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As an important part of die steels, hot-work die steels are mainly used to manufacture molds made of solid metal or high-temperature liquid metal from heating to recrystallization temperature. In view of the requirements for mechanical properties and service life for hot-work die steel, it is conducive to improve the thermal fatigue resistance, wear resistance, and oxidation resistance of hot work die steel. In this review, the main failure modes of hot-work die steel were analyzed. Four traditional methods of strengthening and toughening die steel were summarized, including optimizing alloying elements, electroslag remelting, increasing the forging ratio, and heat treatment process enhancement. A new nano-strengthening method was introduced that aimed to refine the microstructure of hot-work abrasive steel and improve its service performance by adding nanoparticles into molten steel to achieve uniform dispersion. This review provides an overview to improve the service performance and service life of hot work die steel.
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Despite the success of programmed cell death 1 (PD-1)/programmed death ligand 1 (PD-L1) inhibition in tumor therapy, many patients do not benefit. This failure may be attributed to the intrinsic functions of PD-L1. We perform a genome-wide CRISPR synthetic lethality screen to systematically explore the intrinsic functions of PD-L1 in head and neck squamous cell carcinoma (HNSCC) cells, identifying ferroptosis-related genes as essential for the viability of PD-L1-deficient cells. Genetic and pharmacological induction of ferroptosis accelerates cell death in PD-L1 knockout cells, which are also more susceptible to immunogenic ferroptosis. Mechanistically, nuclear PD-L1 transcriptionally activates SOD2 to maintain redox homeostasis. Lower reactive oxygen species (ROS) and ferroptosis are observed in patients with HNSCC who have higher PD-L1 expression. Our study illustrates that PD-L1 confers ferroptosis resistance in HNSCC cells by activating the SOD2-mediated antioxidant pathway, suggesting that targeting the intrinsic functions of PD-L1 could enhance therapeutic efficacy.
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Antigène CD274 , Ferroptose , Animaux , Humains , Souris , Antigène CD274/métabolisme , Antigène CD274/génétique , Lignée cellulaire tumorale , Clustered regularly interspaced short palindromic repeats , Systèmes CRISPR-Cas , Régulation de l'expression des gènes tumoraux , Tumeurs de la tête et du cou/génétique , Tumeurs de la tête et du cou/anatomopathologie , Tumeurs de la tête et du cou/métabolisme , Espèces réactives de l'oxygène/métabolisme , Carcinome épidermoïde de la tête et du cou/génétique , Carcinome épidermoïde de la tête et du cou/anatomopathologie , Carcinome épidermoïde de la tête et du cou/métabolisme , Superoxide dismutase/métabolisme , Superoxide dismutase/génétique , Mutations synthétiques létalesRÉSUMÉ
Magnesium matrix composites are essential lightweight metal matrix composites, following aluminum matrix composites, with outstanding application prospects in automotive, aerospace lightweight and biomedical materials because of their high specific strength, low density and specific stiffness, good casting performance and rich resources. However, the inherent low plasticity and poor fatigue resistance of magnesium hamper its further application to a certain extent. Many researchers have tried many strengthening methods to improve the properties of magnesium alloys, while the relationship between wear resistance and plasticity still needs to be further improved. The nanoparticles added exhibit a good strengthening effect, especially the ceramic nanoparticles. Nanoparticle-reinforced magnesium matrix composites not only exhibit a high impact toughness, but also maintain the high strength and wear resistance of ceramic materials, effectively balancing the restriction between the strength and toughness. Therefore, this work aims to provide a review of the state of the art of research on the matrix, reinforcement, design, properties and potential applications of nano-reinforced phase-reinforced magnesium matrix composites (especially ceramic nanoparticle-reinforced ones). The conventional and potential matrices for the fabrication of magnesium matrix composites are introduced. The classification and influence of ceramic reinforcements are assessed, and the factors influencing interface bonding strength between reinforcements and matrix, regulation and design, performance and application are analyzed. Finally, the scope of future research in this field is discussed.
