Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
1.
Arch Toxicol ; 92(6): 1953-1967, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29721588

RESUMEN

The pharmacokinetics of diclofenac were investigated following single oral doses of 10 mg/kg to chimeric liver humanized and murinized FRG and C57BL/6 mice. In addition, the metabolism and excretion were investigated in chimeric liver humanized and murinized FRG mice. Diclofenac reached maximum blood concentrations of 2.43 ± 0.9 µg/mL (n = 3) at 0.25 h post-dose with an AUCinf of 3.67 µg h/mL and an effective half-life of 0.86 h (n = 2). In the murinized animals, maximum blood concentrations were determined as 3.86 ± 2.31 µg/mL at 0.25 h post-dose with an AUCinf of 4.94 ± 2.93 µg h/mL and a half-life of 0.52 ± 0.03 h (n = 3). In C57BL/6J mice, mean peak blood concentrations of 2.31 ± 0.53 µg/mL were seen 0.25 h post-dose with a mean AUCinf of 2.10 ± 0.49 µg h/mL and a half-life of 0.51 ± 0.49 h (n = 3). Analysis of blood indicated only trace quantities of drug-related material in chimeric humanized and murinized FRG mice. Metabolic profiling of urine, bile and faecal extracts revealed a complex pattern of metabolites for both humanized and murinized animals with, in addition to unchanged parent drug, a variety of hydroxylated and conjugated metabolites detected. The profiles in humanized mice were different to those of both murinized and wild-type animals, e.g., a higher proportion of the dose was detected in the form of acyl glucuronide metabolites and much reduced amounts as taurine conjugates. Comparison of the metabolic profiles obtained from the present study with previously published data from C57BL/6J mice and humans revealed a greater, though not complete, match between chimeric humanized mice and humans, such that the liver humanized FRG model may represent a model for assessing the biotransformation of such compounds in humans.


Asunto(s)
Antiinflamatorios no Esteroideos/farmacocinética , Quimera/metabolismo , Diclofenaco/farmacocinética , Animales , Antiinflamatorios no Esteroideos/sangre , Antiinflamatorios no Esteroideos/orina , Área Bajo la Curva , Bilis/metabolismo , Biotransformación , Quimera/sangre , Quimera/orina , Diclofenaco/sangre , Diclofenaco/orina , Heces/química , Semivida , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Especificidad de la Especie
2.
RSC Adv ; 8(55): 31673-31681, 2018 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-35548201

RESUMEN

Organic-inorganic hybrid materials with urethane functionalities were obtained by simultaneous twin polymerization of twin prepolymers in combination with the ideal twin monomer 2,2'-spirobi[4H-1,3,2-benzodioxasiline]. The twin prepolymers consist of a urethane-based prepolymer with reactive terminal groups which can react during the twin polymerization process. Nanostructured hybrid materials with integrated dialkylsiloxane crosslinked urethane structures, phenolic resin and SiO2 are obtained in a one pot process. The effects of the polymerization temperature as well as those of various catalysts and reagent ratios on the polymerization behavior were investigated. The molecular structures of the obtained materials were determined by 13C- and 29Si-{1H}-CP-MAS NMR spectroscopies. HAADF-STEM-measurements were performed to prove the distribution of silicon in the hybrid material.

3.
Biochem Pharmacol ; 135: 139-150, 2017 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-28351678

RESUMEN

The pharmacokinetics and metabolism of lumiracoxib were studied, after administration of single 10mg/kg oral doses to chimeric liver-humanized and murinized FRG mice. In the chimeric humanized mice, lumiracoxib reached peak observed concentrations in the blood of 1.10±0.08µg/mL at 0.25-0.5h post-dose with an AUCinf of 1.74±0.52µgh/mL and an effective half-life for the drug of 1.42±0.72h (n=3). In the case of the murinized animals peak observed concentrations in the blood were determined as 1.15±0.08µg/mL at 0.25h post-dose with an AUCinf of 1.94±0.22µgh/mL and an effective half-life of 1.28±0.02h (n=3). Analysis of blood indicated only the presence of unchanged lumiracoxib. Metabolic profiling of urine, bile and faecal extracts revealed a complex pattern of metabolites for both humanized and murinized animals with, in addition to unchanged parent drug, a variety of hydroxylated and conjugated metabolites detected. The profiles obtained in humanized mice were different compared to murinized animals with e.g., a higher proportion of the dose detected in the form of acyl glucuronide metabolites and much reduced amounts of taurine conjugates. Comparison of the metabolic profiles obtained from the present study with previously published data from C57bl/6J mice and humans, revealed a greater though not complete match between chimeric humanized mice and humans, such that the liver-humanized FRG model may represent a useful approach to assessing the biotransformation of such compounds in humans.


