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1.
Rev. senol. patol. mamar. (Ed. impr.) ; 24(2): 43-53, 2011. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-89813

RESUMO

Objetivo: El objetivo de este estudio es comparar los resultados obtenidos en la planificación de la radioterapia del cáncer de mama realizada en decúbito supino frente a decúbito prono en pacientes con mamas grandes y/o péndulas, así como la utilidad de un inmovilizador específicamente diseñado para la radioterapia de la mama en decúbito prono. Material y métodos: Se ha diseñado un inmovilizador para el posicionamiento de la mama en decúbito prono comparándolo con la inmovilización tradicional en decúbito supino conseguida mediante cuna-alfa o plano inclinado. Se analizaron los datos de 10 pacientes a las que se les realizó una doble planificación, en supino y prono, tras una cirugía conservadora de la mama. En la TAC obtenida para la planificación, se definió la totalidad de la mama como volumen blanco de planificación (PTV), así como el pulmón ipsilateral, el corazón y el tejido blando circundante a la mama como órganos críticos. La planificación en ambos casos se realizó empleando una técnica de campos tangenciales conformados con multisegmentos para obtener la máxima homogeneidad de la dosis administrada. Resultados: La homogeneidad de dosis alcanzada en el PTV, medida de acuerdo al V95%-107%, fue similar en las dos planificaciones, aunque la dosis máxima en la mama tratada fue mayor en el plan realizado en decúbito supino. El posicionamiento de las pacientes en decúbito prono redujo el porcentaje del pulmón ipsilateral que recibía dosis igual o superior a 20 Gy (V20Gy), pasando del 26,5 al 2,9% (p = 0,007). Del mismo modo, el posicionamiento en decúbito prono redujo el porcentaje del corazón que recibía dosis igual o superior a 35 Gy (V35Gy), desde el 3,4 al 1,2% (p = 0,038). Finalmente, la existencia de áreas de sobredosificación fuera de la mama también se redujeron significativamente con la posición en decúbito prono (p = 0,012). Conclusiones: El empleo de un sistema sencillo de inmovilización en decúbito prono para pacientes que precisen radioterapia de la mama tras cirugía conservadora en el caso de mamas grandes, permite mantener una homogeneidad de dosis adecuada en el volumen blanco al mismo tiempo que disminuye las dosis administradas a órganos sanos críticos como pulmón y corazón(AU)


Objective: The aim of this study is to compare two radiotherapy plans for breast cancer performed in both supine and prone position and the usefulness of a specifically designed device for prone breast radiotherapy. Material and methods: We designed an immobilization device for the positioning of the breast in the prone position comparing it with the traditional supine immobilization. We have analyzed data from 10 patients who underwent a double planning, supine and prone, after breast-conserving surgery. Radiotherapy planning in both cases was performed by using a multiple-segmented tangential-fields technique for maximum uniformity of the administered dose. Dose distributions for PTV (ipsilateral breast) and organs at risk (i.e. ipsilateral lung, heart and extramammary soft tissue) were compared for both plans. Results: The dose homogeneity achieved in the PTV, as measured according to V95%-107%, was similar in the two plans, although the maximum dose in the treated breast was higher for the supine plan. Prone positioning reduced the percentage of ipsilateral lung receiving doses equal to or greater than 20 Gy (V20Gy), from 26.5 to 2.9% (p = 0.007). Similarly, the prone position reduced the percentage of heart receiving doses equal to or greater than 35 Gy (V35Gy), from 3.4 to 1.2% (p = 0.038). Finally, the existence of overdosage areas outside the breast were also significantly reduced by the prone position (p = 0.012). Conclusions: The use of a simple system of breast immobilization in prone position for patients with large or pendulous breasts, can maintain adequate dose homogeneity in the target volume while decreasing the dose administered to critical healthy organs such as lung and heart (AU)


Assuntos
Humanos , Feminino , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Mastectomia Segmentar/métodos , Mastectomia Segmentar/tendências , Neoplasias da Mama , Mastectomia Segmentar/instrumentação , Mastectomia Segmentar/normas , Mastectomia Segmentar
2.
Int J Cosmet Sci ; 32(5): 376-86, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20491990

RESUMO

In this work, a comparative study between two methods to acquire relevant information about a cosmetic formulation has been carried out. A Design of Experiments (DOE) has been applied in two stages to a capillary cosmetic cream: first, a Plackett-Burman (PB) design has been used to reduce the number of variables to be studied; second, a complete factorial design has been implemented. With the experimental data collected from the DOE, a Least Mean Square (LMS) algorithm and Artificial Neural Networks (ANN) have been utilized to obtain an equation (or model) that could explain cream viscosity. Calculations have shown that ANN are the best prediction method to fit a model to experimental data, within the interval of concentrations defined by the whole set of experiments.


