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1.
Immunity ; 56(11): 2555-2569.e5, 2023 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-37967531

RESUMEN

Tumors develop by invoking a supportive environment characterized by aberrant angiogenesis and infiltration of tumor-associated macrophages (TAMs). In a transgenic model of breast cancer, we found that TAMs localized to the tumor parenchyma and were smaller than mammary tissue macrophages. TAMs had low activity of the metabolic regulator mammalian/mechanistic target of rapamycin complex 1 (mTORC1), and depletion of negative regulator of mTORC1 signaling, tuberous sclerosis complex 1 (TSC1), in TAMs inhibited tumor growth in a manner independent of adaptive lymphocytes. Whereas wild-type TAMs exhibited inflammatory and angiogenic gene expression profiles, TSC1-deficient TAMs had a pro-resolving phenotype. TSC1-deficient TAMs relocated to a perivascular niche, depleted protein C receptor (PROCR)-expressing endovascular endothelial progenitor cells, and rectified the hyperpermeable blood vasculature, causing tumor tissue hypoxia and cancer cell death. TSC1-deficient TAMs were metabolically active and effectively eliminated PROCR-expressing endothelial cells in cell competition experiments. Thus, TAMs exhibit a TSC1-dependent mTORC1-low state, and increasing mTORC1 signaling promotes a pro-resolving state that suppresses tumor growth, defining an innate immune tumor suppression pathway that may be exploited for cancer immunotherapy.


Asunto(s)
Células Progenitoras Endoteliales , Proteínas Supresoras de Tumor , Animales , Humanos , Serina-Treonina Quinasas TOR/metabolismo , Proteína 1 del Complejo de la Esclerosis Tuberosa/genética , Macrófagos Asociados a Tumores/metabolismo , Células Progenitoras Endoteliales/metabolismo , Receptor de Proteína C Endotelial , Diana Mecanicista del Complejo 1 de la Rapamicina , Neovascularización Patológica , Mamíferos
2.
Nature ; 619(7970): 616-623, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37380769

RESUMEN

In metazoan organisms, cell competition acts as a quality control mechanism to eliminate unfit cells in favour of their more robust neighbours1,2. This mechanism has the potential to be maladapted, promoting the selection of aggressive cancer cells3-6. Tumours are metabolically active and are populated by stroma cells7,8, but how environmental factors affect cancer cell competition remains largely unknown. Here we show that tumour-associated macrophages (TAMs) can be dietarily or genetically reprogrammed to outcompete MYC-overexpressing cancer cells. In a mouse model of breast cancer, MYC overexpression resulted in an mTORC1-dependent 'winner' cancer cell state. A low-protein diet inhibited mTORC1 signalling in cancer cells and reduced tumour growth, owing unexpectedly to activation of the transcription factors TFEB and TFE3 and mTORC1 in TAMs. Diet-derived cytosolic amino acids are sensed by Rag GTPases through the GTPase-activating proteins GATOR1 and FLCN to control Rag GTPase effectors including TFEB and TFE39-14. Depletion of GATOR1 in TAMs suppressed the activation of TFEB, TFE3 and mTORC1 under the low-protein diet condition, causing accelerated tumour growth; conversely, depletion of FLCN or Rag GTPases in TAMs activated TFEB, TFE3 and mTORC1 under the normal protein diet condition, causing decelerated tumour growth. Furthermore, mTORC1 hyperactivation in TAMs and cancer cells and their competitive fitness were dependent on the endolysosomal engulfment regulator PIKfyve. Thus, noncanonical engulfment-mediated Rag GTPase-independent mTORC1 signalling in TAMs controls competition between TAMs and cancer cells, which defines a novel innate immune tumour suppression pathway that could be targeted for cancer therapy.