Asunto(s)
Quimera/sangre , Inhibidores de la Ciclooxigenasa 2/sangre , Inhibidores de la Ciclooxigenasa 2/farmacocinética , Diclofenaco/análogos & derivados , Animales , Diclofenaco/sangre , Diclofenaco/farmacocinética , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Especificidad de la Especie
4.
Chem Commun (Camb) ; 50(68): 9753-6, 2014 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-25023389

RESUMEN

Amino-functionalized organic-inorganic hybrid materials with a narrow distributed nanostructure of 2-4 nm in size were obtained by means of a template-free and non-aqueous procedure. Simultaneous twin polymerization of novel amino group containing twin monomers with 2,2'-spirobi[4H-1,3,2-benzodioxasiline] has been applied for this purpose. The amino groups of the organic-inorganic hybrid material are useful for post derivatization.

5.
Sci Rep ; 3: 1582, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23545597

RESUMEN

Quantum information science promises transformative impact over a range of key technologies in computing, communication, and sensing. A prominent example uses entangled photons to overcome the resolution-degrading effects of dispersion in the medical-imaging technology, optical coherence tomography. The quantum solution introduces new challenges: inherently low signal and artifacts, additional unwanted signal features. It has recently been shown that entanglement is not a requirement for automatic dispersion cancellation. Such classical techniques could solve the low-signal problem, however they all still suffer from artifacts. Here, we introduce a method of chirped-pulse interferometry based on shaped laser pulses, and use it to produce artifact-free, high-resolution, dispersion-cancelled images of the internal structure of a biological sample. Our work fulfills one of the promises of quantum technologies: automatic-dispersion-cancellation interferometry in biomedical imaging. It also shows how subtle differences between a quantum technique and its classical analogue may have unforeseen, yet beneficial, consequences.


Asunto(s)
Aumento de la Imagen/instrumentación , Interferometría/instrumentación , Nefelometría y Turbidimetría/instrumentación , Refractometría/instrumentación , Diseño de Equipo , Análisis de Falla de Equipo , Teoría Cuántica
6.
Clin Exp Immunol ; 146(1): 169-80, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16968411

RESUMEN

The cathepsins D (CTSD), B (CTSB) and L (CTSL) are important for the intracellular degradation of proteins. Increased cathepsin expression is associated with inflammatory diseases. We have shown previously an induction of CTSD expression in intestinal macrophages (IMAC) in inflamed mucosa of patients with inflammatory bowel disease (IBD). Here we investigated the regulation of CTSB and CTSL in IMAC during IBD and effects of CTSD and CTSB/CTSL inhibition in vivo. Human IMAC were isolated from normal and inflamed mucosa. Reverse transcription-polymerase chain reaction (RT-PCR) was performed for CTSB and CTSL mRNA. Immunostaining was used to confirm PCR results. Cathepsin inhibition was investigated in the dextran-sulphate-sodium (DSS) colitis model in mice with application of pepstatin A (CTSD inhibitor), CA-074 (CTSB inhibitor) and Z-Phe-Tyr-aldehyde (CTSL inhibitor). CTSL mRNA was significantly up-regulated in IMAC isolated from IBD mucosa. Up-regulated protein expression was found mainly in areas of mucosal damage by immunostaining. Inhibition of CTSD in mouse DSS colitis was followed by an amelioration of the disease. Inhibitor-treated mice showed a significant lower histological score (HS) and less colon reduction in comparison to controls. Similarly, simultaneous inhibition of CTSB/CTSL was followed by a significant amelioration of colitis. Expression of tissue-degrading cathepsins is increased in IMAC in IBD. Inhibition of CTSD as well as CTSB/CTSL is followed by an amelioration of experimental colitis. The prevention of mucosal damage by cathepsin inhibition could represent a new approach for the therapy of IBD.


Asunto(s)
Catepsinas/biosíntesis , Enfermedades Inflamatorias del Intestino/enzimología , Macrófagos/enzimología , Animales , Catepsina B/antagonistas & inhibidores , Catepsina B/biosíntesis , Catepsina B/genética , Catepsina D/antagonistas & inhibidores , Catepsina D/biosíntesis , Catepsina D/genética , Catepsina L , Catepsinas/antagonistas & inhibidores , Catepsinas/genética , Colitis/tratamiento farmacológico , Colitis/patología , Cisteína Endopeptidasas/biosíntesis , Cisteína Endopeptidasas/genética , Inhibidores de Cisteína Proteinasa/uso terapéutico , Dipéptidos/uso terapéutico , Modelos Animales de Enfermedad , Femenino , Expresión Génica , Humanos , Mucosa Intestinal/enzimología , Ratones , Ratones Endogámicos BALB C , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos
7.
Gut ; 54(7): 935-43, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15951537

