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1.
Klin Padiatr ; 225(6): 357-61, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24166093

RESUMEN

Since 2007, children and adolescents with Hodgkin lymphomas are treated in the Europe-wide EuroNet-PHL trials. A real time central review process for stratification of the patients enhances quality control and efficient therapy management. This process includes reading of all cross-sectional-images. Since reference evaluation is time critical, a fast, easy to handle and safe data transfer is important. In addition, immediate and constant access to all the data has to be guaranteed in case of queries and for regulatory reasons. To meet the mentioned requirements the EuroNet Paediatric Hodgkin Data Network (funded by the European Union - Project Number: 2007108) was established between 2008 and 2011. A respective tailored data protection plan was formulated. The aim of this article is to describe the networks' mode of operation and the advantages for multi-centre trials that include centralized image review.


Asunto(s)
Ensayos Clínicos como Asunto/estadística & datos numéricos , Redes de Comunicación de Computadores/organización & administración , Sistemas de Administración de Bases de Datos/organización & administración , Diagnóstico por Imagen , Unión Europea , Enfermedad de Hodgkin/terapia , Estudios Multicéntricos como Asunto/estadística & datos numéricos , Sistemas de Información Radiológica/organización & administración , Adolescente , Niño , Seguridad Computacional , Recolección de Datos , Europa (Continente) , Humanos , Control de Calidad
2.
Oper Orthop Traumatol ; 23(2): 121-30, 2011 Apr.
Artículo en Alemán | MEDLINE | ID: mdl-21541729

RESUMEN

OBJECTIVE: Treatment of adult instable drop foot by modified Lambrinudi arthrodesis (removal of a wedge between the talus and calcaneus), followed by a posterior tibial tendon transfer to the medial cuneiform in order to provide active dorsiflexion. INDICATIONS: Severe drop foot (of various etiologies) in combination with hindfoot instability. Sufficient function of the posterior tibial muscle. CONTRAINDICATIONS: Neurologic dysfunction of the posterior tibial muscle, infection of foot/hindfoot, Charcot arthropathy, and insufficient patient compliance. RELATIVE CONTRAINDICATIONS: Previous surgery of posterior tibial tendon, critical soft tissues/skin conditions, insufficient neurovascular conditions. SURGICAL TECHNIQUE: Lateral skin incision. Debridement of sinus tarsi and removal of the bifurcate ligament to expose the subtalar, calcaneocuboidal, and talonavicular joints. Resection of a bone wedge from the calcaneus and talus (25-30°) to correct the drop foot deformity. Cartilage removal from the calcaneocuboid joint. Debridement of both the talar head and the navicular to allow adequate fitting. After reduction (neutral dorsiflexion and 10° foot abduction), preliminary fixation with Kirschner wires. Final fixation with canulated screws (talonavicular, calcaneocuboidal, and subtalar joints). Medial skin incision at the navicular tuberositas to deattach the posterior tibial tendon with a bony fragment. The tendon stump is harvested 10 cm proximal to the tibiotalar joint. Small skin incision at the anterolateral aspect of the distal lower leg. The posterior tibial tendon is transferred through the interosseous membrane and reattached to the medial cuneiform with a screw. POSTOPERATIVE MANAGEMENT: Immobilization with a removable short leg cast for 2-4 days. Ambulation with full weightbearing in a cast for 8 weeks. Radiographic assessment 8 weeks postoperatively. After bony healing, mobilization in normal shoes is allowed. Intensive physiotherapy to train the dorsiflexion. RESULTS: The average correction of drop foot deformity was 18.7°. Active dorsiflexion increased significantly from 30° preoperatively to 10° postoperatively.


