Low-density lipoprotein particle profiles compared with standard lipids measurements in the association with asymptomatic intracranial artery stenosis.

The Shiga Epidemiological Study of Subclinical Atherosclerosis was conducted in Kusatsu City, Shiga, Japan, from 2006 to 2008. Participants were measured for LDL-p through nuclear magnetic resonance technology. 740 men participated in follow-up and underwent 1.5 T brain magnetic resonance angiography from 2012 to 2015. Participants were categorized as no-ICAS, and ICAS consisted of mild-ICAS (1 to < 50%) and severe-ICAS (≥ 50%) in any of the arteries examined. After exclusion criteria, 711 men left for analysis, we used multiple logistic regression to examine the association between lipid profiles and ICAS prevalence. Among the study participants, 205 individuals (28.8%) had ICAS, while 144 individuals (20.3%) demonstrated discordance between LDL-c and LDL-p levels. The discordance "low LDL-c-high LDL-p" group had the highest ICAS risk with an adjusted OR (95% CI) of 2.78 (1.55-5.00) in the reference of the concordance "low LDL-c-low LDL-p" group. This was followed by the concordance "high LDL-c-high LDL-p" group of 2.56 (1.69-3.85) and the discordance "high LDL-c-low LDL-p" group of 2.40 (1.29-4.46). These findings suggest that evaluating LDL-p levels alongside LDL-c may aid in identifying adults at a higher risk for ICAS.

Incidental detection of upper gastrointestinal epithelial neoplasia by screening endoscopy prior to endoscopic ultrasonography in patients with pancreaticobiliary disease.

BACKGROUND: Screening esophagogastroduodenoscopy plays an important role in the early detection of upper gastrointestinal cancer. To provide more opportunities for patients with pancreaticobiliary disease to undergo this screening, we have performed esophagogastroduodenoscopy prior to endoscopic ultrasonography. However, the usefulness of this protocol is not elucidated. This study aimed to investigate the utility of screening esophagogastroduodenoscopy in this protocol in the detection of upper gastrointestinal epithelial neoplasms. METHODS: The outcomes of screening esophagogastroduodenoscopy performed prior to endoscopic ultrasonography in patients with pancreaticobiliary disease at our hospital between April 2020 and September 2022 were investigated. A logistic regression model was used to identify factors affecting the detection of epithelial neoplasms. Additionally, we compared the detection rate of gastric epithelial neoplasms between screening esophagogastroduodenoscopy performed prior to endoscopic ultrasonography and that performed at our medical checkup center. RESULTS: A total of 615 screening esophagogastroduodenoscopies prior to endoscopic ultrasonography were performed, and 12 (2.0%) epithelial neoplasms were detected, including esophageal lesions (n = 2) and gastric lesions (n = 10). Of these lesions, 75% (9/12) underwent curative endoscopic resection. A multivariate analysis showed that open-type gastric mucosal atrophy (odds ratio, 7.7; 95% confidence interval, 1.5-38.4; p = 0.01) and the use of magnification endoscopy (odds ratio, 7.3; 95% confidence interval, 1.9-27.9; p < 0.01) independently affected the detection of epithelial neoplasms. The detection rate of gastric epithelial neoplasms was significantly higher using this protocol than that in our medical checkup center (1.6% versus 0.2%, p < 0.01). CONCLUSIONS: A protocol of screening esophagogastroduodenoscopy prior to endoscopic ultrasonography may be recommended because epithelial neoplasms could be detected at a non-negligible rate.

The tyrosine kinase inhibitor nintedanib enhances the efficacy of 90 Y-labeled B5209B radioimmunotherapy targeting ROBO1 without increased toxicity in small-cell lung cancer xenograft mice.

