Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 72
Filtrar
1.
Expert Syst Appl ; 36(5): 9250-9259, 2009 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-20160889

RESUMEN

In this paper, we present a novel method for the classification of mammograms using a unique weighted association rule based classifier. Images are preprocessed to reveal regions of interest. Texture components are extracted from segmented parts of the image and discretized for rule discovery. Association rules are derived between various texture components extracted from segments of images, and employed for classification based on their intra- and inter-class dependencies. These rules are then employed for the classification of a commonly used mammography dataset, and rigorous experimentation is performed to evaluate the rules' efficacy under different classification scenarios. The experimental results show that this method works well for such datasets, incurring accuracies as high as 89%, which surpasses the accuracy rates of other rule based classification techniques.

2.
Med Hypotheses ; 64(2): 320-7, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15607565

RESUMEN

Herpes simplex virus type 1 (HSV-1) is latent in the nervous system of most humans. Ball [Can J Neurol Sci 9 (1982) 303] first suggested the hypothesis that HSV-1 could be involved in the pathogenesis of Alzheimer's Disease (AD) by noting that regions of the brain particularly and earliest affected in AD were the same as those most damaged during HSV encephalitis. Data from Itzhaki's research suggests that HSV-1 in the brain and the carriage of an apolipoprotein E allele 4 (ApoE e4) together confer risk for AD [J Pathol 97 (2002) 395], [Mol Chem Neuropathol 28 (1996) 135], [Alzheimer's Rep 1 (1998) 173], [Biochem Soc Trans 26 (1998) 273]. Of the two other studies based on Itzhaki's findings, one showed similar results [Lancet 349 (1997) 1102], and the other showed a similar trend [Lancet 351 (1998) 1330], [Lancet 352 (1998) 1312]. To further examine the role of HSV-1 in the etiology of AD, we have formulated a Neuroinvasive Score that quantifies the presence and viral load of HSV-1 in eight brain regions. These regions are: entorhinal cortex, hippocampus, pons, cerebellum, and neocortex (temporal, parietal, occipital, and frontal). We hypothesize that the Neuroinvasive Score that encompasses the presence, amount, and extent of HSV-1 spreading (neuroinvasiveness), will correlate with the genetic risk factor, ApoE e4, in the assessment of autopsy samples from AD patients. If the neuroinvasive score can be directly correlated to the different stages of AD (mild, moderate, severe), this will strengthen the hypothesis that HSV-1 is involved in AD and that ApoE e4 also confers risk for the development and progression of AD.


Asunto(s)
Enfermedad de Alzheimer/etiología , Enfermedad de Alzheimer/virología , Encéfalo/virología , Herpesvirus Humano 1 , Carga Viral/métodos , Humanos , Factores de Riesgo
3.
Br J Ophthalmol ; 87(10): 1284-90, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-14507767

RESUMEN

AIMS: To characterise lamina cribrosa and anterior scleral canal wall architecture in pressurised (IOP 10 mm Hg) and non-pressurised (IOP 0 mm Hg) normal monkey eyes. METHODS: Eight normal eyes from eight monkeys were enucleated before sacrifice and the optic nerve heads (ONH) trephined and immersion fixed in glutaraldehyde (IOP 0). Nine normal eyes from nine monkeys were perfusion fixed in situ with paraformaldehyde at IOP 10 mm Hg (IOP 10), and the ONHs trephined and stored in glutaraldehyde. Each ONH specimen was embedded in glycol methacrylate and cut into vertical or horizontal, 4 micro m thick, serial sections. Within digitised images of every sixth section, anterior laminar position and laminar thickness were measured at nine evenly spaced locations across the scleral canal opening. Additionally, scleral canal diameters at Bruch's membrane (SCD-B) and at the anterior laminar insertion (SCD-ALI) were measured within the 15 middle section images of each vertically sectioned ONH. RESULTS: Anterior laminar position was significantly more anterior (nearer Bruch's membrane) in the IOP 10 eyes, compared with the IOP 0 eyes (116 (+/-95% CI; 2) micro m v 184 (2) micro m, respectively). Also in the IOP 10 eyes, the lamina cribrosa was thinner (195 (2) micro m v 264 (2) micro m) and the scleral canal diameter was larger (SCD-B: 1751 (23) micro m v 1591 (19) micro m; SCD-ALI: 1961 (21) micro m v 1717 (17) micro m), compared with the IOP 0 eyes. CONCLUSION: The anterior scleral canal wall is expanded and the lamina cribrosa is thinned and more tautly stretched within pressurised (perfusion fixed at IOP 10) young monkey eyes, compared with non-pressurised (immersion fixed at IOP 0) young monkey eyes. The constricted scleral canal and the relaxed and thickened lamina in the non-pressurised eyes may represent phenomena that contribute to optic disc swelling in hypotonous eyes.


