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1.
Am Heart J ; 224: 148-155, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32402701

RESUMEN

BACKGROUND: Multiple modern Indian hospitals operate at very low cost while meeting US-equivalent quality accreditation standards. Though US hospitals face intensifying pressure to lower their cost, including proposals to extend Medicare payment rates to all admissions, the transferability of Indian hospitals' cost advantages to US peers remains unclear. METHODS: Using time-driven activity-based costing methods, we estimate the average cost of personnel and space for an elective coronary artery bypass graft (CABG) surgery at two American hospitals and one Indian hospital (NH). All three hospitals are Joint Commission accredited and have reputations for use of modern performance management methods. Our case study applies several analytic steps to distinguish transferable from non-transferable sources of NH's cost savings. RESULTS: After removing non-transferable sources of efficiency, NH's residual cost advantage primarily rests on shifting tasks to less-credentialed and/or less-experienced personnel who are supervised by highly-skilled personnel when perceived risk of complications is low. NH's high annual CABG volume facilitates such supervised work "downshifting." The study is subject to limitations inherent in case studies, does not account for the younger age of NH's patients, or capture savings attributable to NH's negligible frequency of re-admission or post-acute care facility placement. CONCLUSIONS: Most transferable bases for a modern Indian hospital's cost advantage would require more flexible American states' hospital and health professional licensing regulations, greater family participation in inpatient care, and stronger support by hospital executives and clinicians for substantially lowering the cost of care via regionalization of complex surgeries and weekend use of costly operating rooms.


Asunto(s)
Puente de Arteria Coronaria/economía , Enfermedad de la Arteria Coronaria/cirugía , Procedimientos Quirúrgicos Electivos/economía , Costos de Hospital , Medicare/economía , Transferencia de Pacientes/economía , Enfermedad de la Arteria Coronaria/economía , Femenino , Humanos , India , Masculino , Estados Unidos
2.
Eur J Clin Nutr ; 71(6): 798-800, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-27966564

RESUMEN

Hyperphosphatemia in chronic kidney disease (CKD) is associated with vascular calcification, cardiovascular morbidity and mortality. The aim of this study was to estimate the daily dietary phosphorus intake compared with recommendations in CKD patients and to evaluate the reproducibility of the 24-h urinary phosphorus excretion. Twenty CKD patients stage 3-4 from the outpatient clinic, collected 24-h urine and kept dietary records for 3 consecutive days. The mean daily phosphorus intake was 1367±499, 1642±815 and 1426±706 mg/day, respectively (P=0.57). The mean urinary phosphorus excretion was 914±465, 954±414 and 994±479 mg/day, respectively (P=0.21). In this population of CKD patients stage 3-4 the daily phosphorus intake was above the recommended. Twenty-four-hour urinary phosphorus excretion was reproducible and the data indicate that a single 24-h urine collection is sufficient to estimate the individual phosphorus excretion.


Asunto(s)
Fósforo Dietético/administración & dosificación , Fósforo Dietético/orina , Insuficiencia Renal Crónica/tratamiento farmacológico , Insuficiencia Renal Crónica/orina , Adulto , Anciano , Femenino , Humanos , Hiperfosfatemia/complicaciones , Hiperfosfatemia/tratamiento farmacológico , Hiperfosfatemia/orina , Masculino , Persona de Mediana Edad , Estado Nutricional , Insuficiencia Renal Crónica/complicaciones , Reproducibilidad de los Resultados , Adulto Joven
3.
J Natl Cancer Inst ; 89(20): 1530-6, 1997 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-9337350