BACKGROUND: Small cell lung cancer (SCLC) has a poor prognosis, and Roundabout homolog 1 (ROBO1) is frequently expressed in SCLC. ROBO1-targeted radioimmunotherapy (RIT) previously showed tumor shrinkage, but regrowth with fibroblast infiltration was observed. The fibroblasts would support tumor survival by secreting growth factors and cytokines. Inhibition of fibroblasts offers a candidate strategy for increasing RIT efficacy. Here, we evaluated the efficacy of combination therapy with 90 Y-labeled anti-ROBO1 antibody B5209B ( 90 Y-B5209B) and the tyrosine kinase inhibitor nintedanib in SCLC xenograft mice. METHODS: Subcutaneous NCI-H69 SCLC xenograft mice were divided into four groups: saline, nintedanib alone, RIT alone, and a combination of RIT with nintedanib (combination). A single dose of 7.4 MBq of 90 Y-B5209B was injected intravenously. Nintedanib was orally administered at a dose of 400 µg five times a week for 4 weeks. Tumor volumes and body weights were measured regularly. Tumor sections were stained with hematoxylin and eosin or Masson trichrome. RESULTS: All six tumors in the combination therapy group disappeared, and four tumors showed no regrowth. Although RIT alone induced similar tumor shrinkage, regrowth was observed. Prolonged survival in the combination therapy group was found compared with the other groups. Temporary body weight loss was observed in RIT and combination therapy. There is no difference in fibroblast infiltration between RIT alone and the combination. CONCLUSION: Nintedanib significantly enhanced the anti-tumor effects of RIT with the 90 Y-B5209B without an increase in toxicity. These findings encourage further research into the potential clinical application of combining RIT with nintedanib.

Imaging assessment of photosensitizer emission induced by radionuclide-derived Cherenkov radiation using charge-coupled device optical imaging and long-pass filters.

BACKGROUND: Radionuclides produce Cherenkov radiation (CR), which can potentially activate photosensitizers (PSs) in phototherapy. Several groups have studied Cherenkov energy transfer to PSs using optical imaging; however, cost-effectively identifying whether PSs are excited by radionuclide-derived CR and detecting fluorescence emission from excited PSs remain a challenge. Many laboratories face the need for expensive dedicated equipment. AIM: To cost-effectively confirm whether PSs are excited by radionuclide-derived CR and distinguish fluorescence emission from excited PSs. METHODS: The absorbance and fluorescence spectra of PSs were measured using a microplate reader and fluorescence spectrometer to examine the photo-physical properties of PSs. To mitigate the need for expensive dedicated equipment and achieve the aim of the study, we developed a method that utilizes a charge-coupled device optical imaging system and appropriate long-pass filters of different wavelengths (manual sequential application of long-pass filters of 515, 580, 645, 700, 750, and 800 nm). Tetrakis (4-carboxyphenyl) porphyrin (TCPP) was utilized as a model PS. Different doses of copper-64 (64CuCl2) (4, 2, and 1 mCi) were used as CR-producing radionuclides. Imaging and data acquisition were performed 0.5 h after sample preparation. Differential image analysis was conducted by using ImageJ software (National Institutes of Health) to visually evaluate TCPP fluorescence. RESULTS: The maximum absorbance of TCPP was at 390-430 nm, and the emission peak was at 670 nm. The CR and CR-induced TCPP emissions were observed using the optical imaging system and the high-transmittance long-pass filters described above. The emission spectra of TCPP with a peak in the 645-700 nm window were obtained by calculation and subtraction based on the serial signal intensity (total flux) difference between 64CuCl2 + TCPP and 64CuCl2. Moreover, the differential fluorescence images of TCPP were obtained by subtracting the 64CuCl2 image from the 64CuCl2 + TCPP image. The experimental results considering different 64CuCl2 doses showed a dose-dependent trend. These results demonstrate that a bioluminescence imaging device coupled with different long-pass filters and subtraction image processing can confirm the emission spectra and differential fluorescence images of CR-induced TCPP. CONCLUSION: This simple method identifies the PS fluorescence emission generated by radionuclide-derived CR and can contribute to accelerating the development of Cherenkov energy transfer imaging and the discovery of new PSs.

