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1.
Br J Surg ; 108(6): 644-651, 2021 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-33982068

RESUMEN

BACKGROUND: No effective treatment exists for anterior resection syndrome (ARS) following sphincter-saving surgery for rectal cancer. This RCT assessed the safety and efficacy of a 5-HT3 receptor antagonist, ramosetron, for ARS. METHODS: A single-centre, randomized, controlled, open-label, parallel group trial was conducted. Male patients with ARS 1 month after rectal cancer surgery or ileostomy reversal were enrolled and randomly assigned (1 : 1) to 5 µg of ramosetron (Irribow®) daily or conservative treatment for 4 weeks. Low ARS (LARS) score was calculated after randomization and 4 weeks after treatment. The study was designed as a superiority test with a primary endpoint of the proportion of patients with major LARS between the groups. Primary outcome analysis was based on the modified intention-to-treat population. Safety was assessed by monitoring adverse events during the study. RESULTS: : A total of 100 patients were randomized to the ramosetron (49 patients) or conservative treatment group (51 patients). Two patients were excluded, and 48 and 50 patients were analysed in the ramosetron and control groups, respectively. The proportion of major LARS after 4 weeks was 58 per cent (28 of 48 patients) in the ramosetron group versus 82 per cent (41 of 50 patients) in the control group, with a difference of 23.7 per cent (95 per cent c.i. 5.58 to 39.98, P = 0.011). There were minor adverse events in five patients, which were hard stool, frequent stool or anal pain. These were not different between the two groups. There were no serious adverse events. CONCLUSION: : Ramosetron could be safe and feasible for male patients with ARS. TRIAL REGISTRATION NUMBER: NCT02869984 (http://www.clinicaltrials.gov).


Asunto(s)
Bencimidazoles/uso terapéutico , Proctectomía/efectos adversos , Neoplasias del Recto/cirugía , Antagonistas del Receptor de Serotonina 5-HT3/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Proctectomía/métodos , Recto/cirugía , Síndrome , Resultado del Tratamiento
2.
Orthod Craniofac Res ; 19(2): 102-13, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26898506

RESUMEN

OBJECTIVES: The objective of this study was to compare the biomechanical characteristics between two types of self-ligating brackets and conventional metal brackets using finite element analysis of a vertically displaced canine model focusing on the desired force on the canine and undesirable forces on adjacent teeth. MATERIALS AND METHODS: Three-dimensional finite element models of the maxillary dentition with 1-mm, 2-mm, and 3-mm vertically displaced canines were constructed. Two different self-ligating brackets (In-Ovation C and Smart clip) and a conventional metal bracket (Micro-arch) were modeled. After a 0.016-inch NiTi (0.40 mm, round) wire was engaged, the displacement of each tooth was calculated using x-, y-, and z-coordinates, and the tensile and compressive stresses were calculated. RESULTS: The extrusion and maximal tensile stress of the canine differed little between the three brackets, but the intrusion and minimal compressive stress values of the adjacent teeth differed considerably and were highest in the Smart clip and least in the In-Ovation C. The extrusion and maximal tensile stress of the canine in the 3-mm displacement model was less than that in the 2-mm displacement model, and the intrusion and minimal compressive stress of the adjacent teeth increased with the degree of displacement. CONCLUSIONS: Self-ligating brackets were not superior to conventional brackets in leveling a vertically displaced canine. A continuous arch wire may not be recommended for leveling of severely displaced canines whether using self-ligating or conventional brackets.


Asunto(s)
Análisis de Elementos Finitos , Soportes Ortodóncicos , Aleaciones Dentales , Análisis del Estrés Dental , Humanos , Diseño de Aparato Ortodóncico , Alambres para Ortodoncia
3.
Iran J Vet Res ; 24(3): 242-246, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38269008