Assuntos
Algoritmos , Cosméticos , Análise dos Mínimos Quadrados , Redes Neurais de Computação
3.
Thorax ; 64(7): 581-6, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19074930

RESUMO

BACKGROUND: Previous studies have presented contradictory data concerning obstructive sleep apnoea syndrome (OSAS), lipid oxidation and nitric oxide (NO) bioavailability. This study was undertaken to (1) compare the concentration of 8-isoprostane and total nitrate and nitrite (NOx) in plasma of middle-aged men with OSAS and no other known co-morbidity and healthy controls of the same age, gender and body mass index; and (2) test the hypothesis that nasal continuous positive airway pressure (CPAP) therapy attenuates oxidative stress and nitrate deficiency. METHODS: A prospective, randomised, placebo controlled, double-blind, crossover study was performed in 31 consecutive middle-aged men with newly diagnosed OSAS and 15 healthy control subjects. Patients with OSAS were randomised to receive sham CPAP or effective CPAP for 12 weeks. Blood pressure, urinary catecholamine levels and plasma 8-isoprostane and NOx concentrations were obtained before and after both treatment modalities. RESULTS: Patients with OSAS had significantly higher 8-isoprostane levels (median (IQR) 42.5 (29.2-78.2) vs 20.0 (12.5-52.5) pg/ml, p = 0.041, Mann-Whitney test) and lower NOx levels (264 (165-650) vs 590 (251-1465) micromol/l, p = 0.022) than healthy subjects. Body mass index, blood pressure and urinary catecholamines were unchanged by CPAP therapy, but 8-isoprostane concentrations decreased (38.5 (24.2-58.7) pg/ml at baseline vs 22.5 (16.2-35.3) pg/ml on CPAP, p = 0.0001) and NOx levels increased (280 (177-707) vs 1373 (981-1517) micromol/l, p = 0.0001) after CPAP. CONCLUSIONS: OSAS is associated with an increase in oxidative stress and a decrease in NOx that is normalised by CPAP therapy.


Assuntos
Pressão Positiva Contínua nas Vias Aéreas , Nitratos/sangue , Estresse Oxidativo , Apneia Obstrutiva do Sono/terapia , Adulto , Idoso , Pressão Sanguínea/fisiologia , Dinoprosta/análogos & derivados , Dinoprosta/sangue , Método Duplo-Cego , Humanos , Masculino , Pessoa de Meia-Idade , Nitritos/sangue , Estudos Prospectivos , Apneia Obstrutiva do Sono/sangue , Apneia Obstrutiva do Sono/fisiopatologia
4.
Anal Bioanal Chem ; 392(1-2): 263-8, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18649075

RESUMO

The external sixteenth century wall paintings of St. Dumitru's Church in Suceava (Romania) are suffering visually from deterioration. Fragments of these paintings spallated from the external wall have been studied by micro-Raman microscopy in order to elucidate possible causes of this process. Calcite and alpha-quartz are the components of the substratum indicating that the artists used the Roman fresco technique comprising a limewash putty. No organic binders have been detected in the substrate or pigment application. Amorphous carbon and goethite, alpha-FeOOH, have been identified in areas containing residues of grey and yellow pigments, respectively. Small amounts of gypsum have been detected in the grey areas which we attribute to special attention being given to surface preparation and pigment application in these areas. An abundance of sodium nitrate, nitratine, microcrystals have been observed on the surfaces of many fragments which suggests that a biodeterioration process originating from guano deposits could have been operating in these frescoes.


