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1.
Gynecol Oncol ; 153(2): 223-229, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30765148

RESUMO

BACKGROUND: Intraperitoneal (IP) chemotherapy can improve outcomes for women with optimally cytoreduced epithelial ovarian cancer but toxicities are a concern. We conducted 2 phase 2 trials of an IV/IP regimen using carboplatin and paclitaxel without (Trial A) and with bevacizumab (Trial B). METHODS: Both trials consisted of carboplatin AUC 6 day 1, and paclitaxel 60 mg/m2 on days 1,8, 15 of a 21-day cycle; in Trial B, patients received IV bevacizumab 15 mg/kg every cycle starting cycle 2. Chemotherapy was administered IV for cycle 1 and then IP for all subsequent cycles. Primary objectives included safety and tolerability, pathologic CR rate (Trial A), and the rate of completion of IP cycles of therapy (Trial B). Progression-free (PFS), overall survival (OS), and pharmacokinetic analysis were secondary endpoints. RESULTS: 81 patients were treated on both trials (n = 40 and 41 in trials A and B, respectively). Median age for trials A and B was 59 (range, 36-76) and 55 (range, 19-69) years, respectively. 68% and 85% of patients, respectively for A and B, completed at least 4 cycles of treatment in both trials. Treatment with bevacizumab resulted in higher rates of grade 3 fatigue (37 versus 33%) and grade 3-4 diarrhea (22 versus 8%). Median PFS was 23.5 (95%CI 16.2-35.3) and 25 (95%CI 16.4-42.7) months, respectively; median OS was 68 (95%CI 49.5-NR) and 79.7 (95%CI 59.0-79.7) months, respectively for Trial A and B. CONCLUSIONS: Weekly administered IP carboplatin and IP paclitaxel is tolerable and safe with similar activity with and without concommittant bevacizumab in these 2 trials.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma Epitelial do Ovário/terapia , Neoplasias Ovarianas/terapia , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Bevacizumab/administração & dosagem , Bevacizumab/efeitos adversos , Carboplatina/administração & dosagem , Carboplatina/efeitos adversos , Carcinoma Epitelial do Ovário/mortalidade , Carcinoma Epitelial do Ovário/patologia , Quimioterapia Adjuvante/métodos , Procedimentos Cirúrgicos de Citorredução/métodos , Esquema de Medicação , Feminino , Humanos , Infusões Intravenosas , Infusões Parenterais , Pessoa de Meia-Idade , Ductos Paramesonéfricos/patologia , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/patologia , Ovariectomia/métodos , Paclitaxel/administração & dosagem , Paclitaxel/efeitos adversos , Intervalo Livre de Progressão , Adulto Jovem
2.
J Basic Microbiol ; 41(2): 97-104, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11441464

RESUMO

The presence of adenine in the L-alanine defined medium substantially inhibited the growth of the moderately halophilic eubacterium Halomonas elongata. Extensive attempts to reverse the adenine toxicity for growth were made using a variety of purine and pyrimidine compounds, vitamins, and amino acids. Of the compounds tested, only cytosine was found to reverse the adenine growth inhibition. This indicates a mechanism similar to that found for some strains of Escherichia coli in which the presence of exogenous purines (e.g. adenine) was found to stop purine de novo synthesis and repress the synthesis of the pyrimidine salvage enzyme cytosine deaminase. H. elongata was found to possess an active adenine uptake system that was sodium dependent with only lithium having a considerable capacity to replace the sodium. A competition study indicated that the adenine transport system was quite specific. This paper represents the initial study of purine and pyrimidine salvage pathways and adenine uptake for the moderately halophilic eubacteria.


