Novel Organoid Culture System for Improved Safety Assessment of Nanomaterials.

Over the past few decades, the increased application of nanomaterials has raised questions regarding their safety and possible toxic effects. Organoids have been suggested as promising tools, offering efficient assays for nanomaterial-induced toxicity evaluation. However, organoid systems have some limitations, such as size heterogeneity and poor penetration of nanoparticles because of the extracellular matrix, which is necessary for organoid culture. Here, we developed a novel system for the improved safety assessment of nanomaterials by establishing a 3D floating organoid paradigm. In addition to overcoming the limitations of two-dimensional systems including the lack of in vitro-in vivo cross-talk, our method provides multiple benefits as compared with conventional organoid systems that rely on an extracellular matrix for culture. Organoids cultured using our method exhibited relatively uniform sizing and structural integrity and were more conducive to the internalization of nanoparticles. Our floating culture system will accelerate the research and development of safe nanomaterials.

Mithramycin A Alleviates Osteoarthritic Cartilage Destruction by Inhibiting HIF-2α Expression.

Osteoarthritis (OA) is the most common and increasing joint disease worldwide. Current treatment for OA is limited to control of symptoms. The purpose of this study was to determine the effect of specificity protein 1 (SP1) inhibitor Mithramycin A (MitA) on chondrocyte catabolism and OA pathogenesis and to explore the underlying molecular mechanisms involving SP1 and other key factors that are critical for OA. Here, we show that MitA markedly inhibited expressions of matrix-degrading enzymes induced by pro-inflammatory cytokine interleukin-1β (IL-1β) in mouse primary chondrocytes. Intra-articular injection of MitA into mouse knee joint alleviated OA cartilage destruction induced by surgical destabilization of the medial meniscus (DMM). However, modulation of SP1 level in chondrocyte and mouse cartilage did not alter catabolic gene expression or cartilage integrity, respectively. Instead, MitA significantly impaired the expression of HIF-2α known to be critical for OA pathogenesis. Such reduction in expression of HIF-2α by MitA was caused by inhibition of NF-κB activation, at least in part. These results suggest that MitA can alleviate OA pathogenesis by suppressing NF-κB-HIF-2α pathway, thus providing insight into therapeutic strategy for OA.

18F-FDG PET/CT and histology for diagnosing recurrent/remnant tumors in head and neck cancer patients treated with radiotherapy.

OBJECTIVE: The aim of this study was to assess the diagnostic performance of fluorine-18-fluoro-2-deoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) for locoregional recurrent/residual tumor in patients with head and neck cancer (HNC) who underwent previous radiotherapy (RT). SUBJECTS AND METHODS: 18F-FDG PET/CT images from patients with HNC who previously underwent RT were retrospectively reviewed. Only cases with histological confirmation within 4 weeks of PET/CT imaging were included. Standardized uptake values were obtained for lesions and PET/CT findings were compared with histological results. RESULTS: Of 181 cases, 114 (63%) were histologically confirmed as malignant and 67 (37%) as benign. The sensitivity, specificity, and accuracy of PET/CT were 93%, 64%, and 82%, respectively. Inflammation was the most common cause of false positives and small tumor volume and low 18F-FDG avidity were the causes of false negatives. PET/CT had 100% sensitivity and 56% specificity for detecting recurrent or residual disease within 12 weeks after RT and 93% sensitivity and 64% specificity, more than 12 weeks after RT. The frequency of false positives in PET/CT images within 12 weeks of RT was similar to the results obtained 12 weeks after RT (15% vs. 14%). False positives were more frequent in PET/CT cases after two-dimensional or three-dimensional conformal RT than in those after intensity-modulated RT, although not statistically significant (15% vs. 9%, p>0.05). CONCLUSION: 18F-FDG PET/CT might aid the diagnosis of locoregional residual/recurrent tumors in patients with HNC previously treated with RT. Inflammation was the main cause of false positives regardless of the interval between RT and PET/CT, even several years after RT. Therefore, histological verification of positive PET/CT findings should be conducted during follow-up of HNC patients treated with RT.

Effect of bevel direction on the success rate of ultrasound-guided radial arterial catheterization.

BACKGROUND: This study assessed the effect of bevel direction on the success rate of ultrasound guided radial artery catheterization. METHODS: A total of 204 patients requiring radial artery catheterization were randomly divided into bevel-up (n = 102) and bevel-down (n = 102) groups. Success rate, cannulation time, and number of attempts were compared groups. RESULTS: In the bevel-down group, an arterial line was placed on the first attempt in 86 of 102 (84.3 %; 95 % confidence interval [CI] = 76 % to 90 %) patients versus 73 of 102 (71.6 %; 95 % CI = 62.1 % to 79.4 %) in the bevel-up group (p = 0.028). In the bevel-down group, the mean time to a successful radial arterial cannulation was 33.3 ± 6.3 seconds (95 % CI = 32.1-34.6) versus 35.9 ± 7.6 seconds (95 % CI = 34.4-37.2) in the bevel-up group (p = 0.011). The median score was 33.2 and interquartile range [IQR] was 10.9 (30.3-41.2) for the mean cannulation time in the bevel-up group. In the bevel-down group, the mean score was 32.3 (IQR 3.90, 30-33.9) for mean cannulation time. In the bevel-down group, 11 of 102 (7 %; 95 % CI = 0 to 16 %) patients developed a posterior wall puncture versus 22 of 102 ((21.6 %; 95 % CI = 14.7 to 17.2 %) in the bevel-up group. CONCLUSION: The bevel-down approach during ultrasound-guided radial artery catheterization exhibited a higher success with fewer complications compared to the bevel-up approach. TRIAL REGISTRATION: Clinical Research Information Service is Korean Clinical Trials Registry ( KCT0001836 ). It was registered retrospectively 30th Nov 2015.

18F-FDG PET/CT findings in endometrial cancer patients: the correlation between SUVmax and clinicopathologic features.

OBJECTIVE: To study 18F-FDG PET/CT findings in endometrial cancer patients, to analyze the correlation between the maximum standardized uptake value (SUVmax) and clinicopathologic tumor characteristics. MATERIAL AND METHOD: Retrospective study included 33 endometrial cancer patients who underwent pre-operative 18F-FDG PET/CT and abdominal CT or MRI from June 2005 to October 2009. Pattern of FDG uptake was classified as focal and diffuse uptake. SUVmax was measured at primary tumor in endometrial cavity and correlated with maximum tumor size, menopausal state, histological grade, depth of myometrial invasion and nodal metastasis. The diagnostic performance of 18F-FDG PET/CT was assessed for primary tumor and lymph node metastasis and correlated with those of CT/MRI. RESULTS: Sensitivity of 18F-FDG PET/CT in primary tumor detection was slightly higher, without significant difference, than that of either CT or MRI (93.9% vs. 87.9%, p = 0.625). The overall SUVmax mean ofthe primary tumor was 8.24 +/- 5.38. The focal FDG uptake pattern was more common than the diffuse uptake pattern (71.0% and 29.0%, respectively), but the SUVmax was higher in the diffuse uptake pattern (diffuse pattern 12.10 +/- 7.47 vs. focal pattern 6.66 +/- 3.33, p = 0.008). There was significant association between the SUVmax of the primary tumor and maximum tumor size (p = 0.001), but not between the SUVmax of the primary tumor and menopause state, histological grade, depth of myometrial invasion and nodal metastasis (p = 0.522, 0.622, 0.694 and 0.601, respectively). For lymph node detection, the sensitivity of 18F-FDG PET/CT were also higher without statistically significant difference, than those of CT/MRI (on patient basis; 80.0% vs. 40.0%, p = 0.500; on nodal basis 64.7% vs. 47.1%, p = 0.453, respectively). CONCLUSION: 18F-FDG PET/CThad slightly higher diagnostic sensitivity than CT/MRIin both primary tumor and lymph node detection. The finding focal uptake pattern is more common, but the diffuse uptake pattern shows higher FDG uptake. The SUVmax of primary tumors was associated with the maximum tumor size, but not associated with menopause state, histologic grade, depth of myometrial invasion and nodal metastasis.

Atypical Layering of FDG in Pleural Effusion.

ABSTRACT: Radiopharmaceuticals can accumulate in malignant or nonmalignant pleural effusion on γ and PET imaging, and effusion shows a pattern of diffusely or focally increased activity. Herein, we report atypical layering of FDG in pleural effusion on PET/CT of 3 patients with metastatic gynecological cancer.