Novel Auger-Electron-Emitting 191Pt-Labeled Pyrrole-Imidazole Polyamide Targeting MYCN Increases Cytotoxicity and Cytosolic dsDNA Granules in MYCN-Amplified Neuroblastoma.

Auger electrons can cause nanoscale physiochemical damage to specific DNA sites that play a key role in cancer cell survival. Radio-Pt is a promising Auger-electron source for damaging DNA efficiently because of its ability to bind to DNA. Considering that the cancer genome is maintained under abnormal gene amplification and expression, here, we developed a novel 191Pt-labeled agent based on pyrrole-imidazole polyamide (PIP), targeting the oncogene MYCN amplified in human neuroblastoma, and investigated its targeting ability and damaging effects. A conjugate of MYCN-targeting PIP and Cys-(Arg)3-coumarin was labeled with 191Pt via Cys (191Pt-MYCN-PIP) with a radiochemical purity of >99%. The binding potential of 191Pt-MYCN-PIP was evaluated via the gel electrophoretic mobility shift assay, suggesting that the radioagent bound to the DNA including the target sequence of the MYCN gene. In vitro assays using human neuroblastoma cells showed that 191Pt-MYCN-PIP bound to DNA efficiently and caused DNA damage, decreasing MYCN gene expression and MYCN signals in in situ hybridization analysis, as well as cell viability, especially in MYCN-amplified Kelly cells. 191Pt-MYCN-PIP also induced a substantial increase in cytosolic dsDNA granules and generated proinflammatory cytokines, IFN-α/ß, in Kelly cells. Tumor uptake of intravenously injected 191Pt-MYCN-PIP was low and its delivery to tumors should be improved for therapeutic application. The present results provided a potential strategy, targeting the key oncogenes for cancer survival for Auger electron therapy.

Wnt1 induces osteoblastic changes in a well-established osteolytic skeletal metastatic model derived from breast cancer.

BACKGROUND: Osteoblastic skeletal metastasis is frequently observed in prostate cancer. An effective therapy has not been developed due to the unclear molecular mechanism. The Wnt family is involved in various biological phenomena including bone metabolism. There is no direct evidence that the family causes osteoblastic skeletal metastasis. AIMS: The present study aims to evaluate whether overexpressed Wnt induces osteoblastic bone metastasis in a well-established osteolytic bone metastatic model. METHODS AND RESULTS: The breast cancer-derived 5a-D-Luc-ZsGreen cells were transfected with Wnt1, Wnt3A, and Wnt5A expression vectors, producing stably highly expressing cells. These cells were intracardially transplanted in nude mice. Bone metastasis development was confirmed by fluorescence imaging. Hind-limb bones including metastasis were dissected and visualized through micro-CT imaging. After imaging, sections were stained with hematoxylin and eosin (H&E), and immunohistochemically stained with an anti-SATB2 antibody. Luminescent imaging confirmed mice with bone metastases in the hind limbs. Micro-CT imaging found an osteoblastic change only in bone metastasis of mice transplanted with Wnt1-expressing cells. This was confirmed on H&E-stained sections. SATB2 immunostaining showed differentiated osteoblasts were at the site of bone metastases in the diaphysis. SATB2 in the Wnt/ß-catenin pathway activated by overexpressed Wnt1 could induce osteoblastic change. CONCLUSION: Our findings provided direct evidence Wnt1 is involved in osteoblastic bone metastasis development. Our model would be a powerful tool for further elucidating molecular mechanisms underlying the disease and developing effective therapies.

Head-to-head comparison of three chelates reveals DOTAGA promising for 225 Ac labeling of anti-FZD10 antibody OTSA101.