Assuntos
Adenina/metabolismo , Adenina/farmacologia , Halomonas/efeitos dos fármacos , Halomonas/metabolismo , Transporte Biológico Ativo , Meios de Cultura , Citosina/metabolismo , Halomonas/crescimento & desenvolvimento , Purinas/metabolismo , Pirimidinas/metabolismo , Cloreto de Sódio
3.
Arch Ophthalmol ; 119(7): 1009-19, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11448323

RESUMO

OBJECTIVE: To assess the relation between usual nutrient intake and subsequently diagnosed age-related nuclear lens opacities. SUBJECTS: Four hundred seventy-eight nondiabetic women aged 53 to 73 years from the Boston, Mass, area without previously diagnosed cataracts sampled from the Nurses' Health Study cohort. METHODS: Usual nutrient intake was calculated as the average intake from 5 food frequency questionnaires that were collected during a 13- to 15-year period before the evaluation of lens opacities. The duration of vitamin supplement use was determined from 7 questionnaires collected during this same period. We defined nuclear opacities as a nuclear opalescence grade of 2.5 or higher using the Lens Opacification Classification System III. RESULTS: The prevalence of nuclear opacification was significantly lower in the highest nutrient intake quintile category relative to the lowest quintile category for vitamin C (P<.001), vitamin E (P =.02), riboflavin (P =.005), folate (P =.009), beta-carotene (P =.04), and lutein/zeaxanthin (P =.03). After adjustment for other nutrients, only vitamin C intake remained significantly associated (P =.003 for trend) with the prevalence of nuclear opacities. The prevalence of nuclear opacities was significantly lower (P<.001) in the highest vitamin C intake quintile category relative to the lowest quintile category (odds ratio, 0.31; 95% confidence interval, 0.16-0.58). There were also statistically significant trends of decreasing prevalence of nuclear opacities with increasing duration of use of vitamin C (P =.004 for trend), vitamin E (P =.03 for trend), and multivitamin (P =.04 for trend) supplements, but only duration of vitamin C supplement use remained significantly associated with nuclear opacities after mutual adjustment for use of vitamin E (P =.05 for trend) or multivitamin (P =.02 for trend) supplements. The prevalence of nuclear opacities was significantly lower (P =.004) for women who used a vitamin C supplement for 10 or more years relative to women who never used vitamin C supplements (odds ratio, 0.36; 95% confidence interval, 0.18-0.72). Plasma measures of vitamins C and E taken at the eye examination were also inversely associated with the prevalence of nuclear opacities. CONCLUSION: These results provide additional evidence that antioxidant nutrients play a role in the prevention of age-related nuclear lens opacities.


Assuntos
Envelhecimento/efeitos dos fármacos , Antioxidantes/administração & dosagem , Ácido Ascórbico/administração & dosagem , Catarata/prevenção & controle , Inquéritos sobre Dietas , Núcleo do Cristalino/efeitos dos fármacos , Idoso , Ácido Ascórbico/sangue , Catarata/sangue , Catarata/epidemiologia , Estudos de Coortes , Registros de Dieta , Comportamento Alimentar , Feminino , Ácido Fólico/administração & dosagem , Humanos , Luteína/administração & dosagem , Pessoa de Meia-Idade , Razão de Chances , Prevalência , Riboflavina/administração & dosagem , Vitamina E/administração & dosagem , Saúde da Mulher , Xantofilas , Zeaxantinas , beta Caroteno/administração & dosagem , beta Caroteno/análogos & derivados
4.
Exp Eye Res ; 68(5): 547-52, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10328968

