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1.
Phytomedicine ; 18(10): 879-86, 2011 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-21397481

RESUMEN

Genistein aglycone (GEN) has a favorable effect on bone loss. We investigated the effects of GEN alone or in combination with supplemental calcium and vitamin D(3) in an animal model of bone loss to evaluate if there was additional benefit. Ovariectomized (OVX) and SHAM-OVX rats were used. OVX were divided into 12 groups and randomized to receive: GEN at 27, 54, 200, 500 or 1000 mg (human equivalent dose (HED)/day/ip injection alone or with calcium carbonate (Ca) (360 mg/kg/day/gavages) and vitamin D(3) (D(3)) (50 IU/kg/day/gavages) or Ca/D(3) without GEN or untreated for 6 weeks. SHAM-OVX were randomized into 7 groups and treated with: Ca and D(3) alone or in combination with GEN (same doses as OVX), or left untreated. Bone mineral density (BMD), bone-alkaline phosphatase (b-ALP), collagen C-telopeptides (CTX), osteoprotegerin (OPG) and soluble receptor activator of NFκB ligand (sRANKL) were assessed. Femurs were excised and tested for breaking strength and histology. Uterine weight was analyzed to assess GEN's estrogenic effects on the SHAM-OVX. The most effective dose of GEN, independent of Ca/D(3) supplementation, was 54 mg/day. Higher doses yielded no further improvement in bone biomarkers, histology or strength. Only 1000 mg/day HED of genistein produced statistically significant changes in uterine weight of the SHAM-OVX. This study suggests that 54 mg/day of GEN is the threshold dose for efficacy. In addition, supplemental calcium and vitamin D(3), beyond normal dietary intake do not enhance the effects of genistein on improving measures of bone loss. This observation has implications regarding the use of calcium and vitamin D(3) supplementation.


Asunto(s)
Enfermedades Óseas Metabólicas/tratamiento farmacológico , Carbonato de Calcio/farmacología , Colecalciferol/farmacología , Genisteína/uso terapéutico , Fosfatasa Alcalina/metabolismo , Animales , Densidad Ósea , Conservadores de la Densidad Ósea/administración & dosificación , Conservadores de la Densidad Ósea/farmacología , Fuerza Compresiva , Modelos Animales de Enfermedad , Quimioterapia Combinada , Femenino , Fémur/anatomía & histología , Fémur/efectos de los fármacos , Genisteína/administración & dosificación , Osteoprotegerina/efectos de los fármacos , Ovariectomía , Extractos Vegetales/administración & dosificación , Extractos Vegetales/uso terapéutico , Ligando RANK/metabolismo , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Sophora/química , Útero/efectos de los fármacos
2.
Nutr Metab Cardiovasc Dis ; 20(5): 332-40, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19631515

RESUMEN

BACKGROUND AND AIM: Recent evidence suggests that genistein aglycone may act beneficially on surrogate cardiovascular risk markers in postmenopausal women. We assessed the effects of genistein aglycone on some cardiovascular risk factors and homocysteine levels after 3-years of continued therapy in a cohort of osteopenic, postmenopausal women. METHODS AND RESULTS: The parent study was a randomized, double-blind, placebo-controlled trial involving 389 postmenopausal women with low bone mass for 24 months. Subsequently, a subcohort (138 patients) continued therapy for an additional year. Participants received 54mg of genistein aglycone (n=71) or placebo (n=67), daily. Both arms received calcium and vitamin D(3) in therapeutic doses. Moreover, 4 weeks before randomization procedures and during our follow-up study, all patients received dietary instructions in an isocaloric fat-restricted diet. Blood lipid profiles, fasting glucose and insulin, insulin resistance (HOMA-IR), fibrinogen, osteoprotegerin (OPG) and homocysteine at baseline and after 24 and 36 months of treatment were measured. Compared to placebo, genistein significantly decreased fasting glucose and insulin, HOMA-IR, fibrinogen and homocysteine after 24 and 36 months of treatment. By contrast, isoflavone administration did not affect high-density lipoprotein cholesterol and triglycerides though serum OPG was higher in the genistein recipients. There were no differences in adverse events or discomfort between groups. Results on routine biochemical, liver function, and hematologic testing did not change over time in placebo or genistein group. CONCLUSIONS: After 3-years of treatment, genistein aglycone plus calcium, vitamin D(3) and a healthy diet showed positive effects on some cardiovascular risk factors and homocysteine levels in a cohort of postmenopausal women with low bone mass.