Asunto(s)
Presión Intraocular/fisiología , Macaca fascicularis/anatomía & histología , Macaca mulatta/anatomía & histología , Esclerótica/anatomía & histología , Animales , Masculino
4.
Invest Ophthalmol Vis Sci ; 42(13): 3202-8, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11726623

RESUMEN

PURPOSE: To characterize posterior scleral thickness in the normal monkey eye and to assess the effects of acute (15- to 80-minute) and short-term chronic (3- to 7-week) intraocular pressure (IOP) elevations. METHODS: Both eyes of four normal monkeys (both eyes normal) and four monkeys with early glaucoma (one eye normal and one eye with induced chronic elevation of IOP) were cannulated. In each monkey, IOP was set to 10 mm Hg in the normal eye and 30 or 45 mm Hg in the contralateral eye (normal or early glaucoma) for 15 to 80 minutes. All eight monkeys were perfusion fixed, yielding eight low IOP-normal eyes, four high IOP-normal eyes, and four high IOP-early glaucoma eyes. Posterior scleral thickness was measured histomorphometrically at 15 measurement points within each eye, and the data were grouped by region: foveal, midposterior, posterior-equatorial, and equatorial. RESULTS: Overall, posterior scleral thickness was significantly different in the various regions and among the treatment groups (P < 0.0001). In the low IOP-normal eyes, the posterior sclera was thickest in the foveal region (307 microm) and thinner in the midposterior (199 microm), posterior-equatorial (133 microm), and equatorial (179 microm) regions. In the high IOP-normal and high IOP-early glaucoma eyes, the posterior sclera was thinner both overall and within specific regions, compared with the low IOP-normal eyes. CONCLUSIONS: The posterior sclera in the perfusion-fixed normal monkey eye thins progressively from the fovea to the equator and is thinnest just posterior to the equator. Acute and short-term chronic IOP elevations cause regional thinning within the posterior sclera of some monkey eyes, which significantly increases stresses in the scleral wall.


Asunto(s)
Glaucoma/patología , Esclerótica/patología , Animales , Glaucoma/fisiopatología , Técnicas In Vitro , Presión Intraocular/fisiología , Macaca mulatta , Perfusión , Valores de Referencia , Reproducibilidad de los Resultados , Factores de Tiempo
5.
Acta Crystallogr C ; 57(Pt 12): 1434-5, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11740108

RESUMEN

The asymmetric unit of the title compound, C9H14O3, consists of two molecules having conformations that differ by a rotation of 111.7 (5) degrees about the equatorial substituent bond, so that the side chains of the two species extend away from the ring in different directions. Each conformer forms centrosymmetric hydrogen-bonded acid-to-acid dimers with its own enantiomer [O...O = 2.681 (3) and 2.698 (4) A]. There is an intermolecular C-H...O close contact involving the ketone group of one of the conformers.