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Only a minority of cancer patients benefit from immune checkpoint blockade therapy. Sophisticated cross-talk among different immune checkpoint pathways as well as interaction pattern of immune checkpoint molecules carried on circulating small extracellular vesicles (sEV) might contribute to the low response rate. Here we demonstrate that PD-1 and CD80 carried on immunocyte-derived sEVs (I-sEV) induce an adaptive redistribution of PD-L1 in tumour cells. The resulting decreased cell membrane PD-L1 expression and increased sEV PD-L1 secretion into the circulation contribute to systemic immunosuppression. PD-1/CD80+ I-sEVs also induce downregulation of adhesion- and antigen presentation-related molecules on tumour cells and impaired immune cell infiltration, thereby converting tumours to an immunologically cold phenotype. Moreover, synchronous analysis of multiple checkpoint molecules, including PD-1, CD80 and PD-L1, on circulating sEVs distinguishes clinical responders from those patients who poorly respond to anti-PD-1 treatment. Altogether, our study shows that sEVs carry multiple inhibitory immune checkpoints proteins, which form a potentially targetable adaptive loop to suppress antitumour immunity.
Sujet(s)
Antigène CD80 , Antigène CD274 , Vésicules extracellulaires , Récepteur-1 de mort cellulaire programmée , Vésicules extracellulaires/métabolisme , Vésicules extracellulaires/immunologie , Récepteur-1 de mort cellulaire programmée/métabolisme , Humains , Antigène CD80/métabolisme , Antigène CD274/métabolisme , Antigène CD274/immunologie , Animaux , Souris , Lignée cellulaire tumorale , Femelle , Tumeurs/immunologie , Tumeurs/anatomopathologie , Inhibiteurs de points de contrôle immunitaires/usage thérapeutique , Inhibiteurs de points de contrôle immunitaires/pharmacologie , Tolérance immunitaire , Souris de lignée C57BL , Mâle , Microenvironnement tumoral/immunologieRÉSUMÉ
BACKGROUND: Small cell lung cancer (SCLC) is a common and aggressive subtype of lung cancer. It is characterized by rapid growth and a high mortality rate. Approximately 10% of patients with SCLC present with brain metastases at the time of diagnosis, which is associated with a median survival of 5 mo. This study aimed to summarize the effect of bevacizumab on the progression-free survival (PFS) and overall survival of patients with brain metastasis of SCLC. CASE SUMMARY: A 62-year-old man was referred to our hospital in February 2023 because of dizziness and numbness of the right lower extremity without headache or fever for more than four weeks. The patient was diagnosed with limited-stage SCLC. He received 8 cycles of chemotherapy combined with maintenance bevacizumab therapy and achieved a PFS of over 7 mo. CONCLUSION: The combination of bevacizumab and irinotecan effectively alleviated brain metastasis in SCLC and prolonged PFS.
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The immune system of astronauts might become weakened in the microgravity environment in space, and the dormant varicella-zoster virus (VZV) in the body might be reactivated, seriously affecting their work and safety. For working in orbit for the long term, there is currently no efficient and durable delivery system of general vaccines in a microgravity environment. Accordingly, based on the previous foundation, we designed, modified, and synthesized a biodegradable and biocompatible copolymer, polyethylene glycol-polysulfamethazine carbonate urethane (PEG-PSCU) that could be mainly adopted to fabricate a novel sustained-release microneedle (S-R MN) patch. Compared with conventional biodegradable microneedles, this S-R MN patch could not only efficiently encapsulate protein vaccines (varicella-zoster virus glycoprotein E, VZV gE) but also further prolong the release time of VZV gE in a simulated microgravity (SMG) environment. Eventually, we verified the activation of dendritic cells by VZV gE released from the S-R MN patch in an SMG environment and the positive bioeffect of activated dendritic cells on lymphocytes using an in vitro lymph node model. This study is of great significance for the exploration of long-term specific immune responses to the VZV in an SMG environment.