Asunto(s)
Enfermedades Cardiovasculares/prevención & control , Genisteína/farmacología , Homocisteína/sangre , Carbonato de Calcio/administración & dosificación , Colecalciferol/administración & dosificación , Femenino , Estudios de Seguimiento , Genisteína/efectos adversos , Humanos , Resistencia a la Insulina , Lípidos/sangre , Persona de Mediana Edad , Osteoprotegerina/sangre , Posmenopausia , Proyectos de Investigación , Factores de Riesgo
3.
Br J Pharmacol ; 156(8): 1287-95, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19302595

RESUMEN

BACKGROUND AND PURPOSE: Glucocorticoid-induced osteoporosis (GIO) is the leading cause of secondary osteoporosis. Clinical evidence suggests a role for genistein aglycone in the treatment of post-menopausal osteopenia although proof of efficacy in comparison with currently available treatments is still lacking. To clarify this issue, we investigated the effects of genistein on bone compared with alendronate in experimental GIO. EXPERIMENTAL APPROACH: A total of 28 female Sprague-Dawley rats were used. GIO was induced by daily injections of methylprednisolone (MP; 30 mg x kg(-1) s.c.) for 60 days. Sham GIO animals (Sham-MP) were injected daily with the MP vehicle. At the end of the osteoporosis development period, MP rats were randomized to receive: vehicle (n= 7), genistein aglycone (5 mg x kg(-1) s.c.; n= 7) or alendronate (0.03 mg x kg(-1) s.c.; n= 7). Treatment lasted 60 days. Sham-MP animals were treated with vehicle for an additional 60 days. At the beginning and at the end of treatments, animals were examined for bone mineral density and bone mineral content. Bone-alkaline phosphatase and carboxy-terminal collagen cross links were determined; femurs were removed and tested for breaking strength and histology. KEY RESULTS: Genistein aglycone showed a greater increase in bone mineral density, bone mineral content and in breaking strength than alendronate and significantly increased bone-alkaline phosphatase (bone formation marker), reduced carboxy-terminal collagen cross links (bone resorption marker), compared with alendronate. Both treatments improved bone histology and the histological score. CONCLUSION AND IMPLICATIONS: The results strongly suggest that the genistein aglycone might be an alternative therapy for the management of secondary osteoporosis.


Asunto(s)
Alendronato/farmacología , Conservadores de la Densidad Ósea/farmacología , Remodelación Ósea/efectos de los fármacos , Calcificación Fisiológica/efectos de los fármacos , Fracturas del Fémur/prevención & control , Fémur/efectos de los fármacos , Genisteína/farmacología , Osteoporosis/tratamiento farmacológico , Alendronato/administración & dosificación , Fosfatasa Alcalina/metabolismo , Animales , Biomarcadores/metabolismo , Densidad Ósea/efectos de los fármacos , Conservadores de la Densidad Ósea/administración & dosificación , Colágeno Tipo I/metabolismo , Modelos Animales de Enfermedad , Femenino , Fracturas del Fémur/etiología , Fracturas del Fémur/fisiopatología , Fémur/metabolismo , Fémur/patología , Fémur/fisiopatología , Genisteína/administración & dosificación , Inyecciones Subcutáneas , Metilprednisolona , Osteoporosis/inducido químicamente , Osteoporosis/complicaciones , Osteoporosis/fisiopatología , Péptidos/metabolismo , Ratas , Ratas Sprague-Dawley , Factores de Tiempo
4.
Br J Pharmacol ; 155(6): 896-905, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18695641

RESUMEN

BACKGROUND AND PURPOSE: Genistein aglycone positively affects bone loss in postmenopausal women, but bone quality data are still lacking. To clarify this, we investigated the effects of genistein compared with alendronate, raloxifene and oestradiol in an animal model of established osteoporosis. EXPERIMENTAL APPROACH: Six months after ovariectomy, 96 ovariectomized (OVX) rats were divided into 8 equal groups, randomized to treatments (genistein aglycone (1 and 10 mg kg(-1) s.c.); alendronate (0.003 and 0.03 mg kg(-1) s.c.); raloxifene hydrochloride (0.05 and 0.5 mg kg(-1) s.c.); 17-alpha-ethinyl oestradiol (0.003 and 0.03 mg kg(-1) s.c.)) for 12 weeks. Untreated OVX (n=12) and sham OVX (n=12) were used as controls. At the beginning and end of treatment, bone mineral density (BMD) and bone mineral content (BMC) were assessed. At the end of the experiment, calcium, phosphorus, bone-alkaline phosphatase (b-ALP), collagen C-telopeptide (CTX), osteoprotegerin (OPG) and soluble receptor activator of nuclear factor-kappaB ligand (sRANKL) were assayed. Femurs were removed and tested for breaking strength and histology. KEY RESULTS: Genistein (10 mg kg(-1)) showed a greater increase in both BMD (P<0.0001 vs OVX) and BMC than all the other treatments. Moreover, genistein significantly increased breaking strength, bone quality, b-ALP (P<0.0001 vs OVX) and OPG, and reduced CTX and sRANKL compared with the other treatments at all dose levels. CONCLUSIONS AND IMPLICATIONS: The results strongly suggest that the genistein aglycone might be a new therapy for the management of postmenopausal osteoporosis in humans.


Asunto(s)
Alendronato/uso terapéutico , Conservadores de la Densidad Ósea/uso terapéutico , Estradiol/uso terapéutico , Genisteína/uso terapéutico , Osteoporosis/tratamiento farmacológico , Clorhidrato de Raloxifeno/uso terapéutico , Alendronato/farmacología , Animales , Densidad Ósea/efectos de los fármacos , Conservadores de la Densidad Ósea/farmacología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Estradiol/farmacología , Femenino , Genisteína/farmacología , Ovariectomía , Fitoestrógenos/farmacología , Fitoestrógenos/uso terapéutico , Clorhidrato de Raloxifeno/farmacología , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Factores de Tiempo
5.
J Med Food ; 10(3): 442-51, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17887937

RESUMEN

A mixed extract containing two naturally occurring flavonoids, baicalin from Scutellaria baicalensis and catechin from Acacia catechu, was tested for cyclooxygenase (COX) and 5-lipoxygenase (5-LOX) inhibition via enzyme, cellular, and in vivo models. The 50% inhibitory concentration for inhibition of both ovine COX-1 and COX-2 peroxidase enzyme activities was 15 microg/mL, while the mixed extract showed a value for potato 5-LOX enzyme activity of 25 microg/mL. Prostaglandin E2 generation was inhibited by the mixed extract in human osteosarcoma cells expressing COX-2, while leukotriene production was inhibited in both human cell lines, immortalized THP-1 monocyte and HT-29 colorectal adenocarcinoma. In an arachidonic acid-induced mouse ear swelling model, the extract decreased edema in a dose-dependent manner. When arachidonic acid was injected directly into the intra-articular space of mouse ankle joints, the mixed extract abated the swelling and restored function in a rotary drum walking model. These results suggest that this natural, flavonoid mixture acts via "dual inhibition" of COX and LOX enzymes to reduce production of pro-inflammatory eicosanoids and attenuate edema in an in vivo model of inflammation.


