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1.
Animal ; 16(2): 100454, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35121288

RESUMEN

Identification of cattle by ear tagging is legally required to ensure traceability. However, studies indicate that ear tagging causes pain-associated physiological and behavioural responses. The wound healing process and prevalence of wound lesions in calves remain mostly unknown. Therefore, this study sought to estimate the prevalence of wound lesions and identify associated risk factors by assessing ear tagging management in unweaned dairy calves. We conducted one field study with single visits to estimate the prevalence of wound lesions and associated risk factors (Study 1, 42 farms, 802 calves) and one follow-up study with repeated visits to assess farmers' view on ear tag management, the relationship between calf health and wound healing, and the development of wound lesions over time (Study 2, five farms, 42 calves). Study 1 comprised a short interview with the farmer (four questions regarding ear tagging). Ear tag position (on or between ridges) and wound lesions were evaluated using a three-level scoring system (1 = no blood, scab, or pus discharge; 2 = incrustation or scab and slight blood or pus discharge; and 3 = heavy purulent discharge, tissue deformation, or both). In Study 2, farmers were interviewed about ear tagging (30 questions), and 10 calves from each farm were assessed on the day of ear tagging and 1, 3, and 6 weeks after tag insertion. Calf health, ear tag position, and wound characteristics were assessed during all visits. Both studies were analysed descriptively, and odds ratios (ORs) for wound lesions in Study 1 were calculated using logistic regression. Of the ears assessed in Study 1, 31.1% showed clinical signs classified as category 2. Score 3 was less common and was found for 6.7% of all ears. Although the highest incidence of wound lesions was found in calves aged 2-4 weeks, wound lesions were also found in calves aged >10 weeks (18.5%). Identified risk factors for wound lesions were small farm size, calf age, single housing, group size, placement of ear tags on ridges, and other ear's score. Individual farmers in Study 2 were able to place ear tags very accurately, although awareness about ear tag lesions appeared to be low among farmers. Sensitising farmers to this issue, implementing routine check-ups of ear tag wounds 2 weeks after insertion, and considering the identified risk factors may reduce animal welfare impairments associated with ear tagging.


Asunto(s)
Sistemas de Identificación Animal , Oído/lesiones , Heridas y Lesiones/veterinaria , Animales , Bovinos , Industria Lechera , Agricultores , Granjas , Estudios de Seguimiento , Humanos , Prevalencia , Factores de Riesgo
2.
Eur Cell Mater ; 21: 80-93, 2011 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-21267944

RESUMEN

The communication of bone-forming osteoblasts and bone-resorbing osteoclasts is a fundamental requirement for balanced bone remodelling. For biomaterial research, development of in vitro models is necessary to investigate this communication. In the present study human bone marrow stromal cells and human monocytes were cultivated in order to differentiate into osteoblasts and osteoclasts, respectively. Finally, a cultivation regime was identified which firstly induces the differentiation of the human bone marrow stromal cells followed by the induction of osteoclastogenesis through the osteoblasts formed--without the external addition of the factors RANKL and M-CSF. As a feedback on osteoblasts enhanced gene expression of BSP II was detected for modifications which facilitated the formation of large multinuclear osteoclasts. Phenotype characterization was performed by biochemical methods (DNA, LDH, ALP, TRAP 5b), gene expression analysis (ALP, BSP II, RANKL, IL-6, VTNR, CTSK, TRAP, OSCAR, CALCR) as well as light microscopy, confocal laser scanning microscopy, and scanning electron microscopy. After establishing this model on polystyrene, similar positive results were obtained for cultivation on a relevant bone substitution material--a composite xerogel of silica, collagen, and calcium phosphate.


