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1.
J Photochem Photobiol B ; 203: 111730, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31855718

RESUMO

OBJECTIVE: To explore the effectiveness, biosafety, photobleaching and mechanism of antimicrobial photodynamic therapy (aPDT) using methylene blue (MB) plus potassium iodide (KI), for root canal infections. METHODS: Different combinations and concentrations of MB, KI and 660 nm LED light were used against E. faecalis in planktonic and in biofilm states by colony-forming unit (CFU), confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM). Human gingival fibroblasts (HGF) were used for safety testing by Cell Counting Kit-8 (CCK8) and fluorescence microscopy (FLM). The photobleaching effect and mechanisms were analyzed. RESULTS: KI could not only enhance MB aPDT on E. faecalis in both planktonic and biofilm states even in a hypoxic environment, but also produced a long-lasting bactericidal effect after end of the illumination. KI could accelerate photobleaching to reduce tooth staining by MB, and the mixture was harmless for HGFs. Mechanistic studies showed the generation of hydrogen peroxide and free iodine, and iodine radicals may be formed in hypoxia. CONCLUSION: aPDT with MB plus KI could be used for root canal disinfection and clinical studies are worth pursuing.


Assuntos
Biofilmes/efeitos dos fármacos , Cavidade Pulpar/microbiologia , Enterococcus faecalis/fisiologia , Azul de Metileno/farmacologia , Plâncton/efeitos dos fármacos , Iodeto de Potássio/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Enterococcus faecalis/efeitos dos fármacos , Humanos , Peróxido de Hidrogênio/metabolismo , Iodo/metabolismo , Luz , Microscopia Confocal , Microscopia Eletrônica de Varredura , Fotodegradação/efeitos dos fármacos
2.
Int J Mol Sci ; 20(14)2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31311135

RESUMO

Many cell types express an acid-sensitive outwardly rectifying (ASOR) anion current of an unknown function. We characterized such a current in BV-2 microglial cells and then studied its interrelation with the volume-sensitive outwardly rectifying (VSOR) Cl- current and the effect of acidosis on cell volume regulation. We used patch clamp, the Coulter method, and the pH-sensitive dye BCECF to measure Cl- currents and cell membrane potentials, mean cell volume, and intracellular pH, respectively. The ASOR current activated at pH ≤ 5.0 and displayed an I- > Cl- > gluconate- permeability sequence. When compared to the VSOR current, it was similarly sensitive to DIDS, but less sensitive to DCPIB, and insensitive to tamoxifen. Under acidic conditions, the ASOR current was the dominating Cl- conductance, while the VSOR current was apparently inactivated. Acidification caused cell swelling under isotonic conditions and prevented the regulatory volume decrease under hypotonicity. We conclude that acidification, associated with activation of the ASOR- and inactivation of the VSOR current, massively impairs cell volume homeostasis. ASOR current activation could affect microglial function under acidotoxic conditions, since acidosis is a hallmark of pathophysiological events like inflammation, stroke or ischemia and migration and phagocytosis in microglial cells are closely related to cell volume regulation.


Assuntos
Canais de Cloreto/metabolismo , Microglia/metabolismo , Potenciais de Ação , Animais , Linhagem Celular , Cloretos/metabolismo , Concentração de Íons de Hidrogênio , Iodo/metabolismo , Transporte de Íons , Camundongos , Microglia/fisiologia , Pressão Osmótica
3.
J Dairy Sci ; 102(9): 8040-8058, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31279546

RESUMO

Kelp meal (KM) is a supplement made from the brown seaweed Ascophyllum nodosum, known to bioaccumulate iodine (I) and to be the richest source of phlorotannins, which can inhibit ruminal proteolysis and microbial growth. The objective of this study was to investigate the effects of KM on production, milk I, concentrations of blood metabolites, apparent total-tract digestibility of nutrients, and CH4 emissions in grazing dairy cows. Eight multiparous Jersey cows averaging (mean ± SD) 175 ± 60 d in milk and 12 primiparous Jersey cows averaging 142 ± 47 d in milk at the beginning of the study were assigned to either 0 g/d of KM (control diet, CTRL) or 113 g/d of KM (brown seaweed diet, BSW) in a randomized complete block design. Diets were formulated to yield a 70:30 forage-to-concentrate ratio and consisted of (dry matter basis): 48% cool-season perennial herbage and 52% partial TMR (pTMR). Each experimental period (n = 3) lasted 28 d, with data and sample collection taking place during the last 7 d of each period. Cows had approximately 16.5 h of access to pasture daily. Herbage dry matter intake increased, and total dry matter intake tended to increase in cows fed BSW versus the CTRL diet. Milk yield and concentrations and yields of milk components were not affected by diets. Similarly, blood concentrations of cortisol, glucose, fatty acids, and thyroxine did not change with feeding CTRL or BSW. However, a diet × period interaction was observed for milk I concentration; cows offered the BSW diet had greater milk I concentration during periods 1, 2, and 3, but the largest difference between BSW and CTRL was observed in period 2 (579 vs. 111 µg/L, respectively). Except for period 2, the concentration of milk I in cows fed KM did not exceed the 500 µg/L threshold recommended for human consumption. Diet × period interactions were also found for serum triiodothyronine concentration, total-tract digestibilities of crude protein and acid detergent fiber, CH4 production, and urinary excretion of purine derivatives. Overall, the lack of KM effects on milk yield and concentrations and yields of milk components indicate that dairy producers should consider costs before making KM supplementation decisions during the grazing season. Future research is needed to evaluate the concentration of I in retail organic milk because of the high prevalence of KM supplementation in northeastern and midwestern US organic dairies and possibly in other regions of the country.