Assuntos
Pinturas , Análise Espectral Raman/métodos , Arquitetura , Carbonato de Cálcio/análise , Sulfato de Cálcio/análise , Carbono/análise , Corantes/análise , Compostos de Ferro/análise , Minerais , Quartzo/análise , Romênia , Dióxido de Silício/análise , Espectrofotometria Infravermelho/métodos
5.
Eur Respir J ; 32(4): 1009-15, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18508832

RESUMO

There is increasing evidence that inflammation plays an important role in the development of cardiovascular complications in patients with obstructive sleep apnoea (OSA). No previous works have studied levels of soluble tumour necrosis factor-alpha receptor (sTNFR)-1 in patients with OSA. The aims of the present study were to examine serum levels of sTNFR-1 and the effect of nasal continuous positive airway pressure (CPAP) in patients with OSA. A prospective, randomised, placebo-controlled crossover study was performed. In total, 30 consecutive newly diagnosed OSA patients (apnoea/hypopnoea index 43.8+/-27.0 events x h(-1)) and 15 healthy obese patients were selected. Urinary levels of norepinephrine and epinephrine, as well as plasma sTNFR-1, tumour necrosis factor (TNF)-alpha, interleukin (IL)-6 and leukotriene (LT)B(4) levels were obtained at baseline and after 3 months of CPAP or sham CPAP. Nocturnal urinary levels of norepinephrine, epinephrine and sTNFR-1 (1,053+/-269 versus 820+/-166 pg x mL(-1)) were significantly higher in OSA patients. There were no significant differences in plasma levels of IL-6, LTB(4), or TNF-alpha between the two study groups. There were no significant differences in blood pressure, urinary catecholamine levels, or plasma IL-6, LTB(4) and TNF-alpha levels after both treatment modalities. However, after 3 months of effective CPAP usage, sTNFR-1 levels were significantly reduced (1,053+/-269 versus 899+/-254 pg x mL(-1)). Obstructive sleep apnoea patients have higher levels of soluble tumour necrosis factor-alpha receptor 1 than individuals without OSA; soluble tumour necrosis factor-alpha receptor 1 levels are lowered by continuous positive airway pressure therapy. These findings further corroborate a potential role of inflammation in the natural history of obstructive sleep apnoea.


Assuntos
Pressão Positiva Contínua nas Vias Aéreas , Receptores Tipo I de Fatores de Necrose Tumoral/sangue , Apneia Obstrutiva do Sono/sangue , Apneia Obstrutiva do Sono/terapia , Adulto , Estudos Cross-Over , Método Duplo-Cego , Epinefrina/urina , Humanos , Interleucina-6/sangue , Leucotrieno B4/sangue , Masculino , Pessoa de Meia-Idade , Norepinefrina/urina , Placebos , Estudos Prospectivos , Fator de Necrose Tumoral alfa/sangue
6.
Antioxid Redox Signal ; 7(9-10): 1356-66, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16115041

RESUMO

Several studies have shown that both oxidative stress and inflammation are linked to the process of hypertension and that the immune system is also involved in this age-related process. More specifically, the oxygen stress related to immune system dysfunction seems to have a key role in senescence, in agreement with the oxidation/ inflammation theory of aging. From a practical point of view, and according to our own research, the immune functions change in a similar fashion in hypertension and aging. As antioxidant diet supplementation decreases oxidative stress, it may be useful to treat hypertension and increase longevity. Probably, these favorable effects are mediated by an antioxidant-induced improvement of the immune function. The practice of moderate physical exercise shows similar favorable effects, and indeed our studies on exercising hypertensive women demonstrate an improved immune function, probably linked to raised levels of intracellular antioxidant defenses. The present review summarizes a selection of data related to the above from other authors as well as some findings from our own work.


