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1.
Immunity ; 54(12): 2724-2739.e10, 2021 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-34687607

RESUMO

Nitric oxide (NO) is an important antimicrobial effector but also prevents unnecessary tissue damage by shutting down the recruitment of monocyte-derived phagocytes. Intracellular pathogens such as Leishmania major can hijack these cells as a niche for replication. Thus, NO might exert containment by restricting the availability of the cellular niche required for efficient pathogen proliferation. However, such indirect modes of action remain to be established. By combining mathematical modeling with intravital 2-photon biosensors of pathogen viability and proliferation, we show that low L. major proliferation results not from direct NO impact on the pathogen but from reduced availability of proliferation-permissive host cells. Although inhibiting NO production increases recruitment of these cells, and thus pathogen proliferation, blocking cell recruitment uncouples the NO effect from pathogen proliferation. Therefore, NO fulfills two distinct functions for L. major containment: permitting direct killing and restricting the supply of proliferation-permissive host cells.


Assuntos
Leishmania major/fisiologia , Leishmaniose/imunologia , Macrófagos/imunologia , Óxido Nítrico/metabolismo , Animais , Processos de Crescimento Celular , Movimento Celular , Proliferação de Células , Modelos Animais de Doenças , Interações Hospedeiro-Patógeno , Humanos , Microscopia Intravital , Camundongos , Camundongos Endogâmicos C57BL , Modelos Teóricos
2.
Nature ; 618(7966): 712-715, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37286602

RESUMO

The most massive and shortest-lived stars dominate the chemical evolution of the pre-galactic era. On the basis of numerical simulations, it has long been speculated that the mass of such first-generation stars was up to several hundred solar masses1-4. The very massive first-generation stars with a mass range from 140 to 260 solar masses are predicted to enrich the early interstellar medium through pair-instability supernovae (PISNe)5. Decades of observational efforts, however, have not been able to uniquely identify the imprints of such very massive stars on the most metal-poor stars in the Milky Way6,7. Here we report the chemical composition of a very metal-poor (VMP) star with extremely low sodium and cobalt abundances. The sodium with respect to iron in this star is more than two orders of magnitude lower than that of the Sun. This star exhibits very large abundance variance between the odd- and even-charge-number elements, such as sodium/magnesium and cobalt/nickel. Such peculiar odd-even effect, along with deficiencies of sodium and α elements, are consistent with the prediction of primordial pair-instability supernova (PISN) from stars more massive than 140 solar masses. This provides a clear chemical signature indicating the existence of very massive stars in the early universe.

3.
Mol Cell ; 78(2): 359-370.e6, 2020 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-32246903

RESUMO

Yeast cells must grow to a critical size before committing to division. It is unknown how size is measured. We find that as cells grow, mRNAs for some cell-cycle activators scale faster than size, increasing in concentration, while mRNAs for some inhibitors scale slower than size, decreasing in concentration. Size-scaled gene expression could cause an increasing ratio of activators to inhibitors with size, triggering cell-cycle entry. Consistent with this, expression of the CLN2 activator from the promoter of the WHI5 inhibitor, or vice versa, interfered with cell size homeostasis, yielding a broader distribution of cell sizes. We suggest that size homeostasis comes from differential scaling of gene expression with size. Differential regulation of gene expression as a function of cell size could affect many cellular processes.


Assuntos
Divisão Celular/genética , Tamanho Celular , Ciclinas/genética , Proteínas de Saccharomyces cerevisiae/genética , Ciclo Celular/genética , Fase G1/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Regulação Fúngica da Expressão Gênica/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento
4.
Proc Natl Acad Sci U S A ; 120(33): e2220616120, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37549260

RESUMO

Climate change, especially in the form of precipitation and temperature changes, can alter the transformation and delivery of nitrogen on the land surface and to aquatic systems, impacting the trophic states of downstream water bodies. While the expected impacts of changes in precipitation have been explored, a quantitative understanding of the impact of temperature on nitrogen loading is lacking at landscape scales. Here, using several decades of nitrogen loading observations, we quantify how individual and combined future changes in precipitation and temperature will affect riverine nitrogen loading. We find that, contrary to recent decades, rising temperatures are likely to offset or even reverse previously reported impacts of future increases in total and extreme precipitation on nitrogen runoff across the majority of the contiguous United States. These findings highlight the multifaceted impacts of climate change on the global nitrogen cycle.