Assuntos
Ração Animal , Ascophyllum , Bovinos/metabolismo , Suplementos Nutricionais , Iodo/metabolismo , Kelp , Leite/metabolismo , Ração Animal/análise , Animais , Indústria de Laticínios , Dieta/veterinária , Fibras na Dieta/metabolismo , Suplementos Nutricionais/análise , Digestão , Ácidos Graxos/metabolismo , Feminino , Lactação , Nutrientes , Distribuição Aleatória
4.
J Agric Food Chem ; 67(29): 8096-8106, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31260296

RESUMO

Field experiments were conducted on wheat to study the effects of foliar-applied iodine(I) alone, Zn (zinc) alone, and a micronutrient cocktail solution containing I, Zn, Se (selenium), and Fe (iron) on grain yield and grain concentrations of micronutrients. Plants were grown over 2 years in China, India, Mexico, Pakistan, South Africa, and Turkey. Grain-Zn was increased from 28.6 mg kg-1 to 46.0 mg-1 kg with Zn-spray and 47.1 mg-1 kg with micronutrient cocktail spray. Foliar-applied I and micronutrient cocktail increased grain I from 24 µg kg-1 to 361 µg kg-1 and 249 µg kg-1, respectively. Micronutrient cocktail also increased grain-Se from 90 µg kg-1 to 338 µg kg-1 in all countries. Average increase in grain-Fe by micronutrient cocktail solution was about 12%. The results obtained demonstrated that foliar application of a cocktail micronutrient solution represents an effective strategy to biofortify wheat simultaneously with Zn, I, Se and partly with Fe without yield trade-off in wheat.


Assuntos
Biofortificação/métodos , Produção Agrícola/métodos , Iodo/metabolismo , Ferro/metabolismo , Selênio/metabolismo , Triticum/metabolismo , Zinco/metabolismo , China , Fertilizantes/análise , Índia , Iodo/análise , Ferro/análise , México , Micronutrientes/análise , Micronutrientes/metabolismo , Paquistão , Folhas de Planta/química , Folhas de Planta/metabolismo , Sementes/química , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Selênio/análise , África do Sul , Triticum/química , Triticum/crescimento & desenvolvimento , Turquia , Zinco/análise
5.
Chemistry ; 25(48): 11180-11192, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31215686

RESUMO

The plasma membrane regulates the transport of molecules into the cell. Small hydrophobic molecules can diffuse directly across the lipid bilayer. However, larger molecules require specific transporters for their entry into the cell. Regulating the cellular entry of small molecules and proteins is a challenging task. The introduction of halogen, particularly iodine, to small molecules and proteins is emerging to be a promising strategy to improve the cellular uptake. Recent studies reveal that a simple substitution of hydrogen atom with iodine not only increases the cellular uptake, but also regulates the membrane transport. The strong halogen-bond-forming ability of iodine atoms plays a crucial role in the transport and the introduction of iodine may provide an efficient strategy for studying membrane activity and cellular functions and improving the delivery of therapeutic agents. This Concept article does not provide a comprehensive picture of membrane transport but highlights halogen-substitution as a novel strategy for understanding and regulating the cell-membrane traffic.


Assuntos
Membrana Celular/metabolismo , Iodo/metabolismo , Biocatálise , Transporte Biológico , Permeabilidade da Membrana Celular , Corantes Fluorescentes/metabolismo , Células HeLa , Células Hep G2 , Humanos , Interações Hidrofóbicas e Hidrofílicas , Iodeto Peroxidase/metabolismo , Modelos Moleculares , Naftalimidas/metabolismo , Ligação Proteica , Conformação Proteica , Hormônios Tireóideos/metabolismo
6.
Gen Comp Endocrinol ; 280: 62-72, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-30980803

