Publications by authors named "Marlein Miranda Cona"

Aim: To explore the feasibility of using hypericin as an optical imaging probe with affinity for cholesterol for differential fluorescent detection of human gallstones.

Methods: Cholesterol, mixed and pigment stones from cholecystectomy patients were incubated with hypericin or solvent. After 72 h, the stones were analysed for fluorescence (365 nm) and treated with 2-propanol/dimethyl sulfoxide for high performance liquid chromatography (HPLC) analysis.

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Article Synopsis
  • Developed a rat model to study human gallstones by causing bile duct obstruction, allowing observation of gallstone formation through imaging techniques.
  • Surgeries performed on 16 rats showed dilation of the common bile duct, with varying levels of jaundice and bilirubin levels over 28 days.
  • Model proved to be safe and reliable, using human gallstones, paving the way for future research on treatment methods for gallstones.
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Compared with transplanted tumor models or genetically engineered cancer models, chemically induced primary malignancies in experimental animals can mimic the clinical cancer progress from the early stage on. Cancer caused by chemical carcinogens generally develops through three phases namely initiation, promotion and progression. Based on different mechanisms, chemical carcinogens can be divided into genotoxic and non-genotoxic ones, or complete and incomplete ones, usually with an organ-specific property.

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  • The study investigates the use of (131)I-hypericin, a radiopharmaceutical, for treating solid tumors while identifying potential side effects due to its radioactivity after liver metabolism and bile excretion.
  • Thirty-eight rats were injected with (131)I-Hyp, and different bile drainage methods were tested to measure their effectiveness in reducing intestinal radioactivity, with results showing significant reductions in 12 rats subjected to bile drainage.
  • Findings suggest that effective bile drainage can prevent unwanted intestinal radioactivity, and this method might be translated into clinical practice for patients treated with (131)I-Hyp, using specialized drainage catheters.
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  • The study aimed to improve the visualization of the pancreas in rats using advanced imaging techniques like MRI and CT after a specific contrast medium was infused.
  • Researchers used 16 Sprague Dawley rats and employed a custom contrast dye called GadoIodo-EB, which significantly enhanced the visibility of the pancreas compared to baseline imaging without contrast.
  • The results showed that the pancreas's average volume was 1.12 cm³, and the contrast ratios indicated that MRI was more effective for visualization than CT, providing valuable insights for future pancreatic imaging research in rodents.
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Necrosis is an in vivo chaotic event distinguished by uncontrolled disintegration of the cell membrane leading to cytolysis, inflammation and tissue destruction followed by a healing or regenerating process. Targeting necrosis may offer potential diagnostic, therapeutic and/or theragnostic applications in translational medicine. This article reviews the current concept of necrosis including definition, etiology and pathophysiology.

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Translational medicine pursues the conversion of scientific discovery into human health improvement. It aims to establish strategies for diagnosis and treatment of diseases. Cancer treatment is difficult.

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Aim: To develop a method for studying myocardial area at risk (AAR) in ischemic heart disease in correlation with cardiac magnetic resonance imaging (cMRI).

Methods: Nine rabbits were anesthetized, intubated and subjected to occlusion and reperfusion of the left circumflex coronary artery (LCx) to induce myocardial infarction (MI). ECG-triggered cMRI with delayed enhancement was performed at 3.

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Objectives: We determined whether sodium cholate (NaCh) could act as a solubilizing agent for the necrosis avid iodine-123-labeled hypericin ((123)I-Hyp) and investigated biodistribution and targetability of this formulation in rabbits with acute myocardial infarction (AMI).

Materials And Methods: Solubility of radioiodinated hypericin/hypericin (Hyp) in NaCh solutions was evaluated by microscopy. Hyp with (123)I-sodium iodide was performed using hydrogen peroxide as oxidant in 0.

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Objectives: We sought to identify critical components of myocardial infarction (MI) including area at risk (AAR), MI-core and salvageable zone (SZ) by using cardiac magnetic resonance imaging (cMRI) and multifunctional stainings in rabbits.

Materials And Methods: Fifteen rabbits received 90-min coronary artery (CA) ligation and reopening to induce reperfused MI. First-pass perfusion weighted imaging (PWI(90')) was performed immediately before CA reperfusion.

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Aim: To explore whether the antitumor effect of a vascular disrupting agent (VDA) would be enhanced by combining with an antiangiogenic agent, and whether such synergistic effects can be effectively evaluated with separate calculation of diffusion weighted magnetic resonance imaging (DW-MRI).

Methods: Thirty-seven rats with implanted liver tumors were randomized into the following three groups: (1) ZD6126, a kind of VDA; (2) ZDTHA, ZD6126 in combination with an antiangiogenic, thalidomide; and (3) control. Morphological DW-MRI were performed and quantified before, 4 h and 2 d after treatment.

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Iodine-131‑labeled monoiodohypericin (131I‑Hyp) is a necrosis avid compound used as a complementary anticancer agent. Herein, the biodistribution in rats with re-perfused partial liver infarction (RPLI) was used to estimate its human internal radiation dosimetry. Iodine-123‑labeled monoiodohypericin (123I-Hyp) as a safer surrogate for 131I-Hyp was prepared with iodogen as oxidant.

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Hypericin (Hyp) is newly recognized as a necrosis avid agent, but its poor solubility imposes a great hindrance in clinical application. The aim of this paper was to explore sodium cholate (NaCh) as a potential solvent for Hyp and assess the targetability of (131)I-Hyp in rat necrosis models. Hyp solubility in NaCh solutions was evaluated by equilibrium solubility measurement.

