Imaging of cardiac amyloidosis using dynamic F-FPYBF-2 positron emission tomography.

Purpose: This study aimed to evaluate the diagnostic ability of 5-(5-(2-(2-(2-F-fluoroethoxy) ethoxy) ethoxy) benzofuran-2-yl)-N-methylpyridin-2-amine (F-FPYBF-2) dynamic PET for patients with cardiac amyloidosis (CA).

Methods: The subjects were patients diagnosed with proven amyloidosis (n = 16) including transthyretin cardiac amyloidosis (ATTR-CA) (n = 7) and light chain amyloidosis (AL amyloidosis) (n = 9), of which 4 and 5 with (AL-CA) and without (AL-nCA) cardiac involvement, and 4 control subjects suffering from some symptoms of cardiac failure without amyloidosis (CTL). Thirty minutes dynamic F-FPYBF-2 PET/CT was performed to evaluate the time activity curve and the retention index (mRI) as the ratio of the myocardial SUV at 15 to 5 min.

Unique advantages of dynamic l-[11C]methionine PET/CT for assessing the rate of skeletal muscle protein synthesis: A pilot trial in young men.

Although the standard method to evaluate skeletal muscle protein synthesis (MPS) is muscle biopsy, the method is invasive and problematic for multisite use. We conducted a small pilot study in volunteers to investigate changes in MPS according to skeletal muscle site using a noninvasive method in which 6 healthy young men were given yogurt (containing 20 g milk protein) or water, and 1 h later, l-[11C]methionine ([11C]Met) was administered intravenously. Dynamic PET/CT imaging of their thighs was performed for 60 min.

Cu Complexes of Tripodal Amine Ligands' In Vivo Tumor and Liver Uptakes and Intracellular Cu Distribution in the Extrahepatic Bile Duct Carcinoma Cell Line TFK-1: A Basic Comparative Study.

Copper (Cu) is a critical element for cancer cell proliferation and considerably accumulates in the nucleus. Cu is an anticancer radiopharmaceutical that targets the copper requirement of cancer cells. However, intravenously injected Cu ions primarily accumulate in the liver.

Conversion of 5α-Androstane-3α,17β-diol to bis[(4-dimethylamino)phenyl carbamate] derivative for sensitive determination of its rat brain level by LC/ESI-MS/MS.

Rationale: 5α-Androstane-3α,17β-diol (3α,5α-Adiol) is a testosterone-derived neurosteroid and has anxiolytic and analgesic effects via γ-aminobutyric acid type A receptors as with the progesterone-derived neurosteroid, allopregnanolone (AP). Although the psychotropic drug-evoked changes in the brain AP concentration have been intensively studied, those in the brain 3α,5α-Adiol concentration remain poorly understood. One of the causes for this is the limited availability of a validated method for quantifying the brain 3α,5α-Adiol with a sufficient sensitivity and specificity, which is described in this study.

Further evidence for blood-to-brain influx of unconjugated bile acids by passive diffusion: Determination of their brain-to-serum concentration ratios in rats by LC/MS/MS.

Bile acids (BAs) reside in the brain and are probably involved in some neurological disorders. The view that most of unconjugated BAs in the brain are derived across the blood-brain barrier from the periphery by passive diffusion depending on their hydrophobicity is currently dominant, but some studies have made conflicting claims. In this study, the correlation analysis between the rat brain and serum levels of unconjugated BAs with a wider range of hydrophobicity was conducted to obtain further evidence about the blood-to-brain influx of unconjugated BAs by passive diffusion.

Trace Metal Impurities Effects on the Formation of [Cu]Cu-diacetyl-bis(-methylthiosemicarbazone) ([Cu]Cu-ATSM).

[Cu]Cu-diacetyl-bis(-methylthiosemicarbazone) ([Cu]Cu-ATSM) is a radioactive hypoxia-targeting therapeutic agent being investigated in clinical trials for malignant brain tumors. For the quality management of [Cu]Cu-ATSM, understanding trace metal impurities' effects on the chelate formation of Cu and ATSM is important. In this study, we conducted coordination chemistry studies on metal-ATSM complexes.