RESUMO

Oral l-thyroxine (T4) therapy is used to treat human hypothyroidism but T4 fed to teleost fish does not raise plasma thyroid hormone (TH) levels nor induce growth, even though oral 3,5,3'-triiodo-l-thyronine (T3) is effective. This suggests a major difference in TH metabolism between teleosts and humans, often used as a starting thyroid model for lower vertebrates. To gain further insight on the proximate (mechanistic) and ultimate (survival value) factors underlying this difference, the several steps in TH homeostasis from intestinal TH uptake to hypothalamic-hypophyseal regulation were compared between humans and teleosts, and following dietary TH challenges. A major proximate factor limiting trout T4 uptake is a potent constitutive thiol-inhibited intestinal complete T4 deiodination that is ineffective for T3. At the hepatic level, T4 deiodination, conjugation and extensive biliary excretion with negligible T4 enterohepatic recycling can further block teleost T4 uptake to plasma. Such protection of plasma T4 from dietary T4 may be particularly critical for piscivorous fish consuming thyroid tissue, rich in T4 but not T3. It would prevent disruption by unregulated ingested T4 of the characteristic acute and transient changes in teleost plasma T4 due to diel rhythms, food intake and stress-related factors. These marked natural short-term fluctuations in teleost plasma T4 levels are enabled by the relatively small and rapidly-cleared plasma T4 pool, stemming largely from properties of the plasma T4-binding proteins. Humans, however, due mainly to plasma T4-binding globulin, have a relatively massive circulating pool of T4 and an extremely well-buffered free T4 level, consistent with the major TH role in regulating basal metabolic rate. Furthermore, this large well-buffered and slowly-cleared plasma T4 pool, in conjuction with enterohepatic recycling and relaxation of hypothalamic-hypophyseal negative feedback, allows humans to temporarily 'store' ingested T4 in plasma, thereby sparing endogenous TH secretion and conserving thyroidal iodine reserves. Indeed, iodine conservation is likely the key ultimate factor determining the divergent evolution of the human and teleost systems. For humans, ingested iodine in the form of I-, or TH and their derivatives, is the sole iodine source and may be limiting in many environments. However, most freshwater teleosts, in addition to their ability to assimilate dietary I-, can derive sufficient I- from their copious gill irrigation, with no selective advantage in absorbing dietary T4 which would disrupt their natural acute and transient changes in plasma T4. Thus T4 may act also as a vitamin (vitamone) in humans but not in teleosts; in contrast, T3, naturally ingested at much lower levels, may act as a vitamone in both humans and teleosts.


Assuntos
Peixes/metabolismo , Iodo/metabolismo , Glândula Tireoide/metabolismo , Hormônios Tireóideos/metabolismo , Animais , Homeostase/efeitos dos fármacos , Humanos , Especificidade de Órgãos
7.
J Med Food ; 22(4): 421-426, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30990756

RESUMO

Dietary iodine is important to human health, and both low and high iodine intake levels increase the risk of disease. Seaweed is rich in iodine and it is a common component in both Asian and in Arctic cuisines. While the intake and impact are known for Asian people, data are lacking for Arctic people. We aimed to (1) measure iodine content of dietary seaweeds in Greenland, (2) estimate iodine absorption, and (3) assess the impact on iodine intake in Arctic people. A hunter in East Greenland donated household seaweed for (1) measurement of iodine content and (2) ingestion of 45 g by each of eight individuals with subsequent urine collections. (3) In Ammassalik, 96% of 50-69-year-old Inuit reported on the frequency of intake of seaweed and provided a spot urine sample for iodine measurement. Seaweed species provided were Chondrus crispus and Ascophyllum nodosum. (1) The iodine content was 47 and 102 mg/g, respectively. (2) An estimated 1.1 and 1.9 mg of the ingested 2.1 and 4.6 of iodine in seaweed were excreted in the urine within 2 days. (3) More than two in three Inuit reported some dietary use, and 41% (109 of 268) reported a weekly intake of dietary seaweed, which was associated with iodine excretion. In conclusion, the iodine content of edible seaweeds in the Arctic is very high and bioavailable. Dietary intake contributed to the recommended iodine intake level, but marked variation in iodine excretion calls for evaluation of the impact on thyroid function.


Assuntos
Iodo/metabolismo , Alga Marinha/metabolismo , Idoso , Feminino , Groenlândia , Humanos , Iodo/urina , Masculino , Pessoa de Meia-Idade , Estado Nutricional , Alga Marinha/química , Verduras
8.
Eur Radiol ; 29(11): 6109-6118, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31016447

