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1.
Clin Oral Investig ; 18(2): 579-87, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-23636610

RESUMEN

OBJECTIVES: This study aims to evaluate the effect of a minimally invasive mesial-occlusal-distal (mod) preparation on the marginal adaptation of ceramic and composite inlays with the aim of saving sound dental substance. MATERIALS AND METHODS: Class II mod cavities were prepared in 50 extracted human molars and randomly allocated to five groups (n = 10). In all groups, the mesial-proximal box margins were located in the dentin, 1 mm below the cementoenamel junction (CEJ), while the distal box margins were 1 mm above the CEJ. In groups A and B, conventional standard preparations with a divergent angle of α = 6° were prepared. In groups C, D, and E, minimally invasive standard preparations with a convergent angle of α = 10° were prepared. In groups A and D, composite inlays and, in groups B and C, ceramic inlays were fabricated (chairside economical restoration of esthetic ceramics (CEREC)) and adhesively inserted. In group E, a direct composite filling using the incremental technique was placed. Replicas were taken before and after thermomechanical loading (1,200,000 cycles, 50/5 °C, max. load 49 N). Marginal integrity (tooth-luting composite, luting composite-inlay) was evaluated by scanning electron microscopy (× 200). The percentage of continuous margins in the different locations was compared between and within groups before and after cycling, using ANOVA and Scheffé post hoc test. RESULTS: After the thermomechanical loading, no significant differences were observed between the different groups with respect to the interface of luting composite-inlay. At the interface of tooth-luting composite for preparations involving the dentin, groups A and B behaved significantly better compared to the control group E, which in turn were not different to groups C and D. CONCLUSION: Composite and ceramic inlays inserted in minimally invasive prepared mod cavities result in margins not different from those of inlays placed in conventional mod preparations. Direct composite filling margins, however, were inferior to those attained by conventional indirect restorations. CLINICAL RELEVANCE: Minimally invasive preparations for mod inlays with undercuts show marginal adaptation equal to that of conventional inlay preparation design.


Asunto(s)
Cerámica , Resinas Compuestas , Caries Dental/patología , Cementos Dentales , Humanos , Microscopía Electrónica de Rastreo
2.
Int J Comput Dent ; 17(1): 53-64, 2014.
Artículo en Inglés, Alemán | MEDLINE | ID: mdl-24791465

RESUMEN

Intraoral and extraoral scanning systems are continuously improving in terms of operational reliability and image quality. This creates new application options for the standard use of these systems in dental practice. Three-dimensional scans for volumetric and differential analysis of jaw position over time can be generated by superimposing partial or full-arch scans recorded at different time points. These analyses can be performed in a wide range of dental applications to compare and follow treatments or diagnoses over time. In this article, we will describe the indications and applications for OraCheck, a new software application that will be available to Cerec users in Spring 2014.


Asunto(s)
Diseño Asistido por Computadora , Técnica de Impresión Dental , Imagenología Tridimensional/métodos , Programas Informáticos , Presentación de Datos , Técnica de Impresión Dental/normas , Estudios de Seguimiento , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Procesamiento de Imagen Asistido por Computador/normas , Imagenología Tridimensional/normas , Registro de la Relación Maxilomandibular/métodos , Control de Calidad , Interfaz Usuario-Computador
3.
Acta Odontol Scand ; 71(2): 317-24, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23004362

