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Coagulación Intravascular Diseminada , Linfoma de Células del Manto , Humanos , Masculino , Persona de Mediana Edad , Coagulación Intravascular Diseminada/etiología , Coagulación Intravascular Diseminada/diagnóstico , Linfoma de Células del Manto/complicaciones , Linfoma de Células del Manto/diagnóstico , Linfoma de Células del Manto/patologíaRESUMEN
OBJECTIVES: This study aimed to quantify the submandibular gland in suppurative sialadenitis, primary Sjögren's syndrome (pSS) and radiation-induced sialadenitis using the apparent diffusion coefficient (ADC) for differential diagnosis. SUBJECTS AND METHODS: This retrospective study included 16 patients with suppurative sialadenitis (n = 9), pSS (n = 3) and radiation-induced sialadenitis (n = 4) who underwent magnetic resonance imaging between June 2006 and May 2022. The ADC of the submandibular glands in each state was calculated, and the differences were analysed using a one-way analysis of variance and Tukey's post hoc test. Receiver operating characteristic curves were used to assess the ability of the ADC to distinguish each condition. Statistical significance was set at p < 0.05. RESULTS: The mean ADC value (×10-3 mm2/s) ± standard deviation in the control (non-affected side of the suppurative sialadenitis group), suppurative sialadenitis, pSS and radiation-induced groups were 0.94 ± 0.16, 1.24 ± 0.16, 1.33 ± 0.13 and 1.5 ± 0.12, respectively (p < 0.001). The diagnostic value for distinguishing each group was ≥0.75. CONCLUSION: ADC values are useful for quantitatively assessing and distinguishing submandibular glands in suppurative sialadenitis, primary Sjögren's syndrome and radiation-induced sialadenitis.
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Cromosomas Humanos Par 14 , Cromosomas Humanos Par 21 , Cromosomas Humanos Par 8 , Subunidad alfa 2 del Factor de Unión al Sitio Principal , Leucemia Mieloide Aguda , Proteína 1 Compañera de Translocación de RUNX1 , Translocación Genética , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/diagnóstico , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Proteína 1 Compañera de Translocación de RUNX1/genética , Cromosomas Humanos Par 21/genética , Cromosomas Humanos Par 8/genética , Cromosomas Humanos Par 14/genética , Proteínas de Fusión Oncogénica/genética , Cromosomas Humanos Par 15/genética , MasculinoRESUMEN
OBJECTIVES: This study aimed to apply diffusion-weighted imaging to the evaluation of cervical lymph nodes affected by medication-related osteonecrosis of the jaw (MRONJ). METHODS: This retrospective study analysed the diffusion-weighted imaging data of 70 patients with or without MRONJ (Stages 0-3). The mean apparent diffusion coefficient (ADC) values of the submandibular (level IB) and superior internal jugular (level IIA) nodes in the control and MRONJ groups were calculated, and differences were analysed using the Mann-Whitney test. Moreover, receiver operating characteristic (ROC) curve analysis was performed to evaluate the ability of ADC values to predict lymph nodes that were affected by MRONJ. p < 0.05 was considered statistically significant. RESULTS: The median [interquartile range] (×10-3 mm2/s) of level IB was 0.74 [0.7-0.81] and 0.93 [0.84-1.09] and that of level IIA was 0.79 [0.76-0.85] and 0.97 [0.84-1.06] in the control and MRONJ groups respectively. ROC analysis revealed that the ADC value had excellent ability to discriminate between the control and MRONJ groups. CONCLUSIONS: The study findings indicate that diffusion-weighted imaging can contribute to differentiation of MRONJ from other cervical lymph node diseases and facilitate early detection of MRONJ.