Asunto(s)
Competencia Celular , Técnicas de Reprogramación Celular , Inmunidad Innata , Neoplasias , Macrófagos Asociados a Tumores , Animales , Ratones , Aminoácidos/metabolismo , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Competencia Celular/genética , Competencia Celular/inmunología , Proteínas en la Dieta/farmacología , Modelos Animales de Enfermedad , GTP Fosfohidrolasas/metabolismo , Lisosomas/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Neoplasias/genética , Neoplasias/inmunología , Neoplasias/metabolismo , Neoplasias/patología , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Macrófagos Asociados a Tumores/inmunología , Macrófagos Asociados a Tumores/metabolismo
3.
BMC Urol ; 24(1): 188, 2024 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-39217318

RESUMEN

BACKGROUND: Benign prostatic hyperplasia (BPH) is a prevalent condition in aging males, leading to bladder outlet obstruction (BOO) and associated urinary symptoms. With increasing life expectancy, the incidence of BPH and its co-morbidities, like inguinal hernia, has risen. This study explores the efficacy of combining transurethral resection of the prostate (TURP) and inguinal hernioplasty in a single surgical session to address both conditions, potentially reducing the need for multiple hospitalizations and surgical interventions. METHODS: This retrospective study at Chi Mei Medical Center included patients from 2014 to 2023 who underwent concurrent TURP and inguinal hernioplasty. A total of 85 patients met the criteria defined for this study. Preoperative, intraoperative, and postoperative characteristics were meticulously documented. Outcomes evaluated included the duration of the surgery, incidence of intraoperative and postoperative complications, duration of Foley catheterization, length of hospital stay, and treatment efficacy. Additionally, we conducted a comparative assessment of the surgical outcomes between two distinct techniques for inguinal hernia repair: open hernioplasty and laparoscopic hernioplasty (LH). RESULTS: In 85 patients who met the criteria, the mean age was 71.1 ± 7.8 years. The study reported no significant intraoperative complications, and postoperative care was focused on monitoring for blood loss, infection, and managing pain. The average postoperative hospital stay was 2.9 ± 1.0 days and the mean duration of catheterization was 51.6 ± 16.7 h, with a minimal complication rate observed during the one-year follow-up. A significant reduction in both operative duration and catheterization interval was observed in patients undergoing LH as opposed to those receiving open hernioplasty. CONCLUSION: Concurrent TURP and inguinal hernioplasty effectively manage BOO due to BPH and inguinal hernias with minimal complications, suggesting a viable approach to reducing hospital stays and surgical interventions. Laparoscopic techniques, in particular, offer benefits in operative efficiency and recovery time, making combined surgery a feasible option for selected patients.


Asunto(s)
Hernia Inguinal , Herniorrafia , Hiperplasia Prostática , Resección Transuretral de la Próstata , Humanos , Masculino , Hernia Inguinal/cirugía , Estudios Retrospectivos , Anciano , Resección Transuretral de la Próstata/métodos , Herniorrafia/métodos , Hiperplasia Prostática/cirugía , Hiperplasia Prostática/complicaciones , Persona de Mediana Edad , Resultado del Tratamiento , Anciano de 80 o más Años , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología
4.
J Am Chem Soc ; 145(23): 12459-12464, 2023 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-37255463

RESUMEN

The cis/trans stereochemistry of repeating alkenes in polymers provides a powerful handle to modulate the thermal and mechanical properties of these soft materials, but synthetic methods to precisely dictate this parameter remain scarce. We report herein a cis-selective acyclic diene metathesis (ADMET) polymerization of readily available α,ω-diene monomers with high functional group tolerance. Identification of a highly stereoselective cyclometalated Ru catalyst allowed the synthesis of a broad array of polymers with cis contents up to 99%. This platform was leveraged to study the impact of the cis geometry on the thermal and mechanical properties of polyalkenamers, including an ABA triblock copolymer synthesized via extension of a cis-rich telechelic polyoctenamer with d,l-lactide. These results suggest that cis-selective ADMET affords an efficient strategy to tune the properties of a variety of polymers.

