Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 39
Filter
1.
Neuroimage ; 230: 117778, 2021 04 15.
Article in English | MEDLINE | ID: mdl-33497775

ABSTRACT

Information from Magnetic Resonance Imaging (MRI) is useful for diagnosis and treatment management of human neurological patients. MRI monitoring might also prove useful for non-human animals involved in neuroscience research provided that MRI is available and feasible and that there are no MRI contra-indications precluding scanning. However, MRI monitoring is not established in macaques and a resource is urgently needed that could grow with scientific community contributions. Here we show the utility and potential benefits of MRI-based monitoring in a few diverse cases with macaque monkeys. We also establish a PRIMatE MRI Monitoring (PRIME-MRM) resource within the PRIMatE Data Exchange (PRIME-DE) and quantitatively compare the cases to normative information drawn from MRI data from typical macaques in PRIME-DE. In the cases, the monkeys presented with no or mild/moderate clinical signs, were well otherwise and MRI scanning did not present a significant increase in welfare impact. Therefore, they were identified as suitable candidates for clinical investigation, MRI-based monitoring and treatment. For each case, we show MRI quantification of internal controls in relation to treatment steps and comparisons with normative data in typical monkeys drawn from PRIME-DE. We found that MRI assists in precise and early diagnosis of cerebral events and can be useful for visualising, treating and quantifying treatment response. The scientific community could now grow the PRIME-MRM resource with other cases and larger samples to further assess and increase the evidence base on the benefits of MRI monitoring of primates, complementing the animals' clinical monitoring and treatment regime.


Subject(s)
Brain/diagnostic imaging , Data Analysis , Magnetic Resonance Imaging/methods , Nervous System Diseases/diagnostic imaging , Animals , Case-Control Studies , Demyelinating Diseases/diagnostic imaging , Demyelinating Diseases/therapy , Infections/diagnostic imaging , Infections/therapy , Macaca mulatta , Male , Muscle Weakness/diagnostic imaging , Muscle Weakness/therapy , Nervous System Diseases/therapy
2.
J Hum Nutr Diet ; 34(1): 94-105, 2021 02.
Article in English | MEDLINE | ID: mdl-33119948

ABSTRACT

BACKGROUND: The intake of certain types of resistant starch (RS) has been associated in some studies with increased whole-body insulin sensitivity. This randomised, cross-over pilot trial evaluated the effect of consuming cooked, then chilled potatoes, a source of RS, compared to isoenergetic, carbohydrate (CHO)-containing control foods, on insulin sensitivity and related markers. METHODS: Nineteen adults with body mass index 27.0-39.9 kg m-2 consumed 300 g day-1 RS-enriched potatoes (approximately two potatoes; ~18 g RS) or CHO-based control foods, as part of lunch, evening and snack meals, over a 24-h period. After an overnight fast, insulin sensitivity, CHO metabolism markers, free fatty acids, breath hydrogen levels and appetite were assessed for up to 5 h after the intake of a standard breakfast. The primary endpoint was insulin sensitivity, assessed with the Matsuda index. P < 0.05 (one-sided) was considered statistically significant. RESULTS: Insulin sensitivity was not significantly different between the potato and control conditions. The potato intervention resulted in higher postprandial breath hydrogen (P = 0.037), lower postprandial free fatty acid concentrations (P = 0.039) and lower fasting plasma glucose (P = 0.043) compared to the control condition. Fullness ratings were significantly lower after potato versus control (P = 0.002). No other significant effects were observed; however, there was a trend toward lower fasting insulin (P = 0.077) in the potato versus the control condition. CONCLUSIONS: The results of this pilot study suggest RS-enriched potatoes may have a favourable impact on carbohydrate metabolism and support the view that additional research in a larger study sample is warranted.


