Model for predicting colorectal cancer risk. The accuracy of the risk prediction Nomogram Model was assessed through calibration curves, ROC curves, and decision curve analysis (DCA) curves. Results: Clinical data of 719 patients (302 in the case group and 417 in the control group) were included in this study. Based on univariate logistic regression analysis, there is a correlation between Body Mass Index (BMI), red blood cell count (RBC), anemia, Mean Corpuscular Volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), platelet count (PLT), Red Cell Distribution Width-Standard Deviation (RDW-SD), and the incidence of colorectal cancer. Based on the findings of multivariate logistic regression analysis, the variables of BMI and RBC exhibit a decrease, while anemia and PLT demonstrate an increase, all of which are identified as risk factors for the occurrence of colorectal cancer. LASSO regression selected BMI, RBC, anemia, and PLT as prediction factors. LASSO regression and multivariate logistic regression analysis yielded the same results. A nomogram was constructed based on the 4 prediction factors identified by LASSO regression analysis to predict the risk of colorectal cancer. The AUC of the nomogram was 0.751 (95% CI, OR: 0.708-0.793). The calibration curves in the validation and training sets showed good performance, indicating that the constructed nomogram model has good predictive ability. Additionally, the DCA demonstrated that the nomogram model has diagnostic accuracy. Conclusion: The Nomogram Model offers precise prognostications regarding the likelihood of Colorectal Cancer in patients, thereby helping healthcare professionals in their decision-making processes and promoting the rational categorization of patients as well as the allocation of medical resources.

Complex multi-dimensional integration for T2* and R2* mapping.

A dual Multi-Dimensional Integration (dMDI) method was proposed and demonstrated for T2* and R2* mapping. By constructing and jointly using both the original MDI term and an inversed MDI term, T2* and R2* mapping can be performed independently with intrinsic background noise suppression and spike elimination, allowing for high quantitative accuracy and robustness over a wide range of T2*. dMDI was compared to original MDI and curve fitting methods in terms of quantitative specificity, accuracy, reliability and computational efficiency. All methods were tested and compared via simulation and in vivo data. With high signal-to-noise-ratio (SNR), the proposed dMDI method yielded T2*and R2* values similar to curve fitting methods. For low SNR and background noise signals, the dMDI yielded low T2* and R2* values, thus effectively suppressing all background noise. Virtually zero spikes were observed in dMDI T2* and R2* maps in all simulation and imaging results. The dMDI method has the potential to provide improved and reliable T2* and R2* mapping results in routine and SNR-challenging scenarios.

PS5-Net: a medical image segmentation network with multiscale resolution.

Purpose: In recent years, the continuous advancement of convolutional neural networks (CNNs) has led to the widespread integration of deep neural networks as a mainstream approach in clinical diagnostic support. Particularly, the utilization of CNN-based medical image segmentation has delivered favorable outcomes for aiding clinical diagnosis. Within this realm, network architectures based on the U-shaped structure and incorporating skip connections, along with their diverse derivatives, have gained extensive utilization across various medical image segmentation tasks. Nonetheless, two primary challenges persist. First, certain organs or tissues present considerable complexity, substantial morphological variations, and size discrepancies, posing significant challenges for achieving highly accurate segmentation. Second, the predominant focus of current deep neural networks on single-resolution feature extraction limits the effective extraction of feature information from complex medical images, thereby contributing to information loss via continuous pooling operations and contextual information interaction constraints within the U-shaped structure. Approach: We proposed a five-layer pyramid segmentation network (PS5-Net), a multiscale segmentation network with diverse resolutions that is founded on the U-Net architecture. Initially, this network effectively leverages the distinct features of images at varying resolutions across different dimensions, departing from prior single-resolution feature extraction methods to adapt to intricate and variable segmentation scenarios. Subsequently, to comprehensively integrate feature information from diverse resolutions, a kernel selection module is proposed to assign weights to features across different dimensions, enhancing the fusion of feature information from various resolutions. Within the feature extraction network denoted as PS-UNet, we preserve the classical structure of the traditional U-Net while enhancing it through the incorporation of dilated convolutions. Results: PS5-Net attains a Dice score of 0.9613 for liver segmentation on the CHLISC dataset and 0.8587 on the ISIC2018 dataset for skin lesion segmentation. Comparative analysis with diverse medical image segmentation methodologies in recent years reveals that PS5-Net has achieved the highest scores and substantial advancements. Conclusions: PS5-Net effectively harnesses the rich semantic information available at different resolutions, facilitating a comprehensive and nuanced understanding of the input medical images. By capitalizing on global contextual connections, the network adeptly captures the intricate interplay of features and dependencies across the entire image, resulting in more accurate and robust segmentation outcomes. The experimental validation of PS5-Net underscores its superior performance in medical image segmentation tasks, offering promising prospects for enhancing diagnostic and analytical processes within clinical settings. These results highlight the potential of PS5-Net to significantly contribute to the advancement of medical imaging technologies and ultimately improve patient care through more precise and reliable image analysis.