5.
J Phys Chem A ; 126(41): 7548-7556, 2022 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-36217924

RESUMEN

Machine learning predictions of molecular thermochemistry, such as formation enthalpy, have been limited for large and complicated species because of the lack of available training data. Such predictions would be important in the prediction of reaction thermodynamics and the construction of kinetic models. Herein, we introduce a graph-based deep learning approach that can separately learn the enthalpy contribution of each atom in its local environment with the effect of the overall molecular structure taken into account. Because this approach follows the additivity scheme of increment theory, it can be generalized to larger and more complicated species not present in the training data. By training the model on molecules with up to 11 heavy atoms, it can predict the formation enthalpy of testing molecules with up to 42 heavy atoms with a mean absolute error of 2 kcal/mol, which is less than half of the error of the conventional increment theory. We expect that this approach will also enable rapid prediction of other extensive properties of large molecules that are difficult to derive from experiments or ab initio calculation.

6.
J Am Chem Soc ; 142(28): 11983-11987, 2020 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-32588629

RESUMEN

Poly(p-phenylenevinylene)s (PPVs), a staple of the conductive polymer family, consist of alternating alkene and phenyl groups in conjugation. The physical properties of this organic material are intimately linked to the cis/trans configuration of the alkene groups. While many synthetic methods afford PPVs with all-trans stereochemistry, very few deliver the all-cis congeners. We report herein a synthesis of all-cis PPVs with living characteristics via stereoretentive ring-opening metathesis polymerization (ROMP). Exquisite catalyst control allows for the preparation of homopolymers or diblock copolymers with perfect stereoselectivity, narrow dispersities, and predictable average molar masses. All-cis PPVs can then serve as light-responsive polymers through clean photoisomerization of the stilbenoid units.

7.
Am J Otolaryngol ; 40(1): 22-29, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30249374

RESUMEN

PURPOSE: The efficacy of postoperative oral corticosteroids on surgical outcomes in chronic rhinosinusitis with nasal polyps (CRSwNP) patients following endoscopic sinus surgery (ESS) remains controversial. This study evaluated the potential benefits of postoperative oral corticosteroids on surgical outcomes in CRSwNP patients and investigated the differential effects on eosinophilic CRSwNP (ECRSwNP) and noneosinophilic CRSwNP (NECRSwNP). MATERIALS AND METHODS: Patients with bilateral CRSwNP who underwent ESS were enrolled and randomized to receive either oral prednisolone (30 mg/day) or placebo for 2 weeks after surgery. Visual analog scale (VAS) and Sino-Nasal Outcome Test 22 (SNOT-22) scores were chosen as the subjective outcomes, evaluated at preoperative baseline and 1, 3, and 6 months postoperatively. Lund-Kennedy Endoscopic Scores (LKESs) were used as the objective outcome, evaluated at preoperative baseline and at 2 weeks and 2, 3, and 6 months postoperatively. RESULTS: In total, 100 patients with bilateral CRSwNP were enrolled, of whom only 82 completed the 6-month follow-up. The subjective outcomes showed no significant difference at each follow-up points. Of the objective outcomes, the corticosteroid group reporting a trend of improvement in LKESs at 6 months postoperatively (p = 0.05). After stratification by tissue eosinophils, only patients with NECRSwNP (<10 eosinophils/HPF) demonstrated a significant improvement in LKESs at 3 months postoperatively (p = 0.03). CONCLUSIONS: Postoperative oral corticosteroids did not provide additional improvements in VAS and SNOT-22 scores; nevertheless, a trend of LKES improvement was noted at 6 months postoperatively. After stratification by tissue eosinophils, this effect was significant only among NECRSwNP patients at 3 months follow-up.


Asunto(s)
Eosinofilia/terapia , Glucocorticoides/administración & dosificación , Pólipos Nasales/terapia , Prednisolona/administración & dosificación , Rinitis/terapia , Sinusitis/terapia , Administración Oral , Adulto , Enfermedad Crónica , Endoscopía , Eosinofilia/complicaciones , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pólipos Nasales/etiología , Cuidados Posoperatorios , Rinitis/etiología , Sinusitis/etiología , Resultado del Tratamiento
8.
Opt Lett ; 43(16): 4029-4032, 2018 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-30106944

RESUMEN

A noninvasive method for characterizing Si/Mo thin-film stack thickness and its complex transfer function using common-path optical coherence tomography is proposed, analyzed, and experimentally demonstrated. A laser-produced plasma (LPP)-based extreme ultraviolet (EUV) source was excited by a four-stage nanosecond Yb:fiber laser amplifier with a pulse energy of 1.01 mJ. The tabletop LPP EUV source was compact and stable for generating the EUV interference fringes. The measured complex transfer function of the Si/Mo stack was verified near the pristine 13.5-nm wavelength range.