6.
J Glaucoma ; 10(5): 369-82, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11711833

RESUMEN

PURPOSE: To determine the effect of acute, experimentally increased intraocular pressure on deformation of the surface of the optic nerve head (optic nerve head surface compliance testing) in normal monkey eyes using confocal scanning laser tomography. METHODS: A total of 156 compliance tests were performed on 48 normal eyes of 30 monkeys in three separate studies. Compliance testing involved obtaining confocal scanning laser tomographic images using a 10 degrees and/or 15 degrees and/or 20 degrees scan angle at various times after intraocular pressure was raised from 10 to 30 or 45 mm Hg. At each point, six images were analyzed to provide a value for a parameter, called mean position of the disc, which was used to express the amount of deformation the surface of the optic nerve head had undergone at that point. Statistical analysis (ANOVA) was performed to evaluate differences in the amounts of deformation in individual eyes at different intraocular pressures and at different compliance testing sessions (studies 1 and 2) and in the two eyes of individual monkeys under the same conditions (study 3). RESULTS: The majority of eyes showed posterior deformation of the surface of the optic nerve head ranging from 15 to 86 microm as early as 10 minutes after intraocular pressure was increased from 10 to 30 mm Hg. When pressure was increased from 30 to 45 mm Hg in a subset of these eyes, most showed additional deformation. Of the 12 eyes for which both 15 degrees and 20 degrees images were obtained at the same compliance test, 7 showed larger amounts of deformation in the 20 degrees images. Of the 18 monkeys tested in both eyes, 12 showed some differences and 4 showed substantial differences between the two eyes. CONCLUSIONS: In the normal monkey eye, the surface of the optic nerve head deforms rapidly (in as few as 10 minutes) in response to increased intraocular pressure. The amount of deformation varies between subjects and even within the two eyes of individual monkeys. Increasing the scan angle from 15 degrees to 20 degrees frequently increases the amount of deformation detected, suggesting that the peripapillary sclera and the optic nerve head may be involved in the deformation in some eyes.


Asunto(s)
Presión Intraocular , Hipertensión Ocular/fisiopatología , Disco Óptico/patología , Enfermedad Aguda , Animales , Chlorocebus aethiops , Técnicas de Diagnóstico Oftalmológico , Tejido Elástico , Ojo/patología , Rayos Láser , Macaca fascicularis , Macaca mulatta , Masculino , Disco Óptico/fisiopatología , Tomografía
7.
Acta Crystallogr C ; 57(Pt 9): 1075-8, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11588376

RESUMEN

The anhydrous form, (I), of the title compound, (-)-2-(1,2,3,4,4a,7-hexahydro-4a,8-dimethyl-1,7-dioxo-2-naphthyl)propionic acid, C(15)H(18)O(4), derived from a naturally occurring sesquiterpenoid, has two molecules in the asymmetric unit, (I) and (I'), differing in the conformations of the saturated ring and the carboxyl group. The compound aggregates as carboxyl-to-ketone hydrogen-bonding catemers [O.O = 2.776 (3) and 2.775 (3) A]. Two crystallographically independent sets of single-strand hydrogen-bonding helices with opposite end-to-end orientation pass through the cell in the b direction, one consisting exclusively of molecules of (I) and the other entirely of (I'). Three C-H.O=C close contacts are found in (I). The monohydrate, C(15)H(18)O(4).H(2)O, (II), with two molecules of (I) plus two water molecules in its asymmetric unit, forms a complex three-dimensional hydrogen-bonding network including acid-to-water, water-to-acid, water-to-ketone, water-to-water and acid-to-acid hydrogen bonds, plus three C-H.O=C close contacts. In both (I) and (II), only the ketone remote from the acid is involved in hydrogen bonding.

8.
Acta Crystallogr C ; 57(Pt 7): 841-3, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11443260

RESUMEN

In the the title compound, 1,7-dimethyl-8-oxo-4balpha,7alpha-gibba-1,3,4a(10a)-triene-10beta-carboxylic acid monohydrate, C18H20O3*H2O, the water of hydration accepts a hydrogen bond from the carboxyl and donates hydrogen bonds to the carboxyl carbonyl and the ketone in two different screw-related neighbors, which are mutually translational, yielding a complex three-dimensional hydrogen-bonding array.


Asunto(s)
Giberelinas/química , Cristalografía por Rayos X , Enlace de Hidrógeno , Cetoácidos/química , Modelos Moleculares , Conformación Molecular , Estereoisomerismo
9.
Virology ; 284(1): 62-9, 2001 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-11352668

RESUMEN

Herpes simplex virus type 1 (HSV-1) recombinant strain 17CRE contains a site-directed mutation in the 7-bp CRE consensus sequence located 38 nucleotides upstream of the transcription start site. Scarified mouse corneas received inoculations of 17syn+ (parent), 17CRE, and rescue 17CREr. Slit lamp examination of herpetic lesions and tear film swabs containing infectious virus showed that 17CRE had the same acute phenotype as 17syn+ and 17CREr. At 4 weeks, when the corneas had healed and latency was established, mice received hyperthermic shock. Eye swabs taken 24 h after hyperthermia showed that 17CRE reactivated significantly less than 17syn+ and 17CREr, while no significant differences were found in HSV-1 DNA genome copy numbers and latent virus in the trigeminal ganglia. These results are evidence that this CRE site in the LAT promoter facilitates ocular HSV-1 reactivation in mice.


Asunto(s)
Córnea/virología , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/genética , Trastornos de Estrés por Calor/complicaciones , Herpesvirus Humano 1/genética , Queratitis Herpética/genética , Latencia del Virus/genética , Animales , Modelos Animales de Enfermedad , Ratones , Ratones Endogámicos BALB C , Mutagénesis Sitio-Dirigida , Fenotipo , Regiones Promotoras Genéticas , Conejos , Recurrencia , Ganglio del Trigémino/virología
10.
Acta Crystallogr C ; 57(Pt 5): 632-3, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11353275

RESUMEN

The hemihydrate of the title diketo acid, C(24)H(36)O(4).0.5H(2)O, forms hydrogen-bonded carboxyl dimers related by a C(2) axis at crystallographic sites on the a and b edges of the chosen cell [O.O = 2.643 (7) and 2.716 (7) A]. The ketone ends of the molecules approach each other at sites near ((1/2),(1/2),(1/2)), ((1/2),0,(1/2)), (0,0,(1/2)) and (0,(1/2),(1/2)) in an interleaved arrangement incorporating partial-occupancy water hydrogen bonded to the B-ring ketone.

11.
Am J Ophthalmol ; 131(5): 643-6, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11336941

RESUMEN

PURPOSE: To determine the effect of the topical ocular hypotensive drug, isopropyl unoprostone, a docosanoid molecule with very weak prostaglandin activity, on herpes keratitis in the rabbit eye. METHODS: For acute disease, rabbit corneas inoculated with the corticosteroid-sensitive F(MP)E strain of herpes simplex virus type 1 were treated with various combinations of 0.12% isopropyl unoprostone, latanoprost, trifluridine, benzalkonium chloride 0.02%, dexamethasone sodium phosphate, ketorolac tromethamine, or saline solution beginning 1 day after infection. Severity of keratitis was evaluated in a masked manner. For recurrent disease, rabbit corneas infected with McKrae strain herpes simplex virus type 1 were treated with unoprostone or saline solution on postinfection days 25 to 42, and the presence or absence of lesions was recorded. RESULTS: Eyes treated with unoprostone showed significantly less severe disease than saline-treated or latanoprost-treated eyes during acute infection. Unoprostone-treated and saline-treated eyes showed no significant difference in the frequency of recurrent lesions. Eyes treated with latanoprost and/or dexamethasone, separately or in combination, showed increased severity of acute herpes simplex virus keratitis, whereas benzalkonium chloride 0.02%--treated eyes showed no significant difference, compared with saline treatment. Trifluridine resulted in rapid healing. CONCLUSIONS: Unoprostone did not increase the severity or recurrence rate of herpes simplex virus keratitis. Unoprostone requires twice-a-day administration, compared with once-a-day for latanoprost, and unoprostone lowers intraocular pressure less than latanoprost. Nevertheless, unoprostone's superior safety profile may make its use advantageous. Benzalkonium chloride alone did not make the keratitis worse.