RESUMEN

Background: With the increasing use of cementless total hip arthroplasty (THA), stem subsidence has emerged as one of the primary complications. Although electron beam melting (EBM)-manufactured stems have been demonstrated to prevent subsidence, there has been limited investigation into the comparative biomechanical impact of collarless and collared EBM cementless stems on stem subsidence in veterinary medicine. Aims: This study aimed to compare the stem implant resistance and failure mechanical properties between collarless and collared EBM-manufactured stems. Methods: Seven pairs of femurs were harvested from canine cadavers. In each pair of femurs, the left femur was implanted with a collarless, and the right femur with a same-sized collared cementless stem. Specimen constructs were mounted to the loading frame of a testing machine and load was transferred to the femoral stem parallel to the longitudinal axis of the femur until the stem subsided 5 mm. Load and stem displacement data acquired during the tests were used to generate load-displacement curves and obtain stiffness, yield, and failure data for each specimen construct. Yield and failure energies were calculated as the areas under the load-displacement curves to the respective points. The effects of implant type and load during subsidence were analyzed using paired t-tests. Results: The yield and failure loads for the collared stems were approximately 40% greater than for the collarless stems (156.39 ± 43.63 kgf vs. 112.01 ± 59.83 kgf, P<0.05). Conclusion: This study supported the advantages of collared EBM stems, including subsidence prevention and better initial stability for early osteointegration.

4.
J Nanosci Nanotechnol ; 11(7): 5769-74, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22121605

RESUMEN

In this paper, the heat transfer characteristics and pressure drop of the ZnO and Al2O3 nanofluids in a plate heat exchanger were studied. The experimental conditions were 100-500 Reynolds number and the respective volumetric flow rates. The working temperature of the heat exchanger was within 20-40 degrees C. The measured thermophysical properties, such as thermal conductivity and kinematic viscosity, were applied to the calculation of the convective heat transfer coefficient of the plate heat exchanger employing the ZnO and Al2O3 nanofluids made through a two-step method. According to the Reynolds number, the overall heat transfer coefficient for 6 vol% Al2O3 increased to 30% because at the given viscosity and density of the nanofluids, they did not have the same flow rates. At a given volumetric flow rate, however, the performance did not improve. After the nanofluids were placed in the plate heat exchanger, the experimental results pertaining to nanofluid efficiency seemed inauspicious.

5.
J Nanosci Nanotechnol ; 10(5): 3435-9, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20358973

RESUMEN

Scanning electron microscopy (SEM) images and transmission electron microscopy (TEM) images showed that the one-dimensional GaN nanorods were formed on Al2O3 (0001) substrates by using hydride vapor phase epitaxy without a catalyst. Selected area electron diffraction (SAED) pattern and high-resolution TEM (HRTEM) results showed that GaN nanorods grown on Al2O3 (0001) substrates had crystalline wurzite structures and (0001) preferential orientation. The morphologies of GaN nanorods were affected by the flow rates of the source materials. The orientational relationships between the GaN nanorods and the Al2O3 substrates were (0001)GaN perpendicular (0001) Al2O3 and [0110]GaN perpendicular [1120] Al2O3. Cross-sectional and plan-view atomic arrangements of the fully relaxed interfacial region are described on the basis of the TEM, the SAED pattern, and the HRTEM results.

6.
J Anat ; 213(6): 733-42, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19094189

RESUMEN

This study provides a model of the complex deltoid origin and end tendons, as a basis for further anatomical, biomechanical and clinical research. Although the deltoid is used in transpositions with upper limb paralysis, its detailed morphology and segmentation has not been object of much study. Morphologically, the deltoid faces two distinct challenges. It closely envelops a ball joint, and it reduces its width over a short distance from a very wide origin along clavicle, acromion and spina scapula, to an insertion as narrow as the humerus. These challenges necessitate specific morphological tendon adaptations. A qualitative model for these tendons is developed by the stepwise transformation of a unipennate muscle model into a functional deltoid muscle. Each step is the solution to one of the mentioned morphological challenges. The final model is of an end tendon consisting of a continuous succession of bipennate end tendon blades centrally interspaced by unipennate tendon parts. The origin tendon consists of lamellae that interdigitate with the end tendon blades, creating a natural segmentation. The model is illustrated by qualitative dissection results. In addition, in view of a proliferation of terms found in the literature to describe deltoid tendons, tendon concepts are reviewed and the systematic use of the unique and simple terminology of 'origin and end tendons' is proposed.