5.
Am J Pathol ; 194(3): 430-446, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38101566

RESUMO

Heterotopic ossification (HO) is the ectopic bone formation in soft tissues. Aside from hereditary HO, traumatic HO is common after orthopedic surgery, combat-related injuries, severe burns, or neurologic injuries. Recently, mammalian target of rapamycin (mTOR) was demonstrated to be involved in the chondrogenic and osteogenic processes of HO formation. However, its upstream signaling mechanism remains unknown. The current study used an Achilles tendon puncture-induced HO model to show that overactive insulin-like growth factor 1 (IGF-1) was involved in the progression of HO in mice. Micro-computed tomography imaging showed that IGF-1 not only accelerated the rate of osteogenesis and increased ectopic bone volume but also induced spontaneous ectopic bone formation in undamaged Achilles tendons. Blocking IGF-1 activity with IGF-1 antibody or IGF-1 receptor inhibitor picropodophyllin significantly inhibited HO formation. Mechanistically, IGF-1/IGF-1 receptor activates phosphatidylinositol 3-kinase (PI3K)/Akt signaling to promote the phosphorylation of mTOR, resulting in the chondrogenic and osteogenic differentiation of tendon-derived stem cells into chondrocytes and osteoblasts in vitro and in vivo. Inhibitors of PI3K (LY294002) and mTOR (rapamycin) both suppressed the IGF-1-stimulated mTOR signal and mitigated the formation of ectopic bones significantly. In conclusion, these results indicate that IGF-1 mediated the progression of traumatic HO through PI3K/Akt/mTOR signaling, and suppressing IGF-1 signaling cascades attenuated HO formation, providing a promising therapeutic strategy targeting HO.


Assuntos
Ossificação Heterotópica , Osteogênese , Animais , Camundongos , Fator de Crescimento Insulin-Like I , Peptídeos Semelhantes à Insulina , Mamíferos , Ossificação Heterotópica/etiologia , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Receptor IGF Tipo 1 , Serina-Treonina Quinases TOR , Microtomografia por Raio-X
6.
Gastroenterology ; 165(6): 1488-1504.e20, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37634735

RESUMO

BACKGROUND & AIMS: Studies have demonstrated that activated pancreatic stellate cells (PSCs) play a crucial role in pancreatic fibrogenesis in chronic pancreatitis (CP); however, the precise mechanism for PSCs activation has not been fully elucidated. We analyzed the role of injured pancreatic acinar cells (iPACs) in the activation of PSCs of CP. METHODS: Sphingosine kinase 1 (SPHK1)/sphingosine-1-phosphate (S1P) signaling was evaluated in experimental CP induced by cerulein injection or pancreatic duct ligation, as well as in PACs injured by cholecystokinin. The activation of PSCs and pancreatic fibrosis in CP samples was evaluated by immunohistochemical and immunofluorescence analyses. In vitro coculture assay of iPACs and PSCs was created to evaluate the effect of the SPHK1/S1P pathway and S1P receptor 2 (SIPR2) on autophagy and activation of PSCs. The pathogenesis of CP was assessed in SPHK1-/- mice or PACs-specific SPHK1-knockdown mice with recombinant adeno-associated virus serotypes 9-SPHK1-knockdown, as well as in mice treated with inhibitor of SPHK1 and S1P receptor 2 (S1PR2). RESULTS: SPHK1/S1P was remarkably increased in iPACs and acinar cells in pancreatic tissues of CP mice. Meanwhile, the pathogenesis, fibrosis, and PSCs activation of CP was significantly prevented in SPHK1-/- mice and recombinant adeno-associated virus serotypes 9-SPHK1-knockdown mice. Meanwhile, iPACs obviously activated PSCs, which was prevented by SPHK1 knockdown in iPACs. Moreover, iPACs-derived S1P specifically combined to S1PR2 of PSCs, by which modulated 5' adenosine monophosphate-activated protein kinase/mechanistic target of rapamycin pathway and consequently induced autophagy and activation of PSCs. Furthermore, hypoxia-inducible factor 1-α and -2α promoted SPHK1 transcription of PACs under hypoxia conditions, which is a distinct characteristic of the CP microenvironment. Coincidently, inhibition of SPHK1 and S1PR2 activity with inhibitor PF-543 and JTE-013 obviously impeded pancreatic fibrogenesis of CP mice. CONCLUSIONS: The activated SPHK1/S1P pathway in iPACs induces autophagy and activation of PSCs by regulating the S1PR2/5' adenosine monophosphate-activated protein kinase/mammalian target of rapamycin pathway, which promotes fibrogenesis of CP. The hypoxia microenvironment might contribute to the cross talk between PACs and PSCs in pathogenesis of CP.