Asunto(s)
Antihipertensivos/uso terapéutico , Dexametasona/análogos & derivados , Dinoprost/uso terapéutico , Presión Intraocular/efectos de los fármacos , Queratitis Herpética/tratamiento farmacológico , Prostaglandinas F Sintéticas/uso terapéutico , Enfermedad Aguda , Administración Tópica , Animales , Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/uso terapéutico , Antihipertensivos/administración & dosificación , Dexametasona/administración & dosificación , Dexametasona/uso terapéutico , Dinoprost/administración & dosificación , Dinoprost/análogos & derivados , Quimioterapia Combinada , Femenino , Queratitis Herpética/fisiopatología , Latanoprost , Masculino , Soluciones Oftálmicas , Prostaglandinas F Sintéticas/administración & dosificación , Conejos , Distribución Aleatoria , Recurrencia
12.
Acta Crystallogr C ; 57(Pt 3): 325-8, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11250596

RESUMEN

The crystal structure of (+/-)-4-oxo-1,2,3,4-tetrahydronaphthalene-2-carboxylic acid (C(11)H(10)O(3)) involves projection of the carboxyl group nearly orthogonal to the aromatic plane and hydrogen bonding of the acid groups by centrosymmetric pairing across the a edge and the center of the chosen cell [O...O = 2.705 (2) A]. Intermolecular C--H...O==C close contacts to translationally related molecules are found for both the ketone (2.55 A) and the acid (2.67 A). In (+/-)-1-oxo-1,2,3,4-tetrahydronaphthalene-2-acetic acid (C(12)H(12)O(3)), the aggregation involves centrosymmetric carboxyl dimers mutually hydrogen bonded across the bc face and the a edge of the chosen cell [O...O = 2.674 (2) A]. A 2.60 A close C--H...O==C contact is found to the carboxyl group of centrosymmetrically related molecule.

13.
Am J Cardiol ; 87(2): 234-7, A9, 2001 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-11152851

RESUMEN

In a consecutive cohort of patients hospitalized for decompensated heart failure, we found that chronic obstructive pulmonary disease and history of hospitalization for any cause in the preceding 6 months were the strongest correlates of early readmission. Based on these findings, we propose a simple risk stratification system to classify patients who are hospitalized for heart failure as low, medium, or high risk for early readmission.


Asunto(s)
Insuficiencia Cardíaca/fisiopatología , Readmisión del Paciente , Anciano , Femenino , Insuficiencia Cardíaca/epidemiología , Pruebas de Función Cardíaca , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Morbilidad , Análisis Multivariante , Valor Predictivo de las Pruebas , Medición de Riesgo
14.
Immunohematology ; 17(2): 45-9, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-15373591