Asunto(s)
Modelos Anatómicos , Músculo Esquelético/anatomía & histología , Hombro , Tendones/anatomía & histología , Anciano , Anciano de 80 o más Años , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Persona de Mediana Edad
7.
J Neurol Neurosurg Psychiatry ; 79(11): 1295-7, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18940992

RESUMEN

Kernohan's notch phenomenon is the ipsilateral hemiplegia caused by compression of the contralateral cerebral peduncle against the tentorial edge by a supratentorial mass. Diffusion tensor imaging (DTI) and transcranial magnetic stimulation (TMS) could be useful for exploring the state of the corticospinal tract (CST). This report attempts to demonstrate Kernohan's notch phenomenon in a patient with subdural haematoma by using DTI and TMS. One patient and six normal control subjects were recruited. The patient showed severe right hemiplegia even though the subdural haematoma was located in the right hemisphere. Brain CT at the time of onset showed right transtentorial herniation, and T2 weighted images at 6 weeks after onset showed a leucomalacic lesion on the left cerebral peduncle. DTI and TMS were performed at 6 weeks after onset. The fractional anisotrophy value of the left midbrain and medulla of the patient was found to be decreased in comparison with that of the control subjects. On fibre tractography for the CST, an interruption was observed in the left midbrain and medulla. The motor evoked potential obtained from the right hand muscle showed delayed latency, low amplitude and a higher excitatory threshold, thus indicating that the CST of the left hemisphere had been damaged. It seems that the CST had been damaged at the left midbrain, although subdural haematoma and transtentorial herniation had occurred in the right hemisphere in this patient. This report demonstrates Kernohan's notch phenomenon in this patient using DTI and TMS.


Asunto(s)
Imagen de Difusión por Resonancia Magnética , Hematoma Subdural/diagnóstico , Hemiplejía/etiología , Estimulación Magnética Transcraneal/métodos , Anciano , Anisotropía , Encefalocele/patología , Potenciales Evocados Motores/fisiología , Femenino , Hematoma Subdural/complicaciones , Hemiplejía/diagnóstico , Humanos , Imagen por Resonancia Magnética , Masculino , Mesencéfalo/patología , Persona de Mediana Edad , Tomografía Computarizada por Rayos X
8.
Int J Tuberc Lung Dis ; 22(9): 1031-1036, 2018 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-30092868

RESUMEN

SETTING: Nursery for newborns in Busan, Republic of Korea. OBJECTIVE: To evaluate tuberculosis (TB) transmission from a health care worker with active pulmonary TB to neonatal contacts. DESIGN: For the first investigation, infants who had been in the nursery 3 months before the index patient was diagnosed with pulmonary TB were enrolled. After a child who had stayed in the nursery 10 months before the diagnosis of the index patient was diagnosed with tuberculous meningitis, a second contact investigation was conducted. RESULTS: Respectively 315 and 1334 children participated in the first and second investigations. The mean age of the contacts was 66.3 days; the rate of latent tuberculous infection (LTBI) at the first investigation was 42.5% (134/315). Only one infant had an abnormal chest X-ray, and was thought to have pulmonary TB. In the second investigation, the mean age of the participants was 17.6 months. The proportion of children with LTBI was 18.7% (249/1334). CONCLUSIONS: The LTBI rate in the present study was much higher than that estimated from other contact investigations. To minimise the risk of nosocomial TB transmission to neonates, screening and management of TB in health care workers should be strengthened.


Asunto(s)
Infección Hospitalaria/transmisión , Transmisión de Enfermedad Infecciosa de Profesional a Paciente , Salas Cuna en Hospital , Enfermeras y Enfermeros , Tuberculosis Pulmonar/transmisión , Adulto , Trazado de Contacto , Femenino , Humanos , Lactante , Recién Nacido , Tuberculosis Latente/epidemiología , Tuberculosis Latente/transmisión , Masculino , Exposición Profesional/efectos adversos , República de Corea/epidemiología , Factores de Riesgo , Tuberculosis Meníngea/epidemiología , Tuberculosis Meníngea/transmisión , Tuberculosis Pulmonar/epidemiología
9.
Ultrason Sonochem ; 39: 414-419, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28732963