Assuntos
Células Acinares , Pancreatite Crônica , Animais , Camundongos , Receptores de Esfingosina-1-Fosfato , Células Estreladas do Pâncreas , Pancreatite Crônica/induzido quimicamente , Autofagia , Proteínas Quinases Ativadas por AMP , Fibrose , Monofosfato de Adenosina , Hipóxia , Mamíferos
7.
Opt Express ; 32(3): 4334-4345, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38297637

RESUMO

Integrated on-chip femtosecond (fs) laser optoelectronic system, with photodetector as a critical component for light-electrical signal conversion, is a long-sought-after goal for a wide range of frontier applications. However, the high laser peak intensity and complicated nanophotonic waveguide structure of on-chip fs laser are beyond the detectability and integrability of conventional photodetectors. Therefore, flexible photodetector with the response on intense fs laser is in urgent needs. Herein, we demonstrate the first (to our knowledge) two-photon absorption (TPA) flexible photodetector based on the strong TPA nonlinearity of layered hybrid perovskite (IA)2(MA)2Pb3Br10, exhibiting efficient sub-bandgap response on the infrared fs laser at 700-1000 nm. High saturation intensity up to ∼3.8 MW/cm2 is achieved. The device also shows superior current stability even after bending for 1000 cycles. This work may pave the new way for the application of flexible optoelectronics specialized in integrated fs-laser detection.

8.
Opt Express ; 32(7): 11509-11521, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38570996

RESUMO

Stable Q-switched and femtosecond mode-locked erbium-doped fiber laser (EDFL) have been achieved using CuSe nanosheets as novel saturable absorber (SA), where the CuSe nanosheets were prepared by a hydrothermal method. The nonlinear optical properties of CuSe nanosheets were measured using an Z-scan setup, revealing nonlinear absorption coefficients of -3.67 ± 0.22 cm GW-1 at 1560 nm. The prepared CuSe nanosheets were mixed with polyvinyl alcohol (PVA) to obtain a CuSe-PVA SA with a modulation depth of 3.8 ± 0.13%, and it was utilized to realize a Q-switched EDFL, obtaining the narrowest pulse duration of 1.29 µs and the maximum output power of 5.96 mW, which corresponds to a pulse energy of up to 103.7 nJ. In addition, CuSe nanosheets were deposited on a D-shaped fiber (DSF) to fabricate a CuSe-DSF SA with a modulation depth of 5.6 ± 0.17%, and it was utilized to realize a mode-locked EDFL. The mode-locked EDFL demonstrated a low threshold of only 42 mW, a pulse duration of 740 fs, and a maximum output power of 9.7 mW. Meanwhile, it exhibited a high signal-to-noise ratio of 72 dB. To the best of our knowledge, this is the first time of CuSe nanosheets as SA in EDFL. The results demonstrate that CuSe nanosheets are a highly promising nonlinear optical material with great potential for applications in ultrafast photonics.