Asunto(s)
Artrodesis/métodos , Trastornos Neurológicos de la Marcha/cirugía , Neuropatías Peroneas/cirugía , Transferencia Tendinosa/métodos , Adulto , Anciano , Anciano de 80 o más Años , Tornillos Óseos , Hilos Ortopédicos , Calcáneo/cirugía , Femenino , Estudios de Seguimiento , Deformidades Adquiridas del Pie/cirugía , Humanos , Inestabilidad de la Articulación/cirugía , Masculino , Persona de Mediana Edad , Cuidados Posoperatorios , Complicaciones Posoperatorias/etiología , Rango del Movimiento Articular , Astrágalo/cirugía , Huesos Tarsianos/cirugía
3.
Haemophilia ; 16(4): 647-55, 2010 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-20331757

RESUMEN

The standard treatment for end-stage osteoarthritis of the ankle joint in haemophilic patients has been fusion of the ankle joint. Total ankle replacement is still controversial as a treatment option. The objective of this prospective study was to evaluate the mid-term outcome in patients treated with total ankle replacement using an unconstrained three-component ankle implant. Ten haemophilic ankles in eight patients (mean age: 43.2 years, range 26.7-57.5) treated with total ankle replacement were followed up for a minimum of 2.7 years (mean: 5.6, range 2.7-7.6). The outcome was measured with clinical and radiological evaluations. There were no intra- or peri-operative complications. The AOFAS-hindfoot-score increased from 38 (range 8-57) preoperatively to 81 (range 69-95) postoperatively. All patients were satisfied with the results. Four patients became pain free; in the whole patient cohort pain level decreased from 7.1 (range 4-9) preoperatively to 0.8 (range 0-3) postoperatively. All categories of SF-36 score showed significant improvements in quality of life. In one patient, open ankle arthrolysis was performed because of painful arthrofibrosis. For patients with haemophilic osteoarthritis of the ankle joint, total ankle replacement is a valuable alternative treatment to ankle fusion.


Asunto(s)
Articulación del Tobillo/cirugía , Artroplastia de Reemplazo , Hemartrosis/cirugía , Hemofilia A/complicaciones , Prótesis Articulares , Adulto , Articulación del Tobillo/diagnóstico por imagen , Artroplastia de Reemplazo/métodos , Factor VIII/uso terapéutico , Femenino , Hemartrosis/tratamiento farmacológico , Hemofilia A/tratamiento farmacológico , Humanos , Masculino , Persona de Mediana Edad , Satisfacción del Paciente , Estudios Prospectivos , Radiografía , Proteínas Recombinantes/uso terapéutico
4.
J Phys Chem B ; 113(22): 7780-4, 2009 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-19425581

RESUMEN

This paper investigates volume fraction phi and specific surface area s for statistically homogeneous systems of partially penetrating spheres, i.e. so-called 'cherry-pit models'. In contrast to the version where the pits form an equilibrium system of hard spheres, here pits or hard spheres are considered which are packed, can be in direct contact, and form a nonequilibrium distribution. For this kind of system, new formulas for phi and s are given, which yield values in good agreement with the ones for large models constructed from hard sphere packings generated both experimentally and numerically. Surprisingly, the existing formulas for phi and s in the equilibrium cherry-pit model lead to values which deviate substantially from the values obtained here.

5.
Opt Express ; 16(26): 21339-54, 2008 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-19104564

RESUMEN

A new Mueller matrix polarimeter was used to image the retinas of normal subjects. Light from a linearly polarized 780 nm laser was passed through a system of variable retarders and scanned across the retina. Light returned from the eye passed through a second system of retarders and a polarizing beamsplitter to two confocal detection channels. Optimization of the polarimetric data reduction matrix was via a condition number metric. The accuracy and repeatability of polarization parameter measurements were within +/- 5%. The magnitudes and orientations of retardance and diattenuation, plus depolarization, were measured over 15 degrees of retina for 15 normal eyes.


Asunto(s)
Técnicas de Diagnóstico Oftalmológico , Óptica y Fotónica , Retina/anatomía & histología , Retina/fisiología , Visión Ocular , Algoritmos , Calibración , Diagnóstico por Imagen/métodos , Diseño de Equipo , Humanos , Luz , Microscopía de Polarización/métodos , Modelos Estadísticos , Fenómenos Fisiológicos Oculares , Nervio Óptico/anatomía & histología , Reproducibilidad de los Resultados
6.
Orthopade ; 36(3): 265-8, 270-2, 2007 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-17262181