9.
IEEE Robot Autom Lett ; 9(3): 2104-2111, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38313832

RESUMEN

Lower-limb wearable robots designed to assist people in everyday activities must reliably recover from any momentary confusion about what the user is doing. Such confusion might arise from momentary sensor failure, collision with an obstacle, losing track of gait due to an out-of-distribution stride, etc. Systems that infer a user's walking condition from angle measurements using Bayesian filters (e.g., extended Kalman filters) have been shown to accurately track gait across a range of activities. However, due to the fundamental problem structure and assumptions of Bayesian filter implementations, such estimators risk becoming 'lost' with little hope of a quick recovery. In this paper, we 1) introduce a Monte Carlo-based metric to quantify the robustness of pattern-tracking gait estimators, 2) propose strategies for improving tracking robustness, and 3) systematically evaluate them against this new metric using a publicly available gait biomechanics dataset. Our results, aggregating 2,700 trials of simulated walking of 10 able-bodied subjects under random perturbations, suggest that drastic improvements in robustness (from 8.9% to 99%) are possible using relatively simple modifications to the estimation process without noticeably degrading estimator accuracy.

10.
bioRxiv ; 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38617314

RESUMEN

How genetic lesions drive cell transformation and whether they can be circumvented without compromising function of non-transformed cells are enduring questions in oncology. Here we show that in mature T cells-in which physiologic clonal proliferation is a cardinal feature- constitutive MYC transcription and Tsc1 loss in mice modeled aggressive human malignancy by reinforcing each other's oncogenic programs. This cooperation was supported by MYC-induced large neutral amino acid transporter chaperone SLC3A2 and dietary leucine, which in synergy with Tsc1 deletion overstimulated mTORC1 to promote mitochondrial fitness and MYC protein overexpression in a positive feedback circuit. A low leucine diet was therapeutic even in late-stage disease but did not hinder T cell immunity to infectious challenge, nor impede T cell transformation driven by constitutive nutrient mTORC1 signaling via Depdc5 loss. Thus, mTORC1 signaling hypersensitivity to leucine as an onco-nutrient enables an onco-circuit, decoupling pathologic from physiologic utilization of nutrient acquisition pathways.

11.
J Biomed Opt ; 28(9): 096005, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37720189

RESUMEN

Significance: An integrated cellular-resolution optical coherence tomography (OCT) module with near-infrared Raman spectroscopy was developed on the discrimination of various skin cancer cells and normal cells. Micron-level three-dimensional (3D) spatial resolution and the spectroscopic capability on chemical component determination can be obtained simultaneously. Aim: We experimentally verified the effectiveness of morphology, intensity, and spectroscopy features for discriminating skin cells. Approach: Both spatial and spectroscopic features were employed for the discrimination of five types of skin cells, including keratinocytes (HaCaT), the cell line of squamous cell carcinoma (A431), the cell line of basal cell carcinoma (BCC-1/KMC), primary melanocytes, and the cell line of melanoma (A375). The cell volume, compactness, surface roughness, average intensity, and internal intensity standard deviation were extracted from the 3D OCT images. After removing the fluorescence components from the acquired Raman spectra, the entire spectra (600 to 2100 cm-1) were used. Results: An accuracy of 85% in classifying five types of skin cells was achieved. The cellular-resolution OCT images effectively differentiate cancer and normal cells, whereas Raman spectroscopy can distinguish the cancer cells with nearly 100% accuracy. Conclusions: Among the OCT image features, cell surface roughness, internal average intensity, and standard deviation of internal intensity distribution effectively differentiate the cancerous and normal cells. The three features also worked well in sorting the keratinocyte and melanocyte. Using the full Raman spectra, the melanoma and keratinocyte-based cell carcinoma cancer cells can be discriminated effectively.