Histologic Heterogeneity of Chondrosarcoma Reflected on Bone SPECT/CT.

ABSTRACT: Chondrosarcomas are a heterogeneous group of cartilage-forming tumors. The tumor is graded on areas demonstrating the highest grade. A 71-year-old man underwent bone SPECT/CT to investigate a tumorous lesion on his right femur. Correlating with the pathological findings, the high-grade area showed higher uptake in bone SPECT/CT. This case suggests that bone SPECT/CT could aid in selecting an optimal biopsy site for diagnosis, and determining the proper treatment of patients with suspected chondroid tumors.

Current status and prospects of organoid-based regenerative medicine.

Organoids derived from stem cells or organ-specific progenitors are self-organizable, self-renewable, and multicellular threedimensional (3D) structures that can mimic the function and structure of the derived tissue. Due to such characteristics, organoids are attracting attention as an excellent ex vivo model for drug screening at the stage of drug development. In addition, since the applicability of organoids as therapeutics for tissue regeneration has been embossed, the development of various organoids-based regenerative medicine has been rapidly progressing, reaching the clinical trial stage. In this review, we give a general overview of organoids and describe current status and prospects of organoid-based regenerative medicine, focusing on organoid-based regenerative therapeutics currently under development including clinical trials. [BMB Reports 2023; 56(1): 10-14].

SPECT/CT Radiomics for Differentiating between Enchondroma and Grade I Chondrosarcoma.

This study was performed to assess the value of SPECT/CT radiomics parameters in differentiating enchondroma and atypical cartilaginous tumors (ACTs) located in the long bones. Quantitative HDP SPECT/CT data of 49 patients with enchondromas or ACTs in the long bones were retrospectively reviewed. Patients were randomly split into training (n = 32) and test (n = 17) data, and SPECT/CT radiomics parameters were extracted. In training data, LASSO was employed for feature reduction. Selected parameters were compared with classic quantitative parameters for the prediction of diagnosis. Significant parameters from training data were again tested in the test data. A total of 12 (37.5%) and 6 (35.2%) patients were diagnosed as ACTs in training and test data, respectively. LASSO regression selected two radiomics features, zone-length non-uniformity for zone (ZLNUGLZLM) and coarseness for neighborhood grey-level difference (CoarsenessNGLDM). Multivariate analysis revealed higher ZLNUGLZLM as the only significant independent factor for the prediction of ACTs, with sensitivity and specificity of 85.0% and 58.3%, respectively, with a cut-off value of 191.26. In test data, higher ZLNUGLZLM was again associated with the diagnosis of ACTs, with sensitivity and specificity of 83.3% and 90.9%, respectively. HDP SPECT/CT radiomics may provide added value for differentiating between enchondromas and ACTs.

Prostaglandin F2α analogue, bimatoprost ameliorates colistin-induced nephrotoxicity.

Colistin (polymyxin E) is an antibiotic that is effective against multidrug-resistant gram-negative bacteria. However, the high incidence of nephrotoxicity caused by colistin limits its clinical use. To identify compounds that might ameliorate colistin-induced nephrotoxicity, we obtained 1707 compounds from the Korea Chemical Bank and used a high-content screening (HCS) imaging-based assay. In this way, we found that bimatoprost (one of prostaglandin F2α analogue) ameliorated colistin-induced nephrotoxicity. To further assess the effects of bimatoprost on colistin-induced nephrotoxicity, we used in vitro and in vivo models. In cultured human proximal tubular cells (HK-2), colistin induced dose-dependent cytotoxicity. The number of terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)-positive cells, indicative of apoptosis, was higher in colistin-treated cells, but this effect of colistin was ameliorated by cotreatment with bimatoprost. The generation of reactive oxygen species, assessed using 2,7-dichlorodihydrofluorescein diacetate, was less marked in cells treated with both colistin and bimatoprost than in those treated with colistin alone. Female C57BL/6 mice (n = 10 per group) that were intraperitoneally injected with colistin (10 mg/kg/12 hr) for 14 days showed high blood urea nitrogen and serum creatinine concentrations that were reduced by the coadministration of bimatoprost (0.5 mg/kg/12 hr). In addition, kidney injury molecule-1 (KIM1) and Neutrophil gelatinase-associated lipocalin (NGAL) expression also reduced by bimatoprost administration. Further investigation in tubuloid and kidney organoids also showed that bimatoprost attenuated the nephrotoxicity by colistin, showing dose-dependent reducing effect of KIM1 expression. In this study, we have identified bimatoprost, prostaglandin F2α analogue as a drug that ameliorates colistin-induced nephrotoxicity.