RESUMEN

Coa is a high-frequency blood group antigen in the Colton blood group system expressed on red blood cells (RBCs) of approximately 99.8 percent of random persons. Anti-Coa has been reported to cause delayed hemolytic transfusion reactions, hemolytic disease of the newborn, and accelerated clearance of RBCs in vivo. Acute hemolytic transfusion reactions (AHTRs) have not previously been reported. A 58-year-old man was hospitalized for vascular surgery. Initial blood bank evaluation revealed anti-Fya. The patient received six units of RBCs during his initial hospitalization and developed anti-E. A subsequent sample was sent to the reference laboratory when all units of RBCs appeared incompatible. Additional studies, including alloadsorptions, revealed the presence of anti-E, anti-Fya, and an apparent warm autoantibody. One unit of least-incompatible RBCs was transfused during surgery. The patient had an increase in temperature. Hemoglobinuria and a decrease in hematocrit were also noted. Due to the clinical impression of an AHTR, the pre- and postreaction samples were reevaluated in the reference laboratory and demonstrated the presence of anti-Coa in both. Based on clinical and laboratory evaluation this patient appears to have had an AHTR due to anti-Coa. This is the first known reported case of an AHTR caused by anti-Coa.

15.
Virus Genes ; 23(3): 273-80, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11778695

RESUMEN

An understanding of the cellular genes whose expression is altered during HSV reactivation will enable us to better understand host responses and biochemical pathways involved in the process. Furthermore, this knowledge could allow us to develop gene-targeted inhibitors to prevent viral reactivation. Mice latent with HSV-1 strain McKrae and uninfected control mice were subjected to hyperthermic stress (43 degrees C for 10 min) and their trigeminal ganglia (TG) collected 1 h later. Two additional groups included HSV-1 latently infected and uninfected mice not subjected to hyperthermic stress. Poly A+ mRNA was enriched from total mouse TG RNA and reverse transcribed using MMLV RT. Radioactively labeled cDNAs were analyzed by microarray analysis. A stress/toxicology array of 149 mouse genes on a nylon membrane was used. The labeled cDNAs prepared from latently infected, stressed mice demonstrated 3-fold or greater increases in certain mRNA-early response genes (ERGs) compared to cDNAs from uninfected, stressed control mice. The ERG mRNAs that showed increases included two heat shock proteins (HSP60 and HSP40), a basic transcription factor (BTF T62), a DNA repair enzyme, two kinases [MAP kinase and a stress-induced protein kinase (SADK)], an oxidative stress-induced protein, a manganese superoxide dismutase precursor-2 (SOD-2), and cyclooxygenase 2 (COX-2). The gene expression in unstressed, infected TGs was similar to the gene expression in unstressed, uninfected controls. These results suggest that there is a significant difference in the ERG expression profile in latently infected TGs undergoing stress-induced reactivation compared to uninfected TGs.


Asunto(s)
Expresión Génica , Herpesvirus Humano 1/genética , Ganglio del Trigémino/metabolismo , Latencia del Virus , Animales , Femenino , Perfilación de la Expresión Génica , Herpesvirus Humano 1/fisiología , Hipertermia Inducida , Ratones , Ratones Endogámicos BALB C , Análisis de Secuencia por Matrices de Oligonucleótidos , Activación Viral
16.
Acta Crystallogr C ; 56(Pt 12): 1507-9, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11119009

RESUMEN

In the monohydrate of the title compound, (+)-2beta, 4aalpha-dihydroxy-1,7-dimethyl-8-oxo-4bbeta,7alpha- gibbane-1alpha, 10beta-dicarboxylic acid-1,4a-lactone, C(19)H(24)O(6).H(2)O, intermolecular hydrogen bonding progresses helically along b from carboxyl to ketone [O...O = 2.694 (5) A]. The carboxyl and lactone carbonyl groups in translationally related molecules within a helix both accept hydrogen bonds from the same water of hydration. The oxygen of this water in turn accepts a hydrogen bond from the hydroxyl group of a third screw-related molecule in an adjacent counterdirectionally oriented helix, yielding a complex three-dimensional hydrogen-bonding array. Intermolecular O...H-C close contacts were found to the carboxyl and lactone carbonyls, the hydroxyl, and the water.