Asunto(s)
Carcinoma Basocelular , Melanoma , Neoplasias Cutáneas , Humanos , Tomografía de Coherencia Óptica , Espectrometría Raman , Neoplasias Cutáneas/diagnóstico por imagen , Carcinoma Basocelular/diagnóstico por imagen , Melanoma/diagnóstico por imagen , Aprendizaje Automático
12.
Nat Chem ; 15(1): 14-20, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36280767

RESUMEN

The cis/trans geometry of olefins is known to dramatically influence the thermal and mechanical properties of polyalkenamers. Yet, polymerization methods that efficiently control this parameter are scarce. Here we report the development of a stereoretentive acyclic diene metathesis polymerization that uses the reactivity of dithiolate Ru carbenes combined with cis monomers. These Ru catalysts exhibit exquisite retention of the cis geometry and tolerate many polar functional groups, enabling the synthesis of all-cis polyesters, polycarbonates, polyethers and polysulfites. The stereoretentive acyclic diene metathesis polymerization is also characterized by low catalyst loadings and tolerance towards trans impurities in the monomer batch, which should facilitate large-scale implementation. Modulation of the reaction temperature and time leads to an erosion of stereoretention, permitting a stereocontrolled synthesis of polyalkenamers with predictable cis:trans ratios. The impact of the stereochemistry of the repeating alkenes on the thermal properties is clearly demonstrated through differential scanning calorimetry and thermogravimetric analysis.


Asunto(s)
Alquenos , Polienos , Polimerizacion , Alquenos/química , Temperatura , Catálisis
13.
Chem Commun (Camb) ; 59(71): 10660-10663, 2023 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-37581279

RESUMEN

Piperic acid derivatives were found to affect the islet amyloid polypeptide (IAPP) aggregation process. Structure-activity relationship studies revealed that PAD-13 was an efficient molecular modulator to accelerate IAPP fibril formation by promoting primary and secondary nucleation and reducing its antimicrobial activity.


Asunto(s)
Antiinfecciosos , Polipéptido Amiloide de los Islotes Pancreáticos , Polipéptido Amiloide de los Islotes Pancreáticos/farmacología , Polipéptido Amiloide de los Islotes Pancreáticos/química , Amiloide/química , Ácidos Grasos Insaturados , Antiinfecciosos/farmacología
14.
J Appl Crystallogr ; 56(Pt 4): 988-993, 2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37555211

RESUMEN

Liposome development is of great interest owing to increasing requirements for efficient drug carriers. The structural features and thermal stability of such liposomes are crucial in drug transport and delivery. Reported here are the results of the structural characterization of PEGylated liposomes via small- and wide-angle X-ray scattering and an asymmetric flow field-flow fractionation (AF4) system coupled with differential refractive-index detection, multi-angle light scattering (MALS) and dynamic light scattering. This integrated analysis of the exemplar PEGylated liposome formed from hydrogenated soy phosphatid-yl-choline (HSPC) with the addition of cholesterol reveals an average hydro-dynamic radius (R h) of 52 nm with 10% polydispersity, a comparable radius of gyration (R g) and a major liposome particle mass of 118 kDa. The local bilayer structure of the liposome is found to have asymmetric electronic density profiles in the inner and outer leaflets, sandwiched by two PEGylated outer layers ca 5 nm thick. Cholesterol was found to effectively intervene in lipid chain packing, resulting in the thickening of the liposome bilayer, an increase in the area per lipid and an increase in liposome size, especially in the fluid phase of the liposome. These cholesterol effects show signs of saturation at cholesterol concentrations above ca 1:5 cholesterol:lipid molar ratio.