Asunto(s)
Acacia/química , Inhibidores de la Ciclooxigenasa/administración & dosificación , Inflamación/tratamiento farmacológico , Inhibidores de la Lipooxigenasa , Extractos Vegetales/administración & dosificación , Scutellaria baicalensis/química , Animales , Antiinflamatorios/administración & dosificación , Catequina/administración & dosificación , Línea Celular Transformada , Línea Celular Tumoral , Ciclooxigenasa 1 , Ciclooxigenasa 2 , Dinoprostona/metabolismo , Inhibidores Enzimáticos/administración & dosificación , Flavonoides/administración & dosificación , Células HT29 , Humanos , Inflamación/inducido químicamente , Masculino , Ratones , Ratones Endogámicos ICR , Monocitos , Osteosarcoma , Ovinos
6.
Clin Microbiol Infect ; 11(2): 153-5, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15679492

RESUMEN

There are very few reports on the rates of oropharyngeal colonisation by Streptococcus pyogenes and Staphylococcus aureus in young adults. The present study found colonisation rates of 9.6% and 26.2%, respectively. These rates are two-fold higher than historical rates, indicating that these organisms may be more prevalent than thought previously. This finding may have important clinical consequences in certain populations, and requires further investigation.


Asunto(s)
Orofaringe/microbiología , Staphylococcus aureus/aislamiento & purificación , Streptococcus pyogenes/aislamiento & purificación , Adolescente , Adulto , Estudios Transversales , Humanos , Estaciones del Año
7.
Biol Psychiatry ; 50(5): 358-63, 2001 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-11543739

RESUMEN

BACKGROUND: The orbital frontal cortex is involved with processing of performance feedback. This study tests the hypothesis that older depressed subjects, compared with elderly control subjects, commit more subsequent errors after receiving feedback from an initial error. METHODS: We administered 116 older depressed patients and 139 control subjects the Trail Making Test Part B (TRAILS-B). Subjects who committed an error on TRAILS-B were immediately given feedback on performance. We then measured the frequency of making an error on the subsequent three tries. The likelihood of making any subsequent error was examined. RESULTS: After controlling for the overall initial error rate, more depressed patients than control subjects made subsequent errors. This association remained significant in later regression models. When the depressed group was examined in additional models, severity of depression was not associated with increased subsequent errors. CONCLUSIONS: These results extend previous findings suggesting a performance feedback deficit in geriatric depression. The findings support previous studies linking the orbital frontal cortex and depression.


Asunto(s)
Trastorno Depresivo Mayor/fisiopatología , Retroalimentación/fisiología , Lóbulo Frontal/fisiopatología , Pruebas Neuropsicológicas , Anciano , Atención/fisiología , Trastorno Depresivo Mayor/diagnóstico , Trastorno Depresivo Mayor/psicología , Femenino , Humanos , Masculino , Recuerdo Mental/fisiología , Persona de Mediana Edad , Desempeño Psicomotor/fisiología , Tiempo de Reacción/fisiología
8.
J Neurovirol ; 7(4): 382-5, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11517421

RESUMEN

AIDS-related PML continues to be a relatively common and rapidly fatal infection in patients with AIDS, and no effective therapy has been established to alleviate the effects of this disease. Through the years, isolated reports and small case studies have shown somewhat encouraging results using cytosine arabinoside (AraC) in the treatment of PML. The optimism behind the use AraC for this disease began to fade with ACTG trial 243, which suggested that AraC had no benefit in patients with HIV-related PML. In this article, we provide evidence that suggests that the failure of AraC in the ACTG trial may have been due to insufficient delivery of the drug through traditional intravenous and intrathecal routes. Furthermore, we provide evidence that convection-enhanced intraparenchymal delivery of AraC may prove to be a safe and effective means of treating this infection, and we outline a clinical trial that we have recently undertaken to test this hypothesis.


Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/tratamiento farmacológico , Antivirales/farmacología , Citarabina/farmacocinética , Sistemas de Liberación de Medicamentos/métodos , Leucoencefalopatía Multifocal Progresiva/tratamiento farmacológico , Animales , Humanos
9.
J Am Chem Soc ; 123(6): 1222-9, 2001 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-11456677

RESUMEN

NMR residual dipolar couplings have great potential to provide rapid structural information for proteins in the solution state. This information even at low resolution may be used to advantage in proteomics projects that seek to annotate large numbers of gene products for entire genomes. In this paper, we describe a novel approach to the structural interpretation of dipolar couplings which is based on structural motif pattern recognition, where a predefined gapless structural template for a motif is used to search a set of residual dipolar couplings for good matches. We demonstrate the applicability of the method using synthetic and experimental data. We also provide an analysis of the statistical power of the method and the effects of order tensor frame orientation, motif size, and structural complexity on motif detection. Finally, we discuss remaining problems that must be overcome before the method can be used routinely to identify protein homologies.


Asunto(s)
Proteínas/química , Resonancia Magnética Nuclear Biomolecular , Conformación Proteica
10.
J Am Psychoanal Assoc ; 49(4): 1219-34, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11809021

RESUMEN

As preconceptions about the meaning of sexual orientation are increasingly abandoned, analysts are left with the question of how these matters are to be addressed in clinical work. These problems are explored as they emerged in analytic work between a "gay" man and a "straight" analyst. Emphasis is placed on how the search for personal meaning is impacted by the intellectual and social context inhabited by analyst and patient.


Asunto(s)
Homosexualidad Masculina/psicología , Terapia Psicoanalítica , Adulto , Humanos , Masculino
11.
J Biomol NMR ; 21(4): 335-47, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11824753

RESUMEN

Residual dipolar couplings provide significant structural information for proteins in the solution state, which makes them attractive for the rapid determination of protein folds. Unfortunately, dipolar couplings contain inherent structural ambiguities which make them difficult to use in the absence of additional information. In this paper, we describe an approach to the construction of protein backbone folds using experimental dipolar couplings based on a bounded tree search through a structural database. We filter out false positives via an overlap similarity measure that insists that protein fragments assigned to overlapping regions of the sequence must have self-consistent structures. This allows us to determine a backbone fold (including the correct Calpha-Cbeta bond orientations) using only residual dipolar coupling data obtained from one ordering medium. We demonstrate the applicability of the method using experimental data for ubiquitin.


Asunto(s)
Modelos Moleculares , Resonancia Magnética Nuclear Biomolecular/métodos , Conformación Proteica , Proteínas/química , Algoritmos , Bases de Datos de Proteínas , Péptidos/química , Pliegue de Proteína , Ubiquitinas/química
12.
Psychopharmacol Bull ; 35(3): 79-88, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-12397880

RESUMEN

An informant-rated cognitive screen may have the potential to reliably help detect early dementia. A valuable scale should have good interitem associations and strong reliability when tested in groups with and without cognitive impairment. Our scale, the Brief Cognitive Scale (BCS), consists of 18 questions designed to assess cognitive function that affects everyday activities. Each question is coded with one of four levels, ranging from no impairment to severe impairment. We administered this screen to 120 subjects: 26 controls, 28 with a diagnosis of mild cognitive impairment (MCI), and 66 with a diagnosis of dementia. In addition, we administered a Folstein Mini-Mental Status Examination (MMSE) to each subject. Our results showed that the BCS scores were lowest in the control group and highest in the dementia group. In our sample, this scale was effective at discriminating between subjects with no cognitive impairment, MCI, and dementia. However, the scale needs further refinement before it can be employed in a clinical setting.