RESUMO

OBJECTIVE: To compare the effect of contrast medium iodine concentration on contrast enhancement, heart rate, and injection pressure when injected at a constant iodine delivery rate in coronary CT angiography (CTA). METHODS: One thousand twenty-four patients scheduled for coronary CTA were prospectively randomized to receive one of four contrast media: iopromide 300 mg I/ml, iohexol 350 mg I/ml, iopromide 370 mg I/ml, or iomeprol 400 mg I/ml. Contrast media were delivered at an equivalent iodine delivery rate of 2.0 g I/s. Intracoronary attenuation was measured and compared (per vessel and per segment). Heart rate before and after contrast media injection was documented. Injection pressure was recorded (n = 403) during contrast medium injection and compared between groups. RESULTS: Intracoronary attenuation values were similar for the different contrast groups. The mean attenuation over all segments ranged between 384 HU for 350 mg I/ml and 395 HU for 400 mg I/ml (p = 0.079). Dose-length product (p = 0.8424), signal-to-noise ratio (all p > 0.05), time to peak (p = 0.324), and changes in heart rate (p = 0.974) were comparable between groups. The peak pressures differed: 197.4 psi for 300 mg I/ml (viscosity 4.6 mPa s), 229.8 psi for 350 mg I/ml (10.4 mPa s), 216.1 psi for 370 mg I/ml (9.5 mPa s), and 243.7 psi for 400 mg I/ml (12.6 mPa s) (p < 0.0001). CONCLUSION: Intravascular attenuation and changes in heart rate are independent of iodine concentration when contrast media are injected at the same iodine delivery rate. Differences in injection pressures are associated with the viscosity of the contrast media. KEY POINTS: • The contrast enhancement in coronary CT angiography is independent of the iodine concentration when contrast media are injected at body temperature (37 °C) with the same iodine delivery rate. • Iodine concentration does not influence the change in heart rate when contrast media are injected at identical iodine delivery rates. • For a fixed iodine delivery rate and contrast temperature, the viscosity of the contrast medium affects the injection pressure.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Meios de Contraste/farmacocinética , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico , Vasos Coronários/diagnóstico por imagem , Iodo/metabolismo , Iohexol/farmacocinética , Meios de Contraste/administração & dosagem , Doença da Artéria Coronariana/metabolismo , Feminino , Humanos , Injeções Intravenosas , Iohexol/administração & dosagem , Iohexol/análogos & derivados , Iopamidol/administração & dosagem , Iopamidol/análogos & derivados , Iopamidol/farmacocinética , Masculino , Pessoa de Meia-Idade
9.
Artigo em Inglês | MEDLINE | ID: mdl-30917615

RESUMO

The sodium iodide symporter (NIS) is the plasma membrane glycoprotein that mediates active iodide transport in the thyroid and other tissues, such as the salivary, gastric mucosa, rectal mucosa, bronchial mucosa, placenta and mammary glands. In the thyroid, NIS mediates the uptake and accumulation of iodine and its activity is crucial for the development of the central nervous system and disease prevention. Since the discovery of NIS in 1996, research has further shown that NIS functionality and iodine transport is dependent on the activity of the sodium potassium activated adenosine 5'-triphosphatase pump (Na+, K+-ATPase). In this article, I review the molecular mechanisms by which F inhibits NIS expression and functionality which in turn contributes to impaired iodide absorption, diminished iodide-concentrating ability and iodine deficiency disorders. I discuss how NIS expression and activity is inhibited by thyroglobulin (Tg), tumour necrosis factor alpha (TNF-α), transforming growth factor beta 1 (TGF-ß1), interleukin 6 (IL-6) and Interleukin 1 beta (IL-1ß), interferon-γ (IFN-γ), insulin like growth factor 1 (IGF-1) and phosphoinositide 3-kinase (PI3K) and how fluoride upregulates expression and activity of these biomarkers. I further describe the crucial role of prolactin and megalin in regulation of NIS expression and iodine homeostasis and the effect of fluoride in down regulating prolactin and megalin expression. Among many other issues, I discuss the potential conflict between public health policies such as water fluoridation and its contribution to iodine deficiency, neurodevelopmental and pathological disorders. Further studies are warranted to examine these associations.


Assuntos
Fluoretos/toxicidade , Iodo/metabolismo , Simportadores/antagonistas & inibidores , Animais , Humanos , Saúde Pública
10.
Int J Nanomedicine ; 14: 1779-1787, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30880979

RESUMO

Background: This study was designed to explore a novel approach for transferring NIS protein to cells using extracellular vesicle (EV) and enhancing iodine avidity in hepatocellular carcinoma (HCC) cells. Methods: We transfected the HCC cells (Huh7) with NIS gene, designated as Huh7/NIS, and isolated the EVs from them. Presence of NIS protein in EVs and EV-mediated transport of NIS protein to recipient Huh7 cells were tested using Western blotting. We also examined radioiodine uptake in Huh7 cells treated with EV-Huh7/NIS. Results: Successful transfer of NIS protein into Huh7 cells was confirmed by WB and microscopy. EVs showed high levels of NIS protein in them. Treatment of Huh7 cells with EV-Huh7/NIS increased the NIS protein level and enhanced 125I uptake in recipient Huh7 cells. In addition, EV-huh7/NIS pre-treatment enhanced the cytotoxicity of 131I therapy against Huh7 cells by inducing increased DNA damage/increased γH2A.X foci formation. Conclusion: This is the first-of-its-kind demonstration of successful transportation of the NIS protein to cells via EVs, which increased radioiodine uptake. This approach can revert radioiodine-resistant cancers into radioiodine-sensitive cancers.