RESUMEN

PURPOSE: Evaluating the effect of a proximal margin elevation technique on marginal adaptation of ceramic inlays. METHODS: Class II MOD-cavities were prepared in 40 human molars and randomly distributed to four groups (n = 10). In group EN (positive control) proximal margins were located in enamel, 1 mm above the cementoenamel junction, while 2 mm below in groups DE-1In, DE-2In and DE. The groups DE-1In, DE-2In and DE simulated subgingival location of the cervical margin. In group DE-1In one 3 mm and in group DE-2In two 1.5 mm composite layers (Tetric) were placed for margin elevation of the proximal cavities using Syntac classic as an adhesive. The proximal cavities of group DE remained untreated and served as a negative control. In all groups, ceramic inlays (Cerec 3D) were adhesively inserted. Replicas were taken before and after thermomechanical loading (1.200.000 cycles, 50/5°C, max. load 49 N). Marginal integrity (tooth-composite, composite-inlay) was evaluated with scanning electron microscopy (200×). Percentage of continuous margin (% of total proximal margin length) was compared between groups before and after cycling using ANOVA and Scheffé post-hoc test. RESULTS: After thermomechanical loading, no significant differences were observed between the different groups with respect to the interface composite-inlay and tooth-composite with margins in dentin. The interface tooth-composite in enamel of group EN was significantly better compared to group DE-2In, which was not different to the negative control group DE and DE-1In. CONCLUSION: Margin elevation technique by placement of a composite filling in the proximal box before insertion of a ceramic inlay results in marginal integrities not different from margins of ceramic inlays placed in dentin.


Asunto(s)
Cerámica , Incrustaciones , Fenómenos Biomecánicos , Humanos
4.
Int J Comput Dent ; 16(1): 23-36, 2013.
Artículo en Inglés, Alemán | MEDLINE | ID: mdl-23641662

RESUMEN

The quality of intraoral scanning systems is steadily improving, and they are becoming easier and more reliable to operate. This opens up possibilities for routine clinical applications. A special aspect is that overlaying (superimposing) situations recorded at different times facilitates an accurate three-dimensional difference analysis. Such difference analyses can also be used to advantage in other areas of dentistry where target/actual comparisons are required. This article presents potential indications using a newly developed software, explaining the functionality of the evaluation process and the prerequisites and limitations of 3D monitoring.


Asunto(s)
Diseño Asistido por Computadora , Técnica de Impresión Dental/normas , Imagenología Tridimensional/métodos , Dispositivos Ópticos , Control de Calidad , Algoritmos , Calibración , Técnica de Impresión Dental/instrumentación , Profilaxis Dental , Progresión de la Enfermedad , Enfermedades de las Encías/prevención & control , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Programas Informáticos , Técnicas de Movimiento Dental , Desgaste de los Dientes/fisiopatología , Interfaz Usuario-Computador
5.
Clin Res Cardiol ; 111(3): 294-307, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34269863

RESUMEN

AIMS: It remains unclear whether transitional care management outside of a clinical trial setting provides benefits for patients with acute heart failure (AHF) after hospitalization. We evaluated the feasibility and effectiveness of a multidimensional post-discharge disease management programme using a telemedical monitoring system incorporated in a comprehensive network of heart failure nurses, resident physicians, and secondary and tertiary referral centres (HerzMobil Tirol, HMT), METHODS AND RESULTS: The non-randomized study included 508 AHF patients that were managed in HMT (n = 251) or contemporaneously in usual care (UC, n = 257) after discharge from hospital from 2016 to 2019. Groups were retrospectively matched for age and sex. The primary endpoint was time to HF readmission and all-cause mortality within 6 months. Multivariable Cox proportional hazard models were used to assess the effectiveness. The primary endpoint occurred in 48 patients (19.1%) in HMT and 89 (34.6%) in UC. Compared with UC, management by HMT was associated with a 46%-reduction in the primary endpoint (adjusted HR 0.54; 95% CI 0.37-0.77; P < 0.001). Subgroup analyses revealed consistent effectiveness. The composite of recurrent HF hospitalization and death within 6 months per 100 patient-years was 64.2 in HMT and 108.2 in UC (adjusted HR 0.41; 95% CI 0.29-0.55; P < 0.001 with death considered as a competing risk). After 1 year, 25 (10%) patients died in HMT compared with 66 (25.7%) in UC (HR 0.38; 95% CI 0.23-0.61, P < 0.001). CONCLUSIONS: A multidimensional post-discharge disease management programme, comprising a telemedical monitoring system incorporated in a comprehensive network of specialized heart failure nurses and resident physicians, is feasible and effective in clinical practice.


Asunto(s)
Cuidados Posteriores/métodos , Manejo de la Enfermedad , Insuficiencia Cardíaca/rehabilitación , Telemedicina/métodos , Anciano , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Monitoreo Fisiológico , Readmisión del Paciente/estadística & datos numéricos , Evaluación de Programas y Proyectos de Salud , Modelos de Riesgos Proporcionales , Estudios Retrospectivos
6.
Clin Res Cardiol ; 109(1): 78-88, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31134330

RESUMEN

BACKGROUND: Cardiac amyloidosis (CA) is an underappreciated cause of morbidity and mortality. Light-chain (AL) and transthyretin (ATTR) amyloidosis have different disease trajectories. No data are available on subtype-specific modes of death (MOD) in patients with CA. METHODS AND RESULTS: We retrospectively investigated 66 with AL and 48 with wild-type ATTR amyloidosis (ATTRwt) from 2000 to 2018. ATTRwt differed from AL by age (74.6 ± 5.4 years vs. 63 ± 10.8 years), posterior wall thickness (16.8 ± 3.3 mm vs. 14.3 ± 2.2 mm), left ventricular mass index (180.7 ± 63.2 g/m2 vs. 133.5 ± 42.2 g/m2), and the proportions of male gender (91.7% vs. 59.1%), atrial enlargement (92% vs. 68.2%) and atrial fibrillation (50% vs. 12.1%). In AL NYHA Functional Class and proteinuria (72.7% vs. 39.6%) were greater; mean arterial pressure (84.4 ± 13.5 mmHg vs. 90.0 ± 11.3 mmHg) was lower. Unadjusted 5-year mortality rate was 65% in AL-CA vs. 44% in the ATTRwt group. Individuals with AL-CA were 2.28 times ([95%CI 1.27-4.10]; p = 0.006) more likely to die than were individuals with ATTRwt-CA. Information on MOD was available in 56 (94.9%) of 59 deceased patients. MOD was cardiovascular in 40 (66.8%) and non-cardiovascular in 16 (27.1%) patients. Cardiovascular [28 (68.3%) vs. 13 (80%)] death events were distributed equally between AL and ATTRwt (p = 0.51). CONCLUSION: Our data indicate no differences in MOD between patients with AL and ATTRwt cardiac amyloidosis despite significant differences in clinical presentation and disease progression. Cardiovascular events account for more than two-thirds of fatal casualties in both groups.


Asunto(s)
Amiloidosis/mortalidad , Cardiomiopatías/mortalidad , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas/mortalidad , Anciano , Anciano de 80 o más Años , Amiloidosis/fisiopatología , Fibrilación Atrial/epidemiología , Cardiomiopatías/fisiopatología , Estudios de Cohortes , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas/fisiopatología , Masculino , Persona de Mediana Edad , Prealbúmina/metabolismo , Estudios Retrospectivos
7.
J Cell Biol ; 97(4): 1107-12, 1983 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-6137486

RESUMEN

Cerebroside sulfotransferase (CST) catalyzes the final step in the synthesis of sulfatide (sulfogalactocerebroside) by transferring the sulfate from 3'-phosphoadenosine 5'-phosphosulfate (PAPS) to galactocerebroside. Orientation of CST was studied in vesicles enriched in this enzyme obtained from 21-d-old rat brain. Several lines of evidence indicate that CST is located on the luminal side of these vesicles. (a) Sulfation of endogenous galactocerebroside occurred in vesicles only in the presence of a detergent to render the membranes permeable to exogenous PAPS. (b) There is a pool of latent enzyme within the vesicle, which is released by Triton X-100. (c) CST is not destroyed by trypsin unless the vesicle membranes are first made permeable by Triton X-100. (d) Glycolipid substrate, when covalently attached to agarose beads, was not sulfated unless the enzyme was solubilized. These results are similar to those obtained with thiamine pyrophosphatase, which is known to be located within the lumen of the vesicles. This study establishes that an enzyme synthesizing a complex glycolipid is localized within Golgi-enriched vesicles. Since the product of the CST reaction must also be localized to the luminal side of the vesicles, it is most likely that sulfatide is located at the intraperiod line (outer layer) of myelin. The orientation of CST within the vesicle provides a mechanism for the asymmetrical assembly of glycolipids in bilayers.