Asunto(s)
Envejecimiento/psicología , Trastornos del Conocimiento/diagnóstico , Demencia/diagnóstico , Escalas de Valoración Psiquiátrica , Anciano , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/psicología , Trastornos del Conocimiento/psicología , Demencia/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas
13.
J Biomol NMR ; 18(2): 83-100, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11101213

RESUMEN

In this paper, we explore connections between the Lipari-Szabo formalism and reduced spectral density mapping, and show how spectral density estimates can be associated with Lipari-Szabo parameters via a simple geometric construction which we call Lipari-Szabo mapping. This relationship can be used to estimate Lipari-Szabo parameters from spectral density estimates without the need for nonlinear optimization, and to perform 'model selection' in a graphical manner. The Lipari-Szabo map also provides insight into the Lipari-Szabo model, and allows us to determine when a given set of experimental spectral densities are inconsistent with the Lipari-Szabo formalism. Practical applications of Lipari-Szabo mapping in conjunction with more traditional analysis methods are discussed.


Asunto(s)
Modelos Teóricos , Resonancia Magnética Nuclear Biomolecular/métodos , Anisotropía , Proteínas Bacterianas/química , Procesamiento de Imagen Asistido por Computador
14.
J Magn Reson ; 146(1): 66-80, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10968959

RESUMEN

It has recently become more widely appreciated that the presence of rotational diffusional anisotropy in proteins and other macromolecules can have a significant affect on the interpretation of NMR relaxation data in terms of molecular motion. In this paper, we show how commonly used NMR relaxation data (R(1), R(2), and NOE) obtained at two spectrometer frequencies can be analyzed using a Bayesian statistical approach to reliably detect and quantify the degree of rotational diffusion anisotropy. Our approach differs from previous methods in that it does not make assumptions concerning the internal motions experienced by the residues which are used to quantify the diffusion anisotropy, but rather averages the results over all internal motions consistent with the data. We demonstrate our method using synthetic data corresponding to isotropic, axially symmetric anisotropic, and fully asymmetric anisotropic rotational diffusion, as well as experimental NMR data. We compare the Bayesian statistical approach with a widely used method for extracting tumbling parameters using both synthetic and experimental data. While it can be difficult to separate the effects of chemical exchange from rotational anisotropy using this "standard" method, these effects are readily separated using Bayesian statistics. In addition, we find that the Bayesian statistical approach requires considerably less CPU time than an equivalent standard analysis.


Asunto(s)
Teorema de Bayes , Espectroscopía de Resonancia Magnética/métodos , Algoritmos , Anisotropía , Simulación por Computador , Difusión , Método de Montecarlo , Rotación
15.
Protein Eng ; 13(3): 149-52, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10775656

RESUMEN

Protein design experiments have shown that the use of specific subsets of amino acids can produce foldable proteins. This prompts the question of whether there is a minimal amino acid alphabet which could be used to fold all proteins. In this work we make an analogy between sequence patterns which produce foldable sequences and those which make it possible to detect structural homologs by aligning sequences, and use it to suggest the possible size of such a reduced alphabet. We estimate that reduced alphabets containing 10-12 letters can be used to design foldable sequences for a large number of protein families. This estimate is based on the observation that there is little loss of the information necessary to pick out structural homologs in a clustered protein sequence database when a suitable reduction of the amino acid alphabet from 20 to 10 letters is made, but that this information is rapidly degraded when further reductions in the alphabet are made.


Asunto(s)
Aminoácidos , Pliegue de Proteína , Proteínas/química , Algoritmos , Secuencia de Aminoácidos , Alineación de Secuencia , Programas Informáticos
16.
Brain Res ; 856(1-2): 281-90, 2000 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-10677637