Asunto(s)
Materiales Biocompatibles , Técnicas de Cocultivo/métodos , Ensayo de Materiales , Monocitos/citología , Osteoblastos , Osteoclastos , Células del Estroma/citología , Secuencia de Bases , Células de la Médula Ósea , Remodelación Ósea , Diferenciación Celular , Expresión Génica , Humanos , Microscopía , Reacción en Cadena de la Polimerasa , Poliestirenos
3.
Eur Cell Mater ; 19: 96-106, 2010 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-20186669

RESUMEN

Textile chitosan fibre scaffolds were evaluated in terms of interaction with osteoclast-like cells, derived from human primary monocytes. Part of the scaffolds was further modified by coating with fibrillar collagen type I in order to make the surface biocompatible. Monocytes were cultured directly on the scaffolds in the presence of macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor kappaB ligand (RANKL) for up to 18 days. Confocal laser scanning microscopy (CLSM) as well as scanning electron microscopy (SEM) revealed the formation of multinuclear osteoclast-like cells on both the raw chitosan fibres and the collagen-coated scaffolds. The modified surface supported the osteoclastogenesis. Differentiation towards the osteoclastic lineage was confirmed by the microscopic detection of cathepsin K, tartrate resistant acid phosphatase (TRAP), acidic compartments using 3-(2,4-dinitroanillino)-3'-amino-N-methyldipropylamine (DAMP), immunological detection of TRAP isoform 5b, and analysis of gene expression of the osteoclastic markers TRAP, cathepsin K, vitronectin receptor, and calcitonin receptor using reverse transcription-polymerase chain reaction (RT-PCR). The feature of the collagen-coated but also of the raw chitosan fibre scaffolds to support attachment and differentiation of human monocytes facilitates cell-induced material resorption--one main requirement for successful bone tissue engineering.


Asunto(s)
Sustitutos de Huesos/farmacología , Quitosano/farmacología , Monocitos/efectos de los fármacos , Osteoclastos/efectos de los fármacos , Ingeniería de Tejidos/métodos , Andamios del Tejido/tendencias , Fosfatasa Ácida/análisis , Fosfatasa Ácida/metabolismo , Biomarcadores/análisis , Biomarcadores/metabolismo , Sustitutos de Huesos/química , Sustitutos de Huesos/uso terapéutico , Catepsina K/análisis , Catepsina K/metabolismo , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/fisiología , Linaje de la Célula/efectos de los fármacos , Linaje de la Célula/fisiología , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Quitosano/química , Quitosano/uso terapéutico , Colágeno/química , Colágeno/farmacología , Colágeno/uso terapéutico , Humanos , Integrina alfaVbeta3/genética , Isoenzimas/análisis , Isoenzimas/metabolismo , Factor Estimulante de Colonias de Macrófagos/farmacología , Microscopía Confocal , Microscopía Electrónica de Rastreo , Monocitos/fisiología , Monocitos/ultraestructura , Osteoclastos/fisiología , Osteoclastos/ultraestructura , Ligando RANK/farmacología , Receptores de Calcitonina/genética , Fosfatasa Ácida Tartratorresistente
4.
Biomed Mater ; 14(4): 045017, 2019 06 19.
Artículo en Inglés | MEDLINE | ID: mdl-31170696

RESUMEN

Chitosan fibers were processed using the Net-Shape-Nonwoven (NSN) technique in order to create porous scaffolds which were functionalized in two bioinspired ways: collagen type I coating and unique mineralization with organically modified hydroxyapatite (ormoHAP). While collagen is common to enhance cell attachment on surfaces, the electric-field assisted migration and deposition of ormoHAP on the surface of the NSN-scaffolds is a novel technique which enables sub-micrometer sized mineralization while maintaining the original pore structure. Microscopy revealed fast attachment and morphological adaptation of the cells on both, the pure and the functionalized NSN-scaffolds. Remarkably, the cell number of osteogenically induced hBMSC on ormoHAP-modified NSN-scaffolds increased 3.5-5 fold compared to pure NSN-scaffolds. Osteogenic differentiation of hBMSC/osteoblasts was highest on collagen-functionalized NSN-scaffolds. RT-PCR studies revealed gene expression of ALP, BSP II, and osteocalcin to be high for all NSN-scaffolds. Overall, the NSN-scaffold functionalization with collagen and ormoHAP improved attachment, proliferation, and differentiation of hBMSC and therefore revealed the remarkable potential of their application for the tissue engineering of bone.


Asunto(s)
Materiales Biocompatibles/química , Fosfatos de Calcio/química , Quitosano/química , Células Madre Mesenquimatosas/citología , Andamios del Tejido/química , Adulto , Animales , Bovinos , Adhesión Celular , Diferenciación Celular , Proliferación Celular , Colágeno/química , Durapatita/química , Femenino , Humanos , Osteoblastos/citología , Osteogénesis , Ingeniería de Tejidos/métodos , Microtomografía por Rayos X , Adulto Joven
5.
Neuron ; 16(2): 369-76, 1996 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8789951

RESUMEN

Transmitter release from chromaffin cells differs from that in synapses in that it persists for a longer time after Ca2+ entry has stopped. This prolonged secretion is not due to a delay between vesicle fusion and transmitter release, nor to slow detection of released substance: step increases in capacitance due to single vesicle fusion precede the release detected by amperometry by only a few milliseconds. The persistence of secretion after a depolarization is reduced by addition of mobile calcium buffer. This suggests that most of the delay is due to diffusion of Ca2+ between channels and release sites, implying that Ca2+ channels and secretory vesicles are not colocalized in chromaffin cells, in contrast to presynaptic active zones.


Asunto(s)
Glándulas Suprarrenales/metabolismo , Sistema Cromafín/metabolismo , Glándulas Suprarrenales/citología , Glándulas Suprarrenales/fisiología , Animales , Tampones (Química) , Calcio , Bovinos , Quelantes/farmacología , Sistema Cromafín/citología , Sistema Cromafín/fisiología , Conductividad Eléctrica , Electrofisiología , Fura-2/farmacología , Nistatina/farmacología , Tiempo de Reacción , Factores de Tiempo
6.
Mater Sci Eng C Mater Biol Appl ; 93: 265-276, 2018 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-30274058

RESUMEN

The intent of the present study was to demonstrate that multiphasic silica/collagen xerogels are able to manipulate cellular processes. These xerogels were prepared by a sol-gel approach allowing the incorporation of mineral phases. The resulting nanocomposites are designed as biomaterial for bone regeneration. Human osteoclasts derived from peripheral blood mononuclear cells were cultured both indirectly and directly, either in presence of different xerogel types or on their surface, to investigate the factor with the main influence on osteoclastogenesis. To this end, the incorporation of a third phase to silica/collagen xerogels was used to affect osteoclastogenesis. In cell culture, ambient ion conditions controlled by both the degradation products of the xerogel and the bioactivity-dependent ion release and reprecipitation were shown to have the main effect on osteoclast specific enzyme tartrate-resistant acid phosphatase (TRAP) 5b. Late stage of osteoclastogenesis characterized by resorption was strongly dependent on the xerogels composition. Surface chemistry of the xerogels was displayed to play an important role in osteoclast resorption. Biphasic silica/collagen xerogels and triphasic xerogels with calcium carbonate offered widespread resorbed areas, whereas hydroxyapatite containing xerogels showed distinctly reduced resorption. The incorporation of strontium carbonate and phosphate, respectively, as third phase changed TRAP 5b activity dose-dependently and inhibited resorption within 21 days. Quantitative evaluation on osteoclast differentiation was carried out using biochemical methods (TRAP 5b, cathepsin K) and was supported by confocal laser scanning microscopy and scanning electron microscopy (SEM). Qualitative estimation of resorption was carried out by SEM.


Asunto(s)
Regeneración Ósea/efectos de los fármacos , Sustitutos de Huesos , Colágeno , Osteoclastos/metabolismo , Dióxido de Silicio , Antígenos de Diferenciación/biosíntesis , Sustitutos de Huesos/química , Sustitutos de Huesos/farmacología , Catepsina K/biosíntesis , Colágeno/química , Colágeno/farmacología , Femenino , Humanos , Masculino , Osteoclastos/citología , Dióxido de Silicio/química , Dióxido de Silicio/farmacología , Fosfatasa Ácida Tartratorresistente/biosíntesis
7.
Mol Biol Cell ; 8(10): 1863-75, 1997 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9348529

RESUMEN

We report herein that expression of alpha 2 beta 1 integrin increased human erythroleukemia K562 transfectant (KX2C2) cell movement after extravasation into liver parenchyma. In contrast, a previous study demonstrated that alpha 2 beta 1 expression conferred a stationary phenotype to human rhabdomyosarcoma RD transfectant (RDX2C2) cells after extravasation into the liver. We therefore assessed the adhesive and migratory function of alpha 2 beta 1 on KX2C2 and RDX2C2 cells using a alpha 2 beta 1-specific stimulatory monoclonal antibody (mAb), JBS2, and a blocking mAb, BHA2.1. In comparison with RDX2C2 cells, KX2C2 were only weakly adherent to collagen and laminin. JBS2 stimulated alpha 2 beta 1-mediated interaction of KX2C2 cells with both collagen and laminin resulting in increases in cell movement on both matrix proteins. In the presence of Mn2+, JBS2-stimulated adhesion on collagen beyond an optimal level for cell movement. In comparison, an increase in RDX2C2 cell movement on collagen required a reduction in its adhesive strength provided by the blocking mAb BHA2.1. Consistent with these in vitro findings, in vivo videomicroscopy revealed that alpha 2 beta 1-mediated postextravasation cell movement of KX2C2 cells in the liver tissue could also be stimulated by JBS2. Thus, results demonstrate that alpha 2 beta 1 expression can modulate postextravasation cell movement by conferring either a stationary or motile phenotype to different cell types. These findings may be related to the differing metastatic activities of different tumor cell types.


Asunto(s)
Antígenos CD/farmacología , Antígenos CD/fisiología , Integrina beta1/farmacología , Integrina beta1/fisiología , Hígado/citología , Hígado/fisiología , Animales , Anticuerpos Monoclonales/farmacología , Adhesión Celular/efectos de los fármacos , Adhesión Celular/fisiología , Línea Celular , Movimiento Celular/efectos de los fármacos , Movimiento Celular/fisiología , Colágeno/efectos de los fármacos , Colágeno/metabolismo , Humanos , Integrina alfa2 , Laminina/efectos de los fármacos , Laminina/metabolismo , Ratones , Células Tumorales Cultivadas
8.
Acta Biomater ; 44: 135-43, 2016 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-27544814

RESUMEN

UNLABELLED: A biomimetic strategy was developed in order to prepare organically modified hydroxyapatite (ormoHAP) with spherical shape. The technical approach is based on electric field-assisted migration of calcium ions and phosphate ions into a hydrogel composed of carboxymethylated gelatin. The electric field as well as the carboxymethylation using glucuronic acid (GlcA) significantly accelerates the mineralization process, which makes the process feasible for lab scale production of ormoHAP spheres and probably beyond. A further process was developed for gentle separation of the ormoHAP spheres from the gelatin gel without compromising the morphology of the mineral. The term ormoHAP was chosen since morphological analyses using electron microscopy (SEM, TEM) and element analysis (EDX, FT-IR, XRD) confirmed that carboxymethylated gelatin molecules use to act as organic templates for the formation of nanocrystalline HAP. The hydroxyapatite (HAP) crystals self-organize to form hollow spheres with diameters ranging from 100 to 500nm. The combination of the biocompatible chemical composition and the unique structure of the nanocomposites is considered to be a useful basis for future applications in functionalized degradable biomaterials. STATEMENT OF SIGNIFICANCE: A novel bioinspired mineralization process was developed based on electric field-assisted migration of calcium and phosphate ions into biochemically carboxymethylated gelatin acting as organic template. Advantages over conventional hydroxyapatite include particle size distribution and homogeneity as well as achievable mechanical properties of relevant composites. Moreover, specifically developed calcium ion or phosphate ion release during degradation can be useful to adjust the fate of bone cells in order to manipulate remodeling processes. The hollow structure of the spheres can be useful for embedding drugs in the core, encapsulated by the highly mineralized outer shell. In this way, controlled drug release could be achieved, which enables advanced strategies for threating bone-related diseases, e.g. osteoporosis and multiple myeloma.


Asunto(s)
Durapatita/química , Electricidad , Gelatina/química , Geles/química , Ácido Glucurónico/química , Microesferas , Animales , Calcio/análisis , Análisis de Fourier , Iones , Metilación , Minerales/química , Polvos , Espectrometría por Rayos X , Espectroscopía Infrarroja por Transformada de Fourier , Sus scrofa , Factores de Tiempo , Difracción de Rayos X
9.
Biotechniques ; 28(4): 722-8, 730, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10769751

RESUMEN

The generation of spectral mutants of the green fluorescent protein (GFP) set the stage for multiple-color imaging in living cells. However, the use of this technique has been limited by a spectral overlap of the available GFP mutants and/or by insufficient resolution in both time and space. Using a new setup for dual-color imaging, we demonstrate here the visualization of small, fast moving vesicular structures with a high time resolution. Two GFP-fusion proteins were generated: human chromogranin B, a secretory granule matrix protein, and phogrin, a secretory granule membrane protein. They were tagged with enhanced yellow fluorescent protein (EYFP) and enhanced cyan fluorescent protein (ECFP), respectively. Both fusion proteins were cotransfected in Vero cells, a cell line from green monkey kidney. EYFP and ECFP were excited sequentially at high time rates using a monochromator. Charged coupled device (CCD)-based image acquisition resulted in 5-8 dual-color images per second, with a resolution sufficient to detect transport vesicles in mammalian cells. Under these conditions, a fully automated time-resolved analysis of the movement of color-coded objects was achieved. The development of specialized software permitted the analysis of the extent of colocalization between the two differentially labeled sets of cellular structures over time. This technical advance will provide an important tool to study the dynamic interactions of subcellular structures in living cells.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Proteínas de la Membrana , Microscopía Fluorescente/métodos , Animales , Chlorocebus aethiops , Cromograninas/genética , Gránulos Citoplasmáticos/metabolismo , Gránulos Citoplasmáticos/ultraestructura , Proteínas Fluorescentes Verdes , Humanos , Proteínas Luminiscentes/genética , Glicoproteínas de Membrana/genética , Microscopía Fluorescente/instrumentación , Microscopía por Video/instrumentación , Microscopía por Video/métodos , Proteínas Tirosina Fosfatasas/genética , Proteínas Tirosina Fosfatasas Clase 8 Similares a Receptores , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Factores de Tiempo , Transfección , Células Vero
10.
FEMS Microbiol Lett ; 190(1): 177-80, 2000 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-10981710

RESUMEN

Lactobacilli have been shown to be important in the maintenance of the healthy urogenital flora. One strain, Lactobacillus fermentum RC-14, releases surface-active components which can inhibit adhesion of uropathogenic bacteria. Using a quantitative method for determining inhibition of adhesion, a protein with high anti-adhesive properties against Enterococcus faecalis 1131 was purified. The N-terminal sequence of the 29-kDa protein was identical to that of a collagen-binding protein from Lactobacillus reuteri NCIB 11951, and exhibited close homology with a basic surface protein from L. fermentum BR11. The results suggest that this anti-adhesive cell surface protein of Lactobacillus could protect against uropathogens by preventing their adhesion. the Federation of European Microbiological Societies.


Asunto(s)
Adhesión Bacteriana/efectos de los fármacos , Proteínas Bacterianas/aislamiento & purificación , Proteínas Bacterianas/farmacología , Enterococcus faecalis/efectos de los fármacos , Lactobacillus/metabolismo , Secuencia de Aminoácidos , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Enterococcus faecalis/fisiología , Femenino , Enfermedades Urogenitales Femeninas/microbiología , Infecciones por Bacterias Grampositivas/microbiología , Humanos , Integrinas/química , Integrinas/aislamiento & purificación , Integrinas/metabolismo , Datos de Secuencia Molecular , Receptores de Colágeno
11.
FEMS Immunol Med Microbiol ; 32(1): 37-41, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11750220

