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1.
Neuroradiology ; 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-39102086

RESUMO

PURPOSE: Identification of the Adamkiewicz artery before aortic surgery is important for preventing postoperative complications due to spinal cord ischemia. The Adamkiewicz artery is difficult to identify due to its small diameter. Nitroglycerin has a vasodilatory effect and is used clinically to improve visualization of blood vessels on coronary computed tomography (CT) angiography. We investigated whether the vasodilatory effect of nitroglycerin could improve the ability to visualize the Adamkiewicz artery. METHODS: We extracted 33 cases wherein contrast-enhanced CT images were taken before and after aortic aneurysm surgery. Nitroglycerin was administered for coronary artery evaluation on the preoperative CT. However, no nitroglycerin was administered before the postoperative CT. Aortic contrast-to-noise ratio, CT value, image noise, and diameter of the Adamkiewicz artery and anterior spinal artery were measured. The depiction of the Adamkiewicz artery was graded into four grades and evaluated. These measurements were performed by two independent reviewers. RESULTS: In nitroglycerin-administered cases, the contrast-to-noise ratio and CT values were significantly higher (P < 0.001, P < 0.001, respectively); the Adamkiewicz artery and anterior spinal artery diameters were dilated (P = 0.005, P = 0.001, respectively). The Adamkiewicz artery score also improved significantly (P < 0.001). No significant difference was found in image noise. CONCLUSION: Nitroglycerin contributed to improving the Adamkiewicz artery's visualization.

2.
Nano Lett ; 20(3): 2000-2004, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32031816

RESUMO

Chemical identification of individual surface atoms has been achieved by measuring the chemical bonds between tip and surface atoms using atomic force microscopy. On the other hand, the discrimination of chemical species at the tip apex is still a challenging task, even though the differences of the species have significant effects on atomic-scale contrast and atom manipulation. Here, we perform the chemical identification of a foremost tip atom using bond energies measured on precharacterized atomic species on a Si surface. We find that chemically different tips show different trends in the chemical bond energy on the sites and that Pauling's equation for polar covalent bonds well describes those trends. On the basis of this knowledge, in situ chemical identification becomes possible. Using the chemically identified (here, Si and Al) tips, we determine the electronegativity of locally formed silicon oxide solely by experiments. Previously such determination was difficult without the help of theoretical calculations. These successful results confirm the validity and versatility of Pauling's equation for application to atomic-scale objects.

3.
Nephrology (Carlton) ; 16(2): 156-62, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21272127

RESUMO

AIM: Hyperuricaemia is a significant factor in a variety of diseases, including gout and cardiovascular diseases. The kidney plays a dominant role in maintaining plasma urate levels through the excretion process. Human renal urate transporter URAT1 is thought to be an essential molecule that mediates the reabsorption of urate on the apical side of the proximal tubule. In this study the pharmacological characteristics and clinical implications of URAT1 were elucidated. METHODS: Madin-Darby canine kidney (MDCK) cells stably expressing URAT1 (MDCK-URAT1) were established and examined the interactions of URAT1 with various drugs such as benzbromarone and its metabolites including 6-hydroxybenzbromarone, angiotensin-converting enzyme inhibitors, non-steroidal anti-inflammatory drugs and urate transport inhibitors including E3040 and probenecid. RESULTS: MDCK-URAT1 cells exhibited a time- and dose-dependent increase in urate uptake, with a Km value of 570.7 µmol/L. When an URAT1-green fluorescent protein fusion protein construct was expressed in MDCK cells, the protein was sorted mainly to the apical side of the membrane. The drugs except for captoril dose-dependently inhibited urate uptake mediated by URAT1, with half maximal inhibitory concentration (IC(50) ) values ranging 0.05-716 µmol/L. CONCLUSION: Comparing these IC(50) values with intratubular concentrations of unbound drugs in humans, it is thought that URAT1 is a target molecule of uricosuric drugs, including 6-hydroxybenzbromarone, probenecid, indomethacin and salicylate, to inhibit urate reabsorption in vivo. In addition, a cell line that stably expressing URAT1 could be a useful tool for the development of uricosuric drugs.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Transportadores de Ânions Orgânicos/metabolismo , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Ácido Úrico/metabolismo , Uricosúricos/farmacologia , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Benzobromarona/análogos & derivados , Benzobromarona/farmacologia , Benzotiazóis/farmacologia , Transporte Biológico/efeitos dos fármacos , Captopril/farmacologia , Células Cultivadas , Cães , Enalapril/farmacologia , Indometacina/farmacologia , Concentração Inibidora 50 , Fenilbutazona/farmacologia , Probenecid/farmacologia , Piridinas/farmacologia , Salicilatos/farmacologia , Sulfimpirazona/farmacologia , Uricosúricos/administração & dosagem
4.
Leg Med (Tokyo) ; 37: 64-66, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30711876