RESUMEN

We evaluated the delivery of 14C-cytosine arabinoside (AraC) to rat brain by: 1) intravenous (IV) bolus, by 2) intrathecal (IT) and 3) intraventricular (IVT) infusion, and by 4) convection-enhanced delivery (CED) into the caudate nucleus. Plasma and brain AraC metabolites were measured with HPLC, and distribution and concentration of 14C-AraC in brain sections were measured by quantitative autoradiography. After IV administration, the alpha and beta plasma half-lives were 1.9 and 46.5 min, respectively. The blood-to-brain transfer constant of AraC was 2.5+/-1.4 microliter g(-1) min(-1), compatible with high water solubility. After IT and IVT administration, tissue levels were high at the brain and ventricular surfaces, but declined exponentially into brain. After CED, maximum brain levels were up to 10,000 times higher than the IV group, and the distribution pattern was one of high 14C-AraC concentration in the convective component, with exponentially declining concentrations outside this region. The rate loss constant from brain was 0.002+/-0.0004 min(-1), suggesting that AraC was accumulating in brain cells. AraC was metabolized into uracil arabinoside within the brain. 14C-AraC was infused into 1 dog and distributed widely in the ipsilateral hemisphere. These studies suggest that delivery of AraC to brain parenchyma by the IV, IT or IVT routes will be subtherapeutic. Delivery by CED can achieve, and maintain, therapeutic levels of AraC in the brain, and should be further evaluated as a potential method of drug delivery.


Asunto(s)
Encéfalo/metabolismo , Núcleo Caudado/metabolismo , Citarabina/administración & dosificación , Citarabina/farmacocinética , Animales , Radioisótopos de Carbono , Citarabina/sangre , Perros , Semivida , Infusiones Parenterales , Inyecciones Intravenosas , Inyecciones Intraventriculares , Inyecciones Espinales , Ratas , Ratas Sprague-Dawley , Distribución Tisular
18.
Bioinformatics ; 16(11): 988-1002, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11159310

RESUMEN

MOTIVATION: Sequence alignment techniques have been developed into extremely powerful tools for identifying the folding families and function of proteins in newly sequenced genomes. For a sufficiently low sequence identity it is necessary to incorporate additional structural information to positively detect homologous proteins. We have carried out an extensive analysis of the effectiveness of incorporating secondary structure information directly into the alignments for fold recognition and identification of distant protein homologs. A secondary structure similarity matrix based on a database of three-dimensionally aligned proteins was first constructed. An iterative application of dynamic programming was used which incorporates linear combinations of amino acid and secondary structure sequence similarity scores. Initially, only primary sequence information is used. Subsequently contributions from secondary structure are phased in and new homologous proteins are positively identified if their scores are consistent with the predetermined error rate. RESULTS: We used the SCOP40 database, where only PDB sequences that have 40% homology or less are included, to calibrate homology detection by the combined amino acid and secondary structure sequence alignments. Combining predicted secondary structure with sequence information results in a 8-15% increase in homology detection within SCOP40 relative to the pairwise alignments using only amino acid sequence data at an error rate of 0.01 errors per query; a 35% increase is observed when the actual secondary structure sequences are used. Incorporating predicted secondary structure information in the analysis of six small genomes yields an improvement in the homology detection of approximately 20% over SSEARCH pairwise alignments, but no improvement in the total number of homologs detected over PSI-BLAST, at an error rate of 0.01 errors per query. However, because the pairwise alignments based on combinations of amino acid and secondary structure similarity are different from those produced by PSI-BLAST and the error rates can be calibrated, it is possible to combine the results of both searches. An additional 25% relative improvement in the number of genes identified at an error rate of 0.01 is observed when the data is pooled in this way. Similarly for the SCOP40 dataset, PSI-BLAST detected 15% of all possible homologs, whereas the pooled results increased the total number of homologs detected to 19%. These results are compared with recent reports of homology detection using sequence profiling methods. AVAILABILITY: Secondary structure alignment homepage at http://lutece.rutgers.edu/ssas CONTACT: anders@rutchem.rutgers.edu; ronlevy@lutece.rutgers.edu SUPPLEMENTARY INFORMATION: Genome sequence/structure alignment results at http://lutece.rutgers.edu/ss_fold_predictions.


