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1.
Environ Pollut ; 356: 124308, 2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-38844040

RESUMEN

Antibiotics, frequently detected in aquatic ecosystems, can negatively impact the health of resident organisms. Although the study on the possible effects of antibiotics on these organisms has been increasing, there is still little information available on the molecular effects on exposed non-target organisms. In our study we used a label free proteomic approach and sea bream, Sparus aurata, to evaluate the effects of exposure to environmentally relevant concentrations of the antibiotic compounds ciprofloxacin (CIP), sulfadiazine (SULF) and trimethoprim (TRIM) produced at the protein level. Individuals of sea bream were exposed to single compounds at 5.2 ± 2.1 µg L-1 of CIP, 3.8 ± 2.7 µg L-1 of SULF and 25.7 ± 10.8 µg L-1 of TRIM for 21 days. After exposure, the number of differentially expressed proteins in the liver was 39, 73 and 4 for CIP, SULF and TRIM respectively. In the brain, there was no alteration of proteins after CIP and TRIM treatment, while 9 proteins were impacted after SULF treatment. The differentially expressed proteins were involved in cellular biological, metabolic, developmental, growth and biological regulatory processes. Overall, our study evidences the vulnerability of Sparus aurata, after exposure to environmentally relevant concentrations of the major antibiotics CIP, SULF and TRIM and that their chronic exposure could lead to a stress situation, altering the proteomic profile of key organs such as brain and liver.


Asunto(s)
Antibacterianos , Encéfalo , Ciprofloxacina , Hígado , Proteómica , Dorada , Sulfadiazina , Trimetoprim , Contaminantes Químicos del Agua , Animales , Dorada/metabolismo , Hígado/metabolismo , Hígado/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Encéfalo/metabolismo , Encéfalo/efectos de los fármacos
2.
Inorg Chem ; 63(13): 5779-5782, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38488723

RESUMEN

Deprotonation of the thioamidate group of [OsH{κ2-N,S-[NHC(CH3)S]}(≡CPh)(IPr)(PiPr3)]OTf [1; IPr = 1,3-bis(2,6-diisopropylphenyl)imidazolylidene; OTf = CF3SO3] results in the release of acetonitrile and formation of the terminal sulfide complex OsH(S)(≡CPh)(IPr)(PiPr3) (2), which has been transformed into the hydrosulfide [OsH(SH)(≡CPh)(IPr)(PiPr3)]OTf (3) and the methylsulfide [OsH(SMe)(≡CPh)(IPr)(PiPr3)]OTf (4) through protonation and methylation reactions, respectively. The structure, spectroscopic characteristics, and reactivity of these compounds are compared. Reactions of 3 and 4 with 2-hydroxypyridine and 2-mercaptopyridine afford [OsH{κ2-X,N-[X-py]}(≡CPh)(IPr)(PiPr3)]OTf [X = O (5), S(6)].

3.
Sci Total Environ ; 912: 169178, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38072265

RESUMEN

Ultraviolet filters (UV-filters) are compounds extensively used in personal care products. These compounds are produced at increasing rates and discharged into marine ecosystems in unknown quantities and with no regulation, making them emerging contaminants. Among those, the UV-filter 4-Methylbenzylidene camphor (4-MBC) is used in a variety of personal care products such as sunscreens, soaps, or lipsticks. This high consumption has resulted in its presence in various environmental matrices at in concentrations ranging from ng to µg L-1. Very little is known, however, about the possible adverse effects in exposed non-target organisms. Our study presents novel data on the bioconcentration, toxicokinetics, and molecular effects of 4-MBC in a marine bivalve species of commercial interest, Ruditapes philippinarum (Manila clam). Organisms were exposed at two different concentrations (1.34 and 10.79 µg L-1) of 4-MBC for 7 days, followed by a 3-day depuration period (clean sea waters). Bioconcentration factors (BCF) were 3562 and 2229 L kg-1 for the low and high exposure concentrations, respectively, making this pollutant bioaccumulative according to REACH criteria. Up to six 4-MBC biotransformation products (BTPs)were identified, 2 of them for the first time. Transcriptomic analysis revealed between 658 and 1310 differently expressed genes (DEGs) after 4-MBC exposure. Functional and enrichment analysis of the DEGs showed the activation of the detoxification pathway to metabolize and excrete the bioconcentrated 4-MBC, which also involved energy depletion and caused an impact on the metabolism of carbohydrates and lipids and in the oxidative phosphorylation pathways. Oxidative stress and immune response were also evidenced through the activation of cathepsins and the complement system. Such elucidation of the mode of action of a ubiquitous pollutant such as 4-MBC at the molecular level is valuable both from an environmental point of view and for the sustainable production of Manila clam, one of the most cultivated mollusk species worldwide.