RESUMO

We presented allele frequencies of 27 X-chromosomal short tandem repeats (DXS6807, DXS9902, DXS6795, DXS6810, DXS10076, DXS10077, DXS10078, DXS10162, DXS10163, DXS10164, DXS7132, DXS981, DXS6800, DXS6803, DXS6809, DXS6789, DXS6799, DXS7424, DXS101, DXS7133, GATA172D05, DXS10103, HPRTB, GATA31E08, DXS8377, DXS10147, and DXS7423) obtained from 352 unrelated individuals in Egypt. No deviation from Hardy-Weinberg equilibrium was detected. Two pairs of adjacent loci showed significant linkage disequilibrium. In the principal component analysis plot, the Egyptian data were located between Europe and sub-Saharan Africa, away from Asia.


Assuntos
Cromossomos Humanos X/genética , Frequência do Gene/genética , Repetições de Microssatélites/genética , Polimorfismo Genético/genética , Egito , Feminino , Loci Gênicos/genética , Humanos , Desequilíbrio de Ligação/genética , Masculino
5.
Cell Physiol Biochem ; 21(4): 269-78, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18441515

RESUMO

In this study, we demonstrate that a putative membrane unknown solute transporter 1 of the rat kidney (UST1r; Slc22a9) is a multispecific transporter of organic anions (OAs). When expressed in Xenopus oocytes, UST1r mediated uptake of ochratoxin A (OTA; K(m) = 1.0 microM) and sulfate conjugates of steroids, such as estrone-3-sulfate (ES; K(m) = 3.1 microM) and dehydroepiandrosterone sulfate (DHEAS; K(m) = 2.1 microM) in a sodium-independent manner. We herein propose that UST1r be renamed OA transporter 8 (rOat8). rOat8 interacted with chemically heterogenous anionic compounds, such as nonsteroidal anti-inflammatory drugs, diuretics, probenecid, taurocholate, and methotrexate, but not with the organic cation tetraethylammonium. The rOat8-mediated ES transport was: a) cis-inhibited by 4-methylumbelliferyl sulfate and beta-estradiol sulfate, but not by glucuronide conjugates of these compounds, b) cis-inhibited by four- and five- carbon (C4/C5) dicarboxylates (succinate and glutarate (GA)), and c) trans-stimulated by GA, whereas the efflux of GA was significantly trans-stimulated by ES. By RT-PCR, rOat8 mRNA was expressed in proximal convoluted tubules and cortical and outer medullary collecting ducts, whereas in immunochemical studies, Oat8 was identified as the ñ58 kDa protein that in the collecting duct colocalized with the V-ATPase in plasma membranes and intracellular vesicles in various subtypes of intercalated cells. Molecular identification of Oat8 in these cells indicates a possible novel role of OAT family in the renal secretion/reabsorption of OA and acids and bases via affecting the V-ATPase-dependent functions.