Subject(s)
Diabetes Mellitus, Type 2/metabolism , Insulin Resistance , Resistant Starch/administration & dosage , Adult , Appetite/drug effects , Biomarkers/metabolism , Blood Glucose/metabolism , Cross-Over Studies , Fatty Acids, Nonesterified/metabolism , Female , Humans , Male , Meals , Middle Aged , Pilot Projects , Solanum tuberosum/chemistry
3.
World J Surg ; 44(11): 3868-3874, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32591841

ABSTRACT

BACKGROUND: Laparoscopic liver resections (LLR) have been increasingly performed in recent years. Most of the available evidence, however, comes from specialized centers in Asia, Europe and USA. Data from South America are limited and based on single-center experiences. To date, no multicenter studies evaluated the results of LLR in South America. The aim of this study was to evaluate the experience and results with LLR in South American centers. METHODS: From February to November 2019, a survey about LLR was conducted in 61 hepatobiliary centers in South America, composed by 20 questions concerning demographic characteristics, surgical data, and perioperative results. RESULTS: Fifty-one (83.6%) centers from seven different countries answered the survey. A total of 2887 LLR were performed, as follows: Argentina (928), Brazil (1326), Chile (322), Colombia (210), Paraguay (9), Peru (75), and Uruguay (8). The first program began in 1997; however, the majority (60.7%) started after 2010. The percentage of LLR over open resections was 28.4% (4.4-84%). Of the total, 76.5% were minor hepatectomies and 23.5% major, including 266 right hepatectomies and 343 left hepatectomies. The conversion rate was 9.7%, overall morbidity 13%, and mortality 0.7%. CONCLUSIONS: This is the largest study assessing the dissemination and results of LLR in South America. It showed an increasing number of centers performing LLR with the promising perioperative results, aligned with other worldwide excellence centers.


Subject(s)
Laparoscopy , Liver Neoplasms , Argentina , Asia , Brazil , Chile , Colombia , Europe , Hepatectomy , Humans , Liver , Liver Neoplasms/surgery , Peru
4.
Eur J Clin Nutr ; 71(1): 33-38, 2017 01.
Article in English | MEDLINE | ID: mdl-27677368

ABSTRACT

BACKGROUND: Corn oil (CO) and extra-virgin olive oil (EVOO) are rich sources of unsaturated fatty acids (UFA), but UFA profiles differ among oils, which may affect lipoprotein levels. OBJECTIVES: The objective of this study was to assess the effects of CO versus EVOO intake on fasting lipoprotein and subfraction cholesterol levels, apolipoprotein (apo) A1, apo B, and low-density lipoprotein particle concentrations in men and women. SUBJECTS/METHODS: As part of a weight maintenance diet, men and women were provided with food items prepared with 54 g per day of CO or EVOO (21-day treatment, 21-day washout) in a randomized, double-blind, controlled-feeding, crossover trial. Fasting lipoprotein cholesterol and related variables were determined with density gradient ultracentrifugation. RESULTS: Among the 54 completers, CO reduced total cholesterol, low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), apo B and LDL particle concentration to a greater extent compared with EVOO intake. Changes in LDL-C and VLDL-C contributed to the larger reduction in non-HDL-C with CO compared with EVOO intake (-0.39 mmol/l vs -0.04 mmol/l; P<0.001). The larger reduction in LDL-C by CO intake was attributable to changes (P<0.05) caused by CO vs EVOO in large LDL1+2-C (-0.22 mmol/l) and intermediate-density lipoprotein cholesterol (-0.12 mmol/l). HDL-C responses did not differ between treatments, but apo A1 increased more with EVOO compared with CO intake (4.6 versus 0.7 mg/dl, respectively, P=0.016). CONCLUSIONS: CO intake reduced atherogenic lipoprotein cholesterol and particle concentrations to a larger extent than did EVOO, which may have implications for cardiovascular disease risk.


Subject(s)
Apolipoproteins/blood , Cholesterol/blood , Corn Oil/administration & dosage , Eating/physiology , Lipoproteins, LDL/blood , Lipoproteins/blood , Olive Oil/administration & dosage , Apolipoprotein A-I/blood , Apolipoproteins B/blood , Cross-Over Studies , Double-Blind Method , Female , Humans , Male , Middle Aged
5.
NOVA publ. cient ; 14(25): 57-65, 2016. ilus, tab
Article in Spanish | LILACS, COLNAL | ID: biblio-955156

ABSTRACT

Objetivo: Evaluar la actividad antibacteriana y antioxidante de las partes aéreas de Baccharis revoluta. Métodos: La especie fue colectada en el municipio de Chocontá, Cundinamarca (N 05° 08' 26,3" W 73° 38' 59,2"). A los extractos de hojas, tallos y flores de diferente polaridad se les determinó la actividad antibacteriana frente a los microorganismos Staphylococcus aureus Gram (+), Klebsiella pneumoniae Gram (-) y Escherichia coli Gram (-), utilizando el método de difusión en gel por perforación en placa y se le evaluó la actividad antioxidante por el método DPPH•. Resultados: Las pruebas de eficacia antimicrobiana exhibieron inhibición significativa de los extractos. Además, se determinó la concentración crítica, que representa una medida de la susceptibilidad del microorganismo, y los extractos presentaron mayor actividad antibacteriana frente a Staphylococcus aureus que a Klebsiella pneumoniae y Escherichia coli. Los extractos etanólicos presentaron una actividad antioxidante representativa, con una IC50 y actividad antioxidante relativa de 7,2% y 43.64%, para el extracto etanólico de hojas, 6,95% y 45.57% para el extracto etanólico de tallos y 7,1% y 44.16 % para el extracto etanólico de flores, lo que nos determina una gran potencialidad de estos extractos etanólicos.


Objective. To vvaluate the antibacterial and antioxidant activity ofthe aerial parts of Baccharis revolute. Methods. The species was collected in the municipality of Chocontá, Cundinamarca (N 05 ° 08 '26.3 "W 73 ° 38' 59.2"). In extracts of leaves, stems and flowers of different polarity were determined in antibacterial activity against the microorganisms Staphylococcus aureus Gram (+), Klebsiella pneumoniae Gram (-) and Escherichia coli Gram (-) using the gel diffusion method by drilling plate and he evaluated the antioxidant activity by the DPPH• method. Results. Antimicrobial efficacy tests showed significant inhibition of the extracts. Moreover, the critical concentration, which is a measure of the susceptibility of the microorganism was determined, and the extracts showed greater antibacterial activity against Staphylococcus aureus than Klebsiella pneumoniae and Escherichia coli. Ethanolic extracts showed a representative antioxidant activity, an antioxidant activity IC50 and on 7.2% and 43.64% for the ethanol extract of leaves, 6.95 and 45.57% for the ethanol extract of stems and 7.1% and 44.16% for the ethanol extract of flowers wich determines us great potential of these ethanolic extracts.


Subject(s)
Humans , Staphylococcus aureus , Bacteria , Aquatic Microorganisms , Microbiology
6.
Rehabilitación (Madr., Ed. impr.) ; 48(4): 232-240, oct.-dic. 2014.
Article in Spanish | IBECS | ID: ibc-129590

ABSTRACT

Objetivo. Revisar la eficacia del entrenamiento motor bilateral de los miembros superiores, la terapia de restricción del lado sano, la terapia frente a espejo, la estimulación eléctrica funcional, la terapia robótica y la terapia con realidad virtual sobre la recuperación funcional del miembro superior de pacientes con ictus. Estrategia de búsqueda. Estudios publicados entre 2003-2012, en Medline, PubMed, PEDro, Cochrane Library y Tripdatabase. Los términos de búsqueda fueron: eficacia, extremidad superior, ictus, neuroplasticidad, recuperación motora y Rehabilitación. Selección de estudios. Revisiones sistemáticas y ensayos clínicos aleatorizados en fase aguda, subaguda y crónica postictus. Síntesis de resultados. La terapia de restricción del lado sano, los robots, la estimulación eléctrica funcional y terapias con realidad virtual inducen mayor recuperación motora en pacientes subagudos y crónicos con paresia moderada del miembro superior. Conclusiones. Las terapias con orientación funcional a tareas y empleo de nuevas tecnologías facilitan una mayor recuperación funcional del miembro superior. Futuros estudios confirmarán la eficacia de estas terapias (AU)


Objective. This article has aimed to review the efficacy of bilateral upper limb motor training, constraint-induced movement therapy, mirror therapy, functional electrical stimulation, robotic therapy, and virtual reality therapy on upper limb motor function recovery in stroke patients. Search strategy. A review of the studies published between 2003-2012 in Medline, PubMed, PEDro, Cochrane Library databases and Tripdatabase was carried out. MesH key words used were: efficacy, upper limb, stroke, neuroplasticity, motor recovery, and Rehabilitation. Study selection. Study selection included systematic reviews and randomized controlled trials in acute, subacute, and chronic post-stroke patients. Data synthesis. Constraint-induced movement therapy, robotic therapy, exercises coupled to functional electrical stimulation, and virtual reality therapy improve upper limb motor function in subacute and chronic stroke patients with mild upper limb paresis. Conclusions. Therapies based on task-oriented paradigm with application of rehabilitation technology could facilitate upper limb functional recovery. Future studies are required to confirm the efficacy of these emergent therapies (AU)


Subject(s)
Humans , Male , Female , Stroke/complications , Stroke/diagnosis , Stroke/rehabilitation , Nervous System Diseases/complications , Nervous System Diseases/rehabilitation , Upper Extremity/physiopathology , Neuronal Plasticity/physiology , Motor Activity/physiology , Motor Skills Disorders/rehabilitation , Treatment Outcome , Evaluation of the Efficacy-Effectiveness of Interventions
7.
Plant Physiol Biochem ; 83: 300-7, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25208508

ABSTRACT

Wheat (Triticum aestivum) and its derivative products account for a major source of dietary intake of selenium (Se) in humans and animals, because of its essentiality due to its presence in vital enzymes. Se antioxidant role has resulted in the popularity of agronomic biofortification practises in Se deficient areas. Controlling Se uptake, metabolism, translocation and accumulation in plants will be important to decrease healthy risk of toxicity and deficiency and to help selecting adequate methods for biofortification. Selenate and selenite are the two main inorganic Se forms available in soil and in most of the studies are given separately. That study reveals that both Se species behave differently but combined the prevalent pattern is that of selenite; so it is taken up faster and it seems that interferes with selenate uptake and transport. Selenium has dual effects on wheat plants; at low concentrations it acts as growth stimulant whereas at high concentrations it reduces root elongation and biomass production and alters uptake and translocation of several essential nutrients.


Subject(s)
Biomass , Plant Roots/growth & development , Selenium/pharmacology , Triticum/growth & development
8.
Rev. colomb. enferm ; 6(6): 47-60, ago. 2011. tab, graf
Article in Spanish | LILACS, BDENF - Nursing | ID: lil-616057

ABSTRACT

El presente estudio se realizó con el objetivo de evaluar el efecto de la Albahaca (Ocimum basilicum) sobre dolor pélvico en dismenorrea primaria (menstruación dolorosa) en mujeres en edad fértil, durante los meses de julio y agosto del 2010. Para tal fin esta investigación fue aleatoria estratificada y doble ciego controlada con placebo (cápsulas color blanco con azul). Se seleccionaron 44 pacientes en el rango de edad fértil, con ciclos regulares y que presentaban dismenorrea primaria, las cuales fueron distribuidas en dos grupos de tratamiento: Grupo 1: cápsulas de Albahaca, y Grupo 2: cápsulas de placebo, las cuales estuvieron sometidas a dos meses de tratamiento con dosis específica; a las pacientes inicialmente se les fue socializado el consentimiento informado. Los síntomas fueron registrados por medio de encuestas que tenían en cuenta 3 variables principales las cuales fueron: “escala análoga del dolor” (escala numérica: 0 - ausencia del dolor; 10 - dolor insoportable), “intensidad máxima del dolor” y “total del dolor” (tiempo en minutos). Adicional a esto se tuvieron en cuenta comportamientos de “disminución”, “constante” y “aumento” en cuanto al dolor y al aumento o disminución del consumo de medicamentos de síntesis química Los resultados obtenidos en la investigación y los revisados con los estadísticos revelan que la Albahaca presentó un efecto en cuanto a disminución del dolor en las pacientes y, al compararse con el tratamiento con cápsula de placebo, se evidenciaron diferencias significativas en las variables tomadas en cuenta.


Subject(s)
Dysmenorrhea , Simple Random Sampling , Double-Blind Method , Ocimum basilicum
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 75(5): 1398-402, 2010 May.
Article in English | MEDLINE | ID: mdl-20227337

ABSTRACT

Composition of the prehistoric pigments' (from Carriqueo rock shelter, Rio Negro province, Argentina) has been analysed by means of molecular spectroscopy (Fourier transform infrared (FTIR) and micro-Raman) and scanning electron microscopy (SEM) coupled to an energy-dispersive X-ray spectrometer (EDS). Red and yellow pigments were recognized as red and yellow ochre. The matrix of the pigments is composed of one or more substances. According to the matrix composition yellow and red pigments were also divided into two groups-i.e. those containing kaolinite or sulphates. Green pigment was detected as green earth, made up of celadonite as a chromophore.


Subject(s)
Coloring Agents/chemistry , Spectrometry, X-Ray Emission/methods , Argentina , Geography , History, Ancient , Microscopy, Electron, Scanning , Spectroscopy, Fourier Transform Infrared , Spectrum Analysis, Raman
11.
Environ Int ; 33(8): 1040-7, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17698193

ABSTRACT

The amount of sewage sludge generated in Europe is expected to surpass the 10 million tons/year in 2006 as a result of the waste water treatment process according to the Water Policy in European Union. Sewage sludge is what is left behind after water is cleaned in waste treatment plants and is characterized for this high content in nitrogen and phosphorous that could be of great importance in agriculture as fertilizer or soil conditioner. On the other hand, pollutants like metals and organic contaminants are usually removed from water and are accumulated in the sewage sludge, reaching the food chain if their concentrations are not below the safe limits established by the European legislation. The latter issue is of great concern nowadays and in this sense, different works alert against the use of the sewage sludge in agriculture arguing that serious illnesses, even resulting in death as well as adverse environmental impacts are associated to the application of sewage sludge. This work is a continuation of a former comprehensive survey on of priority organic pollutant in sludges for agricultural purposes carried out by our group in Catalonia and this time is focused on the polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F), one of the most toxic group of organic compounds listed in the Work Document on Sludge which is the reference tool in this field in Europe and is also included in the Stockholm Convention. Eighty eight samples were collected from the end of 2003 to April 2006 and the concentrations detected were lower than the 100 ng/kg I-TEQ limit recommended by the European legislation (EC, 2000). Thus, sewage sludges generated in Catalonia do not represent a threat to human health if they are used as fertilizers in agriculture.


Subject(s)
Benzofurans/analysis , Polychlorinated Dibenzodioxins/analogs & derivatives , Sewage/analysis , Agriculture , Dibenzofurans, Polychlorinated , Environment , Environmental Monitoring , Europe , Fertilizers , Polychlorinated Dibenzodioxins/analysis
12.
Chemosphere ; 61(9): 1358-69, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16291406

ABSTRACT

A comprehensive characterization of five of the seven priority organic pollutants listed in the draft of the "Working document on sludge" [EU, 2000. Working Document on Sludge 3rd Draft. Unpublished, 19 p] has been carried out during 2001-2003 in sludge samples from Catalonia (NE Spain). One hundred and thirty-nine samples belonging to 20 Waste Water Treatment Plants (WWTPs), seven sludge treatment (thermal drying) and three composting sludge plants were taken in order to determine the concentration of polychlorinated dibenzo-p-dioxins and -furans (PCDD/Fs), di-2-(ethyl-hexyl)-phthalate (DEHP), nonylphenol and nonylphenol ethoxylates with one or two ethoxy groups (NPE), polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). PCDD/F concentrations were in general lower than the 100 ng I-TEQ/kg limit suggested in the above-mentioned document. In the same way, 98.5% for PCBs, 97% for PAH and 92.8% for DEHP of the samples presented concentrations lower than 0.8 mg/kg dm, 6 mg/kg dm and 100 mg/kg dm, respectively. In contrast, the vast majority of samples contained NPE concentrations much higher than 50mg/kg dm limit. The values ranged from 14.3 to 3150 mg/kg dm (median value=286.6 mg/kg) being composted sludge samples the less contaminated ones (17.9-363.4 mg/kg dm; median value=89.3 mg/kg). Special attention should be paid to the Catalan sludge NPE contamination owing to the high levels detected.