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We sought to reduce the radioactive intestinal waste after intravenous injection of necrosis avid iodine-131-labeled hypericin in dual-targeting anticancer radiotherapy and to study its pharmacokinetics in rats using a newly designed catheter. Iodine-123-labeled hypericin was prepared with iodogen as oxidant and characterized by high-performance liquid chromatography and mass spectrometry. After iodine-123-labeled hypericin administration, duodenal juice was collected via a catheter from groups of rats (n = 5) at intervals of 0-4, 4-8 or 20-24 h.

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Objectives: To study the effect of co-injecting unlabelled hypericin (Hyp) on biodistribution, necrosis uptake and tumour retention of iodine-123 or iodine-131 labelled hypericin ((123/131)I-Hyp), a necrosis avid agent for an anticancer radiotherapy.

Methods: (123/131)I-Hyp was prepared with Iodogen as oxidant and formulated in 0.6 μg/kg no-carrier-added (NCA) or 0.

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Article Synopsis
  • The study investigates how different formulations of radioiodinated hypericin affect its distribution in the body, ability to target necrosis, and effectiveness in killing tumor cells in a cancer treatment context.
  • Researchers prepared two formulations using iodine-labeled hypericin and tested them on rats with vascular-disrupted tumors, analyzing their biodistribution and tumor response through various imaging and histological techniques.
  • Findings revealed significant differences between the two formulations in terms of absorption in necrotic tissue and retention in organs like the lungs, spleen, and liver, highlighting the importance of formulation in the drug's therapeutic impact.
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Background: Necrosis avid tracer (123)I-hypericin ((123)I-HYP) enables hot-spot imaging on acute myocardial infarction (MI). We explored dual-isotope simultaneous acquisition single photon emission computed tomography/computed tomography (DISA-SPECT/CT) by using (123)I-HYP and standard (99m)Tc-sestamibi ((99m)Tc-MIBI), in comparison with cardiac magnetic resonance imaging (cMRI), autoradiography (AutoRx) and histomorphometry.

Methods: Acute MI was induced by 90-min coronary artery occlusion and 24-h reperfusion in 9 rabbits.

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Background: Cardiac lipomatous metaplasia (LM) occurs in patients with chronic ischemic heart disease and heart failure with unclear mechanisms. We studied coronary occlusion/reperfusion-induced myocardial infarction (MI) in rabbits during a 9-months follow-up using 3.0 T magnetic resonance scanner, and confirmed the presence of MI in acute phase and LM in chronic phase using histopathology.

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The aim of the present study was to develop a (68)Ga labeled bis-DOTA derivative of benzylidene-bis-indole and compare the in vivo stability and biodistribution with that of the previously reported bis-DTPA derivate for in vivo imaging of necrosis using PET. Uptake of the tracer was evaluated in a mouse model of Fas-mediated hepatic apoptosis in correlation with histochemical stainings. The novel (68)Ga labeled tracer showed an improved in vivo stability and could therefore be used for selective non-invasive imaging of necrotic cell death using PET.

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Objectives: Based on the soil-to-seeds principle, we explored the small-molecular sequential dual-targeting theranostic strategy (SMSDTTS) for prolonged survival and imaging detectability in a xenograft tumor model.

Materials And Methods: Thirty severe combined immunodeficiency (SCID) mice bearing bilateral radiation-induced fibrosarcoma-1 (RIF-1) subcutaneously were divided into group A of SMSDTTS with sequential intravenous injections of combretastatin A4 phosphate (CA4P) and (131)I-iodohypericin ((131)I-Hyp) at a 24 h interval; group B of single targeting control with CA4P and vehicle of (131)I-Hyp; and group C of vehicle control (10 mice per group). Tumoricidal events were monitored by in vivo magnetic resonance imaging (MRI) and planar gamma scintiscan, and validated by ex vivo autoradiography and histopathology.

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Objective: Differently located tumors of the same origin may exhibit diverse responses to the same therapeutics. To test this hypothesis, we compared the responses of rodent hepatic and subcutaneous engrafts of rhabdomyosarcoma-1 (R1) to a vascular disrupting agent Combretastatin A4 phosphate (CA4P).

Methods: Twelve WAG/Rij rats, each bearing three R1 implanted in the right and left hepatic lobes and subcutaneously in the thoracic region, received CA4P intravenously at 5 mg/kg (n = 6) or solvent (n = 6).

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1. Iodogen (tetrachloro-diphenyl glycoluril) dissolved in DMSO (dimethyl sulphoxide) appears indispensable in radioiodination of hypericin for a new anticancer strategy. We studied the safety of intravenously administered iodogen/DMSO in mice (n = 132).

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New arylthioindole derivatives having different cyclic substituents at position 2 of the indole were synthesized as anticancer agents. Several compounds inhibited tubulin polymerization at submicromolar concentration and inhibited cell growth at low nanomolar concentrations. Compounds 18 and 57 were superior to the previously synthesized 5.

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Objectives: The present animal experiments were conducted to evaluate radioiodinated Hypericin (Hyp) for its regional distribution as well as theranostic potentials.

Materials And Methods: Rat models of reperfused liver infarction (RLI) and hepatic rhabdomyosarcoma (R1) were surgically induced. R1 models received Combretastatin A4 phosphate (CA4P) intravenously at 10 mg/kg 24 h prior to radioiodinated Hyp.

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Article Synopsis
  • The study investigates the safety and toxicity of non-radioactive (127)I-Hyp in normal mice to evaluate its potential for clinical use as a radio-derivative in therapies for ischemic heart diseases and cancers.
  • The research involved administering varying doses of (127)I-Hyp, assessing clinical symptoms, blood chemistry, and histopathological outcomes.
  • Results showed that up to 10 mg/kg was well tolerated without significant adverse effects, with an estimated LD(50) of 20.26 mg/kg, indicating a robust safety margin for future applications of iodinated Hypericin.
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