RESUMEN

BACKGROUND: In the constantly evolving, increasingly important field of foot surgery, the question arises as to whether the incision types currently in use are adequate. Whether Langer's lines should be considered during the operative approach to the foot is examined here. The goal of the current study was to investigate the pattern of skin cleavage lines of cadaveric feet and to establish the optimal incision type for surgical approaches to the foot. MATERIALS AND METHODS: Twelve feet from older deceased subjects were examined. The samples were fixed. The cleavage lines of the individual skin regions were outlined and evaluated. To emphasize the significance of the investigative findings, the cleavage lines and the current, relevant operative approaches were compared. RESULTS: Standard current approaches often ignore skin cleavage lines, understandably resulting in cosmetically unsatisfactory scars. A chart with ideal incision types for individual operations was created. CONCLUSION: The ideal incision should run parallel to skin cleavage lines. If this is not completely possible due to operative requirements, then at least a large part of the incision should follow these lines.


Asunto(s)
Procedimientos Quirúrgicos Dermatologicos , Pie/anatomía & histología , Pie/cirugía , Procedimientos Ortopédicos/métodos , Piel/anatomía & histología , Adulto , Anciano , Anciano de 80 o más Años , Antropometría , Femenino , Humanos , Técnicas In Vitro , Masculino , Persona de Mediana Edad
7.
Eye (Lond) ; 21(3): 353-61, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16397620

RESUMEN

PURPOSE: To investigate the relationship between visual acuity and foveal birefringence in patients with neovascular age-related macular degeneration. METHODS: In total, 40 patients with choroidal neovascularization underwent macular imaging with scanning laser polarimetry. Bowtie patterns, typically seen in birefringence images of the macula, were evaluated and classified into three categories: (1) regular bowtie present; (2) bowtie present, but disrupted; and (3) no bowtie present. The relation of the bowtie appearance to the best-corrected logMAR visual acuities was tested (ANOVA). RESULTS: Mean visual acuity was best for the group that had regular bowties (mean logMAR=0.34) and differed statistically significantly from the disrupted bowtie group and no bowtie group (P=0.01 and 0.0007). Ages for the three groups did not differ (P=0.31). CONCLUSIONS: Appearance of a regular bowtie indicates a substantially intact Henle fibre layer with the potential for good visual function, despite the presence of underlying pathology. Conversely, disruption or absence of a bowtie may indicate severe damage to the photoreceptors, consistent with the finding of poorer visual acuity.


Asunto(s)
Neovascularización Coroidal/fisiopatología , Fóvea Central/fisiopatología , Degeneración Macular/fisiopatología , Agudeza Visual/fisiología , Anciano , Birrefringencia , Neovascularización Coroidal/complicaciones , Estudios de Cohortes , Técnicas de Diagnóstico Oftalmológico , Femenino , Angiografía con Fluoresceína/métodos , Humanos , Rayos Láser , Degeneración Macular/complicaciones , Masculino , Persona de Mediana Edad
8.
Dement Geriatr Cogn Disord ; 19(5-6): 349-56, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15802909

RESUMEN

OBJECTIVE: To study awareness of cognitive dysfunction in patients with very mild Alzheimer's disease (AD) and subjects with mild cognitive impairment (MCI). METHODS: A complaint interview covering 13 cognitive domains was administered to 82 AD and 79 MCI patients and their caregivers. The patient groups were comparable according to age and education, and Mini Mental State Examination (MMSE) scores were > or =24 in all cases. The discrepancy between the patients' and caregivers' estimations of impairments was taken as a measure of anosognosia. RESULTS: Self-reports of cognitive difficulties were comparable for AD and MCI patients. However, while in comparison to caregivers MCI patients reported significantly more cognitive impairment (p < 0.05), AD patients complained significantly less cognitive dysfunctions (p < 0.001). CONCLUSIONS: While most MCI patients tend to overestimate cognitive deficits when compared to their caregiver's assessment, AD patients in early stages of disease underestimate cognitive dysfunctions. Anosognosia can thus be regarded as a characteristic symptom at a stage of very mild AD (MMSE > or =24) but not MCI. Accordingly, medical history even in mildly affected patients should always include information from both patient and caregiver.


Asunto(s)
Agnosia/diagnóstico , Enfermedad de Alzheimer/diagnóstico , Trastornos del Conocimiento/diagnóstico , Índice de Severidad de la Enfermedad , Anciano , Anciano de 80 o más Años , Agnosia/etiología , Enfermedad de Alzheimer/complicaciones , Trastornos del Conocimiento/complicaciones , Femenino , Humanos , Masculino , Anamnesis , Persona de Mediana Edad , Análisis de Regresión
9.
Br J Ophthalmol ; 89(4): 464-9, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15774925

RESUMEN

BACKGROUND/AIM: The loss of short wavelength sensitive (SWS) cone mechanism sensitivity is related to severe vision loss in patients with age related maculopathy (ARM). A case-control study of patients with ARM and age matched controls was performed, using blue on yellow static perimetry. METHODS: A bright yellow background at 594 nm isolated the responses of short wavelength cone mechanisms to 458 nm targets. A scanning laser ophthalmoscope produced stimuli and provided real time, simultaneous fundus illumination. The macula was probed with 16 Goldmann IV targets, 1-10 degrees from fixation, using a staircase method. RESULTS: 24 patients with non-exudative ARM were matched to 24 subjects with normal fundus appearance. SWS cone pathway sensitivity for macular targets was significantly reduced in the patients with ARM compared to normals--15.45 (SD 4.56) dB v 17.22 (0.28) dB, respectively (p<0.0005). There was not only a diffuse loss of sensitivity in ARM patients, but also a localised loss of sensitivity over drusen (p<0.025). Neither the mean age, 69 (8) years, nor the mean visual acuity differed between groups, logMAR 0.09 (0.10) v 0.05 (0.06) for ARM patients v normals, respectively. Patients with soft drusen had lower sensitivity than those with hard drusen (p<0.05). CONCLUSION: A loss of SWS cone pathway sensitivity occurred in most patients with early ARM, despite good visual acuity, demonstrating a loss of visual function that cannot be attributed to ageing changes. The loss of sensitivity, despite good visual acuity, included both a diffuse loss and localised losses.


Asunto(s)
Defectos de la Visión Cromática/diagnóstico , Degeneración Macular/diagnóstico , Células Fotorreceptoras Retinianas Conos/fisiopatología , Pruebas del Campo Visual/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento/fisiología , Estudios de Casos y Controles , Niño , Defectos de la Visión Cromática/etiología , Defectos de la Visión Cromática/fisiopatología , Femenino , Humanos , Rayos Láser , Degeneración Macular/fisiopatología , Degeneración Macular/psicología , Masculino , Persona de Mediana Edad , Oftalmoscopía/métodos , Agudeza Visual
10.
J Anim Sci ; 83(4): 833-41, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15753338

RESUMEN

An experiment was conducted to examine the response to wheat gluten (WG)-based diets at two lysine levels in adult minipigs (23 kg BW) using the indicator AA oxidation (IAAO) approach and N balance. Twenty minipigs (n = five per group), fitted with reentrant ileoileal cannulas allowing collection of ileal effluents, were fed restrictively two WG-based diets (WG and WG + Lys; 2.7 and 6.6 g of lysine/kg, respectively) for adaptation periods of 10 and 100 d. On d 7 and 9, for pigs fed the diets for 10 d, and on d 97 and 99, for pigs fed the diets for 100 d, primed i.v. fasted/fed tracer protocols with [(13)C]bicarbonate, and [(13)C]leucine were performed. With the WG diet, [(13)C]bicarbonate recoveries (%) were lower irrespective of the adaptation period, and higher during the fed period (fasted: WG + Lys = 82.5, and WG = 69.1; fed: WG + Lys = 90.6, and WG = 85.9; P < 0.05). Leucine oxidation rate was higher with the lower lysine intake (WG = 194.6 vs. 109.5 mg/[kg BW x d]; P < 0.05). Wheat gluten feeding resulted in a negative leucine balance independent of the adaptation period (WG = -29.1, and WG + Lys = 48.2 mg/[kg BW x d]; P < 0.05). In contrast with the IAAO method, N balance did not differ between the two lysine intakes, possibly because of an underestimation of N losses. The finding of a lower (13)C bicarbonate recovery with the lower dietary lysine intake suggests that caution should be taken in using a single recovery factor for all AA oxidation studies.


Asunto(s)
Dieta , Glútenes/administración & dosificación , Lisina/administración & dosificación , Lisina/metabolismo , Oxidación-Reducción/efectos de los fármacos , Animales , Bicarbonatos/metabolismo , Radioisótopos de Carbono , Ayuno/fisiología , Leucina/metabolismo , Lisina/sangre , Masculino , Nitrógeno/metabolismo , Trazadores Radiactivos , Porcinos , Porcinos Enanos , Factores de Tiempo , Triticum
11.
Br J Ophthalmol ; 85(12): 1432-6, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11734515

RESUMEN

BACKGROUND/AIMS: Previous studies reported the predictive value of the short wavelength sensitive (SWS) cone mediated sensitivity for visual outcome in age related macular degeneration. In this study SWS sensitivity was measured by commercially available blue on yellow perimetry in patients with non-exudative age related maculopathy (ARM) and compared with the presence of morphological risk factors and the status of the fellow eye. METHODS: In a prospective cross sectional study, 126 patients (57 males, 69 females, mean age 71 (SD 6) years) with ARM (visual acuity >20/50) were tested. Central visual fields (blue on yellow) were obtained with a conventional perimeter. Fundus slides were graded by two independent observers for soft drusen and presence of focal hyperpigmentation. RESULTS: Mean sensitivity and standard deviation of all patients exhibited a significant reduction with age. Patients with soft drusen had significantly lower sensitivity than those without, whereas there were no differences in visual acuity (log MAR). Sensitivity was also reduced in those eyes with fellow eyes having a sight threatening complication of age related macular degeneration (AMD). Eyes with focal hyperpigmentation compared with those without had no loss of sensitivity, but did have a significant decrease in the central part of the field compared with the more eccentric. CONCLUSION: SWS sensitivity loss is associated with common risk factors for progression to AMD. Short wavelength automated perimetry is moderately rapid and readily available. It may serve as a tool in future ARM trials.


Asunto(s)
Degeneración Macular/fisiopatología , Pruebas del Campo Visual/métodos , Campos Visuales , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Estudios Transversales , Progresión de la Enfermedad , Femenino , Humanos , Hiperpigmentación/fisiopatología , Degeneración Macular/diagnóstico , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Drusas Retinianas/fisiopatología , Factores de Riesgo
12.
J Opt Soc Am A Opt Image Sci Vis ; 18(7): 1425-36, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11444532

RESUMEN

The sensitivity of short-wavelength-sensitive (SWS) cone pathways was measured in the central fields of 74 normal subjects, aged 17-86 yr, with healthy maculas. The new fundus perimetry technique used a research scanning laser ophthalmoscope with a small entrance pupil to present blue static perimetry targets on a bright yellow background. Simultaneous infrared imaging aided target positioning and rapid assessment of potential pathology in elderly subjects. Targets were positioned peripheral to fixation, avoiding both the SWS-cone-free area and the peak macular pigment, determined in 11 subjects. Sensitivity declined 0.019 log unit per decade, while intraindividual variability across loci increased. The nasal-temporal asymmetry remained constant. Sensitivity of older subjects was relatively less for the most central targets but was unrelated to transmission through macular pigment. Retinal changes with age occur to differing extents or at differing rates and are readily detectable in the central macula.


Asunto(s)
Envejecimiento/fisiología , Rayos Láser , Mácula Lútea/patología , Mácula Lútea/fisiopatología , Oftalmoscopía , Pruebas del Campo Visual/instrumentación , Pruebas del Campo Visual/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Color , Femenino , Fijación Ocular , Humanos , Masculino , Persona de Mediana Edad , Valores de Referencia , Pigmentos Retinianos/fisiología , Sensibilidad y Especificidad , Campos Visuales
13.
Int Ophthalmol ; 23(4-6): 245-50, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11944848

RESUMEN

PURPOSE: to use a novel technique, Multiply Scattered Light Tomography (MSLT), to provide a comfortable, rapid, and noninvasive method for detection and management of Age-related Macualar Degeneration. METHODS: two patient groups were studied in clinical settings with MSLT and confocal scanning laser tomography. In Poway, CA, 21 retinal patients underwent tomography, and the 17 patients with suspicion of exudation also had ICG. An Angio-Scan (Laser Diagnostic Technologies, Inc.) was used to provide simultaneous fundus reflectance and ICG imaging. In Methuen, MA, 20 retinal patients underwent tomography with fluorescein angiography for suspicion of exudation. The MSLT was based on the TopSS (Laser Diagnostic Technologies, Inc.), with a Vertical Cavity Surface Emitting Laser array at 850 mm as the illumination source. The central laser produced confocal images. The surrounding lasers produced multiply scattered light images. RESULTS: MSLT emphasized structures beneath the retina such as drusen, choroidal new vessel membranes, and pigment epithelial detachments. Exudation seen on angiography was visualized by MSLT as topographical structures with distinct borders. Superficial structures, e.g., cysts and epiretinal membranes, were visualized in 850 nm images. DISCUSSION: confocal tomography and MSLT provided a rapid, noninvasive method to detect and localize macular degeneration and pathological structures found in eyes of older patients.


Asunto(s)
Técnicas de Diagnóstico Oftalmológico , Degeneración Macular/diagnóstico , Adulto , Anciano , Coroides/irrigación sanguínea , Neovascularización Coroidal/diagnóstico , Colorantes , Angiografía con Fluoresceína , Humanos , Verde de Indocianina , Luz , Microscopía Confocal , Persona de Mediana Edad , Dispersión de Radiación , Tomografía
14.
Opt Express ; 9(9): 436-43, 2001 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-19424361

RESUMEN

The ability of confocal scanning laser tomography to quantify the subretinal features was investigated. The slope ratios (anterior slope/posterior slope) of the axial intensity profiles were analyzed. The data fromnormal subjects showed only minimal influence of individual ocular pigmentation. In the eyes with agerelated macular degeneration, the light-tissue interactions vary according to the type of retinal features. Three-dimensional information could be obtained from the axial intensity profiles.

15.
J Nutr ; 130(12): 2889-96, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11110842

RESUMEN

The maximum dietary protein intake that does not cause adverse effects in a healthy population is uncertain. We tested whether a high protein intake enhances oxidative stress. Adult rats were adapted to different casein-based diets containing either an adequate (13.8%; AP), medium (25.7%; MP), or high (51.3%; HP) level of crude protein; a fourth group received a HP diet but no RRR-alpha-tocopherol acetate (HP-toc). After 15 wk of feeding, plasma protein carbonyl concentration, liver lipid peroxide levels [thiobarbituric acid-reacting substances (TBARS)], reduced glutathione (GSH) status and leucine kinetics ([1-(13)C]leucine) were measured. Higher concentrations of protein carbonyls and TBARS were found in rats fed the AP and the HP-toc diets compared with those fed the MP and HP diets (P: < 0.05). GSH concentrations in plasma did not differ but total blood GSH concentrations were significantly (P: < 0.05) lower in rats fed the HP-toc diet compared with those fed the AP, MP and HP diets. Liver GSH concentrations were significantly (P: < 0.01) lower in rats fed the AP diet compared with the other groups. Rates of postabsorptive leucine oxidation (LeuOX) and flux (Q(Leu)) were positively correlated with the dietary protein level (for AP, MP, and HP, respectively: LeuOX, 74.9 +/- 28.5, 109 +/- 35.2, 142.3 +/- 38.4 micromol/(kg. h); Q(Leu), 425 +/- 102, 483 +/- 82, 505 +/- 80 micromol/(kg. h). Only HP-toc resulted in a significantly greater protein breakdown (PB(Leu)) and Q(Leu). No difference was seen in nonoxidative leucine disposal. Long-term intake of high protein diets did not increase variables of oxidative stress, in contrast to our initial hypothesis. An unexpected finding was that adequate protein feeding (AP) may in fact induce oxidative stress.