Genome-Wide Studies of FH Family Members in Soybean (Glycine max) and Their Responses under Abiotic Stresses.

Formins or formin homology 2 (FH2) proteins, evolutionarily conserved multi-domain proteins in eukaryotes, serve as pivotal actin organizers, orchestrating the structure and dynamics of the actin cytoskeleton. However, a comprehensive investigation into the formin family and their plausible involvement in abiotic stress remains undocumented in soybean (Glycine max). In the current study, 34 soybean FH (GmFH)family members were discerned, their genomic distribution spanning the twenty chromosomes in a non-uniform pattern. Evolutionary analysis of the FH gene family across plant species delineated five discernible groups (Group I to V) and displayed a closer evolutionary relationship within Glycine soja, Glycine max, and Arabidopsis thaliana. Analysis of the gene structure of GmFH unveiled variable sequence lengths and substantial diversity in conserved motifs. Structural prediction in the promoter regions of GmFH gene suggested a large set of cis-acting elements associated with hormone signaling, plant growth and development, and stress responses. The investigation of the syntenic relationship revealed a greater convergence of GmFH genes with dicots, indicating a close evolutionary affinity. Transcriptome data unveiled distinctive expression patterns of several GmFH genes across diverse plant tissues and developmental stages, underscoring a spatiotemporal regulatory framework governing the transcriptional dynamics of GmFH gene. Gene expression and qRT-PCR analysis identified many GmFH genes with a dynamic pattern in response to abiotic stresses, revealing their potential roles in regulating plant stress adaptation. Additionally, protein interaction analysis highlighted an intricate web of interactions among diverse GmFH proteins. These findings collectively underscore a novel biological function of GmFH proteins in facilitating stress adaptation in soybeans.

Effects of DeSUMOylated Spastin on AMPA Receptor Surface Delivery and Synaptic Function Are Enhanced by Phosphorylating at Ser210.

Surface trafficking of AMPA receptors (AMPARs) is one of the important mechanisms mediating synaptic plasticity which is essential for cognitive functions such as learning and memory. Spastin, as a novel binding partner for the AMPAR, has been reported to regulate AMPAR surface expression and synaptic function. Additionally, Spastin undergoes two posttranslational modifications, phosphorylation and SUMOylation, both of which are crucial for synaptic function. However, gaps exist in our knowledge of how Spastin phosphorylation cross-talks with its SUMOylation in the regulation of AMPAR surface expression and synaptic function. Here, we reported that deSUMOylation of Spastin at Lys427 increased the surface level of AMPAR GluA2 subunit, the amplitude and frequency of miniature excitatory synaptic currents (mEPSC), and facilitated the morphological maturation of dendritic spines in cultured hippocampal neurons. Further studies demonstrated that Spastin phosphorylation at Ser210 further increased the enhancement of GluA2 surface expression and synaptic function by deSUMOylated Spastin, while dephosphorylation had the opposite effect. Simultaneously, deSUMOylation at Lys427 significantly increased the promoting effect of Spastin phosphorylation on synaptic function. In conclusion, our study suggests that cooperative interactions between phosphorylated and deSUMOylated Spastin are novel pathways to enhance synaptic function.

The causal relationship between bacterial pneumonia and diabetes: a two-sample mendelian randomization study.