Assuntos
Vesículas Extracelulares/metabolismo , Iodo/metabolismo , Simportadores/metabolismo , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Morte Celular , Linhagem Celular Tumoral , Dano ao DNA , Vesículas Extracelulares/ultraestrutura , Regulação Neoplásica da Expressão Gênica , Humanos , Radioisótopos do Iodo/química , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia
11.
Environ Geochem Health ; 41(5): 2145-2156, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30848410

RESUMO

Iodine is an essential micronutrient for human health; phytofortification is a means of improving humans' nutritional iodine status. However, knowledge of iodine uptake and translocation in plants remains limited. In this paper, plant uptake mechanisms were assessed in short-term experiments (24 h) using labelled radioisotopes; the speciation of iodine present in apoplastic and symplastic root solutions was determined by (HPLC)-ICP-QQQ-MS. Iodine storage was investigated in spinach (Spinacia oleracea L.) treated with I- and IO3-. Finally, translocation through the phloem to younger leaves was also investigated using a radioiodine (129I-) label. During uptake, spinach roots demonstrated the ability to reduce IO3- to I-. Once absorbed, iodine was present as org-I or I- with significantly greater concentrations in the apoplast than the symplast. Plants were shown to absorb similar concentrations of iodine applied as I- or IO3-, via the roots, grown in an inert growth substrate. We found that whilst leaves were capable of absorbing radioactively labelled iodine applied to a single leaf, less than 2% was transferred through the phloem to younger leaves. In this paper, we show that iodine uptake is predominantly passive (approximately two-thirds of total uptake); however, I- can be absorbed actively through the symplast. Spinach leaves can absorb iodine via foliar fertilisation, but translocation is severely limited. As such, foliar application is unlikely to significantly increase the iodine content, via phloem translocation, of fruits, grains or tubers.


Assuntos
Iodo/metabolismo , Spinacia oleracea/metabolismo , Compostos de Iodo/metabolismo , Radioisótopos do Iodo/metabolismo , Células Vegetais/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo
12.
J Sci Food Agric ; 99(9): 4353-4362, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30834531

RESUMO

BACKGROUND: The biofortification of crops can counteract human diseases, including selenium (Se) and iodine (I) deficiencies in the diet. Little is known about the effects of combinations of Se and I on microgreens and seeds, or on their accumulation in these tissues. The present study aimed to evaluate Se (SeO3 2- , SeO4 2- ) and I (I- , IO3 - ) biofortification of common buckwheat microgreens and seeds with respect to the effects of the addition of Se, I and Se + I on yield and on physiological and biochemical characteristics. RESULTS: In combination treatments, microgreens yield (600-800 g m-2 ) was 50-70% higher than for Se and I alone. The respiratory potential also increased by 60-120%. Fv /Fm was close to 0.8 in all samples. Se content [0.24 µg g-1 dry weight (DW)] was 50% higher for combination treatments than for Se and I alone. I content was highest for IO3 - treatment (216 µg g-1 DW) and decreased in combination treatments with Se by 50%. CONCLUSION: Biofortification of buckwheat microgreens with Se and I should be performed with care because there are synergistic and antagonistic effects of these elements with respect to their accumulation. IO3 - for the biofortification of microgreens should be kept low to prevent exceeding the recommended daily intake of I. © 2019 Society of Chemical Industry.


Assuntos
Biofortificação/métodos , Fagopyrum/metabolismo , Iodo/análise , Sementes/crescimento & desenvolvimento , Selênio/análise , Fagopyrum/química , Fagopyrum/crescimento & desenvolvimento , Iodo/metabolismo , Sementes/química , Sementes/metabolismo , Selênio/metabolismo
13.
Phys Med Biol ; 64(6): 065007, 2019 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-30708357

RESUMO

Advances in computed tomography (CT) hardware have propelled the development of novel CT contrast agents. In particular, the spectral capabilities of x-ray CT can facilitate simultaneous imaging of multiple contrast agents. This approach is particularly useful for functional imaging of solid tumors by simultaneous visualization of multiple targets or architectural features that govern cancer development and progression. Nanoparticles are a promising platform for contrast agent development. While several novel imaging moieties based on high atomic number elements are being explored, iodine (I) and gadolinium (Gd) are particularly attractive because of their existing approval for clinical use. In this work, we investigate the in vivo discrimination of I and Gd nanoparticle contrast agents using both dual energy micro-CT with energy integrating detectors (DE-EID) and photon counting detector (PCD)-based spectral micro-CT. Simulations and phantom experiments were performed using varying concentrations of I and Gd to determine the imaging performance with optimized acquisition parameters. Quantitative spectral micro-CT imaging using liposomal-iodine (Lip-I) and liposomal-Gd (Lip-Gd) nanoparticle contrast agents was performed in sarcoma bearing mice for anatomical and functional imaging of tumor vasculature. Iterative reconstruction provided high sensitivity to detect and discriminate relatively low I and Gd concentrations. According to the Rose criterion applied to the experimental results, the detectability limits for I and Gd were approximately 2.5 mg ml-1 for both DE-EID CT and PCD micro-CT, even if the radiation dose was approximately 3.8 times lower with PCD micro-CT. The material concentration maps confirmed expected biodistributions of contrast agents in the blood, liver, spleen and kidneys. The PCD provided lower background signal and better simultaneous visualization of tumor vasculature and intratumoral distribution patterns of nanoparticle contrast agent compared to DE-EID decompositions. Preclinical spectral CT systems such as this could be useful for functional characterization of solid tumors, simultaneous quantitative imaging of multiple targets and for identifying clinically-relevant applications that benefit from the use of spectral imaging. Additionally, it could aid in the development nanoparticles that show promise in the developing field of cancer theranostics (therapy and diagnostics) by measuring vascular tumor biomarkers such as fractional blood volume and the delivery of liposomal chemotherapeutics.