RESUMEN

BACKGROUND: The glycoprotein (gp) 96 links the adaptive with the innate immune system. It is a chaperone with a binding domain for peptides generated by proteasomal degradation. During cellular stress, peptide loaded gp96 can be released and presented to T cells by antigen presenting cells (APCs). METHODS: mRNAs from in vitro differentiated macrophages (iv mac) and normal intestinal macrophages (IMACs) were compared by subtractive hybridisation and Affymetrix GeneChip analysis. Differentiation induced expression of gp96 was investigated in the multicellular spheroid (MCS) model. In vivo gp96 protein expression was detected by double labelling immunohistochemistry of human colon and in the CD4+ CD62L+ T cell transfer mouse model. RESULTS: Five of 76 clones obtained by subtractive hybridisation revealed >99% sequence homology to gp96. Affymetrix GeneChip analysis confirmed induction of gp96 in IMACs. Gp96 mRNA was detected in IMACs from normal and intestinal bowel disease mucosa. Induction of gp96 protein was observed after seven days in the MCS model of IMAC differentiation. Immunohistochemistry confirmed the presence of gp96 protein in IMACs in normal mucosa as well as in mucosa from patients with ulcerative colitis and diverticulitis. In mucosa from Crohn's disease (CD) patients, gp96 protein was not detectable. In the CD4+ CD62L+ T cell transfer mouse model, gp96 was verifiable in non-activated IMACs. CONCLUSION: Gp96 is induced during differentiation of normal IMACs but is not detected in IMACs in CD mucosa. As gp96 has been described as having a role in tolerance induction, this may be relevant for loss of tolerance against luminal bacteria found in CD patients.


Asunto(s)
Antígenos de Neoplasias/metabolismo , Enfermedad de Crohn/metabolismo , Mucosa Intestinal/metabolismo , Macrófagos/metabolismo , Animales , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/fisiología , Diferenciación Celular/fisiología , Células Cultivadas , Colitis/metabolismo , Modelos Animales de Enfermedad , Expresión Génica , Humanos , Técnicas para Inmunoenzimas , Ratones , Ratones Endogámicos BALB C , Ratones SCID , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Esferoides Celulares
8.
Laryngol Rhinol Otol (Stuttg) ; 58(3): 201-9, 1979 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-439985

RESUMEN

57% of the preserved human cartilage chips being implanted in the nose lead to a remarkable up to a complete resorption. 94% of the patients have nevertheless a sufficiently or well working function of the nose; besides that they are as well satisfied with the shape of their nose. The most important reason for the resorption are mechanical factors; this has been shown by comparing the load of implanted tissue on the columella and on the dorsum of the nose. We can't exclude the possibility of late immunologic reaction. Comparing these results with those of the middle ear by missing any mechanical load, we registered nevertheless a remarkable loss of the volume of the cartilage. This is an intense indication for an immunologic reaction, especially because there is a more intense vascularisation in the middle ear and a strong activity of fibroblasts based on the mesenchymal potency of middle ear mucosa. It's only in the middle ear that preserved cartilage can be substituted by connective tissue, viable cartilage or viable bone.


Asunto(s)
Cartílago/trasplante , Oído Medio/cirugía , Nariz/cirugía , Cartílago/irrigación sanguínea , Cartílago/inmunología , Colesteatoma/cirugía , Enfermedades del Oído/cirugía , Supervivencia de Injerto , Humanos , Deformidades Adquiridas Nasales/cirugía , Conservación de Tejido , Trasplante Autólogo , Trasplante Homólogo
9.
Clin Exp Immunol ; 136(1): 157-67, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15030527

RESUMEN

Down-regulation of receptors involved in the recognition or transmission of inflammatory signals and a reduced responsiveness support the concept that macrophages are 'desensitized' during their differentiation in the intestinal mucosa. During inflammatory bowel disease (IBD) intestinal macrophages (IMACs) change to a reactive or 'aggressive' type. After having established a method of isolation and purification of IMACs, message for cathepsin D was one of the mRNAs we found to be up-regulated in a subtractive hybridization of Crohn's disease (CD) macrophages versus IMACs from control mucosa. The expression of cathepsin D in intestinal mucosa was analysed by immunohistochemistry in biopsies from IBD and control patients and in a mouse model of dextran sulphate sodium (DSS)-induced acute and chronic colitis. IMACs were isolated and purified from normal and inflamed mucosa by immunomagnetic beads armed with a CD33 antibody. RT-PCR was performed for cathepsin D mRNA. Results were confirmed by Northern blot and flow cytometrical analysis. Immunohistochemistry revealed a significant increase in the cathepsin D protein expression in inflamed intestinal mucosa from IBD patients compared to non-inflamed mucosa. No cathepsin D polymerase chain reaction (PCR) product could be obtained with mRNA from CD33-positive IMACs from normal mucosa. Reverse transcription (RT)-PCR showed an induction of mRNA for cathepsin D in purified IMACs from IBD patients. Northern blot and flow cytometry analysis confirmed these results. Cathepsin D protein was also found in intestinal mucosa in acute and chronic DSS-colitis but was absent in normal mucosa. This study shows that expression of cathepsin D is induced in inflammation-associated IMACs. The presence of cathepsin D might contribute to the mucosal damage in IBD.


Asunto(s)
Catepsina D/metabolismo , Enfermedades Inflamatorias del Intestino/enzimología , Macrófagos/enzimología , Enfermedad Aguda , Animales , Catepsina D/genética , Enfermedad Crónica , Sulfato de Dextran , Femenino , Técnicas para Inmunoenzimas , Enfermedades Inflamatorias del Intestino/inducido químicamente , Mucosa Intestinal/enzimología , Ratones , Ratones Endogámicos BALB C , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Regulación hacia Arriba
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA