Nafamostat mesylate decreases skin flap necrosis in a mouse model of type 2 diabetes by protecting the endothelial glycocalyx.

The success rate of flap tissue reconstruction has increased in recent years owing to advancements in microsurgical techniques. However, complications, such as necrosis, are still more prevalent in diabetic patients compared to non-diabetic individuals, presenting an ongoing challenge. To address this issue, many previous studies have examined vascular anastomoses dilation and stability, primarily concerning surgical techniques or drugs. In contrast, in the present study, we focused on microvascular damage of the peripheral microvessels in patients with diabetes mellitus and the preventative impact of nafamostat mesylate. Herein, we aimed to investigate the effects of hyperglycemia on glycocalyx (GCX) levels in mice with type 2 diabetes. We examined the endothelial GCX (eGCX) in skin flap tissue of 9-12-week-old type 2 diabetic mice (db/db mice) using a perforator skin flap and explored treatment with nafamostat mesylate. The growth rates were compared after 1 week. Heterotype (db/+) mice were used as the control group. Morphological examination of postoperative tissues was performed at 1, 3, 5, and 7 days post-surgery. In addition, db/db mice were treated with 30 mg/kg/day of nafamostat mesylate daily and were evaluated on postoperative day 7. Seven days after surgery, all db/db mice showed significant partial flap necrosis. Temporal observation of the skin flaps revealed a stasis-like discoloration and necrosis starting from the contralateral side of the remaining perforating branch. The control group did not exhibit flap necrosis, and the flap remained intact. In the quantitative assessment of endothelial glycans using lectins, intensity scoring showed that the eGCX in the db/db group was significantly thinner than that in the db/+ group. These results were consistent with the scanning electron microscopy findings. In contrast, treatment with nafamostat mesylate significantly improved the flap engraftment rate and suppressed eGCX injury. In conclusion, treatment with nafamostat mesylate improves the disrupted eGCX structure of skin flap tissue in db/db mice, potentially ameliorating the impaired capillary-to-venous return in the skin flap tissue.

In Situ Hybridization of Brain Slices.

In situ hybridization (ISH) is an important technique for identifying gene expression at the cellular level in various organs, including brain slices. This approach hybridizes nucleic acid probes to cellular mRNA, allowing the detection of transcriptional products. Recent advances have enabled RNA preservation in formalin-fixed paraffin-embedded (FFPE) samples, making ISH applicable to brain tumor diagnosis and research. Here, we provide a concise overview of the standard application of chromogenic ISH in neuroscience research and neuropathology practice using FFPE blocks of brain slice sections.

Immunohistochemistry of Brain Tissues.

Immunohistochemistry (IHC) is the basis of histological or pathological analysis and is widely used to enable the detection and characterization of proteins in various organ tissues, including brain tissues. IHC is commonly performed on formalin-fixed paraffin-embedded (FFPE) tissues because of their easy storage and versatility. IHC is a key method for providing more accurate analysis of localization and function of neurons, neuroendocrine cells, and neural stem cells in the brain and other nervous systems. The related cells such as glial cells and neurovascular units have also been analyzed by IHC. Visualization of antibody-antigen interactions can be performed primarily in one of the following ways: chromogenically stained IHC and fluorescently stained IHC. In chromogenically stained IHC, an antibody is chemically conjugated to an enzyme, such as peroxidase, that can be reacted with a suitable substrate to give a colored product. In fluorescently stained IHC, the antibodies are finally tagged with fluorescent chemicals such as fluorescein isothiocyanate (FITC) or rhodamine. Here, we describe the standard methods of IHC applied to brain slice sections. Furthermore, an automated immunostainer is presented as another option for standardized immunohistochemistry.

Mouse Brain Tissue Preparation for Scanning Electron Microscopy.