Prognostic Value of FDG PET/CT in Patients with Nodal Peripheral T-Cell Lymphoma.

This study evaluated the prognostic significance of FDG PET/CT in patients with nodal peripheral T-cell lymphoma (PTCL). We retrospectively reviewed patients with histologically confirmed nodal PTCL who underwent FDG PET/CT at baseline, after three cycles of first-line chemotherapy (interim), and at the end of therapy. Response was assessed visually using the Deauville 5-point scale (D5PS); scores of 1, 2, and 3 were considered PET-negative, and scores of 4 and 5 were considered PET-positive. The associations between FDG PET/CT findings and survival were assessed using Cox regression analysis. A total of 79 patients (44 males and 35 females; median age 56 years) were included in this study. In response assessment, 17 (22%) had an interim PET-positive result and 10 (13%) had an end-of-therapy PET-positive result. During a median follow-up of 50 months, 37 patients (47%) presented with disease progression and 30 patients (38%) died. The estimated 5-year progression-free survival (PFS) and overall survival (OS) were 57% and 64%, respectively. An interim PET-positive result was the only significant indicator of PFS. Higher International Prognostic Index and end-of-therapy PET-positive result were significant independent prognostic factors of OS. Interim and end-of-therapy FDG PET/CT responses based on D5PS are meaningful in predicting the outcomes of patients with nodal PTCL.

Safety and therapeutic effects of personalized transcranial direct current stimulation based on electrical field simulation for prolonged disorders of consciousness: study protocol for a multi-center, double-blind, randomized controlled trial.

Background: Disorders of consciousness (DOC) resulting from acquired brain injury (ABI) increase the mortality rate of patients, complicate rehabilitation, and increase the physical and economic burden that DOC imposes on patients and their families. Thus, treatment to promote early awakening from DOC is vital. Transcranial direct current stimulation (tDCS) has shown great potential for promoting neuro-electrochemical activity. However, previous tDCS studies did not consider structural damage or head and brain lesions, so the applicability of the results to all DOC patients was limited. In this study, to establish a patient-specific tDCS treatment plan considering the brain lesions of and damage sustained by DOC patients, we considered the electric field calculated by a the "finite electric" three-dimensional brain model based on magnetic resonance images. This protocol was developed to aid tDCS treatment of actual patients, and to verify its safety and effectiveness. Methods/design: Twenty-four patients with DOC after ABI will be enrolled in this cross-over trial. All participants will receive typical rehabilitation combined with sham tDCS and typical rehabilitation plus personalized tDCS (P-tDCS). Each interventional period will last 2 weeks (30 min/day, 5 days/week). The primary outcome [score on the Korean version of the Coma Recovery Scale-Revised (K-CRS-R)] will be assessed at baseline and the end of the first day of the intervention. Secondary outcomes (K-CRS-R at 1 week and 2 weeks after experimental session and quantitative EEG changes quantitative electroencephalography changes) will be measured at baseline and the end of week 4. Adverse events will be recorded during each treatment session. Discussion: For patients with neurological disorders, tDCS has served as a painless, non-invasive, easily applied, and effective therapy for several decades, and there is some evidence that it can improve the level of consciousness of patients with DOC. However, variability in the effects on consciousness among subjects have been reported and personalized strategies are lacking. This protocol is for a randomized controlled trial designed to validate the effectiveness and safety of P-tDCS combined with typical rehabilitation for DOC. Clinical trial registration: https://cris.nih.go.kr, identifier KCT0007157.

Effects of Sevoflurane Exposure on Fetal Brain Development Using Cerebral Organoids.