RESUMO

Human lens nuclei were collected during routine cataract surgery and used to study the role of oxidation in cataract formation and brunescence. This study focused on the comparison of the intensities of nuclear opacity and pigmentation (brunescence) with the changes in free glutathione (GSH) and the three species of protein-thiol mixed disulfides: protein-S-S-glutathione (PSSG), protein-S S-cysteine (PSSC) and protein-S-S-gamma-glutamylcysteine (PSSGC). Eighty-one freshly excised human lens nuclei from a population with a mean age of 77 were used. The nuclear color was graded using the CCRG system, ranging from yellow to dark brown. The nuclear cataract opalescence of these lenses was also graded using the LOCS II system, ranging from LOCS II NO-1 to NO-4. Three normal human lenses (average age of 88 yr) were also included in the study as controls. The nuclear samples were each analyzed for free GSH and protein-thiol mixed disulfides, respectively. It was found that nuclear GSH decreased as the nuclear color increased from yellow to dark brown (from 0.73+/-0.13 to 0.13+/-0.03 micromole g wet wt-1) and as the nuclear opalescence increased from NO.1 to NO.4 (from 0. 80+/-0.19 to 0.20+/-0.01 micromole g wet wt-1). All these values were lower than that of GSH in normal controls (1.43+/-0.59 micromole g wet wt-1). Levels of both PSSG and PSSC progressively increased, however, as the nuclear color intensified. PSSG increased from 0.29+/-0.05 to 0.91+/-0.11 micromole g wet wt-1while PSSC increased from 0.13+/-0.04 to 0.41+/- 0.06 micromole g wet wt-1. PSSGC concentration progressively increased with increases in both nuclear pigmentation (from 0.05+/-0.01 to 0.23+/-0.05 micromole g wet wt-1) and nuclear opacity (from 0.02+/-0.00 to 0.20+/-0.02 micromole g wet wt-1). In comparison, normal controls had lower levels of all three mixed disulfide species: PSSG, 0.22+/-0.06; PSSC, 0.08+/-0.02; PSSGC, 0.02+/-0.06 micromole g wet wt-1, respectively. The correlation of lens nuclear color and opalescence intensity with nuclear protein S-thiolation indicates that protein-thiol mixed disulfides may play an important role in cataractogenesis and development of brunescence in human lenses.


Assuntos
Catarata/metabolismo , Dissulfetos/metabolismo , Núcleo do Cristalino/metabolismo , Proteína S/metabolismo , Compostos de Sulfidrila/metabolismo , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Estudos de Casos e Controles , Glutationa/metabolismo , Humanos , Pessoa de Meia-Idade , Oxirredução , Pigmentação
6.
Ophthalmic Epidemiol ; 2(2): 59-75, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7585237

RESUMO

The Roche European-American Anticataract Trial (REACT) will assess the effect of antioxidants on progression of cataract in humans. This report evaluates the methods used in REACT. Seventy three subjects (139 eyes) with cortical (C), posterior subcapsular (P), nuclear (N) or mixed cataract were seen twice within two weeks for eye examinations, assessments of visual function, lens photographs and CCD images. The degree of cataract and nuclear color (NC) were assessed with subjective (LOCS III) and objective (computerized, CASE 2000 CCD) methods. Repeat visit values were used to calculate intraclass correlation coefficients (r1) and 95% tolerance limits (TL). A clinically significant change (CSC) was defined as one step in LOCS III. The relative power of each method to detect cataract change and sample sizes needed to achieve statistically significant results were calculated. The r1 values for visual function tests ranged from 0.76 to 0.88; if these tests of visual function were used to detect a clinically significant change in cataract severity, sample sizes of 840 to 2707 per group would be needed. The r1 values for LOCS III were 0.88 to 0.97, and sample sizes ranged from 50 to 135 per group. The r1 values for the CCD were 0.93 to 0.98, and sample sizes ranged from 1 to 42 with poorer values relating to measurement of P. We conclude that the methods used in REACT are reproducible. The analytical algorithms in the image analysis programs did not permit differentiation between C and P opacification; therefore, P cataract is best measured with LOCS III. REACT sample sizes are adequate to detect a difference of 0.2 LOCS III units/year between the mean rates of cataract progression in two groups.


Assuntos
Catarata/fisiopatologia , Oftalmologia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Catarata/terapia , Método Duplo-Cego , Europa (Continente) , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Cristalino/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fotografação/métodos , Estudos Prospectivos , Reprodutibilidade dos Testes , Estados Unidos , Testes Visuais/métodos , Acuidade Visual , Vitaminas/uso terapêutico
7.
Optom Vis Sci ; 70(11): 886-95, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8302524