To select the most suitable chelate for 225 Ac radiolabeling of the anti-FZD10 antibody OTSA101, we directly compared three chelates: S-2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane tetraacetic acid (p-SCN-Bn-DOTA), 2,2',2″-(10-(1-carboxy-4-((4-isothiocyanatobenzyl)amino)-4-oxobutyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl) triacetic acid (p-SCN-Bn-DOTAGA), and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid mono-N-hydroxysuccinimide ester (DO3A-NHS-ester). We evaluated the binding affinity of the chelate-conjugated OTSA101 antibodies, as well as the labeling efficiency and stability in murine serum of 225 Ac-labeled OTSA101 as in vitro properties. The biodistribution, intratumoral distribution, absorbed doses, and therapeutic effects of the chelate-conjugated OTSA101 antibodies were assessed in the synovial sarcoma mouse model SYO-1. Of the three conjugates, DOTAGA conjugation had the smallest impact on the binding affinity (p < 0.01). The labeling efficiencies of DOTAGA-OTSA101 and DO3A-OTSA101 were 1.8-fold higher than that of DOTA-OTSA101 (p < 0.01). The stabilities were similar between 225 Ac-labeled DOTA-OTSA101, DOTAGA-OTSA101, and DO3A-OTSA101in serum at 37 and 4°C. The dosimetric analysis based on the biodistribution revealed significantly higher tumor-absorbed doses by 225 Ac-labeled DOTA-OTSA101 and DOTAGA-OTSA101 compared with 225 Ac-DO3A-OTSA101 (p < 0.05). 225 Ac-DOTAGA-OTSA101 exhibited the highest tumor-to-bone marrow ratio, with bone marrow being the dose-limiting tissue. The therapeutic and adverse effects were not significantly different between the three conjugates. Our findings indicate that among the three evaluated chelates, DOTAGA appears to be the most promising chelate to produce 225 Ac-labeled OTSA101 with high binding affinity and high radiochemical yields while providing high absorbed doses to tumors and limited absorbed doses to bone marrow.

Bone marrow-derived mononuclear cells ameliorate neurological function in chronic cerebral infarction model mice via improvement of cerebral blood flow.

BACKGROUND AIMS: Stroke is a frequently observed neurological disorder that might lead to permanent and severe disability. Recently, various regenerative therapies have been developed, some of which have already been applied clinically. However, their outcomes have not been fully satisfactory. In particular, the development of regenerative therapies for chronic ischemic stroke is greatly needed. Herein intracerebral administration of bone marrow-derived mononuclear cells (BM-MNCs) was assessed as a potential treatment for chronic ischemic stroke using a severe combined immunodeficiency mouse model characterized by minimal vascular variation unrelated to immunodeficiency. METHODS: A reproducible model of permanent middle cerebral artery occlusion was prepared, and intracerebral BM-MNC transplantation was performed 14 days after stroke induction in the infarcted brain. RESULTS: Sensorimotor behavioral function and cerebral blood flow were significantly improved upon treatment with BM-MNCs compared to control medium injection. The transplanted cells exhibited characteristics of the vascular endothelium and microglia/macrophages. Significant angiogenesis and suppression of astrogliosis and microgliosis were observed in the affected brain. Messenger RNA expression analysis showed significant increases in anti-inflammatory cytokines, A2 astrocyte/anti-inflammatory microglia markers and vascular endothelial markers such as vascular endothelial growth factor and significant decreases in pro-inflammatory cytokines and A1 astrocyte/pro-inflammatory microglia markers following BM-MNC transplantation. CONCLUSIONS: These results suggest that intracerebral administration of BM-MNCs should be considered an effective cell therapy for chronic stroke.

Unilateral rete mirabile in multiple intracranial arteries with ipsilateral agenesis of the internal carotid artery: a case report.