RESUMEN

BACKGROUND: Retinoblastoma is the most common childhood tumor of the eye, arising from cells that are defective in both copies of the retinoblastoma susceptibility gene (RB1). Most retinoblastoma tumor cells eventually undergo programmed cell death (i.e., apoptosis); however, some cells can acquire the ability to metastasize and become immortal. Transfection of immortal retinoblastoma cells with DNA sequences encoding wild-type p53 protein induces cell death, suggesting that the loss of both RB1 and p53 functions may be required for cell immortalization. We have examined this possibility by characterizing the p53 protein and messenger RNA in six independently isolated, immortalized retinoblastoma cell lines. METHODS: Western blotting methods were used to assess p53 protein level in each cell line, and Cleavase Fragment-Length Polymorphism analysis of complementary DNAs was used to screen for mutations in p53 messenger RNA. Localization of p53 protein in cells of the immortalized lines and in specimens of retinoblastoma tumors was achieved by means of indirect immunofluorescence and immunocytochemistry, respectively. RESULTS: All six immortalized cell lines expressed wild-type p53 messenger RNA and high levels of p53 protein. Although p53 is normally a nuclear protein, the p53 in four of the six cell lines was located predominately in the cytoplasm; in the remaining two cell lines, p53 was localized in both the nucleus and the cytoplasm. Cytoplasmic localization of p53 in retinoblastoma tumor specimens was rare and usually restricted to cells that had invaded adjacent ocular tissues, indicative of the early stages of metastasis. CONCLUSIONS: Some immortalized retinoblastoma cells may exhibit p53 dysfunction through nuclear exclusion of wild-type p53 protein.


Asunto(s)
Neoplasias del Ojo/genética , Genes p53 , Polimorfismo de Longitud del Fragmento de Restricción , Retinoblastoma/genética , Proteína p53 Supresora de Tumor/biosíntesis , Línea Celular Transformada , Núcleo Celular/metabolismo , Núcleo Celular/patología , Niño , Neoplasias del Ojo/patología , Técnica del Anticuerpo Fluorescente Indirecta , Humanos , Inmunohistoquímica , ARN Mensajero/biosíntesis , Retinoblastoma/patología , Transcripción Genética , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/análisis
4.
Gene ; 96(1): 37-41, 1990 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-2265757

RESUMEN

This paper describes a novel method for creating exact DNA fusions between any two points in a plasmid carried in Bacillus subtilis. It exploits the homologous in vivo recombination between directly repeated sequences that can be established by insertion of a synthetic oligodeoxyribonucleotide. The method was used to enhance the productivity in B. subtilis of a cloned alpha-amylase (Amy)-encoding gene originating from Bacillus stearothermophilus. Thus, an exact fusion between nucleotide sequences encoding the expression signals, including the signal peptide, of a Bacillus licheniformis Amy-encoding gene and the mature Amy of B. stearothermophilus, was created. The resulting hybrid translational product was processed correctly in B. subtilis during secretion, giving rise to an Amy identical to the mature Amy secreted by B. stearothermophilus.


Asunto(s)
Bacillus/genética , Ingeniería Genética , Plásmidos , Recombinación Genética , Secuencia de Aminoácidos , Secuencia de Bases , ADN Bacteriano/genética , Escherichia coli/genética , Expresión Génica , Genes Bacterianos , Datos de Secuencia Molecular , Señales de Clasificación de Proteína/genética
5.
Mol Aspects Med ; 15 Suppl: s273-80, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-7752839

RESUMEN

The bioavailability of four different Coenzyme Q10 (CoQ) formulations was compared in ten healthy volunteers in a four-way randomised cross-over trial. The included formulations were: A hard gelatin capsule containing 100 mg of CoQ and 400 mg of Emcompress. Three soft gelatin capsules containing: 100 mg of CoQ with 400 mg of soy bean oil (Bioquinon); 100 mg of CoQ with 20 mg of polysorbate 80, 100 mg of lecithin and 280 mg of soy bean oil; and 100 mg of CoQ with 20 mg of polysorbate 80 and 380 mg of soy bean oil, respectively. The result suggests that the soya bean oil suspension of CoQ (Bioquinon has the highest bioavailability. A difference in basic AUC and AUC after p.o. administration of CoQ was observed with respect to sex. A characteristic two peak-pattern was observed at the concentration-time profile.