RESUMO

Subjective and objective systems are used to quantify cataract at The Center for Clinical Cataract Research. We have described each system and its use, presented data on reproducibility and validity, and for objective systems, demonstrated the correlation to the subjective grade of the cataract as defined by the Lens Opacities Classification Systems, Versions II and III (LOCS II and III). The subjective systems are used to classify nuclear color, nuclear opalescence, cortical cataract, and posterior subcapsular cataract. Reported kappa scores for LOCS II range from 0.85 to 1.0. Intraclass correlation coefficients for LOCS III (r1) range from 0.67 to 0.94. The computerized objective system are: (1) fast spectral scanning colorimetry (FSSC) for assessment of nuclear color (r1 = 0.96 to 0.98); (2) nuclear mean density (NMD) for assessment of nuclear opalescence (r1 = 0.97); and (3) percent area opacity (anterior = a; posterior = p) (OPAC-a and OPAC-p) for assessment of cortical and posterior subcapsular cataract (r1 = 0.92 to 0.96).


Assuntos
Catarata/classificação , Córtex do Cristalino/patologia , Núcleo do Cristalino/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Catarata/patologia , Colorimetria/métodos , Feminino , Humanos , Masculino , Massachusetts , Pessoa de Meia-Idade , Fotografação/métodos , Reprodutibilidade dos Testes , Faculdades de Medicina , Sensibilidade e Especificidade , Estatística como Assunto/métodos
8.
Optom Vis Sci ; 70(11): 929-36, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8302529

RESUMO

The crystallin profiles of the cortices and nuclei of intracapsular cataractous lenses were studied by high pressure liquid chromatography (HPLC), polyacrylamide gel electrophoresis (PAGE), and dot blotting. The complete personal and medical history of 381 patients and the Cooperative Cataract Research Group (CCRG) classification of each were obtained. Few statistically significant associations between patient personal history and cataract types were found. Protein profiles of selected cataracts which had specifically located opacities (i.e., nuclear only, cortical only, etc.) were studied in detail. Sodium dodecyl sulphate-PAGE revealed few differences in lens-soluble proteins between cataractous and normal cortices or nuclei. By HPLC, the proteins of cataractous cortices and their nuclei differed very little from age-matched controls. The cortical proteins of nuclear cataracts appeared normal. However, two major alterations of proteins were observed in the nuclei of dense nuclear cataracts. Increased high molecular weight protein and increased components with molecular weights < 20,000 Da were found in cataractous nuclei as compared with normal age-matched control lens nuclei. Dot blot (immunological) analyses identified the crystallins of normal lenses that eluted from the HPLC column more efficiently than those of cataractous lenses. Cortical protein HPLC samples had the most specificity. Nuclear protein HPLC samples of older normal and cataractous lenses had little if any alpha crystallin specificity in the void volume peak. A relation between the presence of opacities and changes in molecular weight distribution of crystallins was found in the opaque nuclei but not in the opaque cortices.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Catarata/classificação , Cristalinas/metabolismo , Córtex do Cristalino/metabolismo , Núcleo do Cristalino/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Catarata/metabolismo , Catarata/patologia , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Feminino , Humanos , Córtex do Cristalino/patologia , Núcleo do Cristalino/patologia , Masculino , Pessoa de Meia-Idade , Peso Molecular
9.
Optom Vis Sci ; 70(11): 937-43, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8302530

RESUMO

Lovastatin has been associated with development of subcapsular cataract in dogs given high doses. To test the cataractogenic potential of lovastatin in humans, 192 patients were divided into 2 groups, A (N = 94) and B (N = 98), 1 taking 40 mg/day of lovastatin and 1 taking placebo. Both groups were enrolled for 2 years in this double-blind, randomized study and were followed with eye examinations including assessment of visual function, Lens Opacities Classification System II (LOCS II) cataract and nuclear color classification, and computerized lens image analysis. There were no statistically significant differences in visual function between the two groups. Similarly, cataract progression, assessed by LOCS II measurement and by computerized measurements of cataract, showed no important differences between the treatment groups. These data show no cataractogenic effect of lovastatin in humans.