Scanning electron microscopy (SEM) is used to observe the surface structure of an object by irradiating an electron beam onto the sample and detecting the reflected and emitted electrons. Because of its large depth of focus, SEM can provide the three-dimensional structure of small surfaces that cannot be observed using an optical microscope. Furthermore, the cross-sectional structure of the tissue can be observed by freeze-cracking. Observing the ultrastructure of organisms that contain large amounts of water in their bodies while maintaining high resolution is challenging; however, this has recently become possible. Here, we explain the fixation and freeze-cracking method for mouse brain samples.

Prognostic value of radiological T category using conventional MRI in patients with oral tongue cancer: comparison with pathological T category.

PURPOSE: This study aimed to compare the radiological tumor (T)-category using multiparametric MRI with the pathological T category in patients with oral tongue squamous cell carcinoma (OTSCC) and to examine which is a better predictor of prognosis. METHODS: This retrospective study included 110 consecutive patients with surgically resected primary OTSCC who underwent preoperative contrast-enhanced MRI. T categories determined by maximum diameter and depth of invasion were retrospectively assessed based on the pathological specimen and multiparametric MRI. The MRI assessment included the axial and coronal T1-weighted image (T1WI), axial T2-weighted image (T2WI), coronal fat-suppressed T2WI, and axial and coronal fat-suppressed contrast-enhanced T1WI (CET1WI). Axial and coronal CET1WI measurements were divided into two groups: measurements excluding peritumoral enhancement (MEP) and measurements including peritumoral enhancement. The prognostic values for recurrence and disease-specific survival after radiological and pathological T categorization of cases into T1/T2 and T3/T4 groups were compared. RESULTS: The T category of MEP on coronal CET1WI was the most relevant prognostic factor for recurrence [hazard ratio (HR) = 3.30, p = 0.001] and the HR was higher than the HR for pathological assessment (HR = 2.26, p = 0.026). The T category determined by MEP on coronal CET1WI was also the most relevant prognostic factor for disease-specific survival (HR = 3.12, p = 0.03), and the HR was higher than the HR for pathological assessment (HR = 2.02, p = 0.20). CONCLUSION: The T category determined by MEP on the coronal CET1WI was the best prognostic factor among all radiological and pathological T category measurements.

Association of Preoperative and Postoperative Plasma Syndecan-1 and Colorectal Cancer Outcome.

BACKGROUND/AIM: A three-dimensional network constructed using glycocalyx (GCX) extends throughout the cancer cell nest in human colorectal cancer (CRC). GCX was found to be closely related to cancer. We examined the prognostic correlation and potential of syndecan-1 (SDC1), a representative proteoglycan of GCX, as a biomarker. PATIENTS AND METHODS: We analyzed SDC1 in the transcriptomic profiles of a major publicly available CRC cohort from The Cancer Genome Atlas (TCGA) using a computational algorithm. We investigated serum SDC1 levels preoperatively and on postoperative day seven in 48 patients with stage I-III CRC who underwent surgery during July-December 2019 at Gifu University Hospital. RESULTS: For TCGA, no significant differences existed between the high and low SDC1 expression groups regarding disease-free, disease-specific, and overall survival for stage I-III, and only overall survival for stage IV was significantly different. In our study, among the 48 patients, 17 (no recurrence), 13 (1 recurrence), and 18 (10 recurrences) had stage I-III, respectively. Preoperative and postoperative day 7 SDC1 levels for patients with stage I-III were 10.7±2.3 and 9.9±3.1 ng/ml (p=0.40), 11.1±1.7 and 10.1±0.8 ng/ml (p=0.07), and 10.3±2.0 and 9.5±1.4 ng/ml (p=0.15), respectively. In stage II and III, patients were divided into two groups according to differences between preoperative and postoperative SDC1 levels (SDC1pre-pro). SDC1pre-pro ≤0 group significantly prolonged disease-free survival compared with SDC1pre-pro >0 group (p=0.048). CONCLUSION: Dynamic change in serum SDC1 levels serves as a prognostic biomarker for stage II and III colorectal cancer.

Time-course analysis of liver and serum galectin-3 in acute liver injury after alpha-galactosylceramide injection.