Asunto(s)
Adaptación Fisiológica , Proteínas en la Dieta/administración & dosificación , Estrés Oxidativo , Aminoácidos/sangre , Aminoácidos/metabolismo , Animales , Caseínas/administración & dosificación , Proteínas en la Dieta/efectos adversos , Glutatión/análisis , Leucina/análisis , Masculino , Ratas , Ratas Wistar , Sustancias Reactivas al Ácido Tiobarbitúrico/análisis , Vitamina E/administración & dosificación
16.
J Lipid Res ; 41(10): 1543-51, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11013295

RESUMEN

Patients with alpha-tocopherol transfer protein (alpha-TTP) defects experience neurological symptoms characteristic of vitamin E deficiency and depend on continuous high alpha-tocopherol supplements. We investigated the excretion of 2,5,7, 8-tetramethyl-2(2'-carboxyethyl)-6-hydroxychroman (alpha-CEHC), a urinary metabolite of alpha-tocopherol, as a putative marker for the alpha-tocopherol status of alpha-TTP-deficient patients and control subjects. In three patients vitamin E supplementation was stopped for short periods of time, during which plasma alpha-tocopherol concentrations and urinary alpha-CEHC excretion were measured. In the patients, plasma alpha-tocopherol decreased below normal (<5 micromol/l) but alpha-CEHC excretion remained above the range of unsupplemented control subjects (0.118-0.306 mg/day, n = 6). In healthy subjects, however, alpha-CEHC excretion was increased only after surpassing a plasma alpha-tocopherol threshold of 30-40 micromol/l. Such a threshold did not exist in patients. The general mechanism of alpha-tocopherol degradation did not appear to differ between patients and control subjects. The presumed mechanism of omega- and subsequent beta-oxidation was supported by the detection of alpha- CPHC, an alpha -CEHC homolog with a side chain longer by 3 carbon atoms, both in supplemented patients and in control subjects.


Asunto(s)
Proteínas Portadoras/genética , Vitamina E/metabolismo , Adolescente , Adulto , Ataxia/genética , Ataxia/metabolismo , Cromanos/química , Cromanos/orina , Suplementos Dietéticos , Femenino , Humanos , Masculino , Espectrometría de Masas , Oxidación-Reducción , Ácidos Pentanoicos/química , Ácidos Pentanoicos/orina , Propionatos/orina , Vitamina E/administración & dosificación , Vitamina E/sangre , Deficiencia de Vitamina E/genética , Deficiencia de Vitamina E/metabolismo
17.
Ophthalmology ; 107(2): 375-85, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10690842

RESUMEN

OBJECTIVE: To perform three-dimensional, noninvasive, quantitative analysis of cystoid macular edema and macular cysts using infrared scanning laser tomography and to correlate findings with visual acuity (VA) as a basis for interventional studies. DESIGN: Cross-sectional, nonrandomized study. PARTICIPANTS: Seventeen patients (29-86 years of age) with macular cysts associated with a broad spectrum of diseases. INTERVENTION: Confocal infrared imaging with scanning laser tomography with the TopSS (790 nm) (Laser Diagnostic Technologies, San Diego, CA) with digitized images was used to perform three-dimensional, quantitative analysis of cysts in the central 5 degrees of the macula. MAIN OUTCOME MEASURES: Measurements of macular cyst number, area, volume, depth, slope, height of the surrounding macular elevation, and correlation with VA. RESULTS: Scanning laser tomography detected macular cysts in all patients. The number per patient ranged from 1 through 15. Cysts were accompanied by surrounding macular elevation in 16 patients (mean macular height, 216 microm). The area covered by cysts in the central 5 degrees was 0.087 to 0.969 mm2, and volume was 0.007 to 0.549 mm3. Visual acuity was significantly poorer in patients with greater cyst area (P = 0.0007), cyst volume (P = 0.0009), macular thickening (P = 0.0002), and cyst depth (P = 0.0013). Cyst number, average slope, and maximum slope, however, did not correlate significantly with VA. Grouping of macular cysts according to macular height and average cyst depth revealed that cysts in a more thickened retina were significantly deeper, had steeper slopes, and corresponded to worse VA. Macular height and average cyst depth were highly associated with each other, suggesting that in eyes with surrounding macular edema, cysts were deeper and may reflect more widespread tissue destruction. Individual confocal tomographic images provided additional information. Neither ophthalmoscopy nor fluorescein angiography delineated features such as retinal folds that suggested vitreous traction or changes in deeper layers that suggested occult choroidal new vessels. CONCLUSIONS: Infrared scanning laser tomography is a rapid and noninvasive imaging method that provides quantitative analysis of macular cysts in addition to qualitative information not seen clinically. Because poor VA is related to severe involvement of the central retina, scanning laser tomography could provide an objective outcome measure for interventional studies.