9.
Opt Express ; 32(7): 12428-12437, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38571065

RESUMO

The challenges presented by the directly reflected field in optical feedback cavity-enhanced spectroscopy systems serve as substantial obstacles, introducing additional complexity to existing systems and compromising their sensitivity, as the underlying mechanisms of its adverse effects remain not fully understood. This study aims to address this issue by introducing a comprehensive analytical model. Additionally, frequency locking can be achieved by decreasing the feedback rate, the laser's linewidth enhancement factor, and the directly reflected field, and by increasing the refractive index of the gain medium, the length of the laser's resonant cavity, the electric field reflectivity of the laser's output facet, and the resonant field. These parameters can affect the feedback coupling rate pre-factor, and for a resonant cavity with a length of 0.394 m, optical feedback can only be established when the feedback coupling rate pre-factor is less than 1.05 × 109. Through experimental validation, we successfully confirm the effectiveness of the proposed solution in eliminating the detrimental effects of the directly reflected field. Importantly, this suppression is achieved without compromising other aspects of the system's performance. The research findings not only offer the potential to optimize various cavity-enhanced spectroscopy systems that rely on optical feedback but also show promising applications in advancing the development of high-purity spectrum diode lasers utilizing optical feedback from an external high-finesse cavity.

10.
Hum Reprod ; 39(6): 1275-1290, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38592717

RESUMO

STUDY QUESTION: Can the addition of late embryogenesis-abundant (LEA) proteins as a cryoprotective agent during the vitrification cryopreservation of in vitro matured oocytes enhance their developmental potential after fertilization? SUMMARY ANSWER: LEA proteins improve the developmental potential of human in vitro matured oocytes following cryopreservation, mostly by downregulating FOS genes, reducing oxidative stress, and inhibiting the formation of ice crystals. WHAT IS KNOWN ALREADY: Various factors in the vitrification process, including cryoprotectant toxicity, osmotic stress, and ice crystal formation during rewarming, can cause fatal damage to oocytes, thereby affecting the oocytes developmental potential and subsequent clinical outcomes. Recent studies have shown that LEA proteins possess high hydrophilicity and inherent stress tolerance, and can reduce low-temperature damage, although the molecular mechanism it exerts protective effects is still unclear. STUDY DESIGN, SIZE, DURATION: Two LEA proteins extracted and purified by us were added to solutions for vitrification-warming of oocytes at concentrations of 10, 100, and 200 µg/mL, to determine the optimal protective concentration for each protein. Individual oocyte samples were collected for transcriptomic analysis, with each group consisting of three sample replicates. PARTICIPANTS/MATERIALS, SETTING, METHODS: Immature oocytes were collected from patients who were undergoing combined in vitro fertilization (IVF) treatment and who had met the designated inclusion and exclusion criteria. These oocytes underwent in vitro maturation (IVM) culture for experimental research. A fluorescence microscope was used to detect the levels of mitochondrial membrane potential (MMP), reactive oxygen species (ROS), and calcium in the mitochondria of vitrified-warmed human oocytes treated with different concentrations of LEA proteins, and the protective effect of the protein on mitochondrial function was assessed. The levels of intracellular ice recrystallization inhibition (IRI) in human oocytes after vitrification-warming were characterized by the cryomicroscope, to determine the LEA proteins inhibitory effect on recrystallization. By analyzing transcriptome sequencing data to investigate the potential mechanism through which LEA proteins exert their cryoprotective effects. MAIN RESULTS AND THE ROLE OF CHANCE: The secondary structures of AfrLEA2 and AfrLEA3m proteins were shown to consist of a large number of α-helices and the proteins were shown to be highly hydrophilic, in agreement with previous reports. Confocal microscopy results showed that the immunofluorescence of AfrLEA2-FITC and AfrLEA3m-FITC-labeled proteins appeared to be extracellular and did not penetrate the cell membrane compared with the fluorescein isothiocyanate (FITC) control group, indicating that both AfrLEA2 and AfrLEA3m proteins were extracellular. The group treated with 100 µg/mL AfrLEA2 or AfrLEA3m protein had more uniform cytoplasmic particles and fewer vacuoles compared to the 10 and 200 µg/mL groups and were closest to the fresh group. In the 100 µg/mL groups, MMPs were significantly higher while ROS and calcium levels were significantly lower than those in the control group and were closer to the levels observed in fresh oocytes. Meanwhile, 100 µg/mL of AfrLEA2 or AfrLEA3m protein caused smaller ice crystal formation in the IRI assay compared to the control group treated with dimethylsulphoxide (DMSO) and ethylene glycol (EG); thus, the recrystallization inhibition was superior to that with the conventional cryoprotectants DMSO and EG. Further results revealed that the proteins improved the developmental potential of human oocytes following cryopreservation, likely by downregulating FOS genes and reducing oxidative stress. LIMITATIONS, REASONS FOR CAUTION: The in vitro-matured metaphase II (IVM-MII) oocytes used in the study, due to ethical constraints, may not accurately reflect the condition of MII oocytes in general. The AfrLEA2 and AfrLEA3m proteins are recombinant proteins and their synthetic stability needs to be further explored. WIDER IMPLICATIONS OF THE FINDINGS: LEA proteins, as a non-toxic and effective cryoprotectant, can reduce the cryoinjury of oocytes during cryopreservation. It provides a new promising method for cryopreservation of various cell types. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the National Key Research and Development Program of China (2022YFC2703000) and the National Natural Science Foundation of China (52206064). The authors declare no competing interest. TRIAL REGISTRATION NUMBER: N/A.