Galectin-3 is a beta-galactoside-binding lectin that plays important roles in diverse physiological functions, such as cell proliferation, apoptosis, and mRNA splicing. This protein is expressed on inflammatory cells and acts as a local inflammatory mediator. Recently, galectin-3 has been detected in several diseases, such as chronic liver, heart, and kidney diseases, diabetes, viral infection, autoimmune and neurodegenerative diseases, and tumors, and its role as a biomarker has attracted attention. Alpha-galactosylceramide is an artificially synthesized sphingolipid that can induce acute liver injury via the natural killer T pathway. However, the pathophysiological roles and kinetics of galectin-3 in acute liver injury are not fully understood. This study aimed to elucidate the expression and time course of galectin-3 in liver tissues during acute liver injury following alpha-galactosylceramide injection. Animals were histologically examined on days 1, 2, 4, and 7 after intraperitoneal injection of alpha-galactosylceramide, and the expressions of galectin-3 and ionized calcium-binding adaptor molecule 1 were analyzed. Notably, galectin-3 formed characteristic cluster foci, particularly on day 2 after injection. Cluster formation was not observed in chronic liver disease. Simultaneously, ionized calcium-binding adaptor molecule 1-positive cells were observed in the cluster foci. Serum galectin-3 levels increased on day 2 of treatment and correlated well with the number of galectin-3-positive cell clusters in the liver. Moreover, galectin-3 expression was an important mediator of the early phase of liver injury after alpha-galactosylceramide injection. These results suggest that serum galectin-3 may be a biomarker for the early diagnosis of acute liver injury and that clusters of galectin-3-positive cells may be a specific finding in acute liver injury.

Calcitriol ameliorates motor deficits and prolongs survival of Chrne-deficient mouse, a model for congenital myasthenic syndrome, by inducing Rspo2.

Signal transduction at the neuromuscular junction (NMJ) is compromised in a diverse array of diseases including congenital myasthenic syndromes (CMS). Germline mutations in CHRNE encoding the acetylcholine receptor (AChR) ε subunit are the most common cause of CMS. An active form of vitamin D, calcitriol, binds to vitamin D receptor (VDR) and regulates gene expressions. We found that calcitriol enhanced MuSK phosphorylation, AChR clustering, and myotube twitching in co-cultured C2C12 myotubes and NSC34 motor neurons. RNA-seq analysis of co-cultured cells showed that calcitriol increased the expressions of Rspo2, Rapsn, and Dusp6. ChIP-seq of VDR revealed that VDR binds to a region approximately 15 â€‹kbp upstream to Rspo2. Biallelic deletion of the VDR-binding site of Rspo2 by CRISPR/Cas9 in C2C12 myoblasts/myotubes nullified the calcitriol-mediated induction of Rspo2 expression and MuSK phosphorylation. We generated Chrne knockout (Chrne KO) mouse by CRISPR/Cas9. Intraperitoneal administration of calcitriol markedly increased the number of AChR clusters, as well as the area, the intensity, and the number of synaptophysin-positive synaptic vesicles, in Chrne KO mice. In addition, calcitriol ameliorated motor deficits and prolonged survival of Chrne KO mice. In the skeletal muscle, calcitriol increased the gene expressions of Rspo2, Rapsn, and Dusp6. We propose that calcitriol is a potential therapeutic agent for CMS and other diseases with defective neuromuscular signal transmission.

Endothelial Glycocalyx in the Peripheral Capillaries is Injured Under Oxaliplatin-Induced Neuropathy.