RESUMEN

Forty-two healthy women were randomized to receive one of three encapsulated Lactobacillus rhamnosus GR-1 plus Lactobacillus fermentum RC-14 probiotic dosage regimens or L. rhamnosus GG by mouth each day for 28 days. However, the vaginal flora, assessed by Nugent scoring, was only normal in 40% of the cases, and 14 patients had asymptomatic bacterial vaginosis. Treatment with L. rhamnosus GR-1/L. fermentum RC-14 once and twice daily correlated with a healthy vaginal flora in up to 90% of patients, and 7/11 patients with bacterial vaginosis converted to normal or intermediate scores within 1 month. Ingestion of L. rhamnosus GG failed to have an effect. This study confirms the potential efficacy of orally administered lactobacilli as a non-chemotherapeutic means to restore and maintain a normal urogenital flora, and shows that over 10(8) viable organisms per day is the required dose.


Asunto(s)
Lactobacillus , Probióticos/administración & dosificación , Vagina/microbiología , Vaginosis Bacteriana/terapia , Adolescente , Adulto , Cápsulas , Femenino , Humanos , Persona de Mediana Edad
12.
FEMS Immunol Med Microbiol ; 30(1): 49-52, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11172991

RESUMEN

We report the first clinical evidence that probiotic lactobacilli can be delivered to the vagina following oral intake. In 10 women with a history of recurrent yeast vaginitis, bacterial vaginosis (BV) and urinary tract infections, strains Lactobacillus rhamnosus GR-1 and Lactobacillus fermentum RC-14 suspended in skim milk and given twice daily for 14 days, were recovered from the vagina and identified by morphology and molecular typing within 1 week of commencement of therapy. In six cases of asymptomatic BV or intermediate BV (based upon Nugent scoring) was resolved within 1 week of therapy.


Asunto(s)
Infecciones Bacterianas/terapia , Enfermedades Urogenitales Femeninas/terapia , Lactobacillus , Probióticos/uso terapéutico , Administración Oral , Infecciones Bacterianas/microbiología , Femenino , Enfermedades Urogenitales Femeninas/microbiología , Humanos , Lactobacillus/clasificación , Lactobacillus/aislamiento & purificación , Vagina/microbiología
13.
Oncol Rep ; 6(6): 1405-10, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10523720

RESUMEN

The CXC-chemokines Groalpha and interleukin-8 (IL-8) are well characterized growth factors for melanoma cells. Here the constitutive expression of Groalpha, IL-8 and their receptors (CXCR1 and CXCR2) as well as their functional involvement in the proliferation response were analyzed in normal keratinocytes and epidermoid carcinoma cell lines A431 and KB. Flow cytometric measurements, ELISA and semi-quantitative RT-PCR revealed low constitutive protein secretion and mRNA expression of both CXC-chemokines as well as CXCR1 and 2 in normal keratinocytes, whereas significant higher levels of CXC-chemokines and CXCR2 were deteced in epidermoid carcinoma cells. Proliferation of epidermoid carcinoma cells could be induced by CXC-chemokines and constitutive proliferation could be inhibited by neutralizing antibodies against CXC-chemokines and CXCR2. These studies indicate that constitutive Groalpha, IL-8 and CXCR2 protein expression enable an autocrine growth mechanism in epidermoid carcinoma cells.


Asunto(s)
Antígenos CD/biosíntesis , Carcinoma de Células Escamosas/metabolismo , Factores Quimiotácticos/biosíntesis , Sustancias de Crecimiento/biosíntesis , Péptidos y Proteínas de Señalización Intercelular , Interleucina-8/biosíntesis , Queratinocitos/metabolismo , Receptores de Quimiocina/biosíntesis , Receptores de Interleucina/biosíntesis , Neoplasias Cutáneas/metabolismo , Comunicación Autocrina , Carcinoma de Células Escamosas/patología , División Celular , Quimiocina CXCL1 , Quimiocinas CXC/biosíntesis , Humanos , Queratinocitos/patología , ARN Mensajero/análisis , ARN Mensajero/biosíntesis , Receptores de Interleucina-8A , Receptores de Interleucina-8B , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Neoplasias Cutáneas/patología , Células Tumorales Cultivadas
14.
J Agric Food Chem ; 49(3): 1370-6, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11312866