Sevoflurane is a safe and well-known inhaled anesthetic. Given that sevoflurane can be delivered to developing fetuses through the mother, it is critical to determine whether this agent affects fetal neurodevelopment. Recent research has sought to determine whether sevoflurane affects fetal brain development when the mother is exposed during the second to third trimester of pregnancy, considered to be the crucial period for the development of nervous system. However, even though the first trimester is a critical period for fetal organogenesis and the most susceptible time to teratogen exposure, research regarding the effects of sevoflurane on organogenesis, especially on brain development, is insufficient. In the present study, human embryonic stem cells (hESC)-derived cerebral organoids were exposed to sevoflurane during the time corresponding to the first trimester to investigate the effect of early sevoflurane exposure on fetal brain development, specifically the processes of neuronal differentiation and maturation. Organoid size exposed to the intermediate concentration of sevoflurane did not differ from control, immunofluorescence demonstrated that sevoflurane temporarily decreased the size of SOX2 + /N-cad + ventricular zone structures only during the mid-time point, and upregulated expression of TUJ1 and MAP2 only during the early time point. However, all markers returned to normal levels, and organoids formed normal cortical structures at the late time point. Our results suggest that maternal sevoflurane exposure during the first trimester of pregnancy can cause abnormal neuronal differentiation in the fetal brain. However, considering the recovery observed in later periods, sevoflurane exposure might not have lasting impacts on fetal brain development.

Modeling Pancreatic Cancer with Patient-Derived Organoids Integrating Cancer-Associated Fibroblasts.

Pancreatic cancer is a devastating disease and is highly resistant to anticancer drugs because of its complex microenvironment. Cancer-associated fibroblasts (CAFs) are an important source of extracellular matrix (ECM) components, which alter the physical and chemical properties of pancreatic tissue, thus impairing effective intratumoral drug delivery and resulting in resistance to conventional chemotherapy. The objective of this study was to develop a new cancer organoid model, including a fibrous tumor microenvironment (TME) using CAFs. The CAF-integrated pancreatic cancer organoid (CIPCO) model developed in this study histologically mimicked human pancreatic cancer and included ECM production by CAFs. The cancer cell-CAF interaction in the CIPCO promoted epithelial-mesenchymal transition of cancer cells, which was reversed by CAF inhibition using all-trans retinoic acid. Deposition of newly synthesized collagen I in the CIPCO disturbed the delivery of gemcitabine to cancer cells, and treatment with collagenase increased the cytotoxic effect of gemcitabine. This model may lead to the development of next-generation cancer organoid models recapitulating the fibrous TME.

Generation of human tonsil epithelial organoids as an ex vivo model for SARS-CoV-2 infection.

The palatine tonsils (hereinafter referred to as "tonsils") serve as a reservoir for viral infections and play roles in the immune system's first line of defense. The aims of this study were to establish tonsil epithelial cell-derived organoids and examine their feasibility as an ex vivo model for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The tonsil organoids successfully recapitulated the key characteristics of the tonsil epithelium, including cellular composition, histologic properties, and biomarker distribution. Notably, the basal layer cells of the organoids express molecules essential for SARS-CoV-2 entry, such as angiotensin-converting enzyme 2 (ACE2), transmembrane serine protease 2 (TMPRSS2) and furin, being susceptible to the viral infection. Changes in the gene expression profile in tonsil organoids revealed that 395 genes associated with oncostatin M signaling and lipid metabolism were highly upregulated within 72 h after SARS-CoV-2 infection. Notably, remdesivir suppressed the viral RNA copy number in organoid culture supernatants and intracellular viral protein levels in a dose-dependent manner. Here, we suggest that tonsil epithelial organoids could provide a preclinical and translational research platform for investigating SARS-CoV-2 infectivity and transmissibility or for evaluating antiviral candidates.

Nanostructured films as a novel substrate for chondrocytes growth.

We fabricated a large area silica nano-particle monolayer on glass substrates for the cell growth by the Langmuir-Blodgett technique. A thin film of 300 nm sized mono-dispersed silica particles was constructed on the air-water interface and transferred onto a glass substrate. Chondrocytes were cultured on nano-structured substrates and bare glass substrates for 8 days. The characterizations of chondrocytes on nano-structured substrate were conducted on 3rd and 6th day using confocal laser microscopy and with MTT assay for 8 days. The chondrocytes cultured on nano-structured substrate showed podia like spike and their size was larger than that formed on bare glass substrate. The metabolic activity of chondrocytes on nano-structured substrate was lower than that on bare glass substrate at early-stage, but it was recovered after 4 days.