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Vaccins , Impesanteur , Herpèsvirus humain de type 3 , Préparations à action retardée , Antigènes virauxRÉSUMÉ
To tackle the obstacles related to tumor targeting and overcome the limitations of single treatment models, we have developed a nanoplatform that is both tumor-targeted and enzyme-responsive. This nanoplatform integrates photothermal gold nanorods (AuNRs) and protein drugs into a single system. This nanosystem, known as AuNRs@HA-mPEG-Deta-LA, was fabricated by modifying gold nanorods (AuNRs) with a polymeric ligand called hyaluronic acid-grafted-(mPEG/diethylenetriamine-conjugated-lipoic acid). The purpose of this fabrication was to load cytochrome c (CC) and utilize it for the synergetic protein-photothermal therapy of cancer. The resulting nanoplatform exhibited a high efficiency in loading proteins and demonstrated excellent stability in different biological environments. Additionally, CC-loaded AuNRs@HA-mPEG-Deta-LA not only enabled localized hyperthermia for photothermal therapy (PTT) with laser irradiation but also facilitated the release of CC under the action of hyaluronidase, an enzyme known to be overexpressed in tumor cells. The confocal imaging results demonstrated that the presence of a specific polymeric ligand on this nanoparticle enhances the internalization of CD44-positive cancer cells, accelerates endo/lysosomal escape, and facilitates the controlled release of CC within the cells. Furthermore, the results of the MTT assay also showed that AuNRs@HA-mPEG-Deta-LA as a protein nanocarrier demonstrated excellent biocompatibility. Importantly, this synergistic therapeutic strategy effectively induced apoptosis in A549 cancer cells by increasing the intracellular concentration of CC and utilizing the photothermal conversion of AuNRs, which was observed to be more effective compared to using only protein therapy or PTT. Therefore, this study showcased a nanoplatform based on AuNRs that has great potential for tumor-targeted protein delivery in combination with PTT in cancer treatment.
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Hyperthermie provoquée , Nanotubes , Tumeurs , Polyéthylène glycols , Humains , Photothérapie , Thérapie photothermique , Or/pharmacologie , Ligands , N,N-Diéthyl-méta-toluamide , Tumeurs/thérapie , Tumeurs/anatomopathologie , Lysosomes , Lignée cellulaire tumoraleRÉSUMÉ
BACKGROUND: Neurofibromas are benign tumors of a neurogenic origin. If these tumors occur without any other signs of neurofibromatosis, they are classified as isolated neurofibromas. Neurofibromas in the oral cavity mostly occur within soft tissues, indicating that solitary intraosseous neurofibromas in the mandible are rare. Due to the absence of specific clinical manifestations, early diagnosis and treatment of these tumors are difficult to achieve. CASE SUMMARY: A 37-year-old female patient visited our hospital due to numbness and swelling of the gums in the right lower molar area that had persisted for half a month. The patient's overall condition and intraoral examination revealed no significant abnormalities. She was initially diagnosed with a cystic lesion in the right mandible. However, after a more thorough examination, the final pathological diagnosis was confirmed to be neurofibroma. Complete tumor resection and partial removal of the right inferior alveolar nerve were performed. As of writing this report, there have been no signs of tumor recurrence for nine months following the surgery. CONCLUSION: This case report discusses the key features that are useful for differentiating solitary intraosseous neurofibromas from other cystic lesions.
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BACKGROUND: Immune checkpoint inhibitors, including programmed death-ligand 1 (PD-L1) and programmed death-1 (PD-1) have recently been approved to treat locally advanced and metastatic urothelial carcinoma (UC). However, some patients experience rapid tumor progression rather than any clinical benefit from anti-PD-L1/PD-1 therapy. CASE SUMMARY: A 73-year-old woman with bladder UC showed the progression of multiple metastases after surgery and chemotherapy for over 12 mo. The patient could not tolerate further chemotherapy. Next-generation sequencing was performed, and the results indicated that the tumor mutational burden was 6.4 mutations/Mb. The patient received the anti-PD-L1 agent toripalimab combined with albumin-bound paclitaxel. Compared with the baseline staging before immunotherapy, the patient had a treatment failure time of < 2 mo, an increase in tumor burden of > 50%, and a > 2-fold increase in progression, indicating hyperprogression. CONCLUSION: Selecting patients most likely to respond to treatment with immunotherapeutic agents remains challenging. For older patients with advanced UC who have already exhausted multi-line chemotherapy options, immunotherapy should be used prudently if no effective biomarker is available. Further studies are required to clarify the causes and mechanisms of hyperprogression.
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In the general environment of lightweight automobiles, the integrated die-casting technology proposed by Tesla has become the general mode to better achieve weight reduction in automobiles. The die-casting mold required by integrated die-casting technology has the characteristics of large scale and complexity. Hence, higher requirements are put forward for the comprehensive performance of the die steel. Despite the stagnation in the progress of conventional strengthening methods, enhancing the performance of die steel has become increasingly challenging. Indeed, it necessitates exploring novel die steel and optimizing heat treatment and reinforcement technologies. This article summarizes and analyzes the development status of die steel and corresponding heat treatment and microstructure manipulation as well as strengthening methods and elaborates on an excellent nano-strengthening technology. Furthermore, this review will aid researchers in establishing a comprehensive understanding of the development status of die steel and the processes utilized for its strengthening. It will also assist them in developing die steel with improved comprehensive performance to meet the high demand for mold steel in the integrated die-casting technology of the new era.