15.
J Biophotonics ; 15(1): e202100249, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34662510

RESUMEN

With homemade active crystalline fibers, we generated bright and broadband light sources for full-field optical coherence tomography, offering deep penetration into skin tissues with cellular resolution at a high frame rate. Extraction of backscattered spectra from the tissue has potential applications in biomedicine. The hysteresis nonlinearity of the piezoelectric transducer actuating the Mirau interferometer has been greatly reduced by a feedforward compensation approach. The linearized hysteresis response enables us to extract depth-dependent spectra accurately. To validate, the complex dispersion of a fused silica plate was characterized with 2% error. Further validation on an in vitro setting, the backscattered spectra from indocyanine green pigment and nonpigmented microspheres were obtained and verified. For in vivo skin measurement, the backscattered spectra show depth-dependent spectral shift and bandwidth variation due to the complex skin anatomy and pigment absorption. Such a high-speed spectra acquisition of in vivo deep tissue backscattering could lead to disease diagnosis in clinical settings.


Asunto(s)
Piel , Tomografía de Coherencia Óptica , Humanos , Piel/diagnóstico por imagen
16.
Materials (Basel) ; 15(7)2022 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-35407685

RESUMEN

In this study, a negative replica layer of leaf surface microstructures was used to cover the top surfaces of semitransparent thin-film luminescent solar concentrators (LSCs) to enhance the concentrators' performance. With low reflection on the air-glass interface of the glass plate in a thin-film LSC, a negative replica layer enables the scattering of incident sunlight and increases the path of light transmitted into the LSC and the thin phosphor layer at the bottom surface of the LSC. The incident sunlight is therefore more likely to interact with the phosphor particles in the thin-film phosphor layer, thereby enhancing the performance of the LSC. In this study, semitransparent thin-film LSCs with different inorganic phosphors were examined. The experimental results revealed that the optical collection efficiency of semitransparent thin-film LSCs covered with negative replica layers of leaf surface microstructures was higher than that of the semitransparent thin-film LSCs without negative replica layers. Furthermore, the LSCs with negative replica layers with high haze ratios exhibited high optical collection efficiency. Integrating negative replica layers of leaf surface microstructures as semitransparent layers in thin-film LSCs may optimize the application of LSCs in building-integrated photovoltaics (BIPVs).

17.
PLoS One ; 17(10): e0275450, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36194586

RESUMEN

OBJECTIVE: This study investigated how peripheral axonal excitability changes in ischemic stroke patients with hemiparesis or hemiplegia, reflecting the plasticity of motor axons due to corticospinal tract alterations along the poststroke stage. METHODS: Each subject received a clinical evaluation, nerve conduction study, and nerve excitability test. Nerve excitability tests were performed on motor median nerves in paretic and non-paretic limbs in the acute stage of stroke. Control nerve excitability test data were obtained from age-matched control subjects. Some patients underwent excitability examinations several times in subacute or chronic stages. RESULTS: A total of thirty patients with acute ischemic stroke were enrolled. Eight patients were excluded due to severe entrapment neuropathy in the median nerve. The threshold current for 50% compound muscle action potential (CMAP) was higher in paretic limbs than in control subjects. Furthermore, in the cohort with severe patients (muscle power ≤ 3/5 in affected hands), increased threshold current for 50% CMAP and reduced subexcitability were noted in affected limbs than in unaffected limbs. In addition, in the subsequent study of those severe patients, threshold electrotonus increased in the hyperpolarization direction: TEh (100-109 ms), and the minimum I/V slope decreased. The above findings suggest the less excitable and less accommodation in lower motor axons in the paretic limb caused by ischemic stroke. CONCLUSION: Upper motor neuron injury after stroke can alter nerve excitability in lower motor neurons, and the changes are more obvious in severely paretic limbs. The accommodative changes of axons progress from the subacute to the chronic stage after stroke. Further investigation is necessary to explore the downstream effects of an upper motor neuron insult in the peripheral nerve system.