Assuntos
Túbulos Renais Coletores/imunologia , Túbulos Renais Coletores/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Transportadores de Ânions Orgânicos/metabolismo , Animais , Transporte Biológico , Feminino , Imuno-Histoquímica , Masculino , Oócitos , Transportadores de Ânions Orgânicos/genética , Transportadores de Ânions Orgânicos Sódio-Independentes/genética , Ratos , Ratos Wistar , Xenopus laevis
6.
Acta Crystallogr E Crystallogr Commun ; 74(Pt 11): 1637-1642, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30443397

RESUMO

The reaction cavities of the nitro groups in the title compounds, trans-bis-(acetyl-acetonato-κ2 O,O')(nitro)(pyridine-κN)cobalt(III), [Co(C5H7O2)2(NO2)(C5H5N)], (I), trans-bis-(acetyl-acetonato-κ2 O,O')(4-methyl-pyridine-κN)(nitro)cobalt(III), [Co(C5H7O2)2(NO2)(C6H7N)], (II), and trans-bis-(acetyl-acetonato-κ2 O,O')(3-hy-droxy-pyridine-κN)(nitro)cobalt(III) monohydrate, [Co(C5H7O2)2(NO2)(C5H5NO)]·H2O, (III), have been investigated to reveal that bifurcated inter-molecular C(py)-H⋯O,O contacts in (III) are unfeasible for the nitro-nitrito photochemical linkage isomerization process. In each structure, the pyridine ring and the Co atom lie on a crystallographic mirror plane; in (I) and (II) the nitro group lies in the same plane, whereas in (III), which crystallizes as a monohydrate, the nitro group is disordered over three orientations in a 0.672 (16):0.164 (8):0.164 (8) ratio; the water mol-ecule of crystallization is statistically disordered over two sites adjacent to the mirror plane. In the crystals of (I) and (II), the mol-ecules are linked into [100] chains by C-H⋯O hydrogen bonds, whereas the extended structure of (III) features (010) layers linked by O-H⋯O and C-H⋯O hydrogen bonds. Compounds (I) and (II) were refined as inversion twins.

7.
J Cancer Res Ther ; 12(2): 876-80, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27461667

RESUMO

INTRODUCTION: The aim of this study was to quantify the effects of diabetes with pharmacotherapy-treated breast cancer on care resource use. MATERIALS AND METHODS: The study was designed as a single institutional retrospective cohort study using hospital administrative data. The subjects were 152 patients admitted to a hospital from 2008 to 2012 diagnosed with breast cancer, and who underwent pharmacotherapy. We identified diabetes group and nondiabetes group in addition to other variables and quantified the effects of diabetes with breast cancer patients undergoing pharmacotherapy on care resource use, using a multilevel linear regression model. RESULTS: Diabetes was significantly correlated to both longer length of stay (coefficient standard error: 0.75 [0.19], P < 0.001) and higher total hospital charge (0.72 [0.18], P < 0.001), controlled for age, pharmacotherapeutic agent, steroid use, admission route, procedures, and postpharmacotherapy events. CONCLUSION: This study showed that diabetes itself is a risk factor for greater care resource use after controlling for confounding factors. Pharmacotherapy for breast cancer may influence poor glycemic control, thus leading to greater care resource use. Early detection and careful monitoring of diabetes are essential in malignancy to eliminate this burden on the health care system.


Assuntos
Neoplasias da Mama/complicações , Neoplasias da Mama/epidemiologia , Diabetes Mellitus , Recursos em Saúde , Aceitação pelo Paciente de Cuidados de Saúde , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Feminino , Mortalidade Hospitalar , Hospitalização , Humanos , Pessoa de Meia-Idade
8.
Trends Pharmacol Sci ; 25(12): 654-62, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15530644

RESUMO

Physiological and pharmacological studies indicate that the renal and hepatic organic anion transport systems are responsible for the elimination of numerous compounds, such as drugs, environmental substances and metabolites of both endogenous and exogenous origins. Recently, the molecular identity of the organic anion transport system, the OAT family, was revealed. To date, six OAT members have been identified and shown to have important roles not only in detoxification in the kidneys, liver and brain, but also in the reabsorption of essential compounds such as urate. The OAT family members are closely associated with the pharmacokinetics, drug-drug interactions and toxicity of anionic substances such as nephrotoxic drugs and uremic toxins. The molecular characterization of the OAT family encoded by SLC22A will be discussed.