Assuntos
Envelhecimento , Antioxidantes/farmacologia , Estresse Oxidativo , Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Proliferação de Células , Quimiotaxia , Ensaio de Imunoadsorção Enzimática , Exercício Físico , Feminino , Humanos , Hipertensão/metabolismo , Sistema Imunitário , Interleucina-2/metabolismo , Células K562 , Células Matadoras Naturais/metabolismo , Leucócitos/citologia , Linfócitos/metabolismo , Modelos Biológicos , Neutrófilos/metabolismo
7.
Biopolymers ; 77(6): 361-7, 2005 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15690411

RESUMO

1H-NMR spectra of aqueous solutions of fenbufen and two cyclodextrins (alpha- or gamma-cyclodextrin, respectively) mixtures confirm the formation of an inclusion complex if gamma-cyclodextrin is used, whereas in the case of alpha-cyclodextrin no inclusion complex was obtained. The stoichiometry of the fenbufen/gamma-cyclodextrin complex is of the [2:1] type. The geometry of this supramolecular architecture was established through MM+ molecular mechanics calculations.


Assuntos
Fenilbutiratos , alfa-Ciclodextrinas/química , gama-Ciclodextrinas/química , Anti-Inflamatórios não Esteroides , Configuração de Carboidratos , Sequência de Carboidratos , Hidrogênio , Espectroscopia de Ressonância Magnética/métodos , Conformação Molecular , Dados de Sequência Molecular
8.
Acta Neurol Scand ; 111(2): 114-7, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15644071

RESUMO

OBJECTIVE: To elucidate whether cerebrospinal fluid (CSF) concentrations of the microtubule-associated tau protein are related to the risk for sporadic amyotrophic lateral sclerosis (SALS). PATIENTS/METHODS: We measured tau concentrations in the CSF of 18 patients with SALS and 75 age- and sex-matched controls, using a specific ELISA method. RESULTS: The mean CSF concentrations of tau protein did not differ significantly between SALS patient and control groups, were not influenced by the clinical form (spinal vs bulbar) of ALS, and were not correlated with age, age at onset, and duration of the disease. CONCLUSIONS: CSF tau concentrations are not a biochemical marker of ALS.


Assuntos
Esclerose Lateral Amiotrófica/líquido cefalorraquidiano , Proteínas tau/líquido cefalorraquidiano , Fatores Etários , Idoso , Biomarcadores/líquido cefalorraquidiano , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Vértebras Lombares , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Punção Espinal
9.
Pharmacol Biochem Behav ; 80(1): 45-51, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15652379

RESUMO

We have studied in a model of premature ageing in mice based on their impaired behavioural response in a simple T-maze test the effect of the ingestion of thioproline (TP) plus N-acetylcysteine (NAC) (0.1% w/w of each antioxidant) by female and male mice of Swiss and BALB/c strains on performance in two behaviour tests. The antioxidant treatment (4 weeks in two different periods of life, i.e., adult and old age) protected all animals against early-age-associated behavioural impairment, but this improvement was more evident in the prematurely ageing mice (PAM) in comparison to the control group or non-prematurely ageing mice (NPAM). An improvement of the exploratory activity and neuromuscular coordination after the thiolic antioxidant treatment was found in the PAM, bringing the behavioural parameters to the NPAM levels. These effects could be due to the glutathione precursor role of NAC and TP that replenish the intracellular reduced glutathione (GSH) levels despite advancing age. In conclusion, diet supplementation with thiolic compounds appears to be an effective therapy for protection against early behavioural decline in prematurely ageing mice.


Assuntos
Senilidade Prematura/tratamento farmacológico , Envelhecimento/efeitos dos fármacos , Antioxidantes/administração & dosagem , Suplementos Nutricionais , Compostos de Sulfidrila/administração & dosagem , Envelhecimento/fisiologia , Envelhecimento/psicologia , Senilidade Prematura/fisiopatologia , Senilidade Prematura/psicologia , Animais , Feminino , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos ICR
10.
Cell Mol Biol (Noisy-le-grand) ; 50 Online Pub: OL683-90, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15607049

RESUMO

The age-related deterioration of the immune cells contributes to the increased morbidity and mortality of the aged populations. Since ageing is the result of oxidative stress and macrophages are an important source of oxidation, which is produced in order to carry out many of their functions, the changes with age of several macrophage functions as well as of oxidative stress parameters (oxidants, inflammatory mediators and antioxidants) of peritoneal leukocytes have been investigated using young (4 months), adult (7 months), mature (12 months) and old (20 months) female ICR (CD-1) mice. With age the macrophage functions suffer deterioration. Thus, chemotaxis, phagocytosis and intracellular superoxide anion production decrease in old animals. Moreover, the levels of antioxidant defenses, such as superoxide dismutase activity, decrease with ageing. However, the adherence capacity and the release of oxidant and inflammatory mediators, such as extracellular superoxide anion, TNF-alpha and PGE2, as well as oxidized glutathione/ reduced glutathione ratio, increase with age. These results show that these cells suffer oxidative stress with ageing, which results in an increase of the oxidative damage to nuclear DNA. These changes in peritoneal immune cells could contribute to the chronic oxidative stress state linked to senescence.