Assuntos
Cristalino/efeitos dos fármacos , Lovastatina/uso terapêutico , Catarata/induzido quimicamente , Catarata/patologia , Sensibilidades de Contraste , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Hipercolesterolemia/tratamento farmacológico , Processamento de Imagem Assistida por Computador , Cristalino/patologia , Estudos Longitudinais , Lovastatina/efeitos adversos , Masculino , Pessoa de Meia-Idade , Fotografação , Acuidade Visual
10.
Optom Vis Sci ; 70(11): 956-62, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8302532

RESUMO

We tested an instrument to measure the line spread function (LSF) of the eye in order to assess objectively retinal image degradation due to cataract. Optical aberrations from 62 eyes with early to moderate cataract were assessed by measuring the extent of blurring of a best-focused fine line image (LSF) projected onto a subject's retina. The instrument consisted of a slitlamp equipped with a Hruby lens to project the line and a computer-coupled CCD camera to record and measure the blurred image. We hypothesized that the width of the blurred line image (called WSCAT) due to light scattering in the cataractous lens would be affected most by nuclear and subcapsular cataracts. The WSCAT results were compared to the data from two other tests: (1) Snellen acuity and (2) LOCS II cataract classification. Grouping eyes by Snellen acuity we found that WSCAT from the group with 6/4.5 (20/15) or 6/6 (20/20) acuity was distinguishable from the group with 6/9 (20/30) or worse acuity (95% confidence interval). Data also were analyzed using a regression model which corrects for the intraclass correlation between the two eyes of an individual. Results show a significant association between WSCAT and minimum angular resolution (MAR) derived from Snellen visual acuity (regression coefficient of 5.45, p = 0.008). WSCAT also is correlated with both LOCS II nuclear opalescence (NO) and posterior subcapsular (P) categories with regression coefficients of 3.03 (p = 0.004) and 2.07 (p = 0.054), respectively. Results from measurement of LSF indicate the potential for this instrument to assess retinal image degradation associated with nuclear and posterior subcapsular cataract objectively.


Assuntos
Catarata/classificação , Fotografação , Testes Visuais/métodos , Acuidade Visual , Percepção Visual/fisiologia , Idoso , Idoso de 80 Anos ou mais , Catarata/fisiopatologia , Humanos , Luz , Pessoa de Meia-Idade , Retina/fisiologia , Espalhamento de Radiação , Limiar Sensorial , Testes Visuais/instrumentação
11.
Arch Ophthalmol ; 111(6): 831-6, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8512486

RESUMO

OBJECTIVE: To develop the Lens Opacities Classification System III (LOCS III) to overcome the limitations inherent in lens classification using LOCS II. These limitations include unequal intervals between standards, only one standard for color grading, use of integer grading, and wide 95% tolerance limits. DESIGN AND RESULTS: The LOCS III contains an expanded set of standards that were selected from the Longitudinal Study of Cataract slide library at the Center for Clinical Cataract Research, Boston, Mass. It consists of six slit-lamp images for grading nuclear color (NC) and nuclear opalescence (NO), five retroillumination images for grading cortical cataract (C), and five retroillumination images for grading posterior subcapsular (P) cataract. Cataract severity is graded on a decimal scale, and the standards have regularly spaced intervals on a decimal scale. The 95% tolerance limits are reduced from 2.0 for each class with LOCS II to 0.7 for nuclear opalescence, 0.7 for nuclear color, 0.5 for cortical cataract, and 1.0 for posterior subcapsular cataract with the LOCS III, with excellent interobserver agreement. CONCLUSION: The LOCS III is an improved LOCS system for grading slit-lamp and retroillumination images of age-related cataract.