An In Vivo Dual-Observation Method to Monitor Tumor Mass and Tumor-Surface Blood Vessels for Developing Anti-Angiogenesis Agents against Submillimeter Tumors.

Managing metastasis at the early stage and detecting and treating submillimeter tumors at early metastasis are crucial for improving cancer prognosis. Angiogenesis is a critical target for developing drugs to detect and inhibit submillimeter tumor growth; however, drug development remains challenging because there are no suitable models for observing the submillimeter tumor mass and the surrounding blood vessels in vivo. We have established a xenograft subcutaneous submillimeter tumor mouse model with HT-29-RFP by transplanting a single spheroid grown on radiation-crosslinked gelatin hydrogel microwells.

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.

Process to Remove the Size Variants Contained in the Antibody-Chelator Complex PCTA-NCAB001 for Radiolabeling with Copper-64.

Understanding the physicochemical properties of antibody-drug conjugates is critical to assess their quality at manufacturing and monitor them during subsequent storage. For radiometal-antibody complexes, it is important to control the properties of the antibody-chelator conjugate to maintain the quality of the final product. We have been developing Cu-labeled anti-epidermal growth factor receptor antibody NCAB001 (Cu-NCAB001) for the early diagnosis and therapy of pancreatic cancer with positron-emission tomography.

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.

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

To select the most suitable chelate for 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 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.

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.

Drugs possessing aryloxypropanamine pharmacophore, duloxetine, dapoxetine and propranolol, increase allopregnanolone in rat brain: Possible involvement of allopregnanolone in their central nervous system effects.

Allopregnanolone (AP) is a neurosteroid synthesized in the brain and a positive allosteric modulator of γ-aminobutyric acid (GABA) type A receptors. Some drugs possessing the aryloxypropanamine (AOPA) pharmacophore, such as fluoxetine, exert their central nervous system (CNS) effects by increasing the brain AP. Although duloxetine (DLX), dapoxetine (DPX), atomoxetine (ATX) and propranolol (PRL) also possess the AOPA pharmacophore and are used to treat some psychiatric disorders, the capabilities of these drugs to increase the brain AP and the possible involvement of AP in their CNS effects remain to be fully elucidated.

Separation and identification of monoglucuronides of vitamin D metabolites in urine by derivatization-assisted LC/ESI-MS/MS using a new Cookson-type reagent.

A liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) method was developed using a new Cookson-type reagent, 4-[4-(1-pipelidinyl)phenyl]-1,2,4-triazoline-3,5-dione (PIPTAD), to analyze the monoglucuronides (Gs) of vitamin D metabolites in human urine. The G of 23S,25-dihydroxyvitamin D [23,25(OH)D] was previously found as a major metabolite of vitamin D in the urine, but its conjugation position remained undetermined. Determination of the position was an important research issue to clarify the whole picture of the excretion of surplus 25-hydroxyvitamin D [25(OH)D, the circulating form of vitamin D] in humans.

[The 44th Report on Survey of the Adverse Reaction to Radiopharmaceuticals (The 47th Survey in 2021)].

This survey was performed in order to investigate the incidence of adverse reactions to radiopharmaceuticals in FY2021 in Japan. It was based on responses to questionnaires sent to nuclear medicine institutions. Replies were obtained from 970 institutions out of 1,194 to which the questionnaire had been sent.

FDG-PET findings associated with various medical procedures and treatments.

[F]-fluorodeoxyglucose (FDG) positron emission tomography (PET) is a well-established modality with high sensitivity for the diagnosis and staging of oncologic patients. FDG is taken up by the glucose transporter of the cell membrane and becomes trapped within the cell. In addition to malignant neoplasms, active inflammatory lesions and some kinds of benign tumors also accumulate FDG.

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.