Assuntos
Meios de Contraste , Gadolínio/metabolismo , Iodo/metabolismo , Nanopartículas/química , Imagens de Fantasmas , Sarcoma/patologia , Microtomografia por Raio-X/métodos , Animais , Humanos , Imagem por Ressonância Magnética , Camundongos , Camundongos Endogâmicos C57BL , Neovascularização Patológica , Fótons , Sarcoma/irrigação sanguínea , Sarcoma/diagnóstico por imagem , Sarcoma/metabolismo , Tomógrafos Computadorizados , Microtomografia por Raio-X/instrumentação
14.
Biosci Biotechnol Biochem ; 83(5): 970-973, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30727829

RESUMO

We here characterized 27 japonica rice cultivars grown in Heilongjiang province and evaluated the relationship among their iodine absorption curve, physical properties, and ratio of 13 kDa prolamin. We developed the novel estimation formulae for ratio of 13 kDa prolamin and overall hardness (H2) with the use of Aλmax and λmax.


Assuntos
Oryza/química , Oryza/classificação , China , Dureza , Hibridização Genética , Iodo/metabolismo , Oryza/metabolismo , Oryza/fisiologia , Prolaminas/metabolismo
15.
Cell Commun Signal ; 17(1): 12, 2019 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-30760304

RESUMO

BACKGROUND: The existence of differentiated thyroid cells is critical to respond radioactive iodide treatment strategy in thyroid cancer, and loss of the differentiated phenotype is a trademark of iodide-refractive thyroid disease. While high-dose therapy has been beneficial to several cancer patients, many studies have indicated this clinical benefit was limited to patients having BRAF mutation. BRAF-targeted paired box gene-8 (PAX8), a thyroid-specific transcription factor, generally dysregulated in BRAF-mutated thyroid cancer. METHODS: In this study, thyroid iodine-metabolizing gene levels were detected in BRAF-transformed thyroid cells after low and high dose of ionizing radiation. Also, an mRNA-targeted approach was used to figure out the underlying mechanism of low (0.01Gyx10 or 0.1Gy) and high (2Gy) radiation function on thyroid cancer cells after BRAFV600E mutation. RESULTS: Low dose radiation (LDR)-induced PAX8 upregulation restores not only BRAF-suppressive sodium/iodide symporter (NIS) expression, one of the major protein necessary for iodine uptake in healthy thyroid, on plasma membrane but also regulate other thyroid metabolizing genes levels. Importantly, LDR-induced PAX8 results in decreased cellular transformation in BRAF-mutated thyroid cells. CONCLUSION: The present findings provide evidence that LDR-induced PAX8 acts as an important regulator for suppression of thyroid carcinogenesis through novel STAT3/miR-330-5p pathway in thyroid cancers.


Assuntos
Transformação Celular Neoplásica/patologia , Transformação Celular Neoplásica/efeitos da radiação , Proteínas Proto-Oncogênicas B-raf/metabolismo , Glândula Tireoide/patologia , Glândula Tireoide/efeitos da radiação , Animais , Carcinogênese/patologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Relação Dose-Resposta à Radiação , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Humanos , Hipotireoidismo/patologia , Iodo/metabolismo , Camundongos Mutantes , MicroRNAs/genética , MicroRNAs/metabolismo , Modelos Biológicos , Mutação/genética , Fator de Transcrição PAX8/metabolismo , Proteínas Proto-Oncogênicas B-raf/genética , Fator de Transcrição STAT3/metabolismo , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/radioterapia , Regulação para Cima/genética , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Nutrients ; 11(2)2019 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-30795581