Asunto(s)
Diterpenos/química , Giberelinas/química , Cristalografía por Rayos X , Enlace de Hidrógeno , Estructura Molecular , Estereoisomerismo
17.
Nutr Neurosci ; 3(2): 143-9, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-27416372

RESUMEN

This article extends the analysis of 2*2 tables considered in the preceding paper of this three-part series. The methods described in the previous paper for analysis of frequency counts of categorical variables in 2*2 tables, including overall tests, partitioned tests, odds ratios, and estimation of required sample size, are applied to tables with multiple levels, such as those with more than two response factors and/or more than two levels for each factor.

18.
Arch Ophthalmol ; 117(7): 868-70, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10408449

RESUMEN

OBJECTIVE: To compare the reproducibility of measurements obtained with a new pachymetry instrument, the Topcon specular microscope (Topcon SP-2000P; Topcon America Corp, Paramus, NJ), with those obtained by ultrasound pachymetry. METHODS: Corneal thickness was measured in 40 eyes of 40 patients 3 times each with the Topcon SP-2000P and an ultrasound pachymeter (DGH 500, DGH Technology Inc, Exton, Pa) by 2 separate investigators. Comparisons included average thickness as measured by each instrument, average thickness for each instrument as measured by each investigator, and differences in thickness due to corneal abnormalities. RESULTS: Mean corneal thickness measured by the Topcon instrument was significantly less (32 microm; P<.001) than the mean value obtained with the ultrasound pachymeter. Similarly, mean values obtained with the 2 instruments by the 2 investigators were significantly different (P<.001 and .008 for investigators 1 and 2, respectively), with the Topcon value less than the ultrasound value in both cases. Both instruments detected abnormalities in corneal thickness equally well. However, the measurements obtained with the Topcon instrument by the 2 investigators were more consistent (no significant difference [P=.32]) than those obtained with the ultrasound unit (difference was significant [P=.02]). CONCLUSIONS: The new noncontact Topcon specular microscope provides measurements of corneal thickness that are somewhat less than those of ultrasound pachymetry, but that seem to be more consistent from one operator to another, possibly as a result of the elimination of observer bias induced by probe placement required by the ultrasound unit. This consistency may be important in the comparison of measurements by different operators over time in patients being followed up after refractive surgery or other therapeutic interventions.


Asunto(s)
Córnea/patología , Enfermedades de la Córnea/patología , Técnicas de Diagnóstico Oftalmológico/instrumentación , Microscopía/métodos , Ultrasonografía/métodos , Humanos , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados
19.
Arch Ophthalmol ; 117(7): 925-8, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10408458

RESUMEN

OBJECTIVE: To compare topical cidofovir with topical trifluridine for the prevention and treatment of herpes simplex type 1 stromal keratitis in rabbits. METHODS: The RE strain of herpes simplex virus 1 was injected into the central stroma of both eyes of New Zealand white rabbits. Two to 3 days after virus inoculation, the rabbits were randomized to treatment groups of 10 each and treated with 1% trifluridine administered 5 or 7 times a day, 1%, 0.5%, or 0.2% cidofovir administered twice a day, fluorometholone administered twice a day, or balanced salt solution (BSS) administered twice a day (control) until day 21 after injection. The treated corneas were examined 3 times a week and the severity of stromal keratitis was graded in a masked fashion. To evaluate the ability of cidofovir to treat established stromal disease, groups of 10 rabbits each were inoculated with herpes simplex virus and treated with 1% cidofovir twice a day, 1% trifluridine 5 times a day, fluorometholone twice a day, or BSS twice a day beginning on day 7 after virus inoculation through day 21. RESULTS: Treatment with 0.2% cidofovir twice a day was not effective in preventing the appearance of stromal disease (P = .89), whereas treatment with 0.5% (P<.001) or 1% (P<.001) cidofovir twice a day or 1% trifluridine 5 times a day (P<.001) or 7 times a day (P = .006) significantly reduced the appearance of stromal keratitis on the 8 evaluation days, compared with BSS treatment (F test analysis of variance). There was no difference between the eyes treated with 0.5% cidofovir twice a day and those treated with 1% trifluridine 5 times a day. Treatment with 1% cidofovir was not effective in treating established stromal disease. CONCLUSIONS: Cidofovir and trifluridine are highly effective in preventing the appearance of herpetic stromal disease. Cidofovir is as effective as, but no more effective than, trifluridine in this model. Neither cidofovir nor trifluridine benefits established stromal disease, however. CLINICAL RELEVANCE: Cidofovir is a new, potent antiviral that seems similar in efficacy to trifluridine and is effective in the prevention of the development of stromal herpes, but is not effective in the treatment of established stromal disease in which hypersensitivity predominates.