Asunto(s)
Bivalvos , Contaminantes Ambientales , Contaminantes Químicos del Agua , Animales , Bioacumulación , Ecosistema , Perfilación de la Expresión Génica , Bivalvos/metabolismo , Biotransformación , Protectores Solares/toxicidad , Protectores Solares/metabolismo , Contaminantes Ambientales/análisis , Contaminantes Químicos del Agua/análisis
4.
Environ Pollut ; 316(Pt 2): 120678, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36403875

RESUMEN

DEET is one of the most frequently detected insect repellents in the environment reaching concentrations of several µg L-1 in surface water. There is scarce information available regarding its mode of action in non-target organisms. Here, we have used an integrated metabolomic and transcriptomic approach to elucidate the possible adverse effects of DEET exposure in the marine fish gilthead sea bream (Sparus aurata). Individuals were exposed at an environmentally relevant concentration of DEET (10 µg L-1) for 22 days in a continuous flow-through system. Transcriptomic analysis revealed 250 differentially expressed genes in liver, while metabolomic analysis identified 190 differentially modulated features in liver and 98 in plasma. Multi-omic data integration and visualization allowed elucidation of the modes of action of DEET exposure, including: energy depletion through the disruption of carbohydrate and amino acids metabolisms, oxidative stress leading to DNA damage, lipid peroxidation, and damage to cell membrane and apoptosis. Activation of xenobiotic pathway as well as the inmune-inflammatory reaction was evidenced in the present work.


Asunto(s)
Repelentes de Insectos , Dorada , Animales , Transcriptoma , DEET , Metabolómica
5.
Organometallics ; 42(4): 327-338, 2023 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38601006

RESUMEN

An osmathiazole skeleton has been generated starting from the cation of the salt [OsH(OH)(≡CPh)(IPr)(PiPr3)]OTf (1; IPr = 1,3-bis(2,6-diisopropylphenyl)imidazolylidene; OTf = CF3SO3) and thioacetamide; its aromaticity degree was compared with that of thiazole, and its aromatic reactivity was confirmed through a reaction with phenylacetylene. Salt 1 reacts with the thioamide to initially afford the synthetic intermediate [OsH{κ2-N,S-[NHC(CH3)S]}(≡CPh)(IPr)(PiPr3)]OTf (2). Thioamidate and alkylidyne ligands of 2 couple in acetonitrile at 70 °C, forming a 1:1 mixture of the salts [OsH{κ2-C,S-[C(Ph)NHC(CH3)S]}(CH3CN)(IPr)(PiPr3)]OTf (3) and [Os{κ2-C,S-[CH(Ph)NHC(CH3)S]}(CH3CN)3(IPr)]OTf (4). Treatment of 3 with potassium tert-butoxide produces the NH-deprotonation of its five-membered ring and gives OsH{κ2-C,S-[C(Ph)NC(CH3)S]}(IPr)(PiPr3) (5). The osmathiazole ring of 5 is slightly less aromatic than the osmathiazolium cycle of 3 and the purely organic thiazole. However, it is more aromatic than related osmaoxazoles and osmaoxazoliums. There are significant differences in behavior between 3 and 5 toward phenylacetylene. In acetonitrile, the cation of 3 loses the phosphine and adds the alkyne to afford [Os{η3-C3,κ1-S-[CH2C(Ph)C(Ph)NHC(CH3)S]}(CH3CN)2(IPr)]OTf (6), bearing a functionalized allyl ligand. In contrast, the osmathiazole ring of 5 undergoes a vicarious nucleophilic substitution of hydride, by acetylide, via the dihydride OsH2(C≡CPh){κ2-C,S-[C(Ph)NC(CH3)S]}(IPr)(PiPr3) (7), which releases H2 to yield Os(C≡CPh){κ2-C,S-[C(Ph)NC(CH3)S]}(IPr)(PiPr3) (8).