Assuntos
Catarata/classificação , Envelhecimento/fisiologia , Estudos de Casos e Controles , Estudos de Avaliação como Assunto , Humanos , Córtex do Cristalino/patologia , Núcleo do Cristalino/patologia , Variações Dependentes do Observador , Fotografação , Padrões de Referência
12.
J Cataract Refract Surg ; 19(3): 399-404, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-8501637

RESUMO

In a population of 188 nondiabetic patients with early cataracts or nuclear brunescence, we assessed the degree to which contrast sensitivity function (CSF) provided more information about a patient's visual disability than high contrast visual acuity measurements. Data collected included LOCS II cataract classification, Bailey-Lovie visual acuity (LogMAR score), Lotmar interferometric visual acuity (LI VA), and distance contrast sensitivity function (CSF) using the Vistech 6500. Generalized least squares regression models in which CS was the dependent variable and either LogMAR score or LI VA was among the independent variables were used to ascertain whether CSF provided additional information about visual disability to that provided by LogMAR score or LI VA. Contrast sensitivity function was decreased only by nuclear opalescence at high frequencies (12 to 18 cpd); for all other cataract types and nuclear color, CSF testing provided no more information about cataract-related visual loss than LI VA or LogMAR score. Measurement of CSF using the Vistech 6500 system in patients with early cataracts provides information on visual dysfunction beyond that provided by LogMAR score or LI VA only in patients with nuclear opalescence, and that may not be clinically significant.


Assuntos
Catarata/fisiopatologia , Sensibilidades de Contraste/fisiologia , Acuidade Visual/fisiologia , Adulto , Idoso , Catarata/classificação , Feminino , Humanos , Cristalino/fisiopatologia , Masculino , Pessoa de Meia-Idade
13.
Acta Ophthalmol (Copenh) ; 70(3): 376-82, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1636402

RESUMO

A new objective approach to characterize color and opalescence in the lens nucleus, using wavelength indexed transmission ratios (TR) is described. Transmission ratios, i.e. the transmissivity per unit lens thickness, for the whole visible spectral range (390-720 nm) were calculated using fast scanning spectral colorimetry (FSSC). The lowest transmission ratios values were obtained in the blue part of the spectrum in general and at 450 nm in particular. They inversely followed the subjectively determined LOCS II color grading. The difference between transmission ratios at the absorbed part of the spectrum (less than 500 nm) and the non-absorbed part (greater than 550 nm) also reflects the LOCS II color grading. The overall mean transmission ratios for all wavelengths in the spectrum gives an index that closely followed the nuclear opalescence grading of the LOCS II system. The transmission ratios are theoretically independent of the spectral characteristics of the incident light as long as it contains suprathreshold energies in the whole measured spectral range.


Assuntos
Envelhecimento/fisiologia , Núcleo do Cristalino/fisiologia , Absorção , Idoso , Idoso de 80 Anos ou mais , Colorimetria/instrumentação , Colorimetria/métodos , Feminino , Humanos , Núcleo do Cristalino/fisiopatologia , Luz , Masculino , Pessoa de Meia-Idade , Valores de Referência
14.
Ophthalmic Res ; 22 Suppl 1: 62-7, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2388753

RESUMO

An image analysis system has been developed for the objective analysis of cortical opacification. Lens photographs are obtained using a Neitz CTR retroillumination camera. The images are digitized using an IBM-PC-based imaging system. We have developed a program, called OPAC, through which the computer analyzes the image using a circular grid consisting of 93 sectors. The program outputs the percent of lens area which is opaque. Ninety-eight photographs, previously classified by the Lens Opacities Classification System (LOCS II), were analyzed using OPAC as well as a manual, square-grid counting system (GRID). The results show a linear correlation between OPAC and GRID with a correlation coefficient of 0.94. The results obtained with OPAC are also linearly correlated with the LOCS II classifications.


Assuntos
Catarata/patologia , Cápsula do Cristalino/patologia , Córtex do Cristalino/patologia , Cristalino/patologia , Iluminação/métodos , Fotografação/métodos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Software
15.
Exp Eye Res ; 43(2): 243-9, 1986 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3758223

RESUMO

Metabolism in human senile cataracts has been studied using uniformly labeled [14C]glucose. Intracapsularly extracted lenses were cultured in TC-199 media with a glucose concentration of 5.5 mM. Results show that lactate production accounts for 97% of the glucose metabolized. Under these standard incubation conditions there is negligible accumulation of alpha-glycerol phosphate, glucose-6-phosphate, and sorbitol. The rate of lactate production was found to be relatively uniform over a range of cataract severities which were determined from the CCRG classification. The effects of several perturbants in the medium were measured. An ATP concentration of 3 mM was found to inhibit lactate production. Labeled glucose-6-phosphate in the medium was found to produce lactate at a rate approximately one half that of glucose. Elevated glucose concentration resulted in a slight decrease in lactate production and, in some lenses, production of a small amount of sorbitol. Overall, the glycolytic pathway appears to be functioning normally and without regard for cortical and nuclear opacification.