Asunto(s)
Encéfalo/enzimología , Aparato de Golgi/enzimología , Sulfotransferasas , Sulfurtransferasas/análisis , Animales , Galactosilceramidas/metabolismo , Glucolípidos/metabolismo , Octoxinol , Péptido Hidrolasas/farmacología , Polietilenglicoles/farmacología , Ratas , Ratas Endogámicas , Sulfurtransferasas/metabolismo , Tiamina Pirofosfatasa/análisis , Tiamina Pirofosfatasa/metabolismo
9.
Internist (Berl) ; 50(4): 489-92, 2009 Apr.
Artículo en Alemán | MEDLINE | ID: mdl-19099274

RESUMEN

We report on a 64-year old patient with known Morbus Osler and high cardiac output failure due to distinct arterio-venous malformations of the liver. Since the patient suffered from severe right heart insufficiency despite optimized medical therapy, we decided to conduct an interventional occlusion of the hepatic shunts in three single sessions. The transient elevation of transaminases was reversible. After interventional therapy cardiac output decreased from 20 l/min to 15 l/min (25%) leading to a reduction of diuretic dosage and a sustained stabilization of the clinical condition.


Asunto(s)
Fístula Arteriovenosa/complicaciones , Fístula Arteriovenosa/terapia , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/prevención & control , Arteria Hepática/anomalías , Venas Hepáticas/anomalías , Taquicardia/etiología , Taquicardia/prevención & control , Embolización Terapéutica , Insuficiencia Cardíaca/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Taquicardia/diagnóstico , Resultado del Tratamiento
10.
Sci Rep ; 8(1): 8429, 2018 05 30.
Artículo en Inglés | MEDLINE | ID: mdl-29849175

RESUMEN

Klotho is an antiaging protein which exerts known cardioprotection. In kidney, trans-membrane Klotho acts as essential co-receptor of fibroblast growth factor 23 (FGF23). In the heart, soluble Klotho (sKlotho) protects from systolic dysfunction independently of FGF23. Here, we analyzed the association of FGF23 and sKlotho upon progression of chronic heart failure (CHF) and analyzed Klotho expression in human hearts. Serum levels of sKlotho and FGF23 were measured in 287 patients with cardiomyopathy (CMP). Tissue samples from CMP (n = 10) and healthy control hearts (n = 10) were analyzed for Klotho mRNA and protein expression. Individuals in the first FGF23 tertile were 4.1 times more likely of freedom from death, heart transplantation or assist device implantation compared to third tertile. No relationship was found between sKlotho and the combined endpoint. Instead, Klotho mRNA encoding the full-length form was upregulated in human CMP hearts. Immunoblotting confirmed upregulation of sKlotho associated with increased expression of proteases involved in cleavage of Klotho suggesting rather local effects of Klotho in the heart. Therefore, we conclude that in contrast to FGF23, serum sKlotho is not associated with disease severity or progression in CHF. Instead, Klotho is expressed and upregulated in diseased hearts, suggesting local paracrine effects.


Asunto(s)
Cardiomiopatías/sangre , Cardiomiopatías/genética , Glucuronidasa/sangre , Glucuronidasa/genética , Regulación hacia Arriba , Adulto , Cardiomiopatías/complicaciones , Estudios de Cohortes , Progresión de la Enfermedad , Femenino , Factor-23 de Crecimiento de Fibroblastos , Factores de Crecimiento de Fibroblastos/sangre , Insuficiencia Cardíaca/complicaciones , Humanos , Proteínas Klotho , Masculino , Persona de Mediana Edad , ARN Mensajero/genética , ARN Mensajero/metabolismo
11.
Oper Dent ; 40(1): 80-6, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-24815915