BACKGROUND: Rete mirabile of the cerebral artery is a rare anomaly, with most previous cases occurring in the middle cerebral artery or internal carotid artery. Here, we present the first report of unilateral rete mirabile in multiple intracranial arteries with ipsilateral internal carotid artery agenesis. CASE PRESENTATION: A 64-year-old Japanese woman was brought to the emergency department of our hospital in a deep coma. Computed tomography of the head showed severe intraventricular hemorrhage with subarachnoid hemorrhage. Computed tomography angiography showed not only congenital left internal carotid artery agenesis, but also rete mirabile of the left posterior communicating artery, the left posterior cerebral artery, and the left anterior cerebral artery. This unilateral vessel anomaly complex may have contributed to the formation of a peripheral aneurysm arising from a perforating branch of the pericallosal artery, which ruptured. The patient underwent urgent bilateral external ventricular drainage, but deteriorated and was declared brain dead. CONCLUSIONS: We report the first case of unilateral rete mirabile in multiple intracranial arteries. Because the cerebral arteries in patients with rete mirabile may be vulnerable, close attention should be paid to the development of cerebral aneurysms.

Gallbladder perforation following peroral cholangioscopy-guided lithotripsy: A case report.

Peroral cholangioscopy-guided lithotripsy is highly effective in clearing difficult bile duct stones. It can cause adverse events, such as cholangitis and pancreatitis; however, gallbladder perforation is extremely rare. Herein, we describe the case of a 77-year-old woman who developed gallbladder perforation following peroral cholangioscopy -guided lithotripsy. She was referred to our hospital to treat multiple large bile duct stones. She underwent peroral cholangioscopy-guided lithotripsy because of conventional lithotripsy failure. After a cholangioscope was advanced into the bile duct, saline irrigation was used for visualization. Electronic hydraulic lithotripsy was performed, but it took time for fragmentation because the calculus was hard. The 2-h endoscopic procedure did not completely remove the stone, and treatment was discontinued after placing a biliary plastic stent and nasobiliary tube. After the endoscopic procedure, she started experiencing right hypochondrial pain, which worsened the next day. Computed tomography showed a gallbladder wall defect in the gallbladder fundus with pericholecystic fluid. She was diagnosed with gallbladder perforation and underwent emergency surgery. A perforation site was found at the gallbladder fundus. Open cholecystectomy, choledochotomy, and extraction of residual bile duct stones were performed. The patient was discharged 9 days post-surgery without any complications. The saline irrigation used for visualization may have caused a surge in intra-gallbladder pressure, resulting in gallbladder perforation. Therefore, endoscopists may need to conserve irrigation water during peroral cholangioscopy-guided lithotripsy.

Cranial vault lymphoma - A case report and characteristics contributing to a differential diagnosis.

Background: Lymphomas of the cranial vault are rare and are often misdiagnosed preoperatively as presumptive meningioma with extracranial extension. Case Description: A 58-year-old woman was referred and admitted to our department with a rapidly growing subcutaneous mass over the right frontal forehead of 2 months' duration. The mass was approximately 13 cm at its greatest diameter, elevated 3 cm above the contour of the peripheral scalp, and attached to the skull. Neurological examination showed no abnormalities. Skull X-rays and computed tomography showed preserved original skull contour despite the large extra and intracranial tumor components sandwiching the cranial vault. Digital subtraction angiography showed a partial tumor stain with a large avascular area. Our preoperative diagnostic hypothesis was meningioma. We performed a biopsy and histological findings were characteristic of a diffuse large B-cell lymphoma. A very high preoperative level of soluble interleukin-2 receptor (5390 U/mL; received postoperatively) also suggested lymphoma. The patient received chemotherapy but died of disease progression 10 months after the biopsy. Conclusion: Several preoperative features of the present case are clues to the correct diagnostic hypothesis of cranial vault diffuse large B-cell lymphoma rather than meningioma, including a rapidly growing subcutaneous scalp mass, poor vascularization, and limited skull destruction relative to the size of the soft-tissue mass.

Incidental diffuse low-grade gliomas: A systematic review and meta-analysis of treatment results with correction of lead-time and length-time biases.