Oxaliplatin, a platinum-based anticancer drug, is associated with peripheral neuropathy (oxaliplatin-induced peripheral neuropathy, OIPN), which can lead to worsening of quality of life and treatment interruption. The endothelial glycocalyx, a fragile carbohydrate-rich layer covering the luminal surface of endothelial cells, acts as an endothelial gatekeeper and has been suggested to protect nerves, astrocytes, and other cells from toxins and substances released from the capillary vessels. Mechanisms underlying OIPN and the role of the glycocalyx remain unclear. This study aimed to define changes in the three-dimensional ultrastructure of capillary endothelial glycocalyx near nerve fibers in the hind paws of mice with OIPN. The mouse model of OPIN revealed disruption of the endothelial glycocalyx in the peripheral nerve compartment, accompanied by vascular permeability, edema, and damage to the peripheral nerves. To investigate the potential treatment interventions, nafamostat mesilate, a glycocalyx protective agent was used in tumor-bearing male mice. Nafamostat mesilate suppressed mechanical allodynia associated with neuropathy. It also prevented intra-epidermal nerve fiber loss and improved vascular permeability in the peripheral paws. The disruption of endothelial glycocalyx in the capillaries that lie within peripheral nerve bundles is a novel finding in OPIN. Furthermore, these findings point toward the potential of a new treatment strategy targeting endothelial glycocalyx to prevent vascular injury as an effective treatment of neuropathy as well as of many other diseases. PERSPECTIVE: OIPN damages the endothelial glycocalyx in the peripheral capillaries, increasing vascular permeability. In order to prevent OIPN, this work offers a novel therapy approach that targets endothelial glycocalyx.

Recombinant antithrombin attenuates acute kidney injury associated with rhabdomyolysis: an in vivo animal study.

BACKGROUND: Rhabdomyolysis is characterized by the destruction and necrosis of skeletal muscle tissue, resulting in acute kidney injury (AKI). Recombinant antithrombin (rAT) has DNA repair and vascular endothelial-protection properties. Herein, we investigated whether rAT therapy has beneficial effects against rhabdomyolysis-induced AKI. Ten-week-old male B6 mice were injected with 5 mL/kg of 50% glycerol intramuscularly in the left thigh after 24 h of fasting to create a rhabdomyolysis mouse model. Further, 750 IU/kg rAT was injected intraperitoneally at 24 and 72 h after the rhabdomyolysis model was established. The mice were euthanized after 96 h for histological analysis. Saline was administered to mice in the control group. RESULTS: Blood tests show elevated serum creatinine, urea nitrogen, and neutrophil gelatinase-associated lipocalin levels in rhabdomyolysis. Loss of tubular epithelial cell nuclei and destruction of the tubular luminal surface structure was observed in the untreated group, which improved with rAT treatment. Immunostaining for Ki-67 showed increased Ki-67-positive nuclei in the tubular epithelial cells in the rAT group, suggesting that rAT may promote tubular epithelial cell regeneration. The microvilli of the brush border of the renal tubules were shed during rhabdomyolysis, and rAT treatment reduced this injury. The vascular endothelial glycocalyx, which is usually impaired by rhabdomyolysis, became functional following rAT treatment. CONCLUSIONS: Treatment with rAT suppressed rhabdomyolysis-induced AKI, suggesting that rAT therapy may be a novel therapeutic approach.

Prevention of vincristine-induced peripheral neuropathy by protecting the endothelial glycocalyx shedding.

Vincristine-induced peripheral neuropathy (VIPN) adversely affects the quality of life and treatment continuity of patients. The endothelial glycocalyx (eGCX) protects nerves from harmful substances released from the capillary vessels, but its role in peripheral neuropathy remains unclear. We investigated the impact of eGCX protection on VIPN. Using a murine model of VIPN, we administered nafamostat mesylate to protect the eGCX shedding, and analyzed the eGCX integrity and manifestation of peripheral neuropathy. Nafamostat treatment suppressed allodynia associated with neuropathy. Additionally, nafamostat administration resulted in the suppression of increased vascular permeability in capillaries of peripheral nerves, further indicating its positive influence on eGCX in VIPN model mice. This study provided the importance of eGCX in VIPN. With the potential for rapid clinical translation through drug repositioning, nafamostat may be a new promising treatment for the prevention of VIPN.

Postnatal Expression of Kitl Affects Pigmentation of the Epidermis.