Assuntos
Transportadores de Ânions Orgânicos/fisiologia , Farmacocinética , Animais , Encéfalo/metabolismo , Interações Medicamentosas , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Poluentes Ambientais/farmacocinética , Humanos , Rim/metabolismo , Fígado/metabolismo , Transportadores de Ânions Orgânicos/genética , Preparações Farmacêuticas/metabolismo , Isoformas de Proteínas/fisiologia
9.
Hepatol Res ; 32(4): 218-23, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15936247

RESUMO

Lactoferrin (LF), an iron-binding glycoprotein, exhibits several biological activities, including anti-viral activity and immunomodulatory functions. LF has been reported to inhibit hepatitis C virus (HCV) infection in cultured human hepatocytes and HCV viremia in low pretreatment HCV RNA titers of patients with chronic hepatitis C (CHC). However, the combination of interferon (IFN) alpha-2b plus ribavirin with LF for CHC has not been previously investigated. Thirty-six CHC patients, who were positive for HCV RNA with high serum levels of HCV RNA or who did not respond to or relapsed after interferon monotherapy, were randomly assigned to two groups: IFN alpha-2b and ribavirin plus LF for 24 weeks (18 patients), and IFN alpha-2b and ribavirin plus placebo (18 patients). Treatment was discontinued in three patients (17%) in the LF group and eight patients (44%) in the placebo group. For the 25 patients who finished the 24 weeks of treatment, virological sustained response was seen in 6 (40%) patients in the LF group and in 5 (50%) patients in the placebo group and there was no statistically significant difference between the two groups (p=0.7). Serum alanine aminotransferase concentrations remained normal throughout the follow-up period in nine patients (60%) in the LF group as compared with five patients (50%) in the placebo group (p=0.7). The proportion of patients with a virological or biochemical response at the end of the treatment period did not differ between the two groups. Furthermore, there were no statistically significant differences between the two groups in hemoglobin concentration, serum iron, ferritin, Th1/Th2 ratio or ribavirin concentration throughout the treatment and follow-up periods. In conclusion, we could not demonstrate that LF in combination with IFN alpha-2b and ribavirin increases the virological and biochemical response rate for CHC patients with high serum levels of HCV RNA or for CHC patients who do not response to or relapse after IFN monotherapy.

10.
BMC Pharmacol Toxicol ; 16: 22, 2015 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-26362195

RESUMO

BACKGROUND: Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease worldwide. Renin-angiotensin system (RAS) inhibitors are the first-line treatment for diabetic patients with hypertension. However, whether RAS inhibitors prevent the development of DKD remains controversial. We conducted a retrospective cohort study quantifying the preventive effect of antihypertensive treatment with RAS inhibitors on DKD, using data from specific health check-ups and health insurance claims. METHODS: The study subjects were 418 patients with diabetes and hypertension, drawn from health insurance societies located in Fukuoka and Shizuoka prefectures in Japan. The subjects were divided into three groups, according to the type of antihypertensive treatment they received. They were then compared in terms of the development of DKD, using the diagnostic codes from ICD-10. RESULTS: Thirty subjects (6.2%) developed DKD during the study period between April 2011 and September 2013. RAS inhibitor treated group showed a significantly lower risk of DKD [adjusted odds ratio (AOR) = 0.35; 95% confidential interval (CI): 0.16-0.76] compared with the no treatment group. CONCLUSION: We conclude that antihypertensive treatment with RAS inhibitors is potentially useful for preventing the development of DKD.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Complicações do Diabetes/tratamento farmacológico , Nefropatias Diabéticas/tratamento farmacológico , Falência Renal Crônica/tratamento farmacológico , Sistema Renina-Angiotensina/efeitos dos fármacos , Adulto , Complicações do Diabetes/prevenção & controle , Nefropatias Diabéticas/complicações , Nefropatias Diabéticas/prevenção & controle , Feminino , Humanos , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Falência Renal Crônica/prevenção & controle , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
11.
Intern Med ; 41(8): 633-7, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12211532