Assuntos
Criopreservação , Técnicas de Maturação in Vitro de Oócitos , Oócitos , Vitrificação , Humanos , Oócitos/efeitos dos fármacos , Oócitos/metabolismo , Técnicas de Maturação in Vitro de Oócitos/métodos , Feminino , Criopreservação/métodos , Crioprotetores/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Fertilização in vitro/métodos
11.
Opt Lett ; 49(4): 931-934, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38359219

RESUMO

A continuous-wave, tandem optical parametric oscillator (TOPO) based on a MgO-doped periodically poled LiNbO3 (MgO:PPLN) is demonstrated. Because the MgO:PPLN is tandemly pumped by the OPO's signal beam, it outputs simultaneously two groups of signal and idler with a single pump source. The entire range spans from 1398 to 1490 nm, 1914 to 2107 nm, 3720 to 4444 nm, and 4849 to 5190 nm, which is limited by periods of the MgO:PPLN and cavity mirror coatings. The TOPO, whose oscillation threshold of pump power exceeds 7 W, can be easily triggered by marginally increasing the pump power as long as the OPO process occurs. The maximum idler powers are respectively 2.6 W (at 3896 nm) and 34 mW (at 4863 nm), and the corresponding signal powers are both nearly 100 mW.

12.
Opt Lett ; 49(2): 202-205, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38194528

RESUMO

A novel, to the best of our knowledge, noise-immune cavity-enhanced optical heterodyne molecular spectrometry (NICE-OHMS) has been developed, utilizing optical feedback for laser-to-cavity locking with a common distributed-feedback diode laser. The system incorporates active control of the feedback phase and feedforward control of the laser current, allowing for consecutive laser frequency detuning by scanning a piezoelectric transducer (PZT) attached to the cavity. To enhance the fidelity of the spectroscopic signal, wavelength-modulated (wm) NICE-OHMS is implemented. Benefiting from the optical feedback, a modulation frequency of 15 kHz is achieved, surpassing the frequencies typically used in traditional NICE-OHMS setups. Then, the sub-Doppler-broadened wm-NICE-OHMS signal of acetylene at 1.53 µm is observed. A seven-fold improvement in signal to noise ratio has been demonstrated compared to NICE-OHMS alone and a limit of detection of 6.1 × 10-10cm-1 is achieved.