KITL signaling is important for melanocyte development in mammals; however, its function in the melanocyte stem cells in adult skin is not well-understood. In this study, we have generated genetically modified mice that express a Kitl transgene under the control of a doxycycline-inducible promoter to investigate the impact of its overexpression in embryo, young postnatal, and adult skin with intact hair follicles. We report that overexpression of KITL influences the proliferation and differentiation of melanocytes as well as the self-renewal capacity of resident melanocyte stem cells within the follicular niche. Notably, activation of Kit-KITL signaling induced the migration of melanocytes from hair follicles to the epidermis. In addition, we demonstrate that a single pulse of Kitl transgene expression in postnatal mice results in long-lasting effects on melanocyte stem cells and their differentiated progeny as pigmented skin cells that persist through adulthood. Our findings indicate that regulation of KITL signaling in melanocyte lineage is crucial for melanocyte stem cell homeostasis and melanocyte cell differentiation in postnatal and adult mice.

C-X-C domain ligand 14-mediated stromal cell-macrophage interaction as a therapeutic target for hand dermal fibrosis.

Dupuytren's contracture, a superficial dermal fibrosis, causes flexion contracture of the affected finger, impairing hand function. Specific single-nucleotide polymorphisms within genes in the Wnt signalling pathway are associated with the disease. However, the precise role of Wnt signalling dysregulation in the onset and progression of Dupuytren's contracture remains unclear. Here, using a fibrosis mouse model and clinical samples of human Dupuytren's contractures, we demonstrate that the activation of Wnt/ß-catenin signalling in Tppp3-positive cells in the dermis of the paw is associated with the development of fibrosis. Fibrosis development and progression via Wnt/ß-catenin signalling are closely related to stromal cell-macrophage interactions, and Wnt/ß-catenin signalling activation in Tppp3-positive stromal cells causes M2 macrophage infiltration via chemokine Cxcl14, resulting in the formation of a TGF-ß-expressing fibrotic niche. Inhibition of Cxcl14 mitigates fibrosis by decreasing macrophage infiltration. These findings suggest that Cxcl14-mediated stromal cell-macrophage interaction is a promising therapeutic target for Wnt/ß-catenin-induced fibrosis.

Decreased neutrophil counts prolong inflammation in acute pancreatitis and cause inflammation spillover to distant organs.

BACKGROUND/OBJECTIVE: Acute pancreatitis is an aseptic inflammation caused by pathologically activated pancreatic enzymes and inflammatory mediators produced secondarily by neutrophils and other inflammatory cells and is one of the most difficult diseases to treat. This study aimed to investigate the role of neutrophils in pancreatitis by examining tissue dynamics. METHODS: We created a model of caerulein-induced pancreatitis in 12-week-old male granulocyte colony-stimulating factor knockout mice (G-CSF-KO) and wild-type littermate control mice (six intraperitoneal injections of caerulein [80 µg/kg body weight] at hourly intervals for 2 days). Mice were sacrificed 0, 3, 6, 12, 24, 36, 48, 72, and 168 h after caerulein administration and examined histologically. RESULTS: The survival rate after one week of caerulein administration was 100 % in the control mice, whereas it was significantly lower (10 %) in the G-CSF-KO mice. Histological examination revealed significant hemorrhage and inflammatory cell migration in the G-CSF-KO mice, indicating prolonged inflammation. CONCLUSION: Prolonged inflammation was observed in the G-CSF-KO mice. Tissue cleanup by neutrophils during the acute phase of inflammation may influence healing through the chronic phase.

9-oxo-ODAs suppresses the proliferation of human cervical cancer cells through the inhibition of CDKs and HPV oncoproteins.