RESUMO

The use of iodine-biofortified vegetables may be a health alternative instead of iodine-biofortified salt for preventing iodine (I) deficiency and related human disorders. In this study, four Brassica genotypes (broccoli raab, curly kale, mizuna, red mustard) were hydroponically grown with three I-IO3- rates (0, 0.75 and 1.5 mg/L) to produce iodine-biofortified vegetables. Crop performances and quality traits were analyzed; iodine content was measured on raw, boiled, and steamed vegetables. The highest I rate generally increased I content in all Brassica genotypes, without plants toxicity effects in terms of reduced growth or morphological symptoms. After 21 day-iodine biofortification, the highest I content (49.5 µg/100 g Fresh Weight (FW)) was reached in broccoli raab shoots, while after 43 day-iodine biofortification, genotype differences were flattened and the highest I content (66 µg/100 g FW, on average) was obtained using 1.5 mg I-IO3/L. Nitrate content (ranging from 1800 to 4575 mg/kg FW) was generally higher with 0.75 mg I-IO3/L, although it depended on genotypes. Generally, boiling reduced iodine content, while steaming increased or left it unchanged, depending on genotypes. Applying low levels of I proved to be suitable, since it could contribute to the partial intake of the recommended dose of 150 µg/day: A serving size of 100 g may supply on average 24% of the recommended dose. Cooking method should be chosen in order to preserve and/or enhance the final I amount.


Assuntos
Biofortificação/métodos , Brassica/metabolismo , Alimentos Fortificados , Genótipo , Iodatos/metabolismo , Iodo/metabolismo , Compostos de Potássio/metabolismo , Verduras/química , Brassica/genética , Culinária , Deficiências Nutricionais/prevenção & controle , Dieta , Ingestão de Energia , Humanos , Hidroponia , Iodo/administração & dosagem , Iodo/deficiência , Nitratos/metabolismo , Brotos de Planta/metabolismo , Especificidade da Espécie
17.
Analyst ; 144(7): 2367-2374, 2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30793720

RESUMO

Caenorhabditis elegans is an animal model frequently used in research on the effects of metabolism on organismal aging. This comes with a requirement for methods to investigate metabolite content, turnover, and distribution. The aim of our study was to assess the use of a label-free approach to determine both content and distribution of glycogen, the storage form of glucose, in C. elegans. To this end, we grew C. elegans worms under three different dietary conditions for 24-48 h, representing starvation, regular diet and a high glucose diet, followed by analysis of glycogen content. Glycogen analysis was performed on fixed individual whole worms using Raman micro-spectroscopy (RMS). Results were confirmed by comparison with two conventional assays, i.e. iodine staining of worms and enzymatic determination of glycogen. RMS was further used to assess overall lipid and protein content and distribution in the same samples used for glycogen analysis. Expectedly, both glycogen and lipid content were highest in worms grown on a high glucose diet, lower in regularly fed, and lowest in starved nematodes. In summary, RMS is a method suitable for analysis of glycogen content in C. elegans that has the advantage over established methods that (i) individual worms (rather than hundreds per sample) can be analyzed, (ii) glycogen distribution can be assessed at subcellular resolution and (iii) the distribution patterns of other macromolecules can be assessed from the same worms. Thus, RMS has the potential to be used as a sensitive, accurate, cost-effective and high throughput method to evaluate glycogen stores in C. elegans.


Assuntos
Caenorhabditis elegans/metabolismo , Glicogênio/metabolismo , Análise Espectral Raman , Animais , Proteínas de Caenorhabditis elegans/metabolismo , Iodetos/metabolismo , Iodo/metabolismo , Metabolismo dos Lipídeos
18.
J Cardiovasc Comput Tomogr ; 13(2): 86-91, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30718182

RESUMO

BACKGROUND: Myocardial CT perfusion imaging with dual energy (DE-CTP) can produce myocardial iodine perfusion maps. This study evaluated the accuracy of first pass myocardial iodine concentration in DE-CTP compared to CT derived dynamic myocardial blood flow (MBF) to determine regional myocardial ischemia in an animal model of coronary stenosis using invasive Fractional Flow Reserve (FFR). METHODS: Seven anaesthetised pigs (mean weight 51 ±â€¯4 kg) had a graded coronary artery stenosis produced in six vessels (plus one control animal) using a methacrylate plug with FFR recorded in the target artery (ischemia = FFR<0.80). During adenosine vasodilation, dynamic myocardial CTP and DE-CTP imaging was performed. Using vendor supplied applications, matching regions of interest (ROIs) were drawn in myocardial segments supplied by the target coronary artery to compare the two techniques. RESULTS: FFR correlated strongly to MBF (r = 0.81) and modestly to myocardial iodine concentration (r = 0.65) and myocardial CT attenuation (r = 0.62) (p < 0.0001 each). The correlation to FFR was stronger using relative ratios (absolute value/reference value of normal segments) than absolute values for MBF (r = 0.86), myocardial iodine concentration (r = 0.80) and CT number (r = 0.79) (p < 0.0001 each). Comparing normal and ischaemic territories there were significant differences in MBF (96 ±â€¯14 vs. 27 ±â€¯18 ml/100 ml of tissue/min, p < 0.0001), myocardial iodine concentration (3.5 ±â€¯1 vs. 1.0 ±â€¯0.7 mg/ml, p < 0.0001) and myocardial CT number (89 ±â€¯9 vs. 73 ±â€¯14 HU, p = 0.002). Myocardial iodine concentration had 91% sensitivity and 98% specificity for detecting FFR <0.8. CONCLUSION: Quantified myocardial iodine content from first pass DE-CTP correlates with CT derived myocardial blood flow and FFR and accurately discriminates ischemic territories in a porcine model. The accuracy and utility of myocardial iodine content in DE-CTP warrants further investigation in a clinical population with FFR as a reference standard.