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The detection of nucleic acid sequences in parallel with the discrimination of single nucleotide variations (SNVs) is critical for research and clinical applications. A few limitations make the detection technically challenging, such as too small variation in probe-hybridization energy caused by SNVs, the non-specific amplification of false nucleic acid fragments and the few options of dyes limited by spectral overlaps. To circumvent these limitations, we developed a single-molecule nucleic acid detection assay without amplification or fluorescence termed THREF (hybridization-induced tandem DNA hairpin refolding failure) based on multiplexed magnetic tweezers. THREF can detect DNA and RNA sequences at femtomolar concentrations within 30 min, monitor multiple probes in parallel, quantify the expression level of miR-122 in patient tissues, discriminate SNVs including the hard-to-detect G-U or T-G wobble mutations and reuse the probes to save the cost. In our demonstrative detections using mock clinic samples, we profiled the let-7 family microRNAs in serum and genotyped SARS-CoV-2 strains in saliva. Overall, the THREF assay can discriminate SNVs with the advantages of high sensitivity, ultra-specificity, multiplexing, reusability, sample hands-free and robustness.
Sujet(s)
Techniques génétiques , Polymorphisme génétique , ARN , Humains , COVID-19/diagnostic , ADN/génétique , Mutation , SARS-CoV-2/génétique , ARN/analyseRÉSUMÉ
Tumor phototheranostics is usually compromised by the hypoxic tumor microenvironment and poor theranostic efficiency. The interplay between organic polymers and inorganic nanoparticles in novel nanocomposites has proven to be advantageous, overcoming previous limitations and harnessing their full potential through activation via the tumor microenvironment. This study successfully fabricated hypoxia-activated nanocolloids called HOISNDs through a process of self-assembly involving superparamagnetic iron oxide nanoparticles (SPIONs) and an organic polymer ligand called tetrakis(4-carboxyphenyl) porphyrin (TCPP)-engineered organic polymer ligand [methoxy poly(ethyleneglycol)-block-poly(dopamine-ethylenediamine-conjugated-4-nitrobenzyl chloroformate)-l-glutamate, mPEG-b-P(Dopa-EDA-co-NBCF)LG-TCPP)]. The SPIONs act as an oxygen generator to overcome the challenges posed by hypoxic tumors and enable the use of hypoxic-activatable MR/fluorescence dual-modal imaging-guided photodynamic therapy (PDT). The colloid stability of these HOISNDs proved to be exceptional in diverse biomimetic environments. Furthermore, they not only augment T2-weighted contrast capability as an MRI contrast agent but also function as an oxygen-producing device to amplify the generation and release of reactive oxygen species (ROS). The HOISNDs can significantly target to tumor sites through the enhanced permeability and retention (EPR) effect with prolonged blood circulation time and subsequently are effectively endocytosed into a hypoxic intracellular environment that "turn on" the imaging function and photodynamic activity. Moreover, HOISNDs possess the ability to effectively decompose naturally occurring H2O2 into oxygen (O2) within the tumor utilizing the Fenton reaction. This method can mitigate the impact of hypoxia on oxygen-dependent PDT. The outcomes of in vivo diagnostic and therapeutic evaluations indicated that HOISNDs are a highly promising tool for dual-model imaging-guided cancer theranosis by ameliorating hypoxic conditions and augmenting PDT efficiency.