Background: Better overall survival (OS) reported in patients with incidental diffuse low-grade glioma (iLGG) in comparison to symptomatic LGG (sLGG) may be overestimated by lead-time and length-time. Methods: We performed a systematic review and meta-analysis of studies on adult hemispheric iLGGs according to the PRISMA statement to adjust for biases in their outcomes. Survival data were extracted from Kaplan-Meier curves. Lead-time was estimated by 2 methods: Pooled data of time to become symptomatic (LTs) and time calculated from the tumor growth model (LTg). Results: We selected articles from PubMed, Ovid Medline, and Scopus since 2000. Five compared OS between patients with iLGG (n = 287) and sLGG (n = 3117). The pooled hazard ratio (pHR) for OS of iLGG to sLGG was 0.40 (95% confidence interval [CI] {0.27-0.61}). The estimated mean LTs and LTg were 3.76 years (n = 50) and 4.16-6.12 years, respectively. The corrected pHRs were 0.64 (95% CI [0.51-0.81]) by LTs and 0.70 (95% CI [0.56-0.88]) by LTg. In patients with total removal, the advantage of OS in iLGG was lost after the correction of lead-time. Patients with iLGG were more likely to be female pooled odds ratio (pOR) 1.60 (95% CI [1.25-2.04]) and have oligodendrogliomas (pOR 1.59 [95% CI {1.05-2.39}]). Correction of the length-time bias, which increased the pHR by 0.01 to 0.03, preserved the statistically significant difference in OS. Conclusions: The reported outcome in iLGG was biased by lead-time and length-time. Although iLGG had a longer OS after correction of biases, the difference was less than previously reported.

Folate receptor-targeted near-infrared photodynamic therapy for folate receptor-overexpressing tumors.

BACKGROUND: Photodynamic therapy (PDT) is a minimally invasive form of cancer therapy, and the development of a novel photosensitizer (PS) with optimal properties is important for enhancing PDT efficacy. Folate receptor (FR) membrane protein is frequently overexpressed in 40% of human cancer and a good candidate for tumor-specific targeting. Specific active targeting of PS to FR can be achieved by conjugation with the folate moiety. A folate-linked, near-infrared (NIR)-sensitive probe, folate-Si-rhodamine-1 (FolateSiR-1), was previously developed and is expected to be applicable to NIR-PDT. AIM: To investigate the therapeutic efficacy of NIR-PDT induced by FolateSiR-1, a FR-targeted PS, in preclinical cancer models. METHODS: FolateSiR-1 was developed by conjugating a folate moiety to the Si-rhodamine derivative through a negatively charged tripeptide linker. FR expression in the designated cell lines was examined by western blotting (WB). The selective binding of FolateSiR-1 to FR was confirmed in FR overexpressing KB cells (FR+) and tumors by fluorescence microscopy and in vivo fluorescence imaging. Low FR expressing OVCAR-3 and A4 cell lines were used as negative controls (FR-). The NIR light (635 ± 3 nm)-induced phototoxic effect of FolateSiR-1 was evaluated by cell viability imaging assays. The time-dependent distribution of FolateSiR-1 and its specific accumulation in KB tumors was determined using in vivo longitudinal fluorescence imaging. The PDT effect of FolateSiR-1 was evaluated in KB tumor-bearing mice divided into four experimental groups: (1) FolateSiR-1 (100 µmol/L) alone; (2) FolateSiR-1 (100 µmol/L) followed by NIR irradiation (50 J/cm2); (3) NIR irradiation (50 J/cm2) alone; and (4) no treatment. Tumor volume measurement and immunohistochemical (IHC) and histological examinations of the tumors were performed to analyze the effect of PDT. RESULTS: High FR expression was observed in the KB cells by WB, but not in the OVCAR-3 and A4 cells. Substantial FR-specific binding of FolateSiR-1 was observed by in vitro and in vivo fluorescence imaging. Cell viability imaging assays showed that NIR-PDT induced cell death in KB cells. In vivo longitudinal fluorescence imaging showed rapid peak accumulation of FolateSiR-1 in the KB tumors 2 h after injection. In vivo PDT conducted at this time point caused tumor growth delay. The relative tumor volumes in the PDT group were significantly reduced compared to those in the other groups [5.81 ± 1.74 (NIR-PDT) vs 12.24 ± 2.48 (Folate-SiR-1), vs 11.84 ± 3.67 (IR), vs 12.98 ± 2.78 (Untreated), at Day 16, P < 0.05]. IHC analysis revealed reduced proliferation marker Ki-67-positive cells in the PDT treated tumors, and hematoxylin-eosin staining revealed features of necrotic- and apoptotic cell death. CONCLUSION: FolateSiR-1 has potential for use in PDT, and FR-targeted NIR-PDT may open a new effective strategy for the treatment of FR-overexpressing tumors.