Asunto(s)
Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Potenciales de Acción , Axones/fisiología , Humanos , Nervio Mediano/fisiología , Plasticidad Neuronal , Accidente Cerebrovascular/complicaciones
18.
Trends Cancer ; 7(11): 1010-1019, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34305041

RESUMEN

Investigation of cancer as a cell-level disease has led to the development of cancer cell-directed therapies including cytotoxic T lymphocyte (CTL)-based immunotherapy; yet, many patients are refractory to these modalities of cancer treatment and acquired resistance frequently occurs. Of note, cancer environment controls the manifestation of cancerous cell phenotype. Helper T (Th) cells orchestrate immune defense responses targeting cancer cells as well as the tumor microenvironment. Recent studies have shown that in addition to interferon (IFN)-γ-producing Th1 cells, interleukin (IL)-4-producing Th2 cells function as potent anticancer effectors in part by promoting tumor stroma reconfiguration and tumor tissue repair. Such Th cell-mediated tissue-level immunity may be harnessed for novel modalities of cancer environment immunotherapy.


Asunto(s)
Neoplasias , Células TH1 , Humanos , Neoplasias/terapia , Linfocitos T Citotóxicos , Linfocitos T Colaboradores-Inductores , Células Th2 , Microambiente Tumoral
19.
Nanomaterials (Basel) ; 11(2)2021 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-33562217

RESUMEN

A FePt(B, Ag, C) granular film was formed from post-annealed B4C(1.0 nm)/FePt(Ag, C) layers at a substrate temperature of 470 °C for 2 min. The 6 nm thick FePt(B, Ag, C) film demonstrates high perpendicular magnetic anisotropy (Ku = 2.83 × 107 erg/cm3 at 100 K) and out-of-plane coercivity (Hc = 38.0 kOe at 100 K). The Ku and out-of-plane Hc are respectively increased from 38% and 46% between 350 K and 50 K. The sample with a thickness of 8 nm also shows a similar trend for magnetic properties; however, the tiny magnetization kink which may come from rare Fe-B or disordered FePt grains was observed in the easy axis loop. The intrinsic (ΔHint = 12.6 kOe) and extrinsic switching field distribution (ΔHext = 1.62 kOe) were characterized by major and minor loops to correlate the microstructural grains. The coupled FePt grains grown on a single MgTiON grain were observed in a high-resolution transmission electron microstructure (HRTEM) image. This small intergranular exchange coupling was defined by estimating the magnetic cluster size (46.6 nm) from ΔHext and the average grains size (28.2 nm) from TEM images. The temperature dependence of coercivity was fitted to further understand the magnetization reversal process. The lower microstructural parameter was evidenced in the imperfect grain morphology.

20.
Biomaterials ; 272: 120765, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33780686

RESUMEN

Ischemic stroke, and the consequent brain cell death, is a common cause of death and disability worldwide. Current treatments that primarily aim to relieve symptoms are relatively inefficient in achieving brain tissue regeneration and functional recovery, and thus novel therapeutic options are urgently needed. Although cell-based therapies have shown promise for treating the infarcted brain, a recurring challenge is the inadequate retention and engraftment of transplanted cells at the target tissue, thereby limiting the ultimate therapeutic efficacy. Here, we show that transplantation of preassembled three-dimensional (3D) spheroids of mesenchymal stem cells (MSCs) and vascular endothelial cells (ECs) results in significantly improved cell retention and survival compared with conventional mixed-cell suspensions. The transplanted 3D spheroids exhibit notable neuroprotective, proneurogenic, proangiogenic and anti-scarring potential as evidenced by clear extracellular matrix structure formation and paracrine factor expression and secretion; this ultimately results in increased structural and motor function recovery in the brain of an ischemic stroke mouse model. Therefore, transplantation of MSCs and ECs using the 3D cell spheroid configuration not only reduces cell loss during cell harvesting/administration but also enhances the resultant therapeutic benefit, thus providing important proof-of-concept for future clinical translation.


Asunto(s)
Lesiones Encefálicas , Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Trasplante de Células Madre Mesenquimatosas , Accidente Cerebrovascular , Animales , Isquemia Encefálica/terapia , Células Endoteliales , Ratones , Esferoides Celulares , Accidente Cerebrovascular/terapia
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