Asunto(s)
Ubiquinona/análogos & derivados , Administración Oral , Adulto , Disponibilidad Biológica , Cápsulas , Coenzimas , Estudios Cruzados , Femenino , Gelatina , Humanos , Masculino , Vehículos Farmacéuticos , Fosfatidilcolinas , Polisorbatos , Factores Sexuales , Aceite de Soja , Ubiquinona/administración & dosificación , Ubiquinona/sangre , Ubiquinona/farmacocinética
6.
FEBS Lett ; 303(2-3): 169-72, 1992 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-1607015

RESUMEN

We have exploited the transient expression of foreign genes introduced into plant protoplasts to investigate the effect of the pea seedborne mosaic potyvirus (PSbMV) 5' untranslated region (5'UTR) on the level of gene expression in pea and tobacco protoplasts. The plant viral 5'UTRs were found to increase translation significantly in comparison to a plasmid containing no 5'UTR of viral origin. The enhancement effect of the 5'UTRs of PSbMV and tobacco etch potyvirus (TEV) was found to be similar in pea and tobacco protoplasts, indicating a host-independent role of the potyviral 5'UTRs in enhancing gene expression. Translational enhancement of the two potyviral 5'UTRs was similar to that of the 5'UTR of tobacco mosaic virus (TMV). This observation makes it attractive to use potyviral 5'UTRs as general translational enhancers in future genetic transformations of plants.


Asunto(s)
ADN Viral/fisiología , Elementos de Facilitación Genéticos , Fabaceae/microbiología , Intrones , Virus del Mosaico/genética , Nicotiana/microbiología , Plantas Medicinales , Plantas Tóxicas , Biosíntesis de Proteínas , Secuencia de Bases , Clonación Molecular , Fabaceae/genética , Glucuronidasa/genética , Datos de Secuencia Molecular , Virus del Mosaico/fisiología , Protoplastos , ARN Viral/genética , Nicotiana/genética
7.
Invest Ophthalmol Vis Sci ; 35(6): 2682-92, 1994 May.
Artículo en Inglés | MEDLINE | ID: mdl-8188462

RESUMEN

PURPOSE: To determine whether, by employing recent advances in immunocytochemical technique, it is possible to identify reliably the product of the retinoblastoma (RB) susceptibility gene, p110RB1, in formalin-fixed, paraffin-embedded eyes with commercially available primary antibodies. If so, the authors sought to determine the distribution of p110RB1 in normal human eyes and retinoblastomas in hopes of better understanding its function. METHODS: Four antibodies to p110RB1 were tested on normal human and monkey eyes, as well as on six human retinoblastomas. The human tissue was formalin-fixed and paraffin-embedded. Free antigen was used for an absorbed control. The monkey eye had been injected with tritiated (H3) thymidine 24 hours before enucleation. RESULTS: Three of the four antibodies had acceptable reactivity (a polyclonal against the carboxyl-terminal epitope and two monoclonals against epitopes near the amino-terminus). Staining was confined to nucleated cells of the normal eyes and was strongest in the cycling cells of the lenticular and corneal epithelia. Somewhat weaker reactivity was seen in those corneal epithelial cells in S phase as determined by autoradiography for H3-thymidine. Of the six retinoblastomas, three had strong nuclear and cytoplasmic staining and one showed weaker staining in the tumor cells than in the adjacent vascular endothelial cells. Two of the tumors had positive cytoplasmic and negative nuclear staining with an amino-terminal antibody but were completely negative for carboxyl-terminal p110RB1 reactivity. CONCLUSIONS: Using appropriate immunocytochemical techniques, p110RB1 can be identified in paraffin-embedded tissues with commercially available antibodies. The observed staining pattern in retinoblastoma suggests that RB1 transcripts are commonly produced in the tumor cells and that they are sometimes, but not always, capable of nuclear binding. Thus, nuclear binding by the RB1 gene product per se is not sufficient to prevent tumor growth, nor does it indicate the presence of a normal transcript.