RESUMEN

Colloidal zinc telluride (ZnTe) nanostructures were successfully processed through a simple and facile ultrasonic (sonochemical) treatment for photoelectronic applications. The particle-like morphological features, phase and nature of valence state of various metal ions existing in ZnTe were examined using electron and X-ray photoelectron spectroscopic tools. Raman spectroscopic measurements revealed the dominance of exciton-phonon coupling and occurrence of TeO2 traces in ZnTe through the corresponding vibrations. Optical bandgap of the ZnTe suspension was estimated to be around 2.15eV, authenticating the direct allowed transitions. The p-type electrical conductivity and charge carrier density of ZnTe were additionally estimated from the Bode, Nyquist and Mott-Schottky type impedance plots. The photoelectrical properties of ZnTe were investigated by fabricating p-ZnTe/n-Si heterostructures and studying their corresponding current-voltage characteristics under dark and white light illumination. The diodes revealed excellent rectifying behaviour with significant increase in reverse current under illumination. The stability of the devices were also affirmed through the time-dependent photoresponse characteristics, which actually suggested the improved and effective separation of photo generated electron hole pairs across the integrated heterojunctions. The obtained results also augment the potential of sonochemically processed ZnTe for application in photo detection and sensor related functions.

10.
Ann N Y Acad Sci ; 1049: 118-34, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15965112

RESUMEN

When developing cell transplant strategies to repair the diseased or injured central nervous system (CNS), it is essential to consider host-graft interactions and how they may influence the outcome of the transplants. Recent studies have demonstrated that transplanted neural progenitor cells (NPCs) can differentiate and integrate morphologically into developing mammalian retinas. Is the ability to differentiate and to undergo structural integration into the CNS unique to specific progenitor cells, or is this plasticity a function of host environment, or both? To address these issues we have used the developing retina of the Brazilian opossum and have compared the structural integration of brain and retinal progenitor cells transplanted into the eyes at different developmental stages. The Brazilian opossum, Monodelphis domestica, is a small pouchless marsupial native to South America. This animal's lack of a pouch and fetal-like nature at birth circumvents the need for in utero surgical procedures, and thus provides an ideal environment in which to study the interactions between developing host tissues and transplanted NPCs. To test whether NPCs affect visual function we transplanted adult hippocampal progenitor cells (AHPCs) into normal, healthy adult rat eyes and performed noninvasive functional recordings. Monitoring of the retina and optic nerve over time by electroretinography and pupillometry revealed no severe perturbation in visual function in the transplant recipient eyes. Taken together, our findings suggest that the age of the host environment can strongly influence NPC differentiation and that transplantation of neural progenitor cells may be a useful strategy aimed at treating neurodegeneration and pathology of the CNS.


Asunto(s)
Trasplante de Células , Sistema Nervioso Central/embriología , Sistema Nervioso Central/fisiología , Neuronas/fisiología , Células Madre/fisiología , Animales , Diferenciación Celular , Sistema Nervioso Central/anatomía & histología , Electrorretinografía , Ratones , Neuronas/citología , Zarigüeyas , Fenotipo , Retina/citología , Retina/fisiología , Células Madre/citología , Trasplante Heterólogo
11.
Arch Ophthalmol ; 115(11): 1375-80, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9366666

RESUMEN

OBJECTIVE: To evaluate the effect of temporal clear corneal phacoemulsification on intraocular pressure (IOP) in eyes that underwent prior trabeculectomy. DESIGN: Retrospective case-control study. PATIENTS: Forty consecutive patients who underwent temporal clear corneal phacoemulsification subsequent to trabeculectomy (trabeculectomy-phacoemulsification group) were identified, and 40 control patients who underwent trabeculectomy alone (trabeculectomy group) were matched to the case patients for length of follow-up, age, IOP, number of antiglaucoma medications, number of 5-fluorouracil injections, race, sex, and diagnosis. MAIN OUTCOME MEASURES: Intraocular pressure before vs 1 year after phacoemulsification in the trabeculectomy-phacoemulsification group compared with IOP in the trabeculectomy group and survival analysis of IOP control after trabeculectomy in the 2 groups. RESULTS: In the trabeculectomy-phacoemulsification group, IOP 1 year after phacoemulsification was not significantly different from the prephacoemulsification IOP value (P = .65). Kaplan-Meier survival analysis showed that the rates of IOP control 3, 6, and 9 years after trabeculectomy in the trabeculectomy-phacoemulsification group were 80%, 66%, and 44%, respectively; in the trabeculectomy group, these were 79%, 69%, and 55%, respectively. These survival curves were not statistically different (P = .55). CONCLUSION: Cataract surgery by temporal clear corneal phacoemulsification in eyes with filtering blebs after trabeculectomy does not adversely affect long-term IOP control.