13.
Opt Lett ; 49(4): 956, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38359226

RESUMO

This publisher's note contains a correction to Opt. Lett.49, 202 (2024)10.1364/OL.507004.

14.
FASEB J ; 37(4): e22837, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36934389

RESUMO

Breast cancer is the most frequently diagnosed malignancy and the leading cause of cancer-related deaths in women worldwide. Cancer-associated fibroblasts (CAFs) are one of the fundamental cellular components of the tumor microenvironment and play a critical role in the initiation, progression, and therapy resistance of breast cancer. However, the detailed molecular mechanisms of CAFs activation from normal fibroblasts (NFs) are still not well understood. In the present study, we reported that ZNF32 expression in breast cancer cells was negatively correlated with CAF-related markers (FSP1, α-SMA, and FAP) in stromal fibroblasts, and loss of ZNF32 promoted the activation of CAFs, as evidenced by the enhanced proliferation and contractility of CAFs. ZNF32 deficiency-mediated fibroblast activation promoted the growth and metastasis of breast cancer cells in vitro and in vivo. Mechanistically, we demonstrated that ZNF32 inhibited TGFB1 transcription by directly binding to the -1968/-1962 region of the TGFB1 promoter, leading to the prevention of fibroblast activation. Altogether, our findings reveal an important mechanism by which ZNF32 suppression increases the transcription of the TGFB1 gene in breast cancer cells, and subsequently, elevated levels of secretory TGF-ß stimulate NFs transformation into CAFs, which in turn facilitates the malignant progression of breast cancer. Our data implicated ZNF32 as a potential therapeutic strategy against breast cancer.


Assuntos
Neoplasias da Mama , Fibroblastos Associados a Câncer , Humanos , Feminino , Fibroblastos Associados a Câncer/metabolismo , Neoplasias da Mama/metabolismo , Fibroblastos/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Proliferação de Células , Microambiente Tumoral/genética , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo
15.
Mol Pharm ; 21(4): 1838-1847, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38413029

RESUMO

The extensive use of opioids for chronic pain management has contributed significantly to the current opioid epidemic. While many alternative nonopioid analgesics are available, opioids remain the most potent analgesics for moderate to severe pain management. In addition to the implementation of multimodal analgesia, there is a pressing need for the development of more effective and safer opioids. In this study, we developed a thermoresponsive N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-based hydromorphone (HMP) prodrug (ProGel-HMP, HMP content = 16.2 wt %, in base form). The aqueous solution of ProGel-HMP was free-flowing at 4 °C but became a hydrogel when the temperature was raised to ≥37 °C, allowing sustained local retention when administered in vivo. When tested in the destabilization of the medial meniscus (DMM) mouse model of osteoarthritis (OA), ProGel-HMP was retained after intra-articular injection in the OA knee joint for at least 2 weeks postinjection, with low extra-articular distribution. ProGel-HMP was not detected in the central nervous system (CNS). A single dose of ProGel-HMP produced rapid and sustained joint pain resolution for greater than 14 days when compared to saline and dose-equivalent HMP controls, likely mediated through peripheral µ-opioid receptors in the knee joint. Systemic analgesia effect was absent in the DMM mice treated with ProGel-HMP, as evident in the lack of difference in tail flick response between the ProGel-HMP-treated mice and the controls (i.e., Healthy, Saline, and Sham). Repeated dosing of ProGel-HMP did not induce tolerance. Collectively, these data support the further development of ProGel-HMP as a potent, safe, long-acting and nonaddictive analgesic for better clinical pain management.