RESUMEN

AIM: This study aimed to analyze the effect of different matrix metalloproteinase (MMP) inhibitors on the microtensile bond strength (microTBS) of an etch-and-rinse and a self-etching adhesive after 9 months of aging. METHODS AND MATERIALS: Flat human dentin surfaces were bonded either with an etch-and-rinse adhesive (Optibond FL) or a self-etching adhesive (Clearfil SE Bond). Dentin surfaces were left untreated or were pretreated with MMP inhibitors (2% chlorhexidine digluconate [CHX], 0.05% green tea extract, 1 mM ferrous sulfate, or 0.2 mM galardin) prior to application of the adhesive. Composite buildups were made incrementally. Pretreated groups were tested after 9 months of storage in artificial saliva (37°C) and compared with untreated groups, which were tested immediately (initial microTBS) and upon aging (9-month microTBS). Data were analyzed by linear mixed-model regression. Failure mode analysis was performed microscopically and statistically analyzed by repeated-measures analysis of variance (p<0.05). RESULTS: MicroTBS of the etch-and-rinse adhesive but not of the self-etching adhesive was significantly decreased by aging. For Optibond FL, pretreatment with 2% CHX, 0.05% green tea extract, and 0.2 mM galardin revealed bond strength values (MPa) similar to the initial microTBS (32.1±14.8) and significantly higher compared with the microTBS (20.3±13.6) of aged untreated dentin. No significant differences were observed between groups bonded with Clearfil SE Bond (initial microTBS: 28.3±12.4; 9-month microTBS: 25.3±11.8). Application of the MMP inhibitors decreased the number of adhesive failures compared with untreated controls after 9 months of aging, but this effect was not significant. CONCLUSION: The MMP inhibitors prevented the decrease in microTBS upon aging of the etch-and-rinse but not of the self-etching adhesive.


Asunto(s)
Inhibidores de la Metaloproteinasa de la Matriz/farmacología , Clorhexidina/análogos & derivados , Clorhexidina/farmacología , Recubrimiento Dental Adhesivo/métodos , Grabado Dental/métodos , Análisis del Estrés Dental , Recubrimientos Dentinarios/uso terapéutico , Humanos , Extractos Vegetales/farmacología , Cementos de Resina/uso terapéutico , Té/química , Resistencia a la Tracción/efectos de los fármacos
12.
J Histochem Cytochem ; 27(1): 44-8, 1979 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-438504

RESUMEN

For many cell types, cellular autofluorescence in the 500-600 nm spectral region can result in a significant background signal for measurements of weakly fluorescent probes. Measurements of fluorescence intensity and spectra of a variety of cell types and assays of neuronal homogenates are presented to demonstrate that this autofluorescence is most likely due to endogenous flavoproteins.


Asunto(s)
Fenómenos Fisiológicos Celulares , Flavoproteínas , Animales , Células/metabolismo , Flavoproteínas/metabolismo , Fluorescencia , Neuronas/fisiología , Espectrometría de Fluorescencia
13.
Neurosci Lett ; 37(3): 295-9, 1983 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-6577314

RESUMEN

The regulation of sulfation of galactocerebroside was examined in several tissues from brachymorphic mice, including the central nervous system and kidney. These animals have an inherited defect in the enzymes which synthesize 3'-phosphoadenosine 5'-phosphosulfate (PAPS) resulting in decreased sulfation of glycosaminoglycans. In contrast, sulfation of galactocerebroside to form sulfatide (sulfogalactocerebroside) was normal in brachymorphic mice even in tissues with decreased ability to synthesize PAPS. This suggests that, unlike the regulation of glycosaminoglycan sulfation, the formation of sulfatide is not stringently regulated by tissue levels of PAPS.


Asunto(s)
Nucleótidos de Adenina/metabolismo , Encéfalo/enzimología , Fosfoadenosina Fosfosulfato/metabolismo , Sulfoglicoesfingolípidos/metabolismo , Sulfotransferasas , Animales , Glucolípidos/metabolismo , Riñón/enzimología , Ratones , Ratones Endogámicos , Sulfurtransferasas/metabolismo
14.
Biochem Biophys Res Commun ; 129(2): 522-9, 1985 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-3860202

RESUMEN

The mechanism of inhibition of rat brain cerebroside sulfotransferase (EC 2.8.2.11) by a series of triazine aromatic dyes was examined. These dyes are putative site-specific probes of the "dinucleotide fold". All of the dyes examined were competitive inhibitors of cerebroside sulfotransferase with respect to 3'-phosphoadenosine 5'-phosphosulfate (PAPS) binding. In addition, the binding of the dye, Congo Red, to the sulfotransferase was associated with a red shift in its absorption spectrum. Based on these results, it is suggested that rat brain cerebroside sulfotransferase contains a "dinucleotide fold" as a structural feature of the protein.