Asunto(s)
Córnea/cirugía , Glaucoma/cirugía , Presión Intraocular/fisiología , Facoemulsificación/métodos , Trabeculectomía , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Análisis de Supervivencia , Agudeza Visual
12.
Am J Ophthalmol ; 126(1): 29-36, 1998 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9683146

RESUMEN

PURPOSE: To compare long-term fluctuation of blue-on-yellow automated perimetry with white-on-white automated perimetry in normal subjects. METHODS: White-on-white and blue-on-yellow automated perimetry were performed on a Humphrey Visual Field Analyzer and an Octopus perimeter, both modified for blue-on-yellow perimetry. The study sample consisted of 31 eyes of 31 normal subjects for the Humphrey perimeter and 33 eyes of 33 normal subjects for the Octopus perimeter. After one practice session, each subject completed four testing sessions over a period of 2 to 8 weeks, each separated by at least 1 day. Each testing session consisted of both white-on-white and blue-on-yellow perimetry performed on one eye; the order of the tests was alternated for successive sessions. Long-term fluctuation (expressed as statistical variance) was calculated for each test location. Intersubject variability (expressed as statistical variance) across all subjects was determined for each test location. RESULTS: On the Humphrey perimeter, the long term fluctuation for blue-on-yellow perimetry (4.07 +/- 3.07 dB2) was significantly greater than that for white-on-white perimetry (1.97 +/- 0.99 dB2; P < .001). Long-term fluctuation increased as a function of eccentricity for both blue-on-yellow and white-on-white perimetry. Short-term fluctuation was significantly greater for blue-on-yellow (0.46 +/- 0.25 dB) than that for white-on-white perimetry (0.29 +/- 0.19 dB; P < .02). Finally, the intersubject variability was significantly greater in blue-on-yellow (13.2 +/- 2.8 dB2) than it was in white-on-white perimetry (4.25 +/- 1.13 dB2; P < .001). Similar results were found with the Octopus perimeter. CONCLUSIONS: Long-term fluctuation and short-term fluctuation of blue-on-yellow perimetry are greater than those of white-on-white perimetry in normal subjects. The increased long-term fluctuation requires appropriate statistical approaches when evaluating serial change of blue-on-yellow perimetry.


Asunto(s)
Pruebas del Campo Visual/métodos , Campos Visuales/fisiología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Valores de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Pruebas del Campo Visual/instrumentación
13.
Am J Ophthalmol ; 132(1): 47-56, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11438053

RESUMEN

PURPOSE: To evaluate long-term visual field outcome in primary open-angle glaucoma. METHODS: In this retrospective cohort study, 40 eyes of 40 patients with primary open-angle glaucoma with elevated intraocular pressure and a minimum of 8-year longitudinal series of visual fields were plotted with Goldmann perimeter. Eyes with any other ocular disease except cataract were excluded. Manual grid templates were used to quantify the visual fields. Linear regression was performed to estimate the rate of visual field decline. Pertinent clinical factors were evaluated for statistical association with the rate of decline. Long-term clinical outcome including visual acuity, rate of legal blindness, and rate of medical and surgical interventions was also measured. RESULTS: In the 40 eyes studied, with a mean follow-up of 14 years, the visual field score decreased at the rate of -1.5% per year. Overall, 68% showed significant decrease, and the rate of decrease among these eyes was -2.1% per year. Five eyes became legally blind from glaucoma; the cumulative rate of blindness from glaucoma was 19% at 22 years. Higher intraocular pressure and greater number of antiglaucoma medications on initial presentation were associated with faster and slower deterioration of visual field (compared with the average), respectively. CONCLUSIONS: With standard glaucoma therapy, the rate of visual field loss in primary open-angle glaucoma is slow. Lower intraocular pressure and more antiglaucoma medications are associated with slower visual field decline. Legal blindness from glaucoma is 19% over a follow-up of 22 years.