Asunto(s)
Neoplasias del Ojo/metabolismo , Ojo/metabolismo , Proteína de Retinoblastoma/análisis , Retinoblastoma/metabolismo , Animales , Anticuerpos Monoclonales , Preescolar , Genes de Retinoblastoma , Humanos , Técnicas para Inmunoenzimas , Macaca mulatta
8.
Invest Ophthalmol Vis Sci ; 33(5): 1627-32, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1559760

RESUMEN

The circulating renin-angiotensin system (RAS) is an important determinant in maintaining adequate systemic blood pressure, and it also may modify organ-specific blood flow. All recognized RAS components have been identified in the eye. In this study, angiotensinogen (ANG) was localized using an affinity-purified antibody and paraffin sections of seven human eyes. An antibody for human serum albumin was used for comparison. The ANG was present selectively in the cytoplasm of the nonpigmented ciliary epithelium (NPCE), more prominently in the pars plana than in the pars plicata. Both ANG and albumin were present in the blood vessel lumina of the uvea and retina. Both antibodies also stained perivascular tissue in the uvea, but not in the retina, reflecting the relative tightness of blood-tissue barriers. The detection of ANG in the NPCE may be significant in view of previous descriptions localizing prorenin and angiotensin-converting enzyme in the same cell layer.


Asunto(s)
Angiotensinógeno/metabolismo , Ojo/metabolismo , Sistema Renina-Angiotensina/fisiología , Adulto , Anciano , Electroforesis en Gel de Poliacrilamida , Humanos , Técnicas para Inmunoenzimas , Persona de Mediana Edad , Epitelio Pigmentado Ocular/metabolismo , Vasos Retinianos/metabolismo , Albúmina Sérica/análisis , Úvea/irrigación sanguínea , Úvea/metabolismo
9.
Res Microbiol ; 142(7-8): 793-6, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1784818

RESUMEN

In the industrial process of liquefying starch to make glucose or high fructose syrups, it is crucial that the amylase used is stable and active at about 105 degrees C at pH 6.5 or preferentially at a lower pH. The amylase from Bacillus licheniformis is well suited for this purpose but it is possible that other amylases might perform even better. Therefore, we cloned and characterized amyS encoding a heat-stable alpha-amylase from Bacillus stearothermophilus. Using a newly developed method for creating exact gene fusions by in vivo recombination, we attempted to increase expression of amyS in Bacillus subtilis. However, only by introducing the amyS gene into B. licheniformis, we obtained significantly better yields.


Asunto(s)
Geobacillus stearothermophilus/genética , alfa-Amilasas/genética , Bacillus/enzimología , Bacillus/genética , Bacillus subtilis/enzimología , Bacillus subtilis/genética , Ingeniería Genética/métodos , Geobacillus stearothermophilus/enzimología , Técnicas In Vitro , Plásmidos/genética , Recombinación Genética/genética
10.
Arch Ophthalmol ; 118(1): 27-31, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10636410

RESUMEN

OBJECTIVE: To determine quantitatively the relative contributions of the neurosensory retina (NR) and retinal pigment epithelium (RPE) to the macular hypofluorescence observed during routine fundus fluorescein angiography. METHODS: Macular and peripheral buttons of neurosensory retina and retinal pigment epithelium were obtained from 10 postmortem human eyes. A well was created to simulate a fluorescein-filled choroid. The fluorescence of each tissue and combinations of tissue atop the well was determined using a fluorescence microscope. The percent reduction in the fluorescence of each, relative to the baseline fluorescence of the well alone, was calculated. RESULTS: Macular RPE demonstrated substantially lower fluorescence than peripheral RPE in all subjects. Macular NR demonstrated lower fluorescence than peripheral NR in all but one subject. The addition of macular NR to macular RPE caused significantly less fluorescence in all cases. Macular RPE caused a much greater percent reduction in fluorescence than macular NR in all subjects. CONCLUSIONS: Hypofluorescence of the macula relative to the peripheral retina is a well-known feature of fluorescein angiography. This phenomenon is predominantly owing to the RPE and minimally to the NR, which cause 90.6 and 13.6 mean percent reductions in fluorescence, respectively.