RESUMEN

Starch, in particular the linear amylose, is able to form inclusion complexes with a wide spectrum of ligand molecules, among them flavor compounds. The complexing ability of a homologous series of gamma- and delta-lactones with potato starch was followed by amperometric iodine titration, differential scanning calorimetry, and wide-angle X-ray diffraction measurements. Lactones with a linear chain of a size > or = C(5) form inclusion complexes with starch, whereas lactones with a short linear chain, such as gamma-heptalactone, show poor complexing ability. The thermal stability of starch-lactone complexes increases with increasing chain length of the lactone. In general, lactones induce the formation of V(h) helices. Only delta-decalactone complexes with starch were not definitely identified as V(h) amylose helices. Complexation of starch dispersions with lactones induce turbidity and gelation or phase separation, both phenomena being the result of microphase separation.


Asunto(s)
Amilosa/química , Lactonas/química , Almidón/química , Gusto , Rastreo Diferencial de Calorimetría/métodos , Yodo , Ligandos , Solanum tuberosum , Difracción de Rayos X
15.
Spectrochim Acta A Mol Biomol Spectrosc ; 56(6): 1179-90, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10845547

RESUMEN

The UV photoelectron spectra of several tetracyclic heteroaromatic compounds (2-9) which are pi-isoelectronic with triphenylene (1) have been recorded and analysed making use of semiempirical AM1 and PM3 as well as ab initio/DFT B3LYP calculations. In one series of compounds (2-7), the peripheral benzene rings of 1 are successively substituted by thiophene rings that are either [b]- or [c]-annellated with the central benzene unit. In 2-7 only marginal shifts are found for most of the IPs of electrons. In the benzotrithiophenes 5-7, a systematic variation is displayed by IP(pi7). Compared to 1, the pi electron system of benzo[c]trithiophene (7) is approximately two times as much destabilized as in the isomers 5 and 6 with [b]annellated thiophene rings. The IP[n(S)] values of the thiophene derivatives 2-7 indicate that these orbitals are clearly destabilized relative to thiophene. The same holds for the n(O) orbital of the furane derivative 9 in comparison with that of furane. In 9, only the higher pi MOs (pi7-pi9) are destabilized whereas the lower levels (pi1-pi4) are stabilized, and those in between (pi5-pi6) remain essentially unshifted. In the pyrrole derivative 8, all pi MOs are substantially destabilized by about 0.5-1.6 eV relative to 1.


Asunto(s)
Crisenos/química , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Conformación Molecular
16.
Prax Kinderpsychol Kinderpsychiatr ; 43(4): 130-7, 1994 Apr.
Artículo en Alemán | MEDLINE | ID: mdl-8016023

RESUMEN

A specific group of children, adolescents and young adults with failure syndromes and courses of failure is described and a report is made on the new decision-making therapy, which has been modified for young patients. This is described from its transaction-analytical background as well as in its practical implementation in the in-patient department of a clinic for child and adolescent psychiatry. Here it is not a matter of a single method of therapy but of a therapy direction. The objective of this is to help the young person to review its earlier decisions that were made in connection with relationships in the sense of one's own prohibition of admission, these being the main cause for failure, and to code to a new decision of wanting to have successful relationships in the future. In its implementation different psychotherapeutical processes are applied according to the individual process situation. The new decision-making therapy can be considered to be completed when the typical failure syndrome symptoms have disappeared and the young person begins to open itself towards development-promoting help and to enter into relationships.