Assuntos
Senescência Celular/fisiologia , Leucócitos/fisiologia , Macrófagos Peritoneais/fisiologia , Estresse Oxidativo/fisiologia , Animais , Adesão Celular/fisiologia , Quimiotaxia/fisiologia , Dinoprostona/análise , Dinoprostona/metabolismo , Feminino , Glutationa/análise , Glutationa/metabolismo , Macrófagos Peritoneais/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Fagocitose/fisiologia , Superóxido Dismutase/análise , Superóxido Dismutase/metabolismo , Superóxidos/análise , Superóxidos/metabolismo , Fator de Necrose Tumoral alfa/análise , Fator de Necrose Tumoral alfa/metabolismo
11.
J Biol Inorg Chem ; 9(8): 973-86, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15452776

RESUMO

The chief motive behind this research is the interest provoked by the presence of metal ions as necessary stabilizers of the negative charges of phosphate groups in nucleic acids. The effect that the presence of different metal ions produces on the band principally assigned to the nu(s) PO(3)(2-) mode has been studied using FT-IR and FT-Raman spectroscopy. The results obtained reveal the diagnostic capacity of these techniques in determining the type of metal ion interaction with respect to the mononucleotides that form DNA and RNA, providing a tool for improving the knowledge of the stabilizing or destabilizing effects of these ions on such macromolecules. The metal complexes of the ribonucleotides 5'-CMP and 5'-GMP with Mg(II), Ca(II), Sr(II), Ba(II), Cr(III), Co(II), Cu(II), Zn(II), Cd(II), Al(III) and Ga(III) were obtained in this study. After studying and analyzing the IR and Raman spectra of all these complexes and comparing them with the spectra of the corresponding disodium salts, it was verified that, independently of the type of nucleotide involved, the presence of the metal in the vicinity of the phosphate group produces an alteration in the aforementioned nu(s) PO(3)(2-) band. This effect is related to the type of interaction that the phosphate group has with the metal. Three components are observed: (1) one near 983-975 cm(-1) (detectable in IR and Raman), associated with phosphate groups in an electrostatic type of interaction with the metal ion, separated by two or more water molecules; (2) another near 989-985 cm(-1) (only in IR), associated with phosphate groups in indirect interaction through the water molecules of the coordination sphere of the metal ions; and (3) the IR and Raman bands near 1014-1001 cm(-1), which represent phosphate groups directly bonded to the metal ion. These results are supported by the behavior of 5'-CMP in aqueous solution in the presence of Mg(II) ions.


Assuntos
Cátions/química , Monofosfato de Citidina/química , Guanosina Monofosfato/química , Metais/química , Monofosfato de Citidina/metabolismo , Guanosina Monofosfato/metabolismo , Fosfatos/química , Espectrofotometria Infravermelho/métodos , Análise Espectral Raman/métodos
12.
Biopolymers ; 73(4): 451-6, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14991662

RESUMO

An inclusion complex of fenbufen with beta-cyclodextrin (beta-CD) in aqueous solution was characterized by (1)H-NMR spectroscopy. The [1:1] stoichiometry was determined and a stability constant of several 1000s (M(-1)) was calculated. The geometry of the inclusion complex was established based on MM(+) molecular mechanics calculations.