Assuntos
Meios de Contraste/metabolismo , Estenose Coronária/diagnóstico por imagem , Reserva Fracionada de Fluxo Miocárdico , Iodo/metabolismo , Imagem de Perfusão do Miocárdio/métodos , Miocárdio/metabolismo , Tomografia Computadorizada por Raios X , Adenosina/administração & dosagem , Animais , Meios de Contraste/administração & dosagem , Estenose Coronária/metabolismo , Estenose Coronária/fisiopatologia , Modelos Animais de Doenças , Feminino , Valor Preditivo dos Testes , Interpretação de Imagem Radiográfica Assistida por Computador , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Sus scrofa , Vasodilatadores/administração & dosagem
19.
Food Chem ; 285: 326-333, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30797353

RESUMO

Reducing starch digestibility can significantly benefit efforts to combat obesity and associated chronic diseases. Polymeric proanthocyanidins (PA) form complexes with starch via unknown mechanisms, resulting in dramatically decreased starch digestibility. We hypothesized that V-type complexes are involved in these interactions. Sorghum derived PA was complexed with amylose, amylopectin, and granular maize starches in regular and deuterated solvents, and structural properties and in vitro digestibility of the complexes investigated. Based on iodine binding, X-ray diffraction patterns, crystallinity, and thermal properties, we demonstrated, for the first time, that type II semi-crystalline V-complexes are formed between amylose and PA. Furthermore, suppression of H-bonding led to amorphous complexes, suggesting extensive H-bonding facilitate and/or stabilize the V-complexes. We speculate that the complexation involves inclusion of B-rings of the PA units into the amylose helical cavity. The V-complex formation significantly increased resistant starch in gelatinized normal starch and pure amylose (by 35-45%), indicating likely physiological benefits.


Assuntos
Amilose/química , Proantocianidinas/química , Amido/química , Amilopectina/química , Amilose/farmacocinética , Digestão , Humanos , Ligações de Hidrogênio , Iodo/metabolismo , Proantocianidinas/farmacocinética , Sorghum/química , Amido/farmacocinética , Difração de Raios X , Zea mays/química
20.
Toxicol Appl Pharmacol ; 365: 84-100, 2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30639275

RESUMO

Current practices for evaluating the cumulative risk of thyroid-active chemical mixtures (perchlorate, thiocyanate, nitrate) focus on the inhibition of thyroidal iodide uptake via the sodium iodide symporter (NIS) as the mode of action for potency equivalence calculations. However, unlike perchlorate, thiocyanate presents additional modes of action within the thyroid that could contribute to the overall thyroid perturbation. We tested the hypothesis of whether assuming a single mode of action of thyroidal iodide uptake inhibition is sufficient for describing the observed dose-response relationship for thiocyanate and its effects on serum thyroxine levels. An interaction model was developed by linking a biologically based dose-response model for iodide and thyroid hormones to a thiocyanate physiologically based pharmacokinetic model. Each model, adapted from the literature, was restructured and recalibrated in a Bayesian framework for the current mode of actions study. For a chronic exposure scenario, NIS inhibition alone was found not to be sufficient to describe the dose-response relationship for thiocyanate. Inclusion of additional modes of action involving iodide flux across the thyroid membrane and inhibition of iodide organification via thyroid peroxidase showed only moderate improvements in capturing the dose-response at environmental thiocyanate doses of exposure and failed to capture trends at very high doses. Our findings emphasize the need for more mechanistic data for chronic exposure scenarios to characterize better the overall dose-response relationship for thiocyanate. Risk assessment approaches for thyroid-active chemical mixtures that rely on NIS inhibition as the single mode of action may over-predict the contribution of thiocyanate to thyroid disruption.


Assuntos
Simulação por Computador , Disruptores Endócrinos/toxicidade , Modelos Biológicos , Tiocianatos/toxicidade , Glândula Tireoide/efeitos dos fármacos , Tiroxina/metabolismo , Animais , Teorema de Bayes , Transporte Biológico/efeitos dos fármacos , Relação Dose-Resposta a Droga , Disruptores Endócrinos/farmacocinética , Inibidores Enzimáticos/farmacocinética , Inibidores Enzimáticos/toxicidade , Iodeto Peroxidase/antagonistas & inibidores , Iodeto Peroxidase/metabolismo , Iodo/metabolismo , Masculino , Método de Monte Carlo , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Medição de Risco , Tiocianatos/farmacocinética , Glândula Tireoide/metabolismo , Toxicocinética
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