Subject(s)
Hydrocarbons/analysis , Sewage/chemistry , Waste Disposal, Fluid , Agriculture , Reference Values , Risk Assessment
13.
Appl Radiat Isot ; 58(4): 509-16, 2003 Apr.
Article in English | MEDLINE | ID: mdl-12672632

ABSTRACT

Lithium-based ceramics have been proposed as tritium breeders for fusion reactors. The lithium aluminate (gamma phase) seems to be thermally and structurally stable, the damages produced by neutron irradiation depend on the absorbed dose. A method based on the measurement of neutron activation of foils through neutron capture has been developed to obtain the neutron absorbed dose in lithium aluminates irradiated in the thermal column facility and in the fixed irradiation system of a Triga Mark III Nuclear Reactor.

14.
FEBS Lett ; 533(1-3): 72-8, 2003 Jan 02.
Article in English | MEDLINE | ID: mdl-12505162

ABSTRACT

Drosophila MTO metal binding features were analyzed for comparison with MTN, the paralogous Drosophila metallothionein, and to classify MTO as either zinc- or copper-thionein. This was achieved by a combination of in vivo, in vitro and in silico methodologies. All the results unambiguously classified MTO as a second Drosophila copper-thionein, putting Drosophila forward as the only metazoan in which any zinc-thionein has still to be reported. Interestingly, experimental data only showed minor differences in the coordinative behavior of both MTs, but provided a characteristic spectroscopic fingerprint, revealing the possible binding of chloride anions in certain metal-MTO aggregates.


Subject(s)
Drosophila Proteins/metabolism , Metallothionein/metabolism , Amino Acid Sequence , Animals , Cloning, Molecular , Copper/chemistry , DNA, Complementary/genetics , Drosophila Proteins/chemistry , Drosophila Proteins/genetics , Drosophila melanogaster/genetics , Drosophila melanogaster/metabolism , Metallothionein/chemistry , Metallothionein/genetics , Molecular Sequence Data , Molecular Structure , Phylogeny , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Sequence Homology, Amino Acid , Zinc/chemistry
15.
Adv Ther ; 17(2): 103-16, 2000.
Article in English | MEDLINE | ID: mdl-11010054

ABSTRACT

This multicenter, open study, carried out in 14 countries in Europe, Latin America, and Asia, recruited 4965 patients suffering from recurrent respiratory tract infections to investigate the safety and acceptability of the oral bacterial lysate immunomodulator LW 50020. Patients remained in the study for 4 months (two 4-week courses of LW 50020 separated by a 28-day treatment-free interval and follow-up). The incidence of all adverse events was 7.2%; that of adverse drug reactions was 0.6%. Adverse drug reactions were mild to moderate and not more frequent in the large subgroup of patients (77%) with a known history of allergies or underlying respiratory diseases; however, the incidence of adverse events in this subgroup was twofold higher than in the study population as a whole, probably indicating a generally increased vulnerability to disease. No clinically relevant changes in laboratory variables followed treatment. Comparison of the first study period (first course of LW 50020 and drug-free interval) with the second study period (second course of LW 50020 and follow-up) showed an overall reduction of at least 50% in the number, severity, and duration of respiratory tract infections, the number of antibiotic and symptomatic treatments, and the number of days absent from school or work. Tolerability and acceptability were assessed as good or very good in 99% of patients who completed the study.