Asunto(s)
Fluorescencia , Mácula Lútea/irrigación sanguínea , Epitelio Pigmentado Ocular/fisiología , Vasos Retinianos/fisiología , Adolescente , Adulto , Anciano , Niño , Preescolar , Coroides/irrigación sanguínea , Femenino , Angiografía con Fluoresceína , Humanos , Masculino , Microscopía Fluorescente , Persona de Mediana Edad
11.
Arch Ophthalmol ; 111(5): 608-13, 1993 May.
Artículo en Inglés | MEDLINE | ID: mdl-8489438

RESUMEN

OBJECTIVE: The chronic histopathologic effects of focal and grid argon laser photocoagulation were examined in eyes obtained at autopsy that had previously been treated for diabetic macular edema. The focus was on further characterizing fibrous sub-pigment epithelial membranes that previously had been shown to extend beyond burn edges. DESIGN: A total of 131 argon laser burns were evaluated in five eyes. Tissue was embedded in paraffin or glycol methacrylate, serially sectioned, and examined by light microscopy. MAIN OUTCOME MEASURE: Outer and inner nuclear layer defects were measured, and the frequency and extent of sub-pigment epithelial membranes was estimated. The presence of Müller cell processes among membranes was evaluated by immunostaining for glial fibrillary acidic protein and enzyme histochemical staining for carbonic anhydrase. RESULTS: Burns consistently produced defects in the outer nuclear layer that were larger than the spot size of the laser beam. Inner nuclear layer defects were present in only seven of 131 burns. Glycol methacrylate--embedded tissue sections from 73 burns showed sub-pigment epithelial membranes in all five eyes. In one eye, membranes were confluent between burns. In the remaining four eyes, 37 individual membranes were found among 53 burns, and 47% of membranes contained Müller cell processes. The membranes in paraffin-embedded tissue could not be adequately evaluated. CONCLUSIONS: After focal laser treatment for diabetic macular edema, the inner retina was usually spared. Fibrous sub-pigment epithelial membranes were frequent among burns in all five eyes, and they showed a conspicuous contribution by Müller cell processes. We speculate that by impairing the overlying pigment epithelium, these membranes may contribute to a progressive enlargement of laser scars.


Asunto(s)
Retinopatía Diabética/cirugía , Coagulación con Láser/efectos adversos , Edema Macular/cirugía , Epitelio Pigmentado Ocular/patología , Anciano , Anciano de 80 o más Años , Cicatriz/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad
12.
Arch Ophthalmol ; 118(10): 1393-400, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11030822

RESUMEN

OBJECTIVE: To determine whether selective cone loss could explain the acquired tritan-like color confusion found in diabetic retinopathy. METHODS: Terminal deoxynucleotidyl transferase-mediated biotin-deoxyuridine triphosphate nick end labeling (TUNEL) was employed on paraffin sections of retinas from 5 donors with diabetic retinopathy. For quantitative analysis, postmortem retinas were obtained from 13 human donors; 7 from patients with various durations and stages of diabetic retinopathy (4 background, 3 proliferative) and 6 controls. Enzyme histochemical analysis for carbonic anhydrase (CA) was used to distinguish L/M-cones (positive for CA) from S-cones (negative for CA). Cone topography was determined by sampling 360 degrees from 0.1 to 1.5 mm of foveal eccentricity and along the horizontal meridians from 1.5 to 15.0 mm. RESULTS: Rare cells in both the inner and outer nuclear layers of the diabetic eyes were positively labeled with the TUNEL method. The CA staining revealed incomplete and patchy losses of S-cones that were limited to the diabetic retinas. Statistically significant reduction in the density of S-cones was found at nearly all foveal eccentricities from 0.1 mm to 15.0 mm. This was not the case for the L/M-cones. On average, for all locations, the percentage of S-cones compared with L/M-cones was decreased by 21.0% +/- 3.4% with respect to the controls. CONCLUSION: The S-cones selectively die in diabetic retinopathy. CLINICAL RELEVANCE: Selective loss of S-cones may contribute to the tritan-like color vision deficit seen in patients with diabetic retinopathy.


Asunto(s)
Defectos de la Visión Cromática/diagnóstico , Retinopatía Diabética/diagnóstico , Células Fotorreceptoras Retinianas Conos/patología , Adulto , Anciano , Anhidrasas Carbónicas/análisis , Recuento de Células , Muerte Celular , Niño , Defectos de la Visión Cromática/enzimología , Retinopatía Diabética/enzimología , Femenino , Histocitoquímica , Humanos , Etiquetado Corte-Fin in Situ , Masculino , Persona de Mediana Edad , Células Fotorreceptoras Retinianas Conos/enzimología , Agudeza Visual
13.
Arch Ophthalmol ; 115(2): 213-9, 1997 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9046256

RESUMEN

OBJECTIVES: To determine whether apoptosis is a significant mode of cell death in human retinoblastoma (RB) and if it is regulated by the expression of p53. METHODS: Apoptosis was analyzed using the criterion of internucleosomal DNA degradation as determined by agarose gel electrophoresis of DNA isolated from tumor specimens. Individual cells undergoing apoptosis were identified using terminal transferase-mediated biotin-dUTP nick end labeling (TUNEL) of fragmented DNA. The expression of p53 and WAF1 (a protein involved in p53-mediated cell cycle arrest) in human RB was determined by immunocytochemical analysis. The function of p53 in human RB cell lines was tested by transfecting them with a complementary DNA encoding a temperature-sensitive isoform of murine p53 under the control of a strong viral promoter. RESULTS: DNA from RB tumor specimens showed a strong nucleosomal ladder of DNA fragments typical of apoptosis. The TUNEL staining indicated that poorly and moderately differentiated cells in tumors were undergoing DNA fragmentation. Immunoreactivity for p53 was variable. Cells expressing low levels of p53 seemed viable and expressed WAF1. Cells expressing high levels of p53 were found immediately adjacent to cells undergoing apoptosis. Human RB cells in culture that were expressing a murine temperature-sensitive isoform of p53 died at temperatures that allow this protein to assume a wild-type conformation. CONCLUSIONS: Apoptotic cell death is prevalent in RB. The close association of p53-immunoreactive cells and cells undergoing apoptosis in human tumors, and the ability of exogenous p53 to stimulate cell death in cultured human RB cells, suggests that p53 plays a role in regulating cell death in RB.


Asunto(s)
Apoptosis , Neoplasias del Ojo/metabolismo , Retinoblastoma/metabolismo , Proteína p53 Supresora de Tumor/fisiología , Muerte Celular/efectos de los fármacos , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Ciclinas/metabolismo , Fragmentación del ADN , Cartilla de ADN/química , ADN de Neoplasias/análisis , Electroforesis en Gel de Agar , Inhibidores Enzimáticos/metabolismo , Neoplasias del Ojo/tratamiento farmacológico , Neoplasias del Ojo/patología , Humanos , Técnicas para Inmunoenzimas , Retinoblastoma/tratamiento farmacológico , Retinoblastoma/patología , Transfección , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/farmacología
14.
Arch Ophthalmol ; 118(9): 1242-50, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10980770

RESUMEN

OBJECTIVE: To test a hypothesis of photoreceptor involvement in retinal ganglion cell (RGC) death in chronic glaucoma. METHODS: Laser spots were applied to 6 eyes of 3 rhesus monkeys, causing focal destruction of the outer retina, including the photoreceptors. After 3 to 4 weeks, experimental glaucoma was induced in the right eyes of each monkey using argon laser trabecular destruction (ALTD). The intraocular pressures in these eyes were elevated for 3 to 7 months. As a control, 1 additional monkey underwent retinal laser photocoagulation followed by optic nerve transection instead of ALTD. Following enucleation, the retinas were embedded and sectioned for histologic evaluation. RESULTS: There was extensive loss of RGCs in the eyes with ALTD except over the large retinal laser spots, where there was an increased survival of RGCs. The RGC protection was not observed in the monkey that had undergone optic nerve transection. CONCLUSION: Photocoagulation of the outer retina that completely destroys the photoreceptors results in survival of the overlying RGCs in experimental glaucoma in monkey eyes. CLINICAL RELEVANCE: Although this is an experimental model and not a therapeutic option, these results suggest that treatments other than lowering intraocular pressure may be potential therapies for preventing RGC death in glaucomatous eyes. Arch Ophthalmol. 2000;118:1242-1250


Asunto(s)
Citoprotección/fisiología , Glaucoma/fisiopatología , Coagulación con Láser , Células Ganglionares de la Retina/fisiología , Animales , Axotomía , Muerte Celular , Fondo de Ojo , Glaucoma/etiología , Glaucoma/patología , Presión Intraocular , Macaca mulatta , Nervio Óptico/fisiología , Células Fotorreceptoras de Vertebrados/patología , Células Fotorreceptoras de Vertebrados/fisiología , Retina/cirugía , Trabeculectomía/efectos adversos
15.
Arch Ophthalmol ; 115(6): 758-63, 1997 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9194728