RESUMO

A 32-year-old man was admitted to our hospital complaining of abdominal pain in the left upper quadrant. A mass was palpable on the left side of the umbilicus. Laboratory data revealed anemia, elevated erythrocyte sedimentation rate, hypergammaglobulinemia, and prolonged prothrombin time. Computed tomography demonstrated a soft tissue mass in the mesentery of the jejunum, portal venous thrombosis, and cavernomatous transformation in the porta hepatis. The patient was eventually diagnosed by laparoscopic partial resection as having inflammatory pseudotumor of the mesentery. Four months later, all of his symptoms and abnormal laboratory findings completely disappeared without any therapy. Inflammatory pseudotumor should be kept in mind as a cause of portal venous thrombosis, and/or cavernomatous transformation although it is rare.


Assuntos
Granuloma de Células Plasmáticas/complicações , Mesentério/patologia , Doenças Peritoneais/complicações , Veia Porta/patologia , Trombose Venosa/etiologia , Adulto , Granuloma de Células Plasmáticas/diagnóstico , Humanos , Masculino , Doenças Peritoneais/diagnóstico , Trombose Venosa/diagnóstico
12.
Mol Aspects Med ; 34(2-3): 436-54, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23506882

RESUMO

Transporters for vitamin C and its oxidized form dehydroascorbic acid (DHA) are crucial to maintain physiological concentrations of this important vitamin that is used in a variety of biochemical processes. The human SLC23 family consists of the Na(+)-dependent vitamin C transporters SVCT1 (encoded by the SLC23A1 gene) and SVCT2 (SLC23A2) as well as an orphan transporter SVCT3 (SLC23A3). Phylogenetically, the SLC23 family belongs to the nucleobase-ascorbate transporter (NAT) family, although no nucleobase transport has yet been demonstrated for the human members of this family. The SVCT1 and SVCT2 transporters are rather specific for ascorbic acid, which is an important antioxidant and plays a crucial role in a many metal-containing enzymes. SVCT1 is expressed predominantly in epithelial tissues such as intestine where it contributes to the supply and maintenance of whole-body ascorbic acid levels. In contrast to various other mammals, humans are not capable of synthesizing ascorbic acid from glucose and therefore the uptake of ascorbic acid from the diet via SVCT1 is essential for maintaining appropriate concentrations of vitamin C in the human body. The expression of SVCT2 is relatively widespread, where it serves to either deliver ascorbic acid to tissues with high demand of the vitamin for enzymatic reactions or to protect metabolically highly active cells or specialized tissues from oxidative stress. The murine Slc23a3 gene encoding the orphan transporter SVCT3 was originally cloned from mouse yolk sac, and subsequent studies showed that it is expressed in the kidney. However, the function of SVCT3 has not been reported and it remains speculative as to whether SVCT3 is a nucleobase transporter.


Assuntos
Regulação da Expressão Gênica/fisiologia , Modelos Moleculares , Família Multigênica/genética , Conformação Proteica , Transportadores de Sódio Acoplados à Vitamina C/genética , Transportadores de Sódio Acoplados à Vitamina C/fisiologia , Sequência de Aminoácidos , Animais , Ácido Ascórbico/metabolismo , Clonagem Molecular , Humanos , Camundongos , Modelos Biológicos , Dados de Sequência Molecular , Estrutura Molecular , Filogenia , Ratos , Alinhamento de Sequência , Transportadores de Sódio Acoplados à Vitamina C/metabolismo , Especificidade da Espécie
13.
Pathol Res Pract ; 208(9): 503-9, 2012 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-22795691