Subject(s)
Adjuvants, Immunologic/therapeutic use , Bacterial Vaccines/therapeutic use , Respiratory Tract Infections/drug therapy , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Consumer Product Safety , Female , Humans , Incidence , Male , Middle Aged , Prospective Studies , Recurrence , Respiratory Tract Infections/epidemiology
16.
J Neurochem ; 75(1): 266-73, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10854270

ABSTRACT

Metallothionein (MT)-III, a member of the MT family of metal-binding proteins, is mainly expressed in the CNS and is abundant in glutamatergic neurons. Results in genetically altered mice indicate that MT-III may play neuroprotective roles in the brain, but the mechanisms through which this protein functions have not been elucidated. The aim of this work was to assess whether MT-III is able to prevent glutamate neurotoxicity and to identify the step of the neurotoxic process interfered with by MT-III. Glutamate neurotoxicity in cerebellar neurons in culture is mediated by excessive activation of glutamate receptors, increased intracellular calcium, and increased nitric oxide. It is shown that MT-III prevented glutamate- and nitric oxide-induced neurotoxicity in a dose-dependent manner, with nearly complete protection at 0.3-1 microgram/ml. MT-III did not prevent the glutamate-induced rise of intracellular calcium level but reduced significantly the nitric oxide-induced formation of cyclic GMP. Circular dichroism analysis revealed that nitric oxide triggers the release of the metals coordinated to the cysteine residues of MT-III, indicative of the S(Cys)-nitrosylation of the protein. Therefore, the present results indicate that MT-III can quench pathological levels of nitric oxide, thus preventing glutamate and nitric oxide neurotoxicity.


Subject(s)
Cell Survival/drug effects , Cerebellum/cytology , Glutamic Acid/toxicity , Nerve Tissue Proteins/pharmacology , Neurons/drug effects , Nitric Oxide/toxicity , Animals , Cadmium/pharmacology , Calcium/metabolism , Cells, Cultured , Cerebellum/drug effects , Circular Dichroism , Cyclic GMP/metabolism , Glutamic Acid/pharmacology , Metallothionein 3 , Neurons/metabolism , Neuroprotective Agents/pharmacology , Nitric Oxide/pharmacology , Nitric Oxide Donors/pharmacology , Penicillamine/analogs & derivatives , Penicillamine/pharmacology , Rats , Rats, Wistar
17.
J Inorg Biochem ; 73(1-2): 57-64, 1999.
Article in English | MEDLINE | ID: mdl-10212995

ABSTRACT

The copper(I) and silver(I) binding properties of the beta fragment of recombinant mouse metallothionein I have been studied by electronic absorption and circular dichroism spectroscopy. When possible, the stoichiometry of the species formed was confirmed by electrospray mass spectrometry. The behaviour observed differs from that reported for the native protein. Titration of either Zn3-beta MT at pH 7 or apo-beta MT at pH 3 with Cu+ leads to the formation of species having the same stoichiometry and structure: Cu6-beta MT, Cu7-beta MT and Cu10-beta MT. In the first stage of the titration of Zn3-beta MT with Cu+ at pH 7 one additional species of formula Cu4Zn1-beta MT was detected. In contrast, the titration of Zn3-beta MT at pH 7.5 and of apo-beta MT at pH 2.5 with Ag+ proceeds through different reaction pathways, affording ZnxAg3-beta MT, Ag6-beta MT and Ag9-beta MT or Ag3-beta MT, Ag6-beta MT and Ag9-beta MT, respectively. The CD envelope corresponding to species with the same stoichiometric ratio, Ag6-beta MT and Ag9-beta MT, indicates that they have a different structure at each pH value. On the basis of the differences observed, the postulated similarity between copper and silver binding to metallothionein may be questioned.


Subject(s)
Copper/metabolism , Metallothionein/metabolism , Silver/metabolism , Animals , Binding Sites , Circular Dichroism , Hydrogen-Ion Concentration , Metallothionein/chemistry , Mice , Peptide Fragments/metabolism , Recombinant Proteins/metabolism , Spectrophotometry, Ultraviolet
18.
Biosystems ; 47(3): 129-47, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9793626