BACKGROUND: Previous observational studies have established the high prevalence of bacterial pneumonia in diabetic patients, which in turn leads to increased mortality. However, the presence of a causal connection between bacterial pneumonia and diabetes remains unobserved. METHODS: We chose genome-wide significant (Ρ < 1 × 10-5 and Ρ < 1 × 10-6) and independent (r2 < 0.001) single-nucleotide polymorphisms (SNPs) as instrumental variables (IVs) to proceed a bidirectional two-sample MR study. The extracted SNPs explored the relationship between bacterial pneumonia and diabetes by Inverse variance weighted (IVW), MR-Egger, and weighted median methods. In addition, we conducted the Heterogeneity test, the Pleiotropy test, MR-presso and the Leave-one-out (LOO) sensitivity test to validate the reliability of results. RESULTS: In an MR study with bacterial pneumonia as an exposure factor, four different types of diabetes as outcome. It was observed that bacterial pneumonia increases the incidence of GDM (OR = 1.150 (1.027-1.274, P = 0.011) and T1DM (OR = 1.277 (1.024-1.531), P = 0.016). In the reverse MR analysis, it was observed that GDM (OR = 1.112 (1.023-1.201, P = 0.009) is associated with an elevated risk of bacterial pneumonia. However, no significant association was observed bacterial pneumonia with T1DM and other types of diabetes (P > 0.05). CONCLUSION: This study utilizing MR methodology yields robust evidence supporting a bidirectional causal association between bacterial pneumonia and GDM. Furthermore, our findings suggest a plausible causal link between bacterial pneumonia and T1DM.

The median effective dose of propofol combined with butorphanol during artificial abortion: a randomized controlled trial.

Objective: Propofol-opioids are the most common drug combination and can reduce the dose of propofol and the incidence of adverse events in painless artificial abortion. We hypothesized that butorphanol may reduce the median effective dose (ED50) of propofol, propofol injection pain, and postoperative uterine contraction pain. Methods: This was a randomized, double-blind, controlled study. A total of 54 female patients, who had ASA I or II, aged 18-49 years, undergoing painless artificial abortion, were randomly assigned into two groups, namely, Group P (propofol) and Group PB (propofol plus 10 µg/kg butorphanol). According to the pre-experiment, the initial dose of propofol for the P and PB groups was 3 and 2.5 mg/kg, respectively, with a dose gradient of 0.25 mg/kg. The ED50 of propofol was analyzed using probit regression analysis. The total propofol dose consumed, recovery time, and anesthesia-related adverse events were also recorded. Results: There were 25 and 29 patients in the P and PB groups, respectively. The ED50 (95% CI) of propofol for artificial abortion were 2.477 (2.186-2.737) and 1.555 (1.173-1.846) mg/kg in the P and PB groups, respectively. The total propofol dose consumed was (150.7 ± 21.7) mg and (110.4 ± 28.2) mg in the P and PB groups, respectively (P < 0.001). Compared with the P group, injection-site pain (76 vs. 20.7%) and uterine contraction pain (72 vs. 6.9%) in the PB group had a significant decrease (P < 0.001). Conclusion: Combination of propofol with 10 µg/kg butorphanol reduced the ED50 of propofol and decreased the incidence of propofol injection-site pain and postoperative uterine contraction pain during painless artificial abortion compared with propofol alone. Clinical trial registration: https://www.chictr.org.cn/showproj.html?proj=166610, identifier: ChiCTR2200059795.

Circular RNA circRANGAP1/miR-512-5p/SOD2 Axis Regulates Cell Proliferation and Migration in Non-small Cell Lung Cancer (NSCLC).

Non-small cell lung cancer (NSCLC) is the most prevalent histology type of lung cancer worldwide, accounting for 18% of total cancer-related deaths estimated by GLOBOCAN in 2020. CircRNAs have emerged as potent regulators of NSCLC development. CircRANGAP1 (hsa_circ_0001235/hsa_circ_0063526) is a potential biomarker for NSCLC identified by microarray dataset analysis. Here, we investigated the biological functions of circRANGAP1 in NSCLC development and elucidated the associated competing endogenous RNA (ceRNA) mechanisms. We found that circRANGAP1 expression was upregulated in NSCLC tissues and cells, which was inversely correlated with carcinogenesis and poor clinical outcome of NSCLC patients. CircRANGAP1 knockdown inhibited NSCLC migration by regulating miR-512-5p/SOD2 axis. In conclusion, circRANGAP1 facilitated NSCLC tumorigenesis and development by sponging miR-512-5p to upregulate SOD2 expression. Suppression of circRANGAP1 expression by si-circRANGAP1 treatment could be a strategy to inhibit NSCLC development and metastasis.