RESUMO

Low-vacuum scanning electron microscopy (LV-SEM) has been developed which enables the observation of soft, moist, and electrically insulating materials without any pretreatment unlike conventional scanning electron microscopy, in which samples must be solid, dry and usually electrically conductive. The purpose of this study was to assess the usefulness of LV-SEM for renal biopsy specimens. We analyzed 20 renal biopsy samples obtained for diagnostic purposes. The sections were stained with periodic acid methenamine silver to enhance the contrast, and subsequently examined by LV-SEM. LV-SEM showed a precise and fine structure of the glomerulus in both formalin fixed paraffin and glutaraldehyde-osmium tetroxide-fixed epoxy resin sections up to 10,000-fold magnification. The spike formation on the basement membrane was clearly observed in the membranous nephropathy samples. Similarly to transmission electron microscopy, electron dense deposits were observed in the epoxy resin sections of the IgA nephropathy and membranous nephropathy samples. LV-SEM could accurately show various glomerular lesions at high magnification after a simple and rapid processing of the samples. We consider that this is a novel and useful diagnostic tool for renal pathologies.


Assuntos
Nefropatias/diagnóstico , Rim/ultraestrutura , Microscopia Eletrônica de Varredura/métodos , Biópsia por Agulha , Membrana Basal Glomerular/ultraestrutura , Humanos , Microscopia Eletrônica de Varredura/instrumentação , Microscopia Eletrônica de Transmissão/instrumentação , Microscopia Eletrônica de Transmissão/métodos , Reprodutibilidade dos Testes , Coloração e Rotulagem , Fixação de Tecidos , Vácuo
14.
J Biochem ; 152(5): 463-70, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22923734

RESUMO

Antithrombin (AT) inhibits several blood coagulation proteases, including activated factor X (FXa), by forming stable complexes with these proteases. Herein, we demonstrate that AT forms a stable complex with zymogen factor X (FX). Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and size-exclusion chromatography analyses showed that AT and FX formed an SDS-stable complex, which is distinct in apparent molecular mass from an FXa-AT complex, in the presence of heparin. Amino-terminal sequence analysis of the complex following SDS-PAGE under reducing conditions provided clear evidence that AT forms this complex with the heavy chain of FX, because two sequences, HGSPVDI (residues 1-7 of AT) and SVAQATS (residues 1-7 of the heavy chain of FX), were identified. Furthermore, sequence SLNPNRV, which corresponds to residues 394-400 of AT, was identified in the non-reduced FX-AT complex, indicating that FX cleaved the Arg393-Ser394 bond in a reactive centre loop of AT. Unfractionated heparin induced FX-AT complex formation more effectively than low-molecular weight heparin or AT-binding pentasaccharide, and appeared to promote complex formation mainly via a template effect. These data suggest that AT is capable of forming a stable complex with zymogen FX by acting as an inhibitor in the presence of heparin.


Assuntos
Antitrombinas/química , Precursores Enzimáticos/química , Fator X/metabolismo , Heparina/farmacologia , Inibidores de Serina Proteinase/química , Antitrombinas/farmacologia , Arginina/química , Arginina/metabolismo , Precursores Enzimáticos/antagonistas & inibidores , Precursores Enzimáticos/metabolismo , Fator X/antagonistas & inibidores , Fator X/química , Heparina/metabolismo , Humanos , Serina/química , Serina/metabolismo , Inibidores de Serina Proteinase/farmacologia , Relação Estrutura-Atividade
15.
Thromb Res ; 129(1): 62-7, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21621824