Asunto(s)
Glaucoma de Ángulo Abierto/metabolismo , Trastornos de la Visión/metabolismo , Agudeza Visual/fisiología , Campos Visuales , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Glaucoma de Ángulo Abierto/tratamiento farmacológico , Glaucoma de Ángulo Abierto/fisiopatología , Humanos , Presión Intraocular , Modelos Lineales , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Trastornos de la Visión/fisiopatología , Pruebas del Campo Visual
14.
Am J Ophthalmol ; 128(2): 255-6, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10458196

RESUMEN

PURPOSE: To report two cases in which topical brimonidine resulted in apparent central nervous system depression and unresponsiveness in an infant. METHODS: Review of two patients. An 11-day-old infant became lethargic and apneic after a single drop of brimonidine. These symptoms were reproduced after a second administration of brimonidine. A 5-month-old infant became lethargic and poorly responsive after receiving 1 drop of brimonidine in each eye. RESULTS: The first patient required admission to the hospital for medical stabilization. He recovered without sequelae. The second patient recovered spontaneously approximately 2.5 hours after administration of brimonidine. CONCLUSIONS: Topical brimonidine may be associated with central nervous system depression in infants. The use of brimonidine is not recommended in these patients until further data are available.


Asunto(s)
Agonistas alfa-Adrenérgicos/efectos adversos , Sistema Nervioso Central/efectos de los fármacos , Enfermedades del Sistema Nervioso/inducido químicamente , Quinoxalinas/efectos adversos , Agonistas alfa-Adrenérgicos/administración & dosificación , Tartrato de Brimonidina , Estudios de Seguimiento , Glaucoma/congénito , Glaucoma/tratamiento farmacológico , Glaucoma/cirugía , Humanos , Lactante , Recién Nacido , Presión Intraocular/efectos de los fármacos , Masculino , Hipertensión Ocular/tratamiento farmacológico , Soluciones Oftálmicas , Quinoxalinas/administración & dosificación
15.
J Glaucoma ; 9(4): 281-8, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10958600

RESUMEN

PURPOSE: To correlate Humphrey visual field mean sensitivity and peripapillary nerve fiber layer thickness as measured by scanning laser polarimetry. METHODS: The authors studied 54 eyes of 34 patients who visited a university-based glaucoma clinic and had undergone scanning laser polarimetry and Humphrey perimetry within 6 months. The study population included normal patients and those with glaucoma, ocular hypertension, and glaucoma suspect. The authors correlated visual field sensitivity with peripapillary nerve fiber thickness, and visual field mean deviation with the average deviation from the normal nerve fiber layer thickness. They also correlated the visual field mean deviation with all available GDx Nerve Fiber Analyzer parameters. RESULTS: The visual field mean sensitivity and deviation showed a bilinear correlation to peripapillary nerve fiber layer thickness. The visual field mean sensitivity changed little when the nerve fiber layer thickness was greater than 70 microm. The nerve fiber layer thickness below this level was associated with a rapid decrease in the visual field sensitivity. Similarly, the visual field mean deviation was close to 0 dB when the nerve fiber layer was within -10 microm of the normal value; below this thickness, the mean deviation became substantially more negative. There was a large individual variability around the bilinear fit. Of the scanning laser polarimetry parameters, a calculated index, referred to as the number, had the highest correlation with the Humphrey mean deviation. CONCLUSION: The bilinear correlation and its variability between the scanning laser polarimetry and visual field parameters make it difficult to predict the result of one from the other. In general, the correlation between the two is better when there is a significant visual field defect than when the visual field is close to normal.