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Nanoparticules , Tumeurs , Photothérapie dynamique , Humains , Oxygène , Photothérapie dynamique/méthodes , Peroxyde d'hydrogène , Ligands , Nanoparticules/usage thérapeutique , Tumeurs/imagerie diagnostique , Tumeurs/traitement médicamenteux , Polymères , Imagerie par résonance magnétique , Hypoxie , Photosensibilisants/pharmacologie , Photosensibilisants/usage thérapeutique , Lignée cellulaire tumorale , Microenvironnement tumoralRÉSUMÉ
It is well known that the development of lightweight alloys with improved comprehensive performance and application value are the future development directions for the ultra-high-strength 7xxx series Al-Zn-Mg-Cu alloys used in the aircraft field. As the lightest metal element in nature, lithium (Li) has outstanding advantages in reducing the density and increasing the elastic modulus in aluminum alloys, so Al-Zn-Mg-Cu alloys containing Li have gained widespread attention. Furthermore, since the Al-Zn-Mg-Cu alloy is usually strengthened by aging treatment, it is crucial to understand how Li addition affects its aging precipitation process. As such, in this article, the effects and mechanism of Li on the aging precipitation behavior and the impact of Li content on the aging precipitation phase of Al-Zn-Mg-Cu alloys are briefly reviewed, and the influence of Li on the service properties, including mechanical properties, wear resistance, and fatigue resistance, of Al-Zn-Mg-Cu alloys are explained. In addition, the corresponding development prospects and challenges of the Al-Zn-Mg-Cu-Li alloy are also proposed. This review is helpful to further understand the role of Li in Al-Zn-Mg-Cu alloys and provides a reference for the development of high-strength aluminum alloys containing Li with good comprehensive properties.
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The extraction process, structural characterization and free radical scavenging ability of polysaccharides from Camellia oleifera have already been widely studied. However, the antioxidant activities are still lack of systematic experiments. In this study, we used Hep G2 cells and Caenorhabditis elegans to evaluate the antioxidant potential of polysaccharides that from C. oleifera flowers (P-CF), leaves (P-CL), seed cakes (P-CC) and fruit shells (P-CS). The results showed all these polysaccharides could protect cells from oxidative damage induced by t-BHP. The highest cell viabilities were 66.46 ± 1.36 % (P-CF), 55.2 ± 2.93 % (P-CL), 54.49 ± 1.29 % (P-CC) and 61.45 ± 1.67 % (P-CS), respectively. Studies have shown that four polysaccharides may protect cells from apoptosis by reducing ROS levels and maintaining MMP balance. Moreover, P-CF, P-CL, P-CC and P-CS increased the survival rate of C. elegans under thermal stress, which reduced the production of ROS by 56.1 ± 0.67 %, 59.37 ± 1.79 %, 16.63 ± 2.51 % and 27.55 ± 2.62 %, respectively. P-CF and P-CL showed stronger protective effects on C. elegans by increasing the nuclear entry rate of DAF-16 and stimulating the expression of SOD-3. Our study suggested that C. oleifera polysaccharides have the potential to develop into a natural supplement agent.
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Antioxydants , Camellia , Animaux , Antioxydants/pharmacologie , Antioxydants/composition chimique , Espèces réactives de l'oxygène/pharmacologie , Caenorhabditis elegans , Camellia/composition chimique , Polyosides/pharmacologie , Polyosides/composition chimiqueRÉSUMÉ
Au nanorods (AuNRs) have attracted considerable interest as drug delivery systems because of their enhanced cell internalization and stronger drug-loading ability. In addition, the incorporation of photodynamic therapy (PDT) and photothermal therapy (PTT) into one nanosystem presents great promise to defect multiple drawbacks in cancer therapy. Herein, we fabricated a multifunctional and dual-targeting nanoplatform based on hyaluronic acid-grafted-(mPEG/triethylenetetramine-conjugated-lipoic acid/tetra(4-carboxyphenyl)porphyrin/folic acid) polymer ligand capped AuNRs (AuNRs@HA-g-(mPEG/Teta-co-(LA/TCPP/FA)) for combined photodynamic-photothermal therapy of cancer. The prepared nanoparticles displayed high TCPP loading capacity and excellent stability in different biological media. Furthermore, AuNRs@HA-g-(mPEG/Teta-co-(LA/TCPP/FA)) not only could produce a localized hyperthermia to conduct PTT, but also generate cytotoxic singlet oxygen (1 O2 ) to perform PDT under laser irradiation. Confocal imaging results disclosed that this nanoparticle endowing the specific function of polymeric ligand could enhance cellular uptake, accelerate endo/lysosomal escape, as well as produce higher reactive oxygen species. Importantly, this combination therapy strategy could also induce higher anticancer potential than PDT or PTT only against MCF-7 tumor cells in vitro. Therefore, this work presented an AuNRs-based therapeutic nanoplatform with great potential in dual-targeting and photo-induced combination therapy of cancer.