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Neurotransmitter receptors are essential components of synapses for communication between neurons in the brain. Because the spatiotemporal expression profiles and dynamics of neurotransmitter receptors involved in many functions are delicately governed in the brain, in vivo research tools with high spatiotemporal resolution for receptors in intact brains are highly desirable. Covalent labeling by chemical reaction (chemical labeling) of proteins without genetic manipulation is now a powerful method for analyzing receptors in vitro. However, selective target receptor labeling in the brain has not yet been achieved. This study shows that ligand-directed alkoxyacylimidazole (LDAI) chemistry can be used to selectively tether synthetic probes to target endogenous receptors in living mouse brains. The reactive LDAI reagents with negative charges were found to diffuse well over the whole brain and could selectively label target endogenous receptors, including AMPAR, NMDAR, mGlu1, and GABAAR. This simple and robust labeling protocol was then used for various applications: three-dimensional spatial mapping of endogenous receptors in the brains of healthy and disease-model mice; multi-color receptor imaging; and pulse-chase analysis of the receptor dynamics in postnatal mouse brains. Here, results demonstrated that bioorthogonal receptor modification in living animal brains may provide innovative molecular tools that contribute to the in-depth understanding of complicated brain functions.
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Neuronas , Proteínas , Ratones , Animales , Indicadores y Reactivos , Ligandos , EncéfaloRESUMEN
BACKGROUND: Although mild cognitive impairment (MCI) has received much attention as a precursor of dementia, its prognostic role has not been fully clarified in patients with heart failure (HF). METHODS AND RESULTS: We studied 274 patients admitted for acute decompensated HF. Cognitive function was evaluated using Mini Mental State Examination (MMSE). According to the previous definition, MMSE of 0-23, 24-27, and 28-30 were classified as CI (nâ¯=â¯132), MCI (nâ¯=â¯81), and normal cognitive function (nâ¯=â¯61). The primary endpoint was cardiac events, defined as the composite of unplanned HF hospitalization and cardiovascular mortality. During a mean follow-up period of 4.9⯱â¯3.1â¯years, 145 patients experienced cardiac events. Multivariable logistic regression analysis showed that hypertension (pâ¯=â¯0.043), low cardiac index (pâ¯=â¯0.022), and low serum albumin level (pâ¯=â¯0.041) had a significant association with cognitive abnormalities. Both CI and MCI were significantly associated with cardiac events after Cox multivariable adjustment [CI: pâ¯=â¯0.001, adjusted HR 2.66 (1.48-4.77); MCI: pâ¯=â¯0.025, adjusted HR 1.90 (1.09-3.31), normal cognitive function group: reference]. Patients with MCI had a significantly higher risk of unplanned HF hospitalization [pâ¯=â¯0.033, adjusted HR 1.91 (1.05-3.47)], but not all-cause mortality (pâ¯=â¯0.533) or cardiovascular mortality (pâ¯=â¯0.920), while CI was significantly associated with all-cause mortality (pâ¯=â¯0.025) and cardiovascular mortality (pâ¯=â¯0.036). CONCLUSION: Even MCI had a significant risk of cardiac events in patients with acute decompensated HF. This risk was mainly derived from unplanned HF hospitalization.
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Disfunción Cognitiva , Insuficiencia Cardíaca , Humanos , Relevancia Clínica , Disfunción Cognitiva/etiología , Disfunción Cognitiva/diagnóstico , Insuficiencia Cardíaca/complicaciones , Cognición , Pruebas de Estado Mental y DemenciaRESUMEN
A 74-year-old woman with an implanted physiological DDD pacemaker visited our department complaining of palpitations due to atrial fibrillation (AF). Catheter ablation therapy for AF was scheduled. Preoperative multidetector computed tomography showed that the inferior pulmonary vein (PV) was a common trunk, and the left and right superior PVs branched from the center of the left atrial roof. In addition, mapping of the left atrium before AF ablation revealed no potential in either the inferior PV or common trunk. We performed left and right superior PV and posterior wall isolation. After ablation, AF was not observed on pacemaker recordings.