Asunto(s)
Glaucoma/diagnóstico , Rayos Láser , Fibras Nerviosas/patología , Disco Óptico/patología , Trastornos de la Visión/diagnóstico , Pruebas del Campo Visual/métodos , Campos Visuales , Adulto , Anciano , Síndrome de Exfoliación/diagnóstico , Síndrome de Exfoliación/fisiopatología , Femenino , Glaucoma de Ángulo Abierto/diagnóstico , Glaucoma de Ángulo Abierto/fisiopatología , Humanos , Presión Intraocular , Masculino , Persona de Mediana Edad , Hipertensión Ocular/diagnóstico , Hipertensión Ocular/fisiopatología , Estudios Retrospectivos , Índice de Severidad de la Enfermedad
16.
J Biomed Mater Res B Appl Biomater ; 66(1): 306-10, 2003 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-12808588

RESUMEN

The interaction between bleaching agents and recently introduced compomers has several issues that need to be explored, including morphology and mechanical properties. To investigate the effect of 30% hydrogen peroxide, a bleaching agent, on the color of compomers, three compomers (Compoglass F, Elan, and F2000) were polymerized, bleached up to 120 h, and then measured to determine the reflectance of the specimen during the bleaching process. Color differences were evaluated from the reflectance and color values that were represented by CIE L*a*b* values. Compomers stored in distilled water were used as a source of reference. Teeth were also used for comparison. Color differences for both the tested teeth and compomers and different periods of bleaching and soaking in distilled water showed statistically significant difference (p < 0.0001). Among the tested compomers, Compoglass F demonstrated the highest color difference. In addition, the color differences were maximal during the first 24 h. After 24 h, the color difference increased nearly linearly. Compomers stored in both a bleaching agent and distilled water did not exhibit much color difference between them. However, the color difference between teeth and compomers was considerable.


Asunto(s)
Color , Compómeros , Peróxido de Hidrógeno , Animales , Bovinos , Restauración Dental Permanente , Humanos , Técnicas In Vitro , Ensayo de Materiales , Espectrofotometría , Diente
17.
Adv Exp Med Biol ; 483: 71-85, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11787651

RESUMEN

Changes in hepatic cysteine dioxygenase (CDO) activity in response to diet play a dominant role in regulation of cysteine catabolism and taurine synthesis. We have conducted several studies of the molecular regulation of CDO activity in rat liver and rat hepatocytes. Compared to levels observed in liver of rats fed a basal 10% casein diet, up to 180-fold higher levels of CDO activity and protein were observed in liver of rats fed diets that contained additional protein, complete amino acid mixture, methionine, or cystine. Neither CDO activity nor CDO protein was induced by excess non-sulfur amino acids alone. Excess sulfur amino acids or protein did not significantly increase the concentration of hepatic CDO mRNA. Preliminary studies indicate that the polysome profile for association of CDO mRNA with polysomes is not altered by an increase in dietary protein level, suggesting that regulation may be posttranslational and possibly involve a decrease in the rate of CDO degradation. In primary cultures of rat hepatocytes, CDO mRNA, protein, and activity all virtually disappeared by 12 to 24 h of culture in standard medium whereas CDO protein, but not CDO mRNA, accumulated markedly between 12 and 24 h in hepatocytes cultured in medium with excess methionine or cyst(e)ine. These observations are also consistent with a limited role of transcriptional or translational regulation of CDO in response to diet.


Asunto(s)
Aminoácidos Sulfúricos/metabolismo , Dioxigenasas , Hígado/enzimología , Oxigenasas/genética , Procesamiento Postranscripcional del ARN , Animales , Técnicas de Cultivo de Célula , Células Cultivadas , Cisteína-Dioxigenasa , Hepatocitos/citología , Masculino , Oxigenasas/metabolismo , Polirribosomas , Ratas , Ratas Sprague-Dawley
18.
Yonsei Med J ; 37(1): 59-67, 1996 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8967111