RESUMEN

OBJECTIVE: To describe and classify a retinal tumor found in a dog that histologically resembles human retinoblastoma and to discuss the molecular mechanisms of retinal oncogenesis. METHODS: A dog eye with a retinal tumor was examined histologically. Studies including immunocytochemical analysis for retinal S-antigen and glial fibrillary acidic protein, enzyme histochemical analysis for carbonic anhydrase, and nick-end DNA labeling were used to characterize the tumor. Normal retina from another dog and other tumors from dogs, including 2 ciliary body medulloepitheliomas and a brain medulloepithelioma, were examined as controls. RESULTS: The retinal tumor disclosed characteristics typical of human retinoblastoma, including Flexner-Wintersteiner rosettes. It showed strong immunoreactivity with S-antigen and glial fibrillary acidic protein. Carbonic anhydrase activity also could be shown in the tumor. Apoptosis was found to be the predominant method of cell death as shown by nick-end DNA labeling. In contrast to the other tumors examined, this tumor contained areas with retinal photoreceptor and glial differentiation. CONCLUSIONS: The histopathologic findings and differential staining characteristics in this retinal tumor are compatible with retinoblastoma, making this, to our knowledge, the first documented case of spontaneous retinoblastoma in an animal.


Asunto(s)
Enfermedades de los Perros/patología , Neoplasias del Ojo/veterinaria , Retinoblastoma/veterinaria , Animales , Enfermedades de los Perros/metabolismo , Perros , Neoplasias del Ojo/metabolismo , Neoplasias del Ojo/patología , Inmunohistoquímica , Masculino , Retinoblastoma/metabolismo , Retinoblastoma/patología
16.
Arch Ophthalmol ; 118(2): 235-45, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10676789

RESUMEN

OBJECTIVE: To determine whether outer retinal changes occur in chronic, presumed primary open-angle glaucoma (POAG). METHODS: The outer retinas from 128 human eyes with a diagnosis of chronic glaucoma (presumably POAG in most cases) and 90 control eyes were examined histologically by 3 masked observers for photoreceptor swelling and loss. Retinas from 9 rhesus monkeys with glaucoma induced experimentally by laser trabecular destruction were compared with 7 fellow (control) eyes. The mean pressure elevations in the eyes with laser trabecular destruction ranged from 26.6 to 53.6 mm Hg with durations varying from 7 to 33 weeks. RESULTS: Swelling of the red- and green-sensitive cones was observed in a statistically significantly greater proportion of human eyes with presumed POAG compared with the control eyes. Patchy loss of red/green cones and rods was also found in some of the glaucomatous retinas. In a subset of the human eyes with end-stage disease, cone swelling was a variable finding. Although no photoreceptor loss was found in the 9 monkey eyes with experimental glaucoma, 8 had swelling of their red/green cones that was remarkably similar to that seen in the human eyes. Swelling was not present in any of the control monkey eyes. CONCLUSIONS: The photoreceptors are affected by chronically elevated intraocular pressure. CLINICAL RELEVANCE: These findings may explain some of the abnormalities of color vision and the electrophysiological effects that have been observed in patients with POAG.


Asunto(s)
Edema/etiología , Glaucoma de Ángulo Abierto/complicaciones , Células Fotorreceptoras de Vertebrados/patología , Enfermedades de la Retina/etiología , Anciano , Animales , Muerte Celular , Enfermedad Crónica , Defectos de la Visión Cromática/etiología , Modelos Animales de Enfermedad , Edema/patología , Femenino , Humanos , Presión Intraocular , Macaca mulatta , Masculino , Enfermedades de la Retina/patología , Células Ganglionares de la Retina/patología
17.
FEMS Microbiol Lett ; 61(2-3): 271-5, 1991 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-1903751

RESUMEN

We have cloned and sequenced a gene for a heat-stable alpha-amylase from a natural isolate of Bacillus stearothermophilus. Previously, it had been shown that B. stearothermophilus amylase genes may be harboured on indigenous plasmids. We have found that our isolate harbours the amylase gene only on the chromosome and not on its indigenous plasmid.