6.
Aquat Toxicol ; 250: 106243, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35872527

RESUMEN

The high consumption and subsequent input of antibacterial compounds in marine ecosystems has become a worldwide problem. Their continuous presence in these ecosystems allows a direct interaction with aquatic organisms and can cause negative effects over time. The objective of the present study was to evaluate the effects of exposure to three antibacterial compounds of high consumption and presence in marine ecosystems (Ciprofloxacin CIP, Sulfadiazine SULF and Trimethoprim TRIM) on the physiology of the gilthead sea bream, Sparus aurata. Plasma parameters, enzymatic biomarkers of oxidative stress and damage and expression of genes related to stress and growth were assessed in exposed S. aurata specimens. For this purpose, sea bream specimens were exposed to individual compounds at concentrations of 5.2 ± 2.1 µg L-1 for CIP, 3.8 ± 2.7 µg L-1 for SULF and 25.7 ± 10.8 µg L-1 for TRIM during 21 days. Exposure to CIP up-regulated transcription of genes associated with the hypothalamic-pituitary-thyroid (HPT) (thyrotropin-releasing hormone, trh) and hypothalamic-pituitary-interrenal (HPI) axes (corticotropin-releasing hormone-binding protein, crhbp) in the brain, as well as altering several hepatic stress biomarkers (catalase, CAT; glutathione reductase, GR; and lipid peroxidation, LPO). Similar alterations at the hepatic level were observed after exposure to TRIM. Overall, our study indicates that S. aurata is vulnerable to environmentally relevant concentrations of CIP and TRIM and that their exposure could lead to a stress situation, altering the activity of antioxidant defense mechanisms as well as the activity of HPT and HPI axes.


Asunto(s)
Perciformes , Dorada , Contaminantes Químicos del Agua , Animales , Antibacterianos/farmacología , Biomarcadores/metabolismo , Ciprofloxacina/metabolismo , Ecosistema , Expresión Génica , Glutatión Reductasa/metabolismo , Perciformes/metabolismo , Dorada/metabolismo , Estrés Fisiológico , Sulfadiazina/metabolismo , Sulfadiazina/farmacología , Trimetoprim/metabolismo , Trimetoprim/toxicidad , Contaminantes Químicos del Agua/toxicidad
7.
Sci Total Environ ; 803: 150080, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-34525742

RESUMEN

Sulisobenzone (BP-4) is one of the benzophenone type UV filters most frequently detected in aquatic ecosystems. As a suspected endocrine disrupting compound, scarce information is available yet about other molecular effects and its mechanism of action. Here, we used an integrated transcriptomic and metabolomic approach to improve the current understanding on the toxicity of BP-4 towards aquatic species. Gilt-head sea bream individuals were exposed at environmentally relevant concentrations (10 µg L-1) for 22 days. Transcriptomic analysis revealed 371 differentially expressed genes in liver while metabolomic analysis identified 123 differentially modulated features in plasma and 118 in liver. Integration of transcriptomic and metabolomic data showed disruption of the energy metabolism (>10 pathways related to the metabolism of amino acids and carbohydrates were impacted) and lipid metabolism (5 glycerophospholipids and the expression of 3 enzymes were affected), suggesting oxidative stress. We also observed, for the first time in vivo and at environmental relevant concentrations, the disruption of several enzymes involved in the steroid and thyroid hormones biosynthesis. DNA and RNA synthesis was also impacted by changes in the purine and pyrimidine metabolisms. Overall, the multiomic workflow presented here increases the evidence on suspected effects of BP-4 exposure and identifies additional modes of action of the compounds that could have been overlooked by using single omic approaches.


Asunto(s)
Dorada , Animales , Benzofenonas , Ecosistema , Femenino , Perfilación de la Expresión Génica , Humanos , Porcinos
8.
Organometallics ; 40(24): 4150-4162, 2021 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-35264819

RESUMEN

The preparation of aromatic hydride-osmaoxazolium and hydride-oxazole compounds is reported and their reactivity toward phenylacetylene investigated. Complex [OsH(OH)(≡CPh)(IPr)(PiPr3)]OTf (1; IPr = 1,3-bis(2,6-diisopropylphenyl)imidazolylidene, OTf = CF3SO3) reacts with acetonitrile and benzonitrile to give [OsH{κ2-C,O-[C(Ph)NHC(R)O]}(NCR)(IPr)(PiPr3)]OTf (R = Me (2), Ph (3)) via amidate intermediates, which are generated by addition of the hydroxide ligand to the nitrile. In agreement with this, the addition of 2-phenylacetamide to acetonitrile solutions of 1 gives [OsH{κ2-C,O-[C(Ph)NHC(CH2Ph)O]}(NCCH3)(IPr)(PiPr3)]OTf (4). The deprotonation of the osmaoxazolium ring of 2 and 4 leads to the oxazole derivatives OsH{κ2-C,O-[C(Ph)NC(R)O]}(IPr)(PiPr3) (R = Me (5), CH2Ph (6)). Complexes 2 and 4 add their Os-H and Os-C bonds to the C-C triple bond of phenylacetylene to afford [Os{η3-C 3 ,κ1-O-[CH2C(Ph)C(Ph)NHC(R)O]}(NCCH3)2(IPr)]OTf (R = Me (7), CH2Ph (8)), bearing a tridentate amide-N-functionalized allyl ligand, while complexes 5 and 6 undergo a vicarious nucleophilic substitution of the hydride at the metal center with the alkyne, via the compressed dihydride adduct intermediates OsH2(C≡CPh){κ2-C,O-[C(Ph)NC(R)O]}(IPr)(PiPr3) (R = Me (9), CH2Ph (10)), which reductively eliminate H2 to yield the acetylide-osmaoxazoles Os(C≡CPh){κ2-C,O-[C(Ph)NC(R)O]}(IPr)(PiPr3) (R = Me (11), CH2Ph (12)).