Assuntos
Analgesia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Osteoartrite , Pró-Fármacos , Camundongos , Animais , Hidromorfona , Manejo da Dor , Pró-Fármacos/uso terapêutico , Dor/tratamento farmacológico , Analgésicos Opioides/efeitos adversos , Analgésicos/uso terapêutico
16.
J Org Chem ; 89(12): 9056-9062, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38857440

RESUMO

A palladium(II)-catalyzed Markovnikov hydroboration of aryl alkenes with readily available bis(pinacolato)diboron (B2pin2) is reported. The reaction proceeded with low catalyst loading (0.5 mol %) in the absence of N- or P-containing ligands, affording the products in up to 90% yield. Trifluoracetic acid serves as the hydrogen source, enabling the synthesis of benzylic boronic esters under mild ambient conditions.

17.
Cell Biol Int ; 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38706122

RESUMO

Cisplatin is commonly used for the chemotherapy of tongue squamous cell carcinoma (TSCC); however, adverse side effects and drug resistance impact its therapeutic efficacy. Capsaicin is an active ingredient in chili peppers that exerts antitumor effects, whether it exerts antitumor effects on cisplatin-resistant cells remains unknown. Therefore, in this study, we investigated the effect of capsaicin on cisplatin resistance in TSCC cells and explored the underlying mechanisms. A cisplatin-resistant TSCC cell line was established by treated with increasing cisplatin concentrations. Combined treatment with cisplatin and capsaicin decreased the glucose consumption and lactate dehydrogenase activity and increased the adenosine triphosphate production both in vitro and in vivo, suggesting the inhibition of the Warburg effect. Moreover, this combined treatment induced cell apoptosis and significantly upregulated the levels of proapoptotic proteins, such as Bax, cleaved caspase-3, -7, and -9, and apoptosis-inducing factor. In contrast, levels of the antiapoptotic protein, Bcl-2, were downregulated. Additionally, LKB1 and AMPK activities were stimulated, whereas those of AKT and mTOR were suppressed. Notably, AMPK knockdown abolished the inhibitory effects of capsaicin and cisplatin on the AKT/mTOR signaling pathway and Warburg effect. Overall, combined treatment with capsaicin and cisplatin reversed cisplatin resistance by inhibiting the Warburg effect and facilitating mitochondrial-dependent apoptosis via the AMPK/AKT/mTOR axis. Our findings suggest combination therapy with capsaicin and cisplatin as a potentially novel strategy and highlight capsaicin as a promising adjuvant drug for TSCC treatment.

18.
BMC Gastroenterol ; 24(1): 5, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38166630

RESUMO

INTRODUCTION: Pancreaticobiliary reflux (PBR) can induce gallstone formation; however, its pathogenic mechanism remains unclear. In this study, we explored the mechanism of PBR by the non-targeted metabolomic analysis of bile in patients with PBR. OBJECTIVE: The aim of this study was to investigate the pathogenic mechanism in PBR by the non-targeted metabolomic analysis of bile collected during surgery. METHODS: Sixty patients who underwent gallstone surgery at our center from December 2020 to May 2021 were enrolled in the study. According to the level of bile amylase, 30 patients with increased bile amylase ( > 110 U/L) were classified into the PBR group, and the remaining 30 patients were classified into the control group (≤ 110 U/L). The metabolomic analysis of bile was performed. RESULTS: The orthogonal projections to latent structure-discriminant analysis of liquid chromatography mass spectrometry showed significant differences in bile components between the PBR and control groups, and 40 metabolites were screened by variable importance for the projection value (VIP > 1). The levels of phosphatidylcholine (PC) and PC (20:3(8Z,11Z,14Z)/14:0) decreased significantly, whereas the levels of lysoPC (16:1(9z)/0:0), lysoPC (15:0), lysoPC (16:0), palmitic acid, arachidonic acid, leucine, methionine, L-tyrosine, and phenylalanine increased. CONCLUSIONS: Significant differences in bile metabolites were observed between the PBR and control groups. Changes in amino acids and lipid metabolites may be related to stone formation and mucosal inflammation.