Asunto(s)
Cromosomas Bacterianos , Genes Bacterianos , Geobacillus stearothermophilus/genética , alfa-Amilasas/genética , Secuencia de Aminoácidos , Bacillus subtilis/genética , Secuencia de Bases , Southern Blotting , Clonación Molecular/métodos , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Escherichia coli/genética , Geobacillus stearothermophilus/enzimología , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Plásmidos , Regiones Promotoras Genéticas , Mapeo Restrictivo
18.
Acta Otolaryngol ; 89(5-6): 479-86, 1980.
Artículo en Inglés | MEDLINE | ID: mdl-7192477

RESUMEN

At re-examination of 527 ears with secretory otitis 3 to 8 years after tubulation otomicroscopy and tympanometry revealed different types of retraction of Shrapnell's membrane in 34%, of these 4.2% had pronounced retraction with resorption of the osseous annulus and 0.2% had atticus cholesteatoma. There was a close correlation between the frequency and severity of retraction on the one hand and the age of the patient at reexamination, the tympanometric conditions, and the pathology of pars tensa on the other. The continued progression is further promoted by a lack of natural cleansing of the retraction. As the frequency of secretory otitis is very high in children the 4.2% of pronounced retractions constitute a sufficient quantitative basis for a direct progression to atticus cholesteatoma.


Asunto(s)
Colesteatoma/etiología , Otitis Media con Derrame/complicaciones , Otitis Media/complicaciones , Membrana Timpánica/patología , Pruebas de Impedancia Acústica , Factores de Edad , Audiometría , Niño , Preescolar , Humanos , Otitis Media con Derrame/cirugía , Presión
19.
Acta Otolaryngol ; 88(5-6): 388-94, 1979.
Artículo en Inglés | MEDLINE | ID: mdl-532614

RESUMEN

150 healthy children were regularly investigated with tympanometry during the first year of life. Normal middle ear pressure was found in nearly all children at birth. At the age of 6 months, 62% of the ears had a pressure of 0-99 mmH2O. In 37% the pressure was between -100 and -350 mmH2O and 1% had flat curves. At the age of 9 months, the tympanograms further deteriorated and at 12 months, only 40% of the ears had a pressure of 0 to -99 mmH2O, 28% had a pressure of -100 to -199 mmH2O, 19% a pressure of -200 to -350 mmH2O and 13% had flat curves, indicating secretory otitis. At 1 year, the tympanograms were worse than in any other age group investigated so far. The dominant cause of the reduced middle ear ventilation was catarrhalia, the frequency of which increased during the period from 6 to 12 months.


Asunto(s)
Pruebas de Impedancia Acústica , Otitis Media/epidemiología , Factores de Edad , Oído Medio/fisiología , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Presión , Factores Sexuales
20.
Ann Otol Rhinol Laryngol Suppl ; 89(3 Pt 2): 217-22, 1980.
Artículo en Inglés | MEDLINE | ID: mdl-6778311

RESUMEN

In 150 newborn children tympanometry was repeated each third month until the age of one year. In 222 two-year-old children repetitive tympanometric screenings were performed in November, February, May and August, and the alterations in the tympanogram types were analyzed. There was found a very low stability of the tympanogram types and about 50% of the ears changed type between the investigations. The type A tympanogram (0 to -99 mm H2O) was the most stable type, only 52% of the ears changed tye. All ears with type C1 (-100 to -199 mm H2O), 97% of ears with type C2 (-200 to -350 mm H2O), and 84% of the ears with type B (flat curve) changed tympanogram type at least once at the four evaluations. This large variability in the tympanometric conditions, most often caused by a change in the frequency and severity of catarrhalia, makes the prognostic value of the screening tympanometry very small.


Asunto(s)
Pruebas de Impedancia Acústica , Otitis Media/diagnóstico , Preescolar , Humanos , Lactante , Recién Nacido , Pronóstico
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