Asunto(s)
Nucleótidos de Adenina/metabolismo , Encéfalo/enzimología , Fosfoadenosina Fosfosulfato/metabolismo , Sulfotransferasas , Sulfurtransferasas/antagonistas & inhibidores , Triazinas/farmacología , Animales , Sitios de Unión , Colorantes/farmacología , Técnicas In Vitro , Conformación Proteica , Ratas , Sulfurtransferasas/metabolismo
15.
Arch Biochem Biophys ; 240(2): 932-44, 1985 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-3861135

RESUMEN

Galactocerebroside sulfotransferase (EC 2.8.2.11) was purified to apparent homogeneity from rat kidneys. The purified protein is stable at -20 degrees C, and has an estimated molecular weight of 64,000 and a pI of 5.1. In contrast to other known sulfotransferases, the enzyme appears not to require divalent metal ions for activity. The Km for the donor, 3'-phosphoadenosine 5'-phosphosulfate, is 5.2 microM. Structural studies on this "active" sulfate donor show the requirement of a phosphate group at the 3' position of the ribose moiety. Modification of the amino group at either the 6 or 8 position on the purine ring renders the corresponding compounds poor substrates. Both galactosylceramide and lactosylceramide are effective acceptors for this enzyme, while galactosylsphingosine and galactosylglycerolipids are sulfated only poorly, suggesting that the in vivo sulfation of these glycolipids is carried out by different sulfotransferases. The active site of the enzyme contains arginine residues which appear to be important in binding the sulfate donor. The enzyme protein is hydrophobic and binds 0.17 mg [3H]Triton X-100/mg protein. The purified enzyme contains bound lipids, consisting primarily of cholesterol and phosphatidylcholine. The lipid environment affects the activity of the enzyme which, in turn, regulates the sulfation of glycolipids.


Asunto(s)
Riñón/enzimología , Sulfotransferasas , Sulfurtransferasas/aislamiento & purificación , Animales , Calcio/farmacología , Electroforesis en Gel de Poliacrilamida , Punto Isoeléctrico , Cinética , Magnesio/farmacología , Manganeso/farmacología , Peso Molecular , Octoxinol , Polietilenglicoles , Ratas
16.
Anal Quant Cytol ; 2(1): 66-74, 1980.
Artículo en Inglés | MEDLINE | ID: mdl-6990849

RESUMEN

Cells isolated from rat and bovine brain were analyzed on a two-parameter, flowing, cell-sorting system. All preparations of rat neurons and bovine oligodendroglia were found to transverse the flowing system intact. Rat neurons were successfully maintained in culture medium for several days after passage through the sorter. With the use of low-angle light-scatter measurements, bovine oligodendroglial populations which had been maintained in culture medium for several days were sorted into two cell populations: phase-bright cells, which exhibited bright fluorescence after incubating with fluoresceindiacetate, and phase-dark cells, which were dark in fluorescence. In addition, morphologically heterogeneous rat neuron populations were separated into relatively homogeneous subpopulations. Bovine oligodendroglia and rat neurons exhibited autofluorescence which appears to be related to the flavoproteins within the cells. The autofluorescence of neurons increased dramatically during the first few days of maintenance and approached a plateau after four to five days. An enriched population of oligodendroglia was obtained from mixed cell populations of rat brain.