ABSTRACT

In genetic systems there is a non-trivial interface between the sequence of symbols which constitutes the chromosome, or 'genotype', and the products which this sequence encodes--the 'phenotype'. This interface can be thought of as a 'computer'. In this case the chromosome is viewed as an algorithm and the phenotype as the result of the computation. In general, only a small fraction of all possible sequences of symbols makes any sense for a given computer. The difficulty of finding meaningful algorithms by random mutation is known as the brittleness problem. In this paper we show that mutation and crossover favor the emergence of an algorithmic language which facilitates the production of meaningful sequences following random mutations of the genotype. We base our conclusions on an analysis of the population dynamics of a variant of Kitano's neurogenetic model wherein the chromosome encodes the rules for cellular division and the phenotype is a 16-cell organism interpreted as a connectivity matrix for a feed-forward neural network. We show that an algorithmic language emerges, describe this language in extenso, and show how it helps to solve the brittleness problem.


Subject(s)
Algorithms , Genetics, Population , Genotype , Models, Genetic , Phenotype
19.
Rev Med Chil ; 126(1): 17-26, 1998 Jan.
Article in Spanish | MEDLINE | ID: mdl-9629750

ABSTRACT

BACKGROUND: Resistance of HIV to AZT is the result of mutations in the pol gene that codifies the enzyme reverse transcriptase. AIM: To assess the resistance to antiretroviral drugs in Chilean patients infected with HIV. MATERIAL AND METHODS: The presence of mutations was searched in 22 patients infected with HIV. The emergence or persistence of these mutations was studied in sequential samples of 19 patients. The presence of the mutation that confers resistance to didanosine (DDI) was studied in those subjects exposed to the drug. Polymerase chain reaction techniques were used to analyze mutations in codons 41, 70 and 215 of the pol gene (resistance to AZT) and the mutation in codon 71 (resistance to DDI). RESULTS: On admission, none of the patients without previous exposure to AZT had drug resistance mutations. Seven of 12 patients (58.3%) that had received AZT had mutations in codon 215. In two, they were associated to a mutation in codon 41 and in two, a mutation in codon 70. After a mean follow up of 14 months, 13 of 15 patients (86%) that received AZT had viral strains genotypically resistant to the drug. In nine of these, the resistance was associated with disease progression. None of the 10 patients that received DDI had the mutation in codon 74 that confers resistance to the drug. However, in one of these patients, that never received AZT, a virus with a mutation in codon 215 was detected. CONCLUSIONS: A high percentage of patients that have received monotherapy with AZT have genotypic resistance to the drug. This resistance is associated with clinical and immunological derangement in 70% of these subjects.


Subject(s)
Anti-HIV Agents/therapeutic use , HIV Infections/drug therapy , HIV/drug effects , HIV/genetics , Zidovudine/therapeutic use , Chile , Codon/drug effects , Codon/genetics , Drug Resistance , Follow-Up Studies , Genotype , Humans , Mutation/drug effects , Mutation/genetics , Prospective Studies
20.
Rev Med Chil ; 124(8): 975-9, 1996 Aug.
Article in Spanish | MEDLINE | ID: mdl-9196998

ABSTRACT

Lyme disease, caused by the spirochete Borrelia burgdorferi, has several clinical manifestations and is transmitted to man by tick bites. In Chile and Latin America, several cases have been reported, but none with immunoblot confirmation or isolation of the infecting organism. We report a 9 year old boy consulting with bilateral facial palsy, polyradiculoneuritis with tetraparesis and meningeal irritation. Cerebrospinal fluid analysis showed increased protein concentration without pleocytosis and negative viral or bacterial cultures. IgM antibodies against Borrelia burgdorferi, were positive by ELISA and were confirmed by immunoblot at the Reference Laboratory of the University of Connecticut. The child had a recent contact with hamsters brought from Germany. The substantiation of Lyme disease existence in Chile should prompt the search and isolation of the causal agent.


Subject(s)
Arachnid Vectors/microbiology , Bites and Stings/microbiology , Lyme Disease/transmission , Ticks/parasitology , Animals , Borrelia burgdorferi Group/isolation & purification , Child , Cricetinae/parasitology , Humans , Lyme Disease/diagnosis , Male
SELECTION OF CITATIONS
SEARCH DETAIL
...