RESUMO

INTRODUCTION: MC710 is a mixture agent consisting of plasma-derived activated factor VII (FVIIa) and factor X (FX) at a weight ratio of 1:10 developed as a novel bypassing agent for the management of the bleeding of hemophilia patients with inhibitors. The pharmacokinetics, distribution, and excretion of (125)I-labeled-FVIIa ((125)I-FVIIa) and -FX ((125)I-FX) were studied in male rats after a single intravenous administration of (125)I-FVIIa or (125)I-FX combined with MC710. METHODS: (125)I-FVIIa or (125)I-FX was administered intravenously with MC710 to male rats in a single dosage (FVIIa 0.4 mg and FX 4 mg/kg body weight) and radioactivity and antigen levels in plasma were quantified for 24h. Urine and feces were sampled to study the excretion of radioactivity during 168 h after dosing. Whole-body autoradiography was performed to evaluate the qualitative distribution of radioactivity 168 h after dosing. RESULTS AND CONCLUSIONS: The half-life (t(1/2)α and t(1/2)ß) of radioactivity and FVIIa antigen were 0.704 and 6.27 h, and 0.496 and 1.66 h, respectively and the area under the plasma concentration-time curve (AUC(0-∞)) of radioactivity and FVIIa antigen were 17,932 and 8671 ng·h/mL, respectively. The t(1/2) of radioactivity and FX antigen were 4.06 and 3.05 h, respectively, and the AUC(0-∞) of radioactivity and FX antigen were 320,143 and 395,794 ng·h/mL, respectively. About 80% of the administered dose of radioactivity was excreted in urine and feces by 168 h after administration. Tissue distribution experiments showed that FVIIa- and FX-related (125)I accumulated in bone and bone marrow, and disappeared slowly.


Assuntos
Coagulantes/farmacocinética , Fator VIIa/farmacologia , Fator X/farmacocinética , Animais , Área Sob a Curva , Medula Óssea/metabolismo , Osso e Ossos/metabolismo , Coagulantes/administração & dosagem , Coagulantes/sangue , Coagulantes/urina , Combinação de Medicamentos , Ensaio de Imunoadsorção Enzimática , Fator VIIa/administração & dosagem , Fator VIIa/farmacocinética , Fator VIIa/urina , Fator X/administração & dosagem , Fator X/urina , Fezes/química , Meia-Vida , Humanos , Injeções Intravenosas , Radioisótopos do Iodo , Masculino , Ratos , Distribuição Tecidual
16.
Thromb Res ; 125(5): 457-63, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20080285

RESUMO

INTRODUCTION: We previously reported that a combination of factors VIIa (FVIIa) and X (FX) might represent an effective and attractive alternative to recombinant factor VIIa (rFVIIa) and plasma-derived activated prothrombin complex concentrate (APCC) for controlling bleeding in hemophiliacs with inhibitors. The present study describes the standardization and preparation of a virus-inactivated and nano-filtrated plasma-derived FVIIa/FX concentrate. We hypothesized that the hemostatic capacity was equivalent to or better than current bypassing agents as evaluated by measurements of waveform APTT clotting and thrombin generation. RESULTS: Kinetic analyses showed that a "normal" FX concentration of approximately 140nM in plasma did not induce maximum catalytic efficacy of FVIIa and that an increase in the concentration of FX in hemophilic plasma enhanced the thrombin generation potential of FVIIa. Thus, the FVIIa/FX mixture was prepared by assembling plasma-derived FVIIa and FX at a weight ratio of 1:10. The FVIIa/FX mixture proved superior to rFVIIa with regards to shortening the APTT and accelerating the thrombin generation in hemophilic plasma. The FVIIa/FX mixture promoted the generation of thrombin more than did rFVIIa. CONCLUSIONS: Increasing the FX concentration in hemophilic plasma gives a higher clotting potential of FVIIa. A FVIIa/FX concentrate may serve as a new alternative bypassing agent.


Assuntos
Fator VIIa/administração & dosagem , Fator X/administração & dosagem , Hemofilia A/metabolismo , Plasma/efeitos dos fármacos , Plasma/metabolismo , Trombina/metabolismo , Combinação de Medicamentos , Hemofilia A/tratamento farmacológico , Humanos
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