Investigating the impact of human blood metabolites on the Sepsis development and progression: a study utilizing two-sample Mendelian randomization.

Background: Existing data suggests a potential link between human blood metabolites and sepsis, yet the precise cause-and-effect relationship remains elusive. By using a two-sample Mendelian randomization (MR) analysis, this study aims to establish a causal link between human blood metabolites and sepsis. Methods: A two-sample MR analysis was employed to investigate the relationship between blood metabolites and sepsis. To assess the causal connection between sepsis and human blood metabolites, five different MR methods were employed, A variety of sensitivity analyses were conducted, including Cochrane's Q test, MR-Egger intercept test, MR-PRESSO and leave-one-out (LOO) analysis. In order to ensure the robustness of the causal association between exposure and outcome, the Bonferroni adjustment was employed. Additionally, we conducted analyses of the metabolic pathways of the identified metabolites using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and the Small Molecule Pathway Database (SMPDB) database. Results: The MR analysis revealed a total of 27 metabolites (16 known and 11 unknown) causally linked to the development and progression of sepsis. After applying the Bonferroni correction, 3-carboxy-4-methyl-5-propyl-2-furanpropanoate (CMPF) remained significant in relation to 28-day all-cause mortality in sepsis. By pathway enrichment analysis, we identified four significant metabolic pathways. Notably, the Alpha Linolenic Acid and Linoleic Acid metabolism pathway emerged as a pivotal contributor to the occurrence and progression of sepsis. Conclusion: This study provides preliminary evidence of causal associations between human blood metabolites and sepsis, as ascertained by MR analysis. The findings offer valuable insights into the pathogenesis of sepsis and may provide insight into preventive and therapeutic approaches.

Fully Unattended Online Protein Digestion and LC-MS Peptide Mapping.

LC-MS based peptide mapping, i.e., proteolytic digestion followed by LC-MS/MS analysis, is the method of choice for protein primary structural characterization. Manual proteolytic digestion is usually a labor-intensive procedure. In this work, a novel method was developed for fully automated online protein digestion and LC-MS peptide mapping. The method generates LC-MS data from undigested protein samples without user intervention by utilizing the same HPLC system that performs the chromatographic separation with some additional modules. Each sample is rapidly digested immediately prior to its LC-MS analysis, minimizing artifacts that can grow over longer digestion times or digest storage times as in manual or automated offline digestion methods. In this report, we implemented the method on an Agilent 1290 Infinity II LC system equipped with a Multisampler. The system performs a complete digestion workflow including denaturation, disulfide reduction, cysteine alkylation, buffer exchange, and tryptic digestion. We demonstrated that the system is capable of digesting monoclonal antibodies and other proteins with excellent efficiency and is robust and reproducible and produces fewer artifacts than manually prepared digests. In addition, it consumes only a few micrograms of material as most of the digested sample protein is subjected to LC-MS analysis.

Migrasomes and tetraspanins in hepatocellular carcinoma: current status and future prospects.

In recent years, many studies have attempted to clarify the formation, structure and biological function of migrasomes, which are defined as specialized organelles formed by the tips and intersections of Retraction Fibrils during cell migration. It has confirmed that migrasomes were involved in various critical biological processes and diseases, and has became a new research hotspot. In this paper, we reviewed the formation and biological functions of migrasomes, explored the relationship between migrasomes, tetraspanins and hepatocellular carcinoma and discussed the potential applications of migrasomes in hepatocellular carcinoma.

Migrasomes are specialized parts of the cell that are responsible for transporting proteins and molecules to their designated cellular locations. In this review, we have attempted to understand their formation, structure and biological function. We have also discussed the potential applications of migrasomes in liver cancer. Our study concluded that more research is required for a better understanding of migrasomes and their contents in liver cancer.

Expanding the substrate scope of pyrrolysyl-transfer RNA synthetase enzymes to include non-α-amino acids in vitro and in vivo.