Mucosal human papillomavirus (HPV) subtypes 16 and 18 are causative agents of cervical cancer, a leading cause of cancer-related deaths among women worldwide. In Japan, eggplant calyx is a folk remedy used to treat common warts. 9-oxo-(10E,12E)-octadecadienoic acid, isolated from eggplant calyx, may have antitumor effects. This study investigated the antitumor effects of 9-oxo-(10E, 12Z)-octadecadienoic acid and 9-oxo-(10E,12E)-octadecadienoic acid (9-oxo-ODAs) on human cervical cancer cells. 9-oxo-ODAs suppressed the proliferation of human cervical cancer cell lines (HeLa, and SiHa) in a concentration-dependent manner (IC50 = 25-50 µM). FCM analysis revealed that 9-oxo-ODAs induced apoptosis. Transcriptome, proteomics, and enrichment analyses revealed that treatment with 9-oxo-ODAs significantly altered the cell cycle and p53 pathways and decreased cyclin-dependent kinase 1 (CDK1) protein expression. Real-time PCR analysis demonstrated that 9-oxo-ODAs reduced CDK1 mRNA expression in a concentration-dependent manner. In vitro, 9-oxo-ODAs reduced the HPV oncoprotein expression. In ex vivo human cervical cancer tissues, 9-oxo-ODAs decreased CDK1 expression and increased cleaved caspase 3, an apoptosis marker. Further, 9-oxo-ODAs showed the potential to suppressed metastatic formation and growth of cervical cancer in vivo. These findings suggest that 9-oxo-ODAs induce cell cycle arrest and apoptosis in HPV-positive human cervical cancer cells, and this process involves CDK1. Consequently, 9-oxo-ODAs may be potential therapeutic agents for cervical cancer.

A Novel Mouse Model of Intrahepatic Cholangiocarcinoma Induced by Azoxymethane.

Cholangiocarcinoma is the second most common primary cancer of the liver and has a poor prognosis. Various animal models, including carcinogen-induced and genetically engineered rodent models, have been established to clarify the mechanisms underlying cholangiocarcinoma development. In the present study, we developed a novel mouse model of malignant lesions in the biliary ducts induced by the administration of the carcinogen azoxymethane to obese C57BLKS/J-db/db mice. A histopathological analysis revealed that the biliary tract lesions in the liver appeared to be an intrahepatic cholangiocarcinoma with higher tumor incidence, shorter experimental duration, and a markedly increased incidence in obese mice. Molecular markers analyzed using a microarray and a qPCR indicated that the cancerous lesions originated from the cholangiocytes and developed in the inflamed livers. These findings indicated that this is a novel mouse model of intrahepatic cholangiocarcinoma in the context of steatohepatitis. This model can be used to provide a better understanding of the pathogenic mechanisms of cholangiocarcinoma and to develop novel therapeutic strategies for this malignancy.

Peritumoral Edema in Gliomas: A Review of Mechanisms and Management.

Treating malignant glioma is challenging owing to its highly invasive potential in healthy brain tissue and the formation of intense surrounding edema. Peritumoral edema in gliomas can lead to severe symptoms including neurological dysfunction and brain herniation. For the past 50 years, the standard treatment for peritumoral edema has been steroid therapy. However, the discovery of cerebral lymphatic vessels a decade ago prompted a re-evaluation of the mechanisms involved in brain fluid regulation and the formation of cerebral edema. This review aimed to describe the clinical features of peritumoral edema in gliomas. The mechanisms currently known to cause glioma-related edema are summarized, the limitations in current cerebral edema therapies are discussed, and the prospects for future cerebral edema therapies are presented. Further research concerning edema surrounding gliomas is needed to enhance patient prognosis and improve treatment efficacy.

Investigation of the relationship between intradialytic hypotension during hemodialysis and serum syndecan-1 concentration.