Asunto(s)
Encéfalo/citología , Separación Celular/métodos , Técnicas Citológicas , Neuroglía/citología , Neuronas/citología , Oligodendroglía/citología , Animales , Bovinos , Separación Celular/instrumentación , Frío , Fluorescencia , Luz , Ratas , Dispersión de Radiación
17.
Biochem Biophys Res Commun ; 155(3): 1271-7, 1988 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-3178808

RESUMEN

Adenosine 3'-phosphate 5'-phosphosulfate (PAPS), the "active" sulfate donor for sulfated macromolecules, is synthesized in the cytosolic fraction of rat brains. This molecule is then translocated into the lumen of the Golgi apparatus so that it is available to the sulfotransferase enzymes. The protein responsible for the PAPS translocating activity has been solubilized from vesicles enriched in enzyme markers for the Golgi apparatus and reconstituted into liposomes. In reconstituted liposomes translocating activity has a pH optimum of 7.0 and activity was increased 3-fold by divalent cations, although EDTA produced no inhibition. The affinity of the reconstituted translocator for PAPS showed a Km of 1.2 mM with a Vmax of 14 pmol of PAPS translocated/min/mg of protein. Specificity of the translocator activity was tested with a number of nucleotide analogues and only 3',5'-adenosine diphosphate was a competitive inhibitor. Inhibitors of the mitochondrial ADP/ATP transporter and the red cell anion channel blocked transport of PAPS only at very high concentrations.


Asunto(s)
Encéfalo/enzimología , Proteínas Portadoras/metabolismo , Animales , Encéfalo/citología , Aparato de Golgi/enzimología , Concentración de Iones de Hidrógeno , Cinética , Liposomas , Fosfoadenosina Fosfosulfato/biosíntesis , Ratas , Ratas Endogámicas , Especificidad por Sustrato , Sulfotransferasas/metabolismo
18.
Strahlenther Onkol ; 175(11): 563-8, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10584127

RESUMEN

BACKGROUND: Preclinical and clinical trials demonstrated the antiproliferative and chemopreventive potential of 13-cis retinoic acid in combination with interferon-alpha. The present study was designed to determine the radiosensitizing potential of both drugs after single and combined treatment of human squamous-cell carcinoma cells of the oral cavity in vitro. MATERIAL AND METHODS: The study was performed using the human squamous-cell carcinoma cell line SCC4, which was originally established from a tumor of the oral cavity. Based on clonogenic assays, the inhibition of clonogenic activity and radiosensitizing potential of 13-cis retinoic acid and interferon-alpha after single or combined treatment without and with subsequent irradiation was determined. RESULTS: 13-cis retinoic acid (10 microM) and interferon-alpha (50 IU/ml) showed significant inhibition of clonogenic activity after single treatment. A combined treatment protocol resulted at least in a highly significant additive inhibition of clonogenicity. Treatment with both drugs (5 microM 13-cis retinoic acid, 25 IU/ml IFN-alpha) prior and post irradiation of the cells resulted in a pronounced enhancement of radiation toxicity resulting in significantly decreased SF2- and alpha-values. Combined treatment with both drugs was significantly more effective than single drug treatment. CONCLUSIONS: The data presented indicate that pre- and post-irradiation treatment with 13-cis retinoic acid and interferon-alpha significantly enhance the radiosensitivity of human squamous-cell carcinoma cells, SCC4, in vitro. Therefore, they support the initiation of clinical trials to test the radio-oncological value of such a treatment regime for squamous-cell carcinomas.


Asunto(s)
Antineoplásicos/uso terapéutico , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/radioterapia , Interferón-alfa/uso terapéutico , Isotretinoína/uso terapéutico , Neoplasias de la Boca/tratamiento farmacológico , Neoplasias de la Boca/radioterapia , Fármacos Sensibilizantes a Radiaciones/uso terapéutico , Antineoplásicos/administración & dosificación , Supervivencia Celular , Quimioterapia Adyuvante , Terapia Combinada , Medios de Cultivo , Interpretación Estadística de Datos , Relación Dosis-Respuesta a Droga , Relación Dosis-Respuesta en la Radiación , Combinación de Medicamentos , Humanos , Interferón-alfa/administración & dosificación , Isotretinoína/administración & dosificación , Fármacos Sensibilizantes a Radiaciones/administración & dosificación , Dosificación Radioterapéutica , Factores de Tiempo , Células Tumorales Cultivadas , Ensayo de Tumor de Célula Madre
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