Assuntos
Catarata/metabolismo , Glucose/metabolismo , Trifosfato de Adenosina/farmacologia , Cromatografia Líquida de Alta Pressão , Glucose-6-Fosfato , Glucofosfatos/metabolismo , Glicerofosfatos/metabolismo , Humanos , Técnicas In Vitro , Lactatos/metabolismo
16.
Exp Eye Res ; 40(4): 629-41, 1985 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-4007077

RESUMO

Carbohydrate metabolism in lens homogenates was evaluated using uniformly labeled [14C]-glucose. Metabolites were separated using HPLC and the distribution of 14C among metabolic pathways was determined. Under the standard incubation conditions employed (pH 7.4, 37 degrees C, 5 mM glucose) 40% of the glucose consumed forms lactate. The amount of 14C found in sorbitol and alpha-glycerol phosphate is 1-2%. This pathway distribution is essentially independent of glucose concentration from 2 to 35 mM. Over this range, lactate production is relatively constant at 2-3 mumol 7 hr-1. At 35 mM glucose, sorbitol production increases to 0.182 from 0.036 mumol 7 hr-1 at 5 mM glucose. The level of ATP is clearly a very significant factor in the regulation of glycolytic rate. An increase in ATP concentration from 1 to 3 mM results in a decrease in the rate of lactate production from 2.09 to 0.404 mumol 7 hr-1. The NAD/NADH ratio is significant in the distribution between lactate and alpha-GP. An increase in the level of NADP or NADPH increases sorbitol production as well as alpha-GP production. A computer program was developed to model the experimental incubation system. The calculated results are in agreement with the experimental in showing effects of ATP and perturbations of enzyme cofactor concentrations.


Assuntos
Glucose/metabolismo , Cristalino/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Bovinos , Cromatografia Líquida de Alta Pressão , Glucofosfatos/metabolismo , Glicerofosfatos/metabolismo , Cinética , Lactatos/metabolismo , Modelos Biológicos , NAD/metabolismo , NADP/metabolismo , Sorbitol/metabolismo
17.
Invest Ophthalmol Vis Sci ; 24(10): 1382-9, 1983 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-6352552

RESUMO

Membranes removed during open-sky vitrectomy have been characterized by electron microscopy, reaction with anti-human fibrinogen, susceptibility to enzymatic digestion, amino acid analysis, and electrophoresis in sodium dodecyl sulfate. There were significant differences between longstanding and newly formed membranes. Longstanding membranes contained substantial amounts of hydroxyproline, glycine, and hydroxylysine, were capable of digestion by collagenase but not by plasmin, yielded faint positive results with anti-human fibrinogen, and showed fibrils characteristic of collagen by electron microscopy. After digestion with pepsin, electrophoresis revealed bands that migrated the same distance as vitreous collagen chains. This type of membrane is evidently collagenous in nature. A second type of membrane, which developed in the course of vitrectomy, contained no hydroxyproline, only traces of hydroxylysine, and relatively small amounts of glycine, was digested by plasmin, yielded strong positive results with anti-human fibrinogen, and showed fibers that were not characteristic of collagen by electron microscopy. Electrophoresis demonstrated bands similar to authentic fibrin in these newly formed membranes. These data suggest that this second type of membrane is composed largely of fibrin. Prevention of the formation of this second type of membrane during vitrectomy may require the addition of agents that inhibit fibrin formation.


Assuntos
Vitrectomia/métodos , Corpo Vítreo/ultraestrutura , Aminoácidos/análise , Colágeno/análise , Eletroforese , Fibrina/análise , Imunofluorescência , Humanos , Peso Molecular , Corpo Vítreo/análise
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