Asunto(s)
Adopción/psicología , Niño Institucionalizado/psicología , Cuidados en el Hogar de Adopción/psicología , Control Interno-Externo , Terapia Psicoanalítica , Psicoterapia de Grupo , Adaptación Psicológica , Adolescente , Niño , Femenino , Humanos , Masculino , Autoimagen , Identificación Social , Síndrome , Análisis Transaccional
17.
Acta Biomater ; 9(1): 4878-88, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23072829

RESUMEN

A human co-culture model of osteoblasts and osteoclasts, derived from bone marrow stromal cells and monocytes respectively, was used to characterize the influence of biomaterial modification on the bioactivity and ultimately the ratio of bone-forming to bone-resorbing cells cultivated directly on the surface. Nanocomposites of silica and collagen have been shown to function as skeletal structures in nature and were reproduced in vitro by using a sol-gel approach. The resulting xerogels exhibit a number of features that make it a valuable system for the development of innovative materials for bone substitution applications. In the present study, the incorporation of different calcium phosphate phases in silica/collagen-based gels was demonstrated to enhance the bioactivity of these samples. This ability of the biomaterial to precipitate calcium phosphate on the surface when incubated in simulated body fluids or cell culture medium is generally considered to an advantageous property for bone substitution materials. By co-cultivating human osteoblasts and osteoclasts up to 42 days on the xerogels, we demonstrate that the long-term ratio of these cell types depends on the level of bioactivity of the substrate samples. Biphasic silica/collagen xerogels exhibited comparably low bioactivity but encouraged proliferation of osteoblasts in comparison to osteoclast formation. A balanced ratio of both cell types was detected for moderately bioactive triphasic xerogels with 5% calcium phosphate. However, enhancing the bioactivity of the xerogel samples by increasing the calcium phosphate phase percentage to 20% resulted in a diminished number of osteoblasts in favor of osteoclast formation. Quantitative evaluation was carried out by biochemical methods (calcium, DNA, ALP, TRAP 5b) as well as RT-PCR (ALP, BSP II, OC, RANKL, TRAP, CALCR, VTNR, CTSK), and was supported by confocal laser scanning microscopy (cell nuclei, actin, CD68, TRAP) as well as scanning electron microscopy.


Asunto(s)
Fosfatos de Calcio , Colágeno , Nanocompuestos , Osteoblastos/citología , Osteoclastos/citología , Dióxido de Silicio , Secuencia de Bases , Técnicas de Cocultivo , Cartilla de ADN , Geles , Humanos , Células Madre Mesenquimatosas/citología , Microscopía Confocal , Microscopía Electrónica de Rastreo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
18.
ACS Appl Mater Interfaces ; 3(11): 4323-31, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21942510

RESUMEN

A recently established materials concept of biomimetic composites based on silica, collagen, and calcium phosphates was adapted for the preparation of porous scaffolds suitable for tissue engineering applications. Mineralization was achieved by directed nucleation of silica on the templating organic phase during a sol-gel process with or without addition of hydroxyapatite. Both mineral phases (25 wt %, individually or combined in equal shares) influenced the scaffold's morphology at the nanoscale. Enhancement of apparent density and compressive strength was similar for silica or hydroxyapatite mineralization; however the stiffening effect of hydroxyapatite was much higher. All scaffold modifications provided proper conditions for adhesion, proliferation, and osteogenic differentiation of human bone marrow stromal cells. The open porosity allowed cells to migrate throughout the scaffolds while maintaining their viability, both confirmed by MTT staining and confocal laser scanning microscopy. Initial cell distributions were graduated due to collagen mineralization, but balanced out over the cultivation time of 28 days. RT-PCR analyses revealed higher gene expression of ALP but lower expression of BSP II and osteocalcin because of collagen mineralization. The results demonstrate that both silica and hydroxyapatite offer comparable possibilities to tailor mechanical properties of collagen-based scaffolds without being detrimental to in vitro biocompatibility.


Asunto(s)
Materiales Biocompatibles/química , Colágeno/química , Durapatita/química , Nanocompuestos/química , Dióxido de Silicio/química , Ingeniería de Tejidos/instrumentación , Andamios del Tejido/química , Fenómenos Biomecánicos , Células de la Médula Ósea/citología , Adhesión Celular , Diferenciación Celular , Proliferación Celular , Humanos , Células del Estroma/citología
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