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Fibrilación Atrial , Ablación por Catéter , Venas Pulmonares , Femenino , Humanos , Anciano , Venas Pulmonares/diagnóstico por imagen , Venas Pulmonares/cirugía , Fibrilación Atrial/cirugía , Atrios Cardíacos/cirugía , Tomografía Computarizada Multidetector , Ablación por Catéter/métodos , Resultado del TratamientoRESUMEN
An asymptomatic woman in her early 40s with a history of hyperferritinemia (5,412 ng/ml) was referred to our hospital after repeated phlebotomy for hemosiderosis. She had unexplained hyperferritinemia, low-normal transferrin saturation, and high hepcidin levels, in the absence of iron overload-induced organ injury. She was diagnosed with ferroportin disease based on detection of the SLC40A1 variant SLC40A1 c.485_487del (p.Val162del) on genetic analysis. Her ferritin levels remained stable during pregnancy, and postpartum anemia was successfully treated with 2-week oral iron therapy. Ferroportin disease is characterized by impaired iron export and preferential iron trapping in tissue macrophages. To reduce risk of anemia, a non-aggressive phlebotomy regimen is recommended in patients with ferroportin disease, which shows a milder clinical course compared with other classical hemochromatosis subtypes.
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Anemia , Hemocromatosis , Hiperferritinemia , Sobrecarga de Hierro , Humanos , Femenino , Embarazo , Hemocromatosis/terapia , Hemocromatosis/diagnóstico , Hemocromatosis/genética , Sobrecarga de Hierro/etiología , Hierro , HepcidinasRESUMEN
Although an increased risk of myocarditis has been observed after vaccination with mRNA encoding severe acute respiratory syndrome coronavirus 2 spike protein, its underlying mechanism has not been elucidated. This study investigated the direct effects of spike receptor-binding domain (S-RBD) on human cardiomyocytes differentiated from induced pluripotent stem cells (iPSC-CMs). Immunostaining experiments using ACE2 wild-type (WT) and knockout (KO) iPSC-CMs treated with purified S-RBD demonstrated that S-RBD was bound to ACE2 and internalized into the subcellular space in the iPSC-CMs, depending on ACE2. Immunostaining combined with live cell imaging using a recombinant S-RBD fused to the superfolder GFP (S-RBD-sfGFP) demonstrated that S-RBD was bound to the cell membrane, co-localized with RAB5A, and then delivered from the endosomes to the lysosomes in iPSC-CMs. Quantitative PCR array analysis followed by single cell RNA sequence analysis clarified that S-RBD-sfGFP treatment significantly upregulated the NF-kß pathway-related gene (CXCL1) in the differentiated non-cardiomyocytes, while upregulated interferon (IFN)-responsive genes (IFI6, ISG15, and IFITM3) in the matured cardiomyocytes. S-RBD-sfGFP treatment promoted protein ISGylation, an ISG15-mediated post-translational modification in ACE2-WT-iPSC-CMs, which was suppressed in ACE2-KO-iPSC-CMs. Our experimental study demonstrates that S-RBD is internalized through the endolysosomal pathway, which upregulates IFN-responsive genes and promotes ISGylation in the iPSC-CMs.
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COVID-19 , Células Madre Pluripotentes Inducidas , Humanos , SARS-CoV-2/metabolismo , Células Madre Pluripotentes Inducidas/metabolismo , COVID-19/metabolismo , Miocitos Cardíacos/metabolismo , Enzima Convertidora de Angiotensina 2/genética , Enzima Convertidora de Angiotensina 2/metabolismo , Unión Proteica , Proteínas de la Membrana/metabolismo , Proteínas de Unión al ARN/metabolismoRESUMEN
Aims: Doxorubicin is used in classical chemotherapy for several cancer types. Doxorubicin-induced cardiomyopathy (DOX-CM) is a critical issue among cancer patients. However, differentiating the diagnosis of DOX-CM from that of other cardiomyopathies is difficult. Therefore, in this study, we aimed to determine novel histopathological characteristics to diagnose DOX-CM. Methods and results: Twelve consecutive patients with DOX-CM who underwent cardiac histopathological examination in two medical centres were included. Twelve patients with dilated cardiomyopathy, who were matched with DOX-CM patients in terms of age, sex, and left ventricular ejection fraction, formed the control group. Another control group comprised five consecutive patients with cancer therapy-related cardiac dysfunction induced by tyrosine kinase inhibitors or vascular endothelial growth factor inhibitors were the controls. The positive area of tenascin-C, number of infiltrating macrophages, and presence of p62- and ubiquitin-positive cardiomyocytes were evaluated. Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were used for in vitro investigation. The myocardium exhibited significantly greater tenascin-C-positive area and macrophage number in the DOX-CM group than in the control groups (P < 0.01). The tenascin-C-positive area correlated with the number of both CD68- and CD163-positive cells (r = 0.748 and r = 0.656, respectively). Immunostaining for p62 was positive in 10 (83%) patients with DOX-CM. Furthermore, western blotting analysis revealed significant increase in tenascin-C levels in hiPSC-CMs upon doxorubicin treatment (P < 0.05). Conclusion: The combined histopathological assessment for tenascin-C, macrophages, and p62/ubiquitin may serve as a novel tool for the diagnosis of DOX-CM. Doxorubicin may directly affect the expression of tenascin-C in the myocardium.
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BACKGROUND: Large-volume leukapheresis (LVL) refers to processing of more than three volumes of blood in a single session for peripheral blood stem cell collection. Recently, continuous mononuclear cell collection (cMNC) protocol has been developed using the Spectra Optia system, which is a widely used apheresis device. LVL using the novel protocol has been investigated in patients. However, the efficiency and safety of LVL in healthy donors using this protocol has not been characterized. Therefore, this study aimed to evaluate the efficiency and tolerability of CD34+ collection of LVL with the cMNC protocol in healthy donors. STUDY DESIGN AND METHODS: We retrospectively collected data on LVL (>3 total blood volume) and normal-volume leukapheresis (NVL) performed in healthy donors between October 2019 and December 2021. All procedures were performed using the cMNC protocol. RESULTS: Although pre-apheresis CD34+ cell count was lesser in LVL (23.5 vs. 58.0/µL, p < .001), CD34+ collection efficiency was comparable between LVL and NVL (61.2% vs. 61.4%, p = .966). Platelet loss was significantly higher in LVL compared to NVL (38.0% vs. 29.4%, p < .001), with no correlation between attrition of platelet and processing blood volume. Moreover, the incidence of citrate toxicity during procedures was comparable between the two groups (31.6% vs. 21.4%, p = .322). All LVL procedures could be completed without any adverse events. CONCLUSION: Allogeneic LVL procedure using Spectra Optia cMNC protocol was well tolerated by the donors and resulted in efficient collection of CD34+ cells, which was comparable to that of NVL.