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Nanoparticules , Nanotubes , Tumeurs , Photothérapie dynamique , Humains , Acide hyaluronique , Or/pharmacologie , Thérapie photothermique , Ligands , Polymères , Lysosomes , Lignée cellulaire tumoraleRÉSUMÉ
The present study aimed to investigate the effect of various adjuvant rice on the quality of rice-steamed Rehmanniae Radix(RSRR) with Japonica rice, millet, yellow rice, black rice, and glutinous rice as raw materials, and analyze the anti-osteoporosis effect of RSRR by the optimal adjuvant rice. On the basis of the established UPLC-MS/MS method for the determination of the content of catalpol and rehmannioside D, comprehensive weighted scoring method was employed to evaluate the effect of various auxiliary rice on the quality of RSRR with the content of catalpol and rehmannioside D, character score, and taste score as indicators to optimize adjuvant rice. The osteoporosis model was induced by ovariectomy in rats. SD rats were randomly divided into a sham operation group, a model group, a positive control group, and low-dose and high-dose groups of Rehmanniae Radix, RSRR, steamed Rehmanniae Radix, and Epimedii Folium-RSRR. After treatment for 12 weeks, body weight, bone calcium content, and bone mineral density were mea-sured. The results showed that Japonica rice was selected as the optimal adjuvant due to the highest comprehensive score of RSRR steamed by Japonica rice. Rehmanniae Radix, RSRR, steamed Rehmanniae Radix, as well as Epimedii Folium-RSRR, could improve osteoporosis by increasing bone calcium content and bone mineral density. RSRR was superior to Rehmanniae Radix in improving osteo-porosis. However, there was no significant difference between RSRR and steamed Rehmanniae Radix. This study confirmed that Japo-nica rice was the optimal adjuvant rice of RSRR and verified the anti-osteoporosis effect of RSRR, which laid a foundation for further research on the pharmacological action and mechanism of RSRR.
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Médicaments issus de plantes chinoises , Oryza , Ostéoporose , Rehmannia , Femelle , Rats , Animaux , Chromatographie en phase liquide , Calcium , Rat Sprague-Dawley , Spectrométrie de masse en tandem , Médicaments issus de plantes chinoises/pharmacologie , Ostéoporose/traitement médicamenteux , Adjuvants pharmaceutiquesRÉSUMÉ
In this study, unique hypoxia-activated hyaluronic acid nanogels (HANGs) were reported for CD44-targeted delivery of photosensitizers (chlorin e6, Ce6) for diagnostic imaging and photodynamic therapy (PDT) of cancers. Through the use of a hypoxia-responsive cross-linker (AZO-CDI), the HANGs were prepared by chemically cross-linking primary amine groups-functionalized hyaluronic acid (HA). Under normoxic condition, fluorescence of Ce6 conjugated on the HANGs was highly quenched, and level of reactive oxygen species (ROS) generated from the HANGs was rather low after laser irradiation. However, under hypoxic condition, the HANGs underwent rapid disassociation, and fluorescence of Ce6 conjugated on the HANGs was recovered, triggering high-level singlet oxygen generation after laser irradiation. Due to the presence of HA, the HANGs showed much higher cellular uptake by CD44-positive cancer cells (A549 cells) than that by CD44-negative cancer cells (HepG2 cells). In addition, the HANGs could generate higher level of ROS in A549 cells because of improved cancer cell uptake. This excellent tumor-targeting and singlet oxygen-generating ability of the HANGs was favorable to hypoxia-activated PDT of CD44-positive cancers with significant inhibition of tumor growth within the whole treatment period. Taken together, the HANGs are safe and effective tools in treating CD44-positive cancers.