9.
Rev. chil. nutr ; 43(3): 233-246, set. 2016. ilus, graf, tab
Artículo en Español | LILACS | ID: biblio-830131

RESUMEN

Objectives: To determine if the implementation of a personalized diet for three months improves the nutritional status of pregnant women with overweight and obesity of the UMF No. 56. Methodology: Prospective longitudinal study in 53 overweight or obese pregnant women to whom which were given a specific diet, according to its particular characteristics; were evaluated the characteristics of the right diet, 24 hours recall, frequency of food consumption, weight and biochemical indicators. The real, ideal and projected weight of the patients was compared. McNemar test and Kuskal-Wallis was applied with confidence interval of 95%. Results: the BMI pre-gestational average was 28.5 kg / m2. At the end ofthe study pregnant women improved the characteristics of the right diet: the complete one (9.4% vs 60.4%), the percentage of adequacy of lipids (7.5% vs 45.3%) and increased in active physical activity (22.6% vs 54.7%). Ideal gestational weight wasn't reached, but there was a weight control reflected in a projected weight higher than real in each intervention. No significant changes in the biochemical indicator (p> 0.05). Conclusions: The implementation of a personalized diet improved the nutritional status of overweight or obese pregnant women in their eating patterns and gestational weight control.


Objetivo: Determinar si la implementación de una dieta personalizada durante tres meses, mejora el estado nutricional de mujeres embarazadas con sobrepeso y obesidad de la UMF No. 56. Metodología: Estudio prospectivo longitudinal en 53 embarazadas con sobrepeso u obesidad a las que se les proporcionó una dieta específica, de acuerdo a sus características particulares; se evaluaron las características de la dieta correcta, la R24H, la frecuencia de consumo de alimentos, el peso corporal e indicadores bioquímicos. Se comparó el peso real, peso proyectado y peso ideal de las pacientes. Se aplicó prueba de McNemar y Kuskal-Wallis con nivel de confianza de 95%. Resultados: el promedio del IMC pregestacional fue 28.5 kg/m2. Al finalizar el estudio las gestantes mejoraron las características de la dieta correcta: la completa (9.4% a 60.4%), el porcentaje recomendable de adecuación de lípidos (7.5% a 45.3%) y aumentaron la actividad física activa (22.6% a 54.7%). No se alcanzó el peso ideal gestacional, pero se logró control de peso, reflejado en peso proyectado mayor al real en cada intervención. Sin cambios significativos en el indicador bioquímico (p>0.05). Conclusiones: La implementación de la dieta personalizada mejoró el estado nutricional de mujeres embarazadas con sobrepeso u obesidad en sus patrones de alimentación y en el control de peso gestacional.


Asunto(s)
Humanos , Estado Nutricional , Mujeres Embarazadas , Dieta , Sobrepeso , Obesidad , Aumento de Peso
10.
Org Lett ; 17(10): 2370-3, 2015 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-25932748

RESUMEN

Mechanistic evidence observed in Hofmann-Löffler-Freytag-type reactions has been crucial to achieve the chemoselective functionalization of methyl groups under mild conditions. Radical-mediated methyl iodination and subsequent oxidative deiodination are the key steps in this functionalization, where iodine chemistry has a pivotal role on the formation of the C-N bond. The concepts of single hydrogen atom transfer (SHAT) and multiple hydrogen atom transfer (MHAT) are introduced to describe the observed chemoselectivity.

11.
J Org Chem ; 78(15): 7527-43, 2013 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-23834195

RESUMEN

The synthesis of a novel type of branched iminosugars is described. This synthetic strategy is based on two key reactions: first, an aldol reaction with formaldehyde in order to introduce selectively the hydroxymethyl branch, and second, a tandem ß-fragmentation-intramolecular cyclization reaction. The combination of both reactions afforded a battery of compounds exhibiting a great structural complexity, with the concomitant formation of a quaternary center, starting from readily available aldoses. With this approach we have demonstrated the usefulness of the fragmentation of anomeric alkoxyl radicals