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Eliminación de Componentes Sanguíneos , Células Madre de Sangre Periférica , Humanos , Leucaféresis/métodos , Estudios Retrospectivos , Eliminación de Componentes Sanguíneos/métodos , Leucocitos , Antígenos CD34 , Movilización de Célula Madre Hematopoyética/métodosRESUMEN
Gilteritinib is a multitarget tyrosine kinase inhibitor (TKI), approved for the treatment of FLT3-mutant acute myeloid leukemia, with a broad range of activity against several tyrosine kinases including anaplastic lymphoma kinase (ALK). This study investigated the efficacy of gilteritinib against ALK-rearranged non-small cell lung cancers (NSCLC). To this end, we assessed the effects of gilteritinib on cell proliferation, apoptosis, and acquired resistance responses in several ALK-rearranged NSCLC cell lines and mouse xenograft tumor models and compared its efficacy to alectinib, a standard ALK inhibitor. Gilteritinib was significantly more potent than alectinib, as it inhibited cell proliferation at a lower dose, with complete attenuation of growth observed in several ALK-rearranged NSCLC cell lines and no development of drug tolerance. Immunoblotting showed that gilteritinib strongly suppressed phosphorylated ALK and its downstream effectors, as well as mesenchymal-epithelial transition factor (MET) signaling. By comparison, MET signaling was enhanced in alectinib-treated cells. Furthermore, gilteritinib was found to more effectively abolish growth of ALK-rearranged NSCLC xenograft tumors, many of which completely receded. Interleukin-15 (IL-15) mRNA levels were elevated in gilteritinib-treated cells, together with a concomitant increase in the infiltration of tumors by natural killer (NK) cells, as assessed by immunohistochemistry. This suggests that IL-15 production along with NK cell infiltration may constitute components of the gilteritinib-mediated antitumor responses in ALK-rearranged NSCLCs. In conclusion, gilteritinib demonstrated significantly improved antitumor efficacy compared with alectinib against ALK-rearranged NSCLC cells, which can warrant its candidacy for use in anticancer regimens, after further examination in clinical trial settings.
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Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Animales , Humanos , Ratones , Quinasa de Linfoma Anaplásico/genética , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Interleucina-15 , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Tirosina Quinasas Receptoras/genéticaRESUMEN
The feasibility of lymphocyte isolation and flow cytometry using a single endoscopic biopsy specimen from the gastrointestinal tract of patients who have undergone hematopoietic stem cell transplantation has not been investigated. We acquired 51 endoscopic biopsy specimens from the gastrointestinal tract of 35 patients. We divided the flow cytometry samples into two groups: group A, successful lymphocyte isolation (n=24), and group B, incomplete isolation (n=27). We compared the backgrounds of the samples between the groups to reveal crucial elements in the successful isolation of lymphocytes residing in the gastrointestinal tract. Comparison between the groups revealed lymphocyte isolation success rates differed between biopsy sites. Isolation was most successful in samples from the duodenum (8/9, 88.9%), followed by the ileum (4/8, 50.0%), large intestine (4/11, 36.4%), and stomach (8/23, 34.8%). Tacrolimus was used more frequently in group B (92.6%) than in group A (62.5%) (p=0.015). Logistic regression analysis revealed that isolation from the duodenum or ileum was a significant factor for successful isolation, while tacrolimus use was not statistically significant. In conclusion, the duodenum and ileum are more suitable sites than the stomach and colorectum for acquiring samples for flow cytometry.
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Trasplante de Células Madre Hematopoyéticas , Tacrolimus , Humanos , Estudios de Factibilidad , Citometría de Flujo , Tracto Gastrointestinal , LinfocitosRESUMEN
The distribution and clinical impact of cell-of-origin (COO) subtypes of diffuse large B-cell lymphoma (DLBCL) outside Western countries remain unknown. Recent literature also suggests that there is an additional COO subtype associated with the germinal center dark zone (DZ) that warrants wider validation to generalize clinical relevance. Here, we assembled a cohort of Japanese patients with untreated DLBCL and determined the refined COO subtypes, which include the DZ signature (DZsig), using the NanoString DLBCL90 assay. To compare the distribution and clinical characteristics of the molecular subtypes, we used a data set from the cohort of British Columbia Cancer (BCC) (n = 804). Through the 1050 patient samples on which DLBCL90 assay was successfully performed in our cohort, 35%, 45%, and 6% of patients were identified to have germinal center B-cell-like (GCB) DLBCL, activated B-cell-like (ABC) DLBCL, and DZsig-positive (DZsigpos) DLBCL, respectively, with the highest prevalence of ABC-DLBCL, differing significantly from the BCC result (P < .001). GCB-DLBCL, ABC-DLBCL, and DZsigpos-DLBCL were associated with 2-year overall survival rates of 88%, 75%, and 66%, respectively (P < .0001), with patients with DZsigpos-DLBCL having the poorest prognosis. In contrast, GCB-DLBCL without DZsig showed excellent outcomes after rituximab-containing immunochemotherapy. DZsigpos-DLBCL was associated with the significant enrichment of tumors with CD10 expression, concurrent MYC/BCL2 expression, and depletion of microenvironmental components (all, P < .05). These results provide evidence of the distinct distribution of clinically relevant molecular subtypes in Japanese DLBCL and that refined COO, as measured by the DLBCL90 assay, is a robust prognostic biomarker that is consistent across geographical areas.
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Linfoma de Células B Grandes Difuso , Humanos , Pronóstico , Japón/epidemiología , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfocitos B/metabolismo , Rituximab/uso terapéuticoRESUMEN
Study investigators encountered a female Becker muscular dystrophy (BMD) carrier with advanced heart failure (HF) and identified a stop-gain variant in procollagen-lysine, 2-oxoglutarate 5-dioxygenase 3 (PLOD3) as a potential second-hit variant. Isogenic induced pluripotent stem cells (iPSCs) with dominant expression of WT-DMD, Δ45-48-DMD, or Δ45-48-DMD with corrected PLOD3 variant were established. Microforce testing using 3-dimensional self-organized tissue rings (SOTRs) generated from iPSC-derived cardiomyocytes (iPSC-CMs) demonstrated that correction of the heterozygous PLOD3 variant did not improve the reduced force, but it significantly recovered the reduced stiffness in Δ45-48-DMD SOTRs. Correction of the PLOD3 variant restored collagen synthesis in iPSC-CMs. Our findings revealed the pathogenesis underlying advanced HF in a female BMD carrier.
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BACKGROUND: Granulocyte transfusion therapy is a rational therapeutic option for patients with prolonged, severe neutropenia. Although high molecular weight hydroxyethyl starch (hHES) facilitates the separation of red blood cells during granulocyte collection, renal dysfunction has been noted as a potential side effect. HES130/0.4 (Voluven®) is a medium molecular weight HES (mHES) with superior safety profiles compared to hHES. Although HES130/0.4 is reportedly effective in the collection of granulocytes, we lack studies comparing the efficiency of granulocyte collection using HES130/0.4 and hHES. STUDY DESIGN AND METHODS: We retrospectively collected the data from 60 consecutive apheresis procedures performed on 40 healthy donors at the Okayama University Hospital between July 2013 and December 2021. All procedures were performed using the Spectra Optia system. Based on the HES130/0.4 concentration in the separation chamber, granulocyte collection methods using HES130/0.4 were classified into m0.46, m0.44, m0.37, and m0.8 groups. We used HES130/0.4 and hHES groups to compare the various sample collection methods. RESULTS: The median granulocyte collection efficiency (CE) was approximately 24.0% and 28.1% in the m0.8 and hHES groups, respectively, which were significantly higher than those in the m0.46, m0.44, and m0.37 groups. One month following granulocyte collection with HES130/0.4, no significant changes were observed in serum creatinine levels compared to those before the donation. CONCLUSION: Therefore, we propose a granulocyte collection approach employing HES130/0.4, which is comparable to the use of hHES in terms of the granulocyte CE. A high concentration of HES130/0.4 in the separation chamber was considered crucial for granulocyte collection.
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Eliminación de Componentes Sanguíneos , Neutropenia , Humanos , Peso Molecular , Estudios Retrospectivos , Granulocitos , Derivados de Hidroxietil AlmidónRESUMEN
Central vascular malformations (CVMs) of the mandible are rare and can have varied clinical and radiological characteristics, thus making differential diagnosis difficult. We retrospectively reviewed 5 patients with proven CVM who underwent computed tomography (CT) and magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI) (and magnetic resonance angiography (MRA) for one patient), to assess the characteristic imaging findings of this lesion. CT revealed multilocularity in 3 lesions. All CVMs produced fine, irregular borders and low-to-intermediate density. Lesion continuity with the mandibular canal was discovered in 4 cases and enlarged feeding and outflow vessels in 3 lesions. Bone overgrowth was observed in 2 patients. CT values ranged from 30.84 to 52.87 Hounsfield units (HU). MRI exhibited low to intermediate signals on T1-weighted imaging (T1WI), signals ranging from low to intermediate-to-high on T2WI, and low to high signal intensity on short-tau inversion recovery (STIR) images, with flow voids in all patients and no inflammation in surrounding tissues. As calculated with DWI, the apparent diffusion coefficient (ADC) ranged from 0.69 to 1.74 × 10-3 mm2/s. MRA showed the presence of feeding vessels in 1 lesion. Interexaminer agreement on image interpretation ranged from moderate to excellent. These typical CVM imaging findings may aid in the differential diagnosis of this lesion.
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Imagen por Resonancia Magnética , Malformaciones Vasculares , Humanos , Estudios Retrospectivos , Imagen por Resonancia Magnética/métodos , Imagen de Difusión por Resonancia Magnética/métodos , Tomografía Computarizada por Rayos X , Malformaciones Vasculares/diagnóstico por imagen , Mandíbula/diagnóstico por imagenRESUMEN
Estimation of dynamic change of crossbridge formation in living cardiomyocytes is expected to provide crucial information for elucidating cardiomyopathy mechanisms, efficacy of an intervention, and others. Here, we established an assay system to dynamically measure second harmonic generation (SHG) anisotropy derived from myosin filaments depended on their crossbridge status in pulsating cardiomyocytes. Experiments utilizing an inheritable mutation that induces excessive myosin-actin interactions revealed that the correlation between sarcomere length and SHG anisotropy represents crossbridge formation ratio during pulsation. Furthermore, the present method found that ultraviolet irradiation induced an increased population of attached crossbridges that lost the force-generating ability upon myocardial differentiation. Taking an advantage of infrared two-photon excitation in SHG microscopy, myocardial dysfunction could be intravitally evaluated in a Drosophila disease model. Thus, we successfully demonstrated the applicability and effectiveness of the present method to evaluate the actomyosin activity of a drug or genetic defect on cardiomyocytes. Because genomic inspection alone may not catch the risk of cardiomyopathy in some cases, our study demonstrated herein would be of help in the risk assessment of future heart failure.
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Miocitos Cardíacos , Microscopía de Generación del Segundo Armónico , Miosinas , Actomiosina , MiocardioRESUMEN
Posttransplant cyclophosphamide (PTCy) is associated with a low incidence of chronic graft-versus-host disease (cGVHD) following hematopoietic stem cell (HSC) transplantation. Previous studies have shown the important roles of B cell immunity in cGVHD development. Here, we investigated the long-term reconstitution of B lymphopoiesis after PTCy using murine models. We first demonstrated that the immune homeostatic abnormality leading to cGVHD is characterized by an initial increase in effector T cells in the bone marrow and subsequent B and Treg cytopenia. PTCy, but not cyclosporine A or rapamycin, inhibits the initial alloreactive T cell response, which restores intra-bone marrow B lymphogenesis with a concomitant vigorous increase in Tregs. This leads to profound changes in posttransplant B cell homeostasis, including decreased B cell activating factors, increased transitional and regulatory B cells, and decreased germinal center B cells. To identify the cells responsible for PTCy-induced B cell tolerance, we selectively depleted Treg populations that were graft or HSC derived using DEREG mice. Deletion of either Treg population without PTCy resulted in critical B cytopenia. PTCy rescued B lymphopoiesis from graft-derived Treg deletion. In contrast, the negative effect of HSC-derived Treg deletion could not be overcome by PTCy, indicating that HSC-derived Tregs are essential for maintaining favorable B lymphopoiesis following PTCy. These findings define the mechanisms by which PTCy restores homeostasis of the B cell lineage and reestablishes immune tolerance.