The absence of orthogonal aminoacyl-transfer RNA (tRNA) synthetases that accept non-L-α-amino acids is a primary bottleneck hindering the in vivo translation of sequence-defined hetero-oligomers and biomaterials. Here we report that pyrrolysyl-tRNA synthetase (PylRS) and certain PylRS variants accept α-hydroxy, α-thio and N-formyl-L-α-amino acids, as well as α-carboxy acid monomers that are precursors to polyketide natural products. These monomers are accommodated and accepted by the translation apparatus in vitro; those with reactive nucleophiles are incorporated into proteins in vivo. High-resolution structural analysis of the complex formed between one PylRS enzyme and a m-substituted 2-benzylmalonic acid derivative revealed an active site that discriminates prochiral carboxylates and accommodates the large size and distinct electrostatics of an α-carboxy substituent. This work emphasizes the potential of PylRS-derived enzymes for acylating tRNA with monomers whose α-substituent diverges substantially from the α-amine of proteinogenic amino acids. These enzymes or derivatives thereof could synergize with natural or evolved ribosomes and/or translation factors to generate diverse sequence-defined non-protein heteropolymers.

Method for detecting rare differences between two LC-MS runs.

LC-MS based multi-attribute methods (MAM) have drawn substantial attention due to their capability of simultaneously monitoring a large number of quality attributes of a biopharmaceutical product. For successful implementation of MAM, it is usually considered a requirement that the method is capable of detecting any new or missing peaks in the sample when compared to a control. Comparing a sample to a control for rare differences is also commonly practiced in many fields for investigational purpose. Because MS signal variability differs greatly between signals of different intensities, this type of comparison is often challenging, especially when the comparison is made without enough replicates. In this report we describe a statistical method for detecting rare differences between two very similar samples without replicate analyses. The method assumes that an overwhelming majority of components have equivalent abundance between the two samples, and signals with similar intensities have similar relative variability. By analyzing several monoclonal antibody peptide mapping datasets, we demonstrated that the method is suitable for new-peak detection for MAM as well as for other applications when rare differences between two samples need to be detected. The method greatly reduced false positive rate without a significant increase of false negative rate.

Observation of Heavy-Chain C-Terminal Des-GK Truncation in Recombinant and Human Endogenous IgG4.

Therapeutic IgG mAbs have shown presence of three variations of their heavy chain C-termini, including the unprocessed C-terminal lysine, the processed C-terminal lysine, and C-terminal amidation. These variants are also present in endogenous human IgGs, although the level of unprocessed C-terminal lysine is very low. Here we report a new heavy-chain C-terminal variant, i.e., the des-GK truncation, which exists in both recombinant and endogenous human IgG4. The des-GK truncation was found in negligible amount in IgG1, IgG2 and IgG3 subclasses. Observation of a significant level of heavy-chain C-terminal des-GK truncation in endogenous human IgG4 suggests that low level of this variant present in therapeutic IgG4 is unlikely to be a safety concern.

Simultaneous effect of different chromatographic conditions on the chromatographic retention of pentapeptide derivatives (HGRFG and NPNPT).

Introduction: Oligopeptides exhibit great prospects for clinical application and its separation is of great importance in new drug development. Methods: To accurately predict the retention of pentapeptides with analogous structures in chromatography, the retention times of 57 pentapeptide derivatives in seven buffers at three temperatures and four mobile phase compositions were measured via reversed-phase high-performance liquid chromatography. The parameters ( k H A , k A , and p K a ) of the acid-base equilibrium were obtained by fitting the data corresponding to a sigmoidal function. We then studied the dependence of these parameters on the temperature (T), organic modifier composition (φ, methanol volume fraction), and polarity ( P m N parameter). Finally, we proposed two six-parameter models with (1) pH and T and (2) pH and φ or P m N as the independent variables. These models were validated for their prediction capacities by linearly fitting the predicted retention factor k-value and the experimental k-value. Results: The results showed that log k H A and log k A exhibited linear relationships with 1 / T , φ or P m N for all pentapeptides, especially for the acid pentapeptides. In the model of pH and T, the correlation coefficient (R2) of the acid pentapeptides was 0.8603, suggesting a certain prediction capability of chromatographic retention. Moreover, in the model of pH and φ or P m N , the R2 values of the acid and neutral pentapeptides were greater than 0.93, and the average root mean squared error was approximately 0.3, indicating that the k-values could be effectively predicted. Discussion: In summary, the two six-parameter models were appropriate to characterize the chromatographic retention of amphoteric compounds, especially the acid or neutral pentapeptides, and could predict the chromatographic retention of pentapeptide compounds.