RESUMEN

Unlike most secretory cells, high extra cellular calcium inhibits rather than stimulates hormonal secretion in several cells such as parathyroid cells, Juxtaglomerular cells and osteoclast. To gain further insight into the common but unique stimulus-secretion coupling mechanism in these cells, bovine parathyroid slices were incubated in various conditions of Krebs-Ringer (KR) solution containing essential amino acids. Parathyroid cells showed the inverse dependency of secretion on extra cellular calcium concentration as we expected. Ammonium acetate overcame the inhibitory effect of 2.5 mM of calcium and the maximum effect was as much as the five times of the basal value, while there was a little additive effect under 0 mM CaCl2. PTH secretion was biphasic according to the change of extra cellular osmolarity and the lowest response was observed at 300 mOsm/l. In Na-rich KR solution, high concentration of nigericin (> 10(-4)M) completely overcame the inhibitory effect of 2.5 mM CaCl2 and the maximum stimulatory effect was 8 times greater whereas it was only 2 times greater without CaCl2. In K-rich KR solution that abolished the K-gradient between the extra cellular solution and the cytoplasm, the rate of PTH secretion increased, and furthermore the addition of nigericin increased the rate of secretion significantly. The results above suggested that the osmotic swelling of the secretory vesicle in parathyroid cells might promote exocytosis as in Juxtaglomerular cells. We propose that the swelling of the vesicle is also prerequisite for secretion in several cells inhibited paradoxically by Ca++, whatever the signal transduction pathway for swelling of the secretory granules induced by the lowering of Ca++ in cytoplasm are.


Asunto(s)
Líquidos Corporales/metabolismo , Glándulas Paratiroides/metabolismo , Hormona Paratiroidea/metabolismo , Acetatos/farmacología , Animales , Bovinos , Permeabilidad de la Membrana Celular , Ionóforos/farmacología , Manitol/farmacología , Nigericina/farmacología , Ósmosis , Glándulas Paratiroides/efectos de los fármacos
19.
Arch Pharm Res ; 20(5): 486-90, 1997 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18982495

RESUMEN

A stereospecific HPLC method has been developed for the resolution of the enantiomers of salbutamol in human urine. After solid-phase extraction and derivatization with (S)-(-)-alpha-methylbenzyl isocyanate, the diastereomeric derivatives were resolved (R(s)=1.59) on 5 mum octadecylsilan column using 47% methanol as a mobile phase with fluorescence detection. The detection limit of each enantiomer was 10 ng/ml (S/N=3).

20.
Trans Am Ophthalmol Soc ; 95: 153-67; discussion 167-70, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9440168

RESUMEN

PURPOSE: To evaluate the effect of temporal clear corneal phacoemulsification on intraocular pressure (IOP) in eyes that had prior trabeculectomy. DESIGN: Retrospective case-control study. PATIENTS: Forty consecutive patients (cases; TRAB-PHACO group) who underwent temporal corneal phacoemulsification subsequent to trabeculectomy were identified. Forty patients (controls; TRAB group) who had trabeculectomy alone were matched to the cases for length of follow-up, age, IOP, number of anti-glaucoma medications, number of 5-fluorouracil (5-FU) injections, race, sex and diagnosis. MAIN OUTCOME MEASURES: Comparison of IOP before and one year after phacoemulsification in the TRAB-PHACO group, and comparison with the TRAB group. Survival analysis of IOP control after trabeculectomy in the TRAB-PHACO and TRAB groups. RESULTS: In the TRAB-PHACO group, IOP one year after phacoemulsification was not significantly different from the pre-phacoemulsification IOP value (p = 0.65). Kaplan-Meier survival analysis showed that the rates of IOP control at 3, 6 and 9 years after trabeculectomy in the TRAB-PHACO group were 80%, 66% and 44%; in the TRAB group these were 79%, 69% and 55%. These survival curves were not statistically different (p = 0.55). CONCLUSIONS: Cataract surgery by temporal clear corneal phacoemulsification in eyes with filtering blebs after trabeculectomy does not adversely affect long term IOP control.


Asunto(s)
Córnea/cirugía , Glaucoma/cirugía , Presión Intraocular/fisiología , Facoemulsificación/métodos , Trabeculectomía , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Fluorouracilo/administración & dosificación , Estudios de Seguimiento , Glaucoma/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Análisis de Supervivencia , Resultado del Tratamiento
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