Asunto(s)
Rayos Láser , Mácula Lútea/patología , Edema Macular/diagnóstico , Tomografía/métodos , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Angiografía con Fluoresceína , Fondo de Ojo , Humanos , Rayos Infrarrojos , Persona de Mediana Edad , Procesamiento de Señales Asistido por Computador , Agudeza Visual
18.
J Lipid Res ; 41(1): 148-54, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10627513

RESUMEN

A method for the direct extraction and routine analysis of the vitamin E metabolites gamma- and alpha-carboxyethyl hydroxychroman (gamma- and alpha-CEHC) from human urine has been developed. A relatively small sample volume (5 ml) can be used and, after enzymatic hydrolysis of the conjugated forms and acidification, the metabolites are extracted with diethyl ether. Recovery of alpha- and gamma-CEHC was compared to that of trolox, used as an internal standard, added to 24-h urine collections from vitamin E-unsupplemented volunteers. Various solvent conditions were initially tested; acidification and ether extraction gave the highest recovery. It was found that after addition and extraction from urine, trolox, alpha- and gamma-CEHC are recovered to a similar extent, hence trolox is viable as an internal standard. The samples were analyzed by both GC and HPLC with electrochemical detection (ECD). HPLC-ECD was found to give higher selectivity and higher sensitivity compared to GC or HPLC with UV detection at 290 nm. The HPLC-ECD detection limit was 10 fmol, linearity (r(2) > 0.98) was achieved in the range of 40 to 200 fmol, which was found to be optimal for 24-h urines from unsupplemented subjects. Inter-sample variability was typically 2-5%. This greater sensitivity and selectivity means that vitamin E metabolites can be analyzed even in unsupplemented subjects. It is also possible to measure unconjugated forms of the metabolites. Typically these were found to represent approximately 10% of the total alpha- and gamma-CEHC. This method can be used routinely for the determination of vitamin E metabolites in urine. The new extraction and detection methods described are relatively quick, less laborious, and more cost-effective than previously available methods.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Vitamina E/orina , Calibración , Cromatografía de Gases , Electroquímica , Humanos , Estándares de Referencia , Sensibilidad y Especificidad
19.
Opt Express ; 6(13): 243-50, 2000 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-19404357

RESUMEN

Measurements of the human ocular fundus that make use of the light returning through the pupil are called reflectometry. Early reflectometry studies were limited by poor light return from the retina and strong reflections from the anterior surface of the eye. Artifacts produced misleading results in diseases like age-related macular degeneration. Novel laser sources, scanning, confocal optics, and digital imaging provide improved sampling of the signal from the tissues of interest: photoreceptors and retinal pigment epithelial cells. A wider range of wavelengths is now compared, including the near infrared. Reflectometry now provides functional mapping, even in severe pathology.

20.
Opt Express ; 7(2): 95-106, 2000 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-19404374

RESUMEN

A novel technique, Multiply Scattered Light Tomography (MSLT), and confocal Infrared Imaging are used to provide diagnostic information using a comfortable, rapid, and noninvasive method. We investigated these techniques in detecting neovascularization in age-related macular degeneration. The MSLT used a Vertical Cavity Surface Emitting Laser (VCSEL) at 850 nm, while the confocal imaging technique used either the VCSEL or a 790 nm laser diode. Both were implemented into the topographical scanning system (TopSS, Laser Diagnostic Technologies, Inc.) Confocal imaging with both lasers provided different information about neovascularization as a function of focal plane, and different also from MSLT.

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