Dynamic imaging analysis reveals Auger electron-emitting radio-cisplatin induces DNA damage depending on the cell cycle.

Auger electrons can induce nanoscale physiochemical damage to DNA. The present study reports a sequential and systematic evaluation of the relationship between DNA damage such as double-strand breaks (DSBs) and the cell cycle for the Auger electron-emitting agent radiolabeled cisplatin with DNA binding ability. For dynamic imaging analysis, we used U2OS-derived cancer cells expressing two fluorescent fusion proteins: tumor-suppressor p53 binding protein 1 with a green fluorescent protein (53BP1-EGFP) and proliferating cell nuclear antigen with a red fluorescent protein (PCNA-DsRed). Time-lapse images of the cells were quantitatively analyzed using the ImageJ software with the deepImageJ plugin and the Google Colaboratory platform. From the middle-to-late G1 phase, around the G1-to-S phase transition, we found increased 53BP1 foci in cells treated with the radio-cisplatin. The radio-cisplatin caused significantly more DSBs than the nonradioactive cisplatin and saline in the G1 phase but not in the other phases. These results indicate that Auger electron-induced DNA damage, including DSBs, depends on the cell cycle. The G1 phase, which is associated with low DNA repair capacity and high radiosensitivity, is a promising target; thus, combining radiolabeled cisplatin with agents that arrest cells in the G1 phase could improve the DNA-damaging effect of Auger electrons and their therapeutic efficacy.

Multiplexed Imaging Reveals the Spatial Relationship of the Extracellular Acidity-Targeting pHLIP with Necrosis, Hypoxia, and the Integrin-Targeting cRGD Peptide.

pH (low) insertion peptides (pHLIPs) have been developed for cancer imaging and therapy targeting the acidic extracellular microenvironment. However, the characteristics of intratumoral distribution (ITD) of pHLIPs are not yet fully understood. This study aimed to reveal the details of the ITD of pHLIPs and their spatial relationship with other tumor features of concern. The fluorescent dye-labeled pHLIPs were intravenously administered to subcutaneous xenograft mouse models of U87MG and IGR-OV1 expressing αVß3 integrins (using large necrotic tumors). The αVß3 integrin-targeting Cy5.5-RAFT-c(-RGDfK-)4 was used as a reference. In vivo and ex vivo fluorescence imaging, whole-tumor section imaging, fluorescence microscopy, and multiplexed fluorescence colocalization analysis were performed. The ITD of fluorescent dye-labeled pHLIPs was heterogeneous, having a high degree of colocalization with necrosis. A direct one-to-one comparison of highly magnified images revealed the cellular localization of pHLIP in pyknotic, karyorrhexis, and karyolytic necrotic cells. pHLIP and hypoxia were spatially contiguous but not overlapping cellularly. The hypoxic region was found between the ITDs of pHLIP and the cRGD peptide and the Ki-67 proliferative activity remained detectable in the pHLIP-accumulated regions. The results provide a better understanding of the characteristics of ITD of pHLIPs, leading to new insights into the theranostic applications of pHLIPs.

Efficacy of vorinostat-sensitized intraperitoneal radioimmunotherapy with 64Cu-labeled cetuximab against peritoneal dissemination of gastric cancer in a mouse model.