Assuntos
Bile , Cálculos Biliares , Humanos , Cálculos Biliares/cirurgia , Cálculos Biliares/metabolismo , Metabolômica/métodos , Espectrometria de Massa com Cromatografia Líquida , Amilases
19.
Phys Chem Chem Phys ; 26(16): 12594-12599, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38596870

RESUMO

We report the spin reorientation transition (SRT) and the low field controllable continuous spin switching (SSW) of the Tm0.75Yb0.25FeO3 (TYFO) single crystal in this study. The SRT, characterized by the transition from Γ2(Fx, Cy, Gz)-Γ4(Gx, Ay, Fz), occurs within the temperature range of 20-27 K. Under an external magnetic field of 50 Oe, the SSW occurs along the c-axis at approximately 98 K due to the reversal of Tm3+ magnetic moment induced by the magnetic coupling change between Tm3+ and Fe3+, transitioning from a parallel to an antiparallel alignment. Notably, a continuous SSW is observed along the a-axis at low temperatures, which has not been previously reported in rare earth orthoferrites. This unique behavior can be easily manipulated by low magnetic fields within the temperature range of 2-20 K. Both the spin reorientation transition and spin switching phenomena in the TYFO single crystal arise from interactions between rare earth ions and iron ions and can be effectively regulated by applied low magnetic fields, making it a promising material for low-field spin devices.

20.
Dig Dis Sci ; 69(5): 1852-1862, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38514499

RESUMO

BACKGROUND: Early rebleeding is a significant complication of endoscopic treatment for esophagogastric variceal hemorrhage (EGVH). However, a reliable predictive model is currently lacking. AIMS: To identify risk factors for rebleeding within 6 weeks and establish a nomogram for predicting early rebleeding after endoscopic treatment of EVGH. METHODS: Demographic information, comorbidities, preoperative evaluation, endoscopic features, and laboratory tests were collected from 119 patients who were first endoscopic treatment for EGVH. Independent risk factors for early rebleeding were determined through least absolute shrinkage and selection operator logistic regression. The discrimination, calibration, and clinical utility of the nomogram were assessed and compared with the model for end-stage liver disease (MELD), Child-Pugh, and albumin-bilirubin (ALBI) scores using receiver-operating characteristic (ROC) curves, calibration plots, and decision curve analyses (DCA). RESULTS: Early rebleeding occurred in 39 patients (32.8%) within 6 weeks after endoscopic treatment. Independent early rebleeding factors included gastric variceal hemorrhage (GVH), concomitant hepatocellular carcinoma (HCC), international normalized ratio (INR), and creatinine. The nomogram demonstrated exceptional calibration and discrimination capability. The area under the curve for the nomogram was 0.758 (95% CI 0.668-0.848), and it was validated at 0.71 through cross-validation and bootstrapping validation. The DCA and ROC curves demonstrated that the nomogram outperformed the MELD, Child-Pugh, and ALBI scores. CONCLUSIONS: Compared with existing prediction scores, the nomogram demonstrated superior discrimination, calibration, and clinical applicability for predicting rebleeding in patients with EGVH after endoscopic treatment. Therefore, it may assist clinicians in the early implementation of aggressive treatment and follow-up.


Assuntos
Varizes Esofágicas e Gástricas , Hemorragia Gastrointestinal , Nomogramas , Recidiva , Humanos , Varizes Esofágicas e Gástricas/cirurgia , Varizes Esofágicas e Gástricas/diagnóstico , Varizes Esofágicas e Gástricas/etiologia , Masculino , Feminino , Pessoa de Meia-Idade , Hemorragia Gastrointestinal/etiologia , Hemorragia Gastrointestinal/cirurgia , Hemorragia Gastrointestinal/diagnóstico , Idoso , Fatores de Risco , Estudos Retrospectivos , Curva ROC , Valor Preditivo dos Testes , Adulto
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