Asunto(s)
Estructura Secundaria de Proteína , Proteínas/química , Proteínas/genética , Alineación de Secuencia/estadística & datos numéricos , Algoritmos , Secuencia de Aminoácidos , Animales , Biología Computacional , Bases de Datos Factuales , Genoma , Hemoglobinas/química , Hemoglobinas/genética , Modelos Moleculares , Datos de Secuencia Molecular , Pliegue de Proteína , Programas Informáticos
19.
Arthritis Rheum ; 42(11): 2309-18, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10555025

RESUMEN

OBJECTIVE: Risedronate, a new pyridinyl bisphosphonate, is a potent antiresorptive bone agent. This study examines the safety and efficacy of daily, oral risedronate therapy for the prevention of corticosteroid-induced bone loss. METHODS: This multicenter, randomized, double-blind, placebo-controlled, parallel-group study was conducted in 224 men and women who were initiating long-term corticosteroid treatment. Patients received either risedronate (2.5 mg or 5 mg) or placebo daily for 12 months. Each patient also received 500 mg of elemental calcium daily. The primary outcome measure was the percentage of change in lumbar spine bone mineral density (BMD). Secondary measures included proximal femur BMD and incidence of vertebral fractures. RESULTS: After 12 months, the lumbar spine BMD (mean +/- SEM) did not change significantly compared with baseline in the 5-mg (0.6 +/- 0.5%) or the 2.5-mg (-0.1 +/- 0.7%) risedronate groups, while it decreased in the placebo group (-2.8 +/- 0.5%; P < 0.05). The mean differences in BMD between the 5-mg risedronate and the placebo groups were 3.8 +/- 0.8% at the lumbar spine (P < 0.001), 4.1 +/- 1.0% at the femoral neck (P < 0.001), and 4.6 +/- 0.8% at the femoral trochanter (P < 0.001). A trend toward a decrease in the incidence of vertebral fracture was observed in the 5-mg risedronate group compared with the placebo group (5.7% versus 17.3%; P = 0.072). Risedronate was well tolerated, and the incidence of upper gastrointestinal adverse events was comparable among the 3 groups. CONCLUSION: Risedronate therapy prevents bone loss in patients initiating long-term corticosteroid treatment.


Asunto(s)
Corticoesteroides/efectos adversos , Resorción Ósea/prevención & control , Bloqueadores de los Canales de Calcio/uso terapéutico , Ácido Etidrónico/análogos & derivados , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Biomarcadores , Resorción Ósea/inducido químicamente , Bloqueadores de los Canales de Calcio/efectos adversos , Demografía , Método Doble Ciego , Ácido Etidrónico/efectos adversos , Ácido Etidrónico/uso terapéutico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ácido Risedrónico
20.
J Magn Reson ; 139(2): 408-21, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10423379

RESUMEN

In order to analyze NMR relaxation data in terms of parameters which describe internal motion, one must first obtain a description of the overall tumbling of the macromolecule in solution. Methods currently used to estimate these global parameters may not always provide reliable estimates of their values and uncertainties. In this paper, we present a general data analysis formalism based on products of Bayesian marginal probability densities which can be used to efficiently combine the information content from multiple experiments, such as R(1), R(2), and NOE data collected at multiple magnetic field strengths, or data from cross-correlation or rotating frame relaxation dispersion experiments. Our approach allows the estimation of global tumbling and internal dynamical parameters and their uncertainties without some of the assumptions which are made in the commonly-used methods for model-selection and global parameter estimation. Compared to an equivalent classical statistical approach, the Bayesian method not only is more computationally efficient, but also provides greater insight into the information content of the data. We demonstrate that this approach can be used to estimate both the isotropic rotational correlation time in the context of the original and "extended" Lipari-Szabo formalisms [Lipari & Szabo, J. Am. Chem. Soc. 1982, 104, 4546; Clore et al., J. Am. Chem. Soc. 1990, 112, 4989], as well as the rotational diffusion coefficients for axially symmetric anisotropic tumbling.


Asunto(s)
Espectroscopía de Resonancia Magnética/métodos , Anisotropía , Teorema de Bayes , Método de Montecarlo
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