Assuntos
Ciclodextrinas/química , Hipoglicemiantes/química , Fenilbutiratos/química , beta-Ciclodextrinas , Combinação de Medicamentos , Estabilidade de Medicamentos , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Estrutura Molecular , Soluções , Termodinâmica , Água/química
13.
Acta Neurol Scand ; 106(6): 351-4, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12460140

RESUMO

UNLABELLED: FUNDAMENTALS AND OBJECTIVE: Multiple sclerosis (MS) is the prototype of demyelinating disease, but recently, it has been shown that the existence of axonal lesions contribute to irreversible central nervous system damage in this disease. Tau proteins are considered to be important for maintaining the stability of axonal microtubules involved in the mediation of fast axonal transport of synaptic constituents. There have been reports of increased cerebrospinal fluid (CSF) tau concentrations in patients with MS, and it has been suggested that this could be a marker of axonal damage. The objective of the present study was to elucidate whether CSF tau levels could be a marker of MS activity. PATIENT AND METHODS: We measured tau concentrations in the CSF of 20 patients with MS (nine in the first, seven in the second, one in the fourth exacerbation, and three patients with chronic progressive course) and 32 age- and sex-matched controls, using a specific enzyme-linked immunosorbent assay method. RESULTS: The CSF tau concentrations of patients with MS did not differ from those of controls, and they were not correlated with age at onset and duration of the disease. CONCLUSION: CSF tau concentrations are not a marker of MS activity.


Assuntos
Esclerose Múltipla/líquido cefalorraquidiano , Esclerose Múltipla/fisiopatologia , Proteínas tau/líquido cefalorraquidiano , Adulto , Idade de Início , Axônios/fisiologia , Biomarcadores/líquido cefalorraquidiano , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Índice de Gravidade de Doença , Punção Espinal , Fatores de Tempo
14.
Nucleosides Nucleotides Nucleic Acids ; 21(6-7): 495-503, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12442966

RESUMO

The commercial mononucleotides are frequently used to obtain metal complexes and isotopic derivatives. Normally, the spectra of these new compounds are compared with the spectra of the commercial mononucleotides. Nevertheless, important variations in the vibrational spectra of the disodium 5'-guanosine monophosphate, 5'-GMP, have been observed in this work produced by submitting the commercial salt to the same general laboratory process that the obtained compounds, i.e., solving the commercial salt in water and subsequent recrystallization. These changes have been analyzed and interpreted. The variations are not significant in disodium 5'-cytosine monophosphate, 5'-CMP. It is important to take this information into account before carrying out vibrational studies with this type of molecules, since some bands attributed to isotopic substitutions or to the metal attack may be a result of manipulation of the nucleotide (solving and recrystallization) instead of the studied effect. Thus, before any work in which the nucleotide salt is manipulated (deuteration, synthesis of other isotopic derivatives or metal-nucleotide complexes), it should be noted that the process to which the sample is submitted on its own is enough to modify the vibrational spectrum. Then, attention should be paid to the changes observed in the vibrational spectra of recrystallized mononucleotides, since recrystallization may lead to a considerable phase change, and this can notably alter the vibrational spectra.


Assuntos
Guanosina Monofosfato/química , Metais/química , Cristalização , Isótopos , Conformação Molecular , Solubilidade , Solventes , Espectrofotometria Infravermelho , Análise Espectral Raman , Termodinâmica , Vibração
15.
J Neural Transm (Vienna) ; 109(7-8): 1035-44, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12111441

RESUMO

Thiamine is an essential cofactor for several important enzymes involved in brain oxidative metabolism, such as the alpha-ketoglutarate dehydrogenase complex (KGDHC), pyruvate-dehydrogenase complex (PDHC), and transketolase. Some investigators reported decreased thiamine-diphosphate levels and decreased activities of KGDHC, pyruvate-dehydrogenase complex and transketolase in the brain tissue of Alzheimer's disease (AD) patients. We measured cerebrospinal (CSF) levels of thiamine-diphosphate, thiamine-monophosphate, free thiamine, and total thiamine, using ion-pair reversed phase high performance liquid chromatography, in 33 patients with sporadic AD and 32 matched controls. The mean CSF levels of thiamine-derivatives did not differ significantly from those of controls, while the mean plasma levels of thiamine-diphosphate, free and total thiamine were significantly lower in the AD-patient group. CSF and plasma thiamine levels were not correlated with age, age at onset, duration of the disease, and scores of the MiniMental State Examination, with the exception of plasma thiamine-diphosphate with MiniMental State Examination (r = 0.41, p < 0.05) in the AD-patients group. CSF and plasma values did not predict dementia progression, assessed with the MiniMental State Examination scores. These results suggest that CSF thiamine levels are not related with the risk for and the progression of AD.