Asunto(s)
Antivirales/uso terapéutico , Sustancia Propia/efectos de los fármacos , Citosina/análogos & derivados , Herpesvirus Humano 1/efectos de los fármacos , Queratitis Herpética/prevención & control , Organofosfonatos , Compuestos Organofosforados/uso terapéutico , Administración Tópica , Animales , Antivirales/administración & dosificación , Cidofovir , Sustancia Propia/virología , Citosina/administración & dosificación , Citosina/uso terapéutico , Femenino , Herpesvirus Humano 1/fisiología , Queratitis Herpética/tratamiento farmacológico , Queratitis Herpética/virología , Masculino , Soluciones Oftálmicas/administración & dosificación , Soluciones Oftálmicas/uso terapéutico , Compuestos Organofosforados/administración & dosificación , Conejos , Distribución Aleatoria , Trifluridina/administración & dosificación , Trifluridina/uso terapéutico
20.
Am J Ophthalmol ; 127(5): 531-6, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-10334345

RESUMEN

PURPOSE: To determine whether topically applied latanoprost increases the severity of acute herpes simplex keratitis, the rate of recurrence of herpes keratitis, or both, in the rabbit. METHODS: To determine the effect on severity of acute herpetic keratitis, the corneas of New Zealand white rabbits were infected with either the less-corticosteroid-sensitive McKrae strain or the corticosteroid-sensitive F(MP)E strain of herpes simplex virus type 1. Rabbits were randomly assigned to twice-a-day treatment with latanoprost 0.005%, dexamethasone sodium phosphate 0.1%, or balanced saline solution within 3 days of infection and evaluated daily for up to 13 days after infection. The severity of keratitis was graded in a masked manner. To determine the effect on recurrences of herpetic keratitis, animals infected with McKrae strain herpes simplex virus type 1 that survived to day 32 after infection were randomized to treatment with latanoprost 0.005% or balanced saline solution and evaluated for the presence of corneal lesions from postinfection day 32 to day 47. RESULTS: In the severity studies, treatment of F(MP)E-infected corneas with latanoprost or dexamethasone significantly worsened herpetic keratitis; by postinfection day 5, F(MP)E-infected eyes treated with dexamethasone or latanoprost demonstrated significantly higher severity scores than the eyes treated with balanced saline solution (P = .0001 and .008, respectively). Scores of McKrae-infected corneas treated with latanoprost or dexamethasone were not significantly different from scores of balanced saline solution-treated corneas. In the recurrence study, treatment with latanoprost significantly increased the appearance of clinical recurrences in McKrae-infected eyes, compared with balanced saline solution treatment (P = .0064). CONCLUSION: Latanoprost may worsen acute herpetic keratitis in the rabbit eye and increase the risk of recurrences in latently infected animals.


Asunto(s)
Córnea/virología , Herpesvirus Humano 1/crecimiento & desarrollo , Queratitis Herpética/virología , Prostaglandinas F Sintéticas/farmacología , Activación Viral/efectos de los fármacos , Enfermedad Aguda , Administración Tópica , Animales , Córnea/patología , Dexametasona/farmacología , Femenino , Queratitis Herpética/patología , Latanoprost , Masculino , Prostaglandinas F Sintéticas/administración & dosificación , Conejos , Recurrencia
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...