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Nanoparticules , Tumeurs , Photothérapie dynamique , Porphyrines , Humains , Photothérapie dynamique/méthodes , Nanogels , Acide hyaluronique/pharmacologie , Espèces réactives de l'oxygène , Oxygène singulet , Tumeurs/traitement médicamenteux , Photosensibilisants/pharmacologie , Porphyrines/pharmacologie , Lignée cellulaire tumorale , Antigènes CD44RÉSUMÉ
The onset of various kidney diseases has been reported after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. However, detailed clinical and pathological features are lacking. We screened and analyzed patients with newly diagnosed kidney diseases after inactivated SARS-CoV-2 vaccination in Peking University First Hospital from January 2021 to August 2021, and compared them with the reported cases in the literature. We obtained samples of blood, urine and renal biopsy tissues. Clinical and laboratory information, as well as light microscopy, immunostaining and ultrastructural observations, were described. The SARS-CoV-2 spike protein and nucleoprotein were stained using the immunofluorescence technique in the kidney biopsy samples. SARS-CoV-2 specific antibodies were tested using magnetic particle chemiluminescence immunoassay. The study group included 17 patients with a range of conditions including immune-complex-mediated kidney diseases (IgA nephropathy, membranous nephropathy and lupus nephritis), podocytopathy (minimal change disease and focal segmental glomerulosclerosis) and others (antineutrophil-cytoplasmic-antibody-associated vasculitis, anti-glomerular basement membrane nephritis, acute tubulointerstitial nephritis and thrombotic microangiopathy). Seven patients (41.18%) developed renal disease after the first dose and ten (58.82%) after the second dose. The kidney disease spectrum as well as clinicopathological features are similar across different types of SARS-CoV-2 vaccines. We found no definitive evidence of SARS-CoV-2 spike protein or nucleoprotein deposition in the kidney biopsy samples. Seropositive markers implicated abnormal immune responses in predisposed individuals. Treatment and follow-up (median = 86 days) showed that biopsy diagnosis informed treatment and prognosis in all patients. In conclusion, we observed various kidney diseases following SARS-CoV-2 vaccine administration, which show a high consistency across different types of SARS-CoV-2 vaccines. Our findings provide evidence against direct vaccine protein deposition as the major pathomechanism, but implicate abnormal immune responses in predisposed individuals. These findings expand our understanding of SARS-CoV-2 vaccine renal safety.
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BACKGROUND: This study examined the postoperative follow-up attendance of oral squamous cell carcinoma (OSCC) patients, evaluated some of the factors associated with it, and assessed its relationship with early detection of postoperative disease progression. METHODS: An exploratory retrospective cohort study of 430 OSCC patients was conducted. We examined associations of follow-up attendance within the first year after surgery with selected demographic and clinical factors, and with early detection of disease progression. RESULTS: The mean number of follow-up visits within the first year after surgery was 3.9 out of the 12 recommended at our center; few patients were fully adherent. Age ≥70 years, unmarried status, high education level, and negative history of surgery for premalignant or malignant lesions from oral cavity or other sites were significantly associated with lower follow-up attendance. Greater follow-up attendance was significantly associated with early detection of disease progression during the first year after surgery (p = 0.025). CONCLUSIONS: Adherence to follow-up visits was poor. Several sociodemographic and clinical factors were related to follow-up attendance, greater follow-up attendance was significantly associated with early detection of disease progression, and these should be further explored in future research.
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Carcinome épidermoïde , Tumeurs de la tête et du cou , Tumeurs de la bouche , Humains , Sujet âgé , Carcinome épidermoïde/épidémiologie , Carcinome épidermoïde/chirurgie , Carcinome épidermoïde/anatomopathologie , Carcinome épidermoïde de la tête et du cou , Tumeurs de la bouche/chirurgie , Tumeurs de la bouche/anatomopathologie , Études de suivi , Études rétrospectives , Évolution de la maladieRÉSUMÉ
5-Methyl-cytosine (5mC) is one of the most important DNA modifications and plays versatile biological roles. It is well known that 5mC stabilizes DNA duplexes. However, it remains unclear how 5mC affects the kinetics of DNA melting and hybridization. Here, we studied the kinetics of unzipping and rezipping using a 502-bp DNA hairpin by single-molecule magnetic tweezers. Under constant loading rates, 5mC increases the unzipping force but counterintuitively decreases the rezipping force at various salt and temperature conditions. Under constant forces, the non-methylated DNA hops between metastable states during unzipping and rezipping, which implies low energy barriers. Surprisingly, the 5mC DNA can't rezip after fully unzipping unless much lower forces are applied, where it rezips stochastically in a one-step manner, which implies 5mC kinetically hinders DNA hybridization and high energy barriers in DNA hybridization. All-atom molecular dynamics simulations reveal that the 5mC kinetically hinders DNA hybridization due to steric effects rather than electrostatic effects caused by the additional methyl groups of cytosines. Considering the possible high speed of DNA unzipping and zipping during replication and transcription, our findings provide new insights into the biological roles of 5mC.