Assuntos
Doença de Alzheimer/líquido cefalorraquidiano , Tiamina/líquido cefalorraquidiano , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/sangue , Doença de Alzheimer/psicologia , Cromatografia Líquida de Alta Pressão/métodos , Progressão da Doença , Feminino , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Valores de Referência , Fatores de Risco , Tiamina/sangue , Tiamina Monofosfato/líquido cefalorraquidiano , Tiamina Pirofosfato/sangue
16.
Brain Res ; 922(1): 148-52, 2001 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-11730714

RESUMO

Increasing evidence suggests that up-regulation of the cAMP-second messenger system is implicated in Alzheimer's disease neurodegeneration. Since previous studies reported an increased level of cAMP in microvessels of Alzheimer's patients compared with those from non-demented elderly controls, we have carried out an immunohistochemical study to compare cAMP immunostaining in brain vessels from patients with dementia and neuropathological criteria of Alzheimer's disease (n=5) with those of age-matched patients (n=10). We have also included a control group of adult patients (n=5) to evaluate the role of aging separate from the effects of dementia. Our results demonstrated an increased cAMP immunostaining in cerebral cortical and meningeal vessels from Alzheimer's patients compared to nondemented elderly and adult controls. Vascular cAMP immunostaining was mainly observed in frontal and temporal cortex, the hippocampus being the region that showed the more intense and widespread vascular cAMP immunostaining. We also observed a conspicuous vascular beta-amyloid immunostaining specifically in those vessels that showed the highest cAMP immunostaining. We suggest that increased vascular cAMP immunostaining is mainly localised in the selectively vulnerable targets of neurodegeneration that characterise AD. Moreover, the co-immunolocalisation of cAMP and beta-amyloid protein in cerebral vessels of patients with AD suggests a possible role of cAMP up-regulation in the accumulation of those amyloidogenic peptides.


Assuntos
Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Circulação Cerebrovascular/fisiologia , AMP Cíclico/metabolismo , Idoso , Peptídeos beta-Amiloides/metabolismo , Capilares/patologia , Feminino , Humanos , Imuno-Histoquímica , Masculino , Inclusão em Parafina
17.
Psiquis (Madr.) ; 22(5): 222-224, sept. 2001. tab
Artigo em Es | IBECS | ID: ibc-11852
18.
Biopolymers ; 62(4): 193-207, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11391569

RESUMO

The FTIR and FT-Raman spectra are reported for the arabinonucleoside ara-T (1-beta-D-arabinofuranosylthymine), which shows antiviral activity. The accurate knowledge of the vibrational modes is a prerequisite for the elucidation of drug-nucleotide and drug-enzyme interactions. The FTIR and FT-Raman spectra of ara-T were recorded from 4000 to 30 cm(-1). A tetradeuterated derivative (deuteration at N3, and hydroxyl groups O'2, O'3, and O'5) was synthesized and the observed isotopic shifts in its spectra were used for the vibrational analysis of ara-T. The theoretical frequencies and the potential energy distribution (PED) of the vibrational modes of ara-T were calculated using the ab initio Hartree-Fock/3-21G method. An assignment of the vibrational spectra of ara-T is proposed considering the scaled PED and the observed band shifts under deuteration. The scaled ab initio frequencies were in reasonable agreement with the experimental data.


Assuntos
Arabinonucleosídeos/química , Modelos Moleculares , Timidina/análogos & derivados , Timidina/química , Antivirais/química , Espectrofotometria Infravermelho , Análise Espectral Raman
19.
Free Radic Res ; 35(6): 873-84, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11811538