Clinical value of integrated [18F]fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography in the preoperative assessment of papillary thyroid carcinoma: comparison with sonography.

OBJECTIVES: The purpose of this study was to evaluate the clinical value of preoperative [(18)F]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) by comparing it to neck sonography in papillary thyroid carcinoma. METHODS: The diagnostic accuracies of PET/CT and sonography for detecting cervical node metastasis were compared. The association between FDG uptake in the primary tumor and the prognostic factors of differentiated thyroid cancer, such as tumor size, multiplicity, extrathyroid extension, and lymph node metastasis, was also assessed. RESULTS: Positron emission tomography/computed tomography showed lower sensitivity and higher specificity than sonography for detection of cervical node metastasis; however, no statistically significant difference was noted (P > .99). Only the tumor size was associated with FDG uptake in the primary tumor. CONCLUSIONS: [(18)F]Fluoro-2-deoxy-d-glucose PET/CT could not provide additional information compared to neck sonography.

Establishment of functional epithelial organoids from human lacrimal glands.

BACKGROUND: Tear deficiency due to lacrimal gland (LG) dysfunction is one of the major causes of dry eye disease (DED). Therefore, LG stem cell-based therapies have been extensively reported to regenerate injured lacrimal tissue; however, the number of stem cells in the LG tissue is low, and 2D long-term cultivation reduces the differentiation capacity of stem cells. Nevertheless, 3D LG organoids could be an alternative for a DED therapy because it is capable of prolonged growth while maintaining the characteristics of the LG tissue. Here, we report the development of LG organoids and their application as cell therapeutics. METHODS: Digested cells from human LG tissue were mixed with Matrigel and cultured in five different media modified from human prostate/salivary organoid culture media. After organoid formation, the growth, specific marker expression, and histological characteristics were analyzed to authenticate the formation of LG organoids. The secretory function of LG organoids was confirmed  through calcium influx or proteomics analysis after pilocarpine treatment. To explore the curability of the developed organoids, mouse-derived LG organoids were fabricated and transplanted into the lacrimal tissue of a mouse model of DED. RESULTS: The histological features and specific marker expression of LG organoids were similar to those of normal LG tissue. In the pilocarpine-treated LG organoid, levels of internal Ca2+ ions and ß-hexosaminidase, a lysosomal protein in tear fluid, were increased. In addition, the secreted proteins from pilocarpine-treated lacrimal organoids were identified through proteomics. More than 70% of the identified proteins were proven to exosome through gene ontology analysis. These results indicate that our developed organoid was pilocarpine reactive, demonstrating the function of LG. Additionally, we developed LG organoids from patients with Sjogren's syndrome patients (SS) and confirmed that their histological features were similar to those of SS-derived LG tissue. Finally, we confirmed that the mouse LG organoids were well engrafted in the lacrimal tissue two weeks after transplantation. CONCLUSION: This study demonstrates that the established LG organoids resemble the characteristics of normal LG tissue and may be used as a therapy for patients with DED.

Functional recovery by colon organoid transplantation in a mouse model of radiation proctitis.

Radiation proctitis is the collateral damage that occurs to healthy cells during radiation treatment of pelvic malignancies. Conservative treatment of radiation proctitis can mitigate inflammatory symptoms, but, to date, no therapeutic options are available for direct recovery of the damaged colonic epithelium. The present study assessed the ability of colon organoid-based regeneration to treat radiation proctitis. Radiation proctitis was induced in mice by irradiating their recta, followed by enema-based transplantation of mouse colon organoids. The transplanted colon organoids were found to successfully engraft onto the damaged rectal mucosa of the irradiated mice, reconstituting epithelial structure and integrity. Lgr5+ stem cells were shown to be pivotal to colon organoid mediated regeneration. Endoscopic examination showed the efficacy of localized transplantation of colon organoids with fibrin glue to irradiated sites. These findings provide useful insights into the use of colon organoid-based regenerative therapy for the treatment of radiation proctitis.