Background: Gastric cancer is a common cause of cancer-related death worldwide, and peritoneal dissemination is the most frequent metastatic pattern of gastric cancer. However, the treatment of this disease condition remains difficult. It has been demonstrated that intraperitoneal radioimmunotherapy (ipRIT) with 64Cu-labeled cetuximab (anti-epidermal growth factor receptor antibody; 64Cu-cetuximab) is a potential treatment for peritoneal dissemination of gastrointestinal cancer in vivo. Recent preclinical and clinical studies have also shown that a histone deacetylase inhibitor, vorinostat, effectively sensitized gastrointestinal cancer to external radiation. Aim: In the present study, we examined the efficacy of the combined use of vorinostat, as a radiosensitizer during ipRIT with 64Cu-cetuximab in a peritoneal dissemination mouse model with human gastric cancer NUGC4 cells stably expressing red fluorescent protein. Methods: The mouse model was treated by ipRIT with 64Cu-cetuximab plus vorinostat, each single treatment, or saline (control). Side effects, including hematological and biochemical parameters, were evaluated in similarly treated, tumor-free mice. Results: Coadministration of ipRIT with 64Cu-cetuximab + vorinostat significantly prolonged survival compared to control and each single treatment. No significant toxicity signals were observed in all treatment groups. Conclusions: Our data suggest that vorinostat is a potentially effective radiosensitizer for use during the treatment of peritoneal dissemination of gastric cancer by ipRIT with 64Cu-cetuximab.

Precise quantitative evaluation of pharmacokinetics of cisplatin using a radio-platinum tracer in tumor-bearing mice.

OBJECTIVE: The platinum-based antineoplastic drug cisplatin is commonly used for chemotherapy in clinics. This work aims to demonstrate a radio-platinum tracer is useful for precisely quantifying small amounts of platinum in pharmacokinetics studies. METHODS: A cisplatin radiotracer (radio-cisplatin) was synthesized, and a comprehensive evaluation of cisplatin over 7 days after its intravenous injection into nude mice bearing a subcutaneous lung tumor (H460) was conducted. RESULTS: A biphasic retention curve in the whole body and blood was observed [ T1/2 (α) = 1.14 h, T1/2 (ß) = 5.33 days for the whole body, and T1/2 (α) = 23.9 min, T1/2 (ß) = 4.72 days for blood]. The blood concentration decreased within 1 day after injection. Most of the intact cisplatin was excreted via the kidneys in the early time points, and a small part was distributed in tissues including tumors. The plasma protein binding rate of cisplatin increased rapidly after injection, and the protein-bound cisplatin remained in the blood longer than intact cisplatin. The peak uptake in H460 tumors was 4.7% injected dose per gram at 15 min after injection, and the area under the curve (AUC 0-7 days ) was approximately one-half to one-third of the AUC 0-7 days in the kidneys, liver, and bone, where some toxicity is observed in humans. CONCLUSION: The radio-platinum tracer revealed the highly quantitative biodistribution of cisplatin, providing insights into the properties of cisplatin, including its adverse effects. The tracer enables a precise evaluation of pharmacokinetics for platinum-based drugs with high sensitivity.

[A fatal case intra-abdominal hemorrhage following self-removal of a percutaneous transhepatic gallbladder drainage tube].

A 92-year-old woman with gallstone pancreatitis and acute cholangitis was admitted to our hospital where endoscopic retrograde cholangiopancreatography was performed for emergency biliary drainage. Biliary cannulation was unsuccessful. Consequently, percutaneous transhepatic gallbladder drainage (PTGBD) was performed, and her symptoms improved. The PTGBD tube was removed by the patient on the third day of admission resulting in cardiopulmonary arrest two hours later. Cardiopulmonary resuscitation restored spontaneous circulation. Contrast computed tomography revealed intra-abdominal hemorrhage from the right hepatic artery by the removed part of the PTGBD tube. The patient died despite hemostasis by transcatheter artery embolization. PTGBD is generally effective and safe;however, it can cause fatal hemorrhage, especially if PTGBD tubes are removed by the patient. Thus, self-removal should be strictly prevented.