Intradialytic hypotension and arrhythmias are complications of hemodialysis. They are associated with decreased intravascular volume due to reduced ultrafiltration volume, cardiac function, and arterial tone. The vascular endothelial glycocalyx, which exists on the surface of healthy vascular endothelial cells and maintains vascular permeability, has been suggested to be impaired by hemodialysis. This single-center retrospective study evaluated the association between syndecan-1, an endothelial glycocalyx dysfunction marker, and complications of hemodialysis. We enrolled 92 patients who underwent outpatient hemodialysis at Gifu Seiryu Hospital from April to July 2022 (346 hemodialysis sessions). The median duration and time of hemodialysis were 40 months and 4.1 h, respectively. Median serum syndecan-1 levels were 67.7 ng/mL before and 98.3 ng/mL after hemodialysis. Hemodialysis complications were noted in 68 sessions, all of which were hypotension. No correlation between pre-hemodialysis syndecan-1 levels and the incidence of complications was observed. However, a positive correlation between the amount of change in syndecan-1 levels before and after hemodialysis and the incidence of hemodialysis complications was noted. Conversely, syndecan-1 levels did not correlate with brain or atrial natriuretic peptides, suggesting that impairment of the vascular endothelial glycocalyx may be a possible cause of intradialytic hypotension and may be useful in preventing intradialytic hypotension.

Effective generation mechanisms of tropical instability waves as represented by high-resolution coupled atmosphere-ocean prediction experiments.

Cusp-shaped fluctuations of the sea surface temperature (SST) front in the tropical Pacific, now known as tropical instability waves (TIWs), were discovered by remote sensing in the 1970s. Their discovery was followed by both theoretical and analytical studies, which, along with in situ observations, identified several possible generation mechanisms. Although modeling studies have shown that TIWs strongly influence the heat budget, their influence on local variations of realistically initialized predictions is not yet understood. We here evaluate a series of medium-range (up to ~ 10 days) coupled atmosphere-ocean predictions by a coupled model with different horizontal resolutions. Observational SST, surface wind stress, heat flux, and pressure data showed that representation of temporally and spatially local variations was improved by resolving fine-scale SST variations around the initialized coarse-scale SST front fluctuations of TIWs. Our study thus demonstrates the advantage of using high-resolution coupled models for medium-range predictions. In addition, analysis of TIW energetics showed two dominant sources of energy to anticyclonic eddies: barotropic instability between equatorial zonal currents and baroclinic instability due to intense density fronts. In turn, the eddy circulation strengthened both instabilities in the resolved simulations. This revealed feedback process refines our understanding of the generation mechanisms of TIWs.

Deuterium Magnetic Resonance Imaging Using Deuterated Water-Induced 2H-Tissue Labeling Allows Monitoring Cancer Treatment at Clinical Field Strength.

PURPOSE: An accurate and noninvasive assessment of tumor response following treatment other than traditional anatomical imaging techniques is essential. Deuterium magnetic resonance spectroscopic (MRS) imaging has been demonstrated as an alternative for cancer metabolic imaging by high-field MRI using deuterium-labeled molecules. The study aim was to use 2H tissue labeling and deuterium MRI at clinical field strength for tumor visualization and assessment of three anticancer therapies in pancreatic cancer model mice. EXPERIMENTAL DESIGN: MIA PaCa-2 pancreatic carcinoma and C26 colorectal carcinoma models of BALB/c-nu mice was prepared, and repeated deuterium MRI was performed during the first 10 days of free drinking of 30% D2O to track 2H distribution in tissues. 2H accumulation in the tumor after irradiation, bevacizumab administration, or gemcitabine administration was also measured in MIA PaCa-2-bearing mice. Confirmatory proton MRI, ex vivo metabolic hyperpolarization 13C-MRS, and histopathology were performed. RESULTS: The mouse's whole-body distribution of 2H was visible 1 day after drinking, and the signal intensity increased daily. Although the tumor size did not change 1 and 3 days after irradiation, the amount of 2H decreased significantly. The 2H image intensity of the tumor also significantly decreased after the administration of bevacizumab or gemcitabine. Metabolic hyperpolarization 13C-MRS, proton MRI, and 2H-NMR spectroscopy confirmed the efficacy of the anticancer treatments. CONCLUSIONS: Deuterium MRI at 1.5T proved feasible to track 2H distribution throughout mouse tissues during D2O administration and revealed a higher 2H accumulation in the tumor xenografts. This research demonstrated a promising successful method for preliminary assessment of radiotherapy and chemotherapy of cancer.