RESUMO

Diabetes mellitus may be associated with intracellular glutathione (GSH) deficiency. Since in vivo studies have shown that plasma intracellular GSH plays a key role in regulating the activation of nuclear factor kappaB (NF-kappaB), we have investigated the relationship between intracellular thiols (GSH, homocysteine, cysteine and cysteinyglycine) and NF-kappaB activity in the peripheral blood mononuclear cells (PBMC) of 63 elderly non-insulin dependent diabetes mellitus (NIDDM) patients (28 microalbuminurics and 35 normoalbuminurics) and 30 healthy age- and sex-matched subjects. In addition, we have measured plasma concentrations of these thiol compounds, serum concentrations of interleukin-6 (IL-6) and vascular cell adhesion molecule-1 (sVCAM-1), that are partly dependent on the NF-kappaB activation, as well as the serum levels of thiobarbituric acid reacting substances (TBARS), as index of lipid peroxidation. Diabetic patients with microalbuminuria (MAB) and normoalbuminuria had NF-kappaB activity 2.1- and 1.5-fold greater, respectively, than the control group. As compared to normoalbuminuric patients, patients with MAB had significantly higher levels of glycemia, plasma homocysteine, and serum concentrations of TBARS, IL-6 and sVCAM-1 (in all cases, p < 0.01), and significantly lower GSH content in the PBMC (p < 0.05). The intracellular GSH in PBMC correlated with NF-kappaB activation (r = -0.82; p < 0.0001), serum TBARS (r = -0.60; p < 0.001), and with fasting glycemia (r = -0.56; p < 0.001) in patients with MAB, whereas a weaker association between GSH levels in PBMC and NF-kappaB activation (r = -0.504, p < 0.001) was seen in patients without MAB. These results suggest that the decrease of intracellular GSH content in elderly NIDDM patients with MAB is strongly associated with enhanced NF-kappaB activation, which could contribute to the development of increased glomerular capillary permeability and its rapid progression.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Glutationa/deficiência , NF-kappa B/metabolismo , Fatores Etários , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/sangue , Ciclofosfamida/sangue , DNA/metabolismo , Diabetes Mellitus Tipo 2/sangue , Doxorrubicina/sangue , Ensaio de Desvio de Mobilidade Eletroforética , Etoposídeo/sangue , Feminino , Humanos , Interleucina-6/sangue , Masculino , Metotrexato/sangue , NF-kappa B/sangue , Compostos de Sulfidrila/metabolismo
20.
Horm Metab Res ; 32(10): 407-12, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11069205

RESUMO

OBJECTIVE: To test whether oxidative stress could promote a systemic acute-phase response in elderly patients with type II diabetes. DESIGN AND METHODS: In a group of 30 older diabetic patients with poor glycemic control, serum levels of lipid peroxides, measured as thiobarbituric acid-reacting substances (TBARS); C-reactive protein (CRP); interleukin (IL)-6 and the soluble form of its receptor (slL-6R), were evaluated at baseline and after 2 and 3 months of therapeutic intervention. Thirty asymptomatic, untreated individuals with abnormal fasting glycemia, but otherwise healthy status, of similar age, sex, and weight served as control group. RESULTS: At baseline, glycemia (8.83 +/- 0.67mmol/l), HbA1C (8.66 +/- 0.59%), TBARS (8.68 +/- 1.21 micromol/l), CRP (16.05 +/- 3.81 mg/l) IL-6 (5.39 +/- 1.25 pg/ml) and sIL-6R (1425 +/- 492 pg/ml) were significantly higher in diabetic patients than in asymptomatic hyperglycemic individuals (p<0.001). After treatment, glycemia significantly decreased with respect to baseline values (- 9.82% after 60 days and -13.74% after 90 days), as did serum levels of TBARS (-14.05% and -21.89%, respectively), CRP (-32.71% and -43.86%), IL-6 (-23.75% and -40.63%) and sIL-6R (-34.53% and -48.49%, respectively). In diabetic patients, multiple regression showed, at each time, that TBARS and IL-6 were independently correlated with CRP, considering CRP as the dependent variable. Similar correlations were found in asymptomatic hyperglycemic subjects. CONCLUSION: These results suggest that oxidative stress might be implicated in promoting a state of low-grade systemic inflammation in elderly patients with type II diabetes.


Assuntos
Reação de Fase Aguda/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Estresse Oxidativo/fisiologia , Idoso , Proteína C-Reativa/metabolismo , Diabetes Mellitus Tipo 2/dietoterapia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Feminino , Humanos , Hiperglicemia/sangue , Interleucina-6/metabolismo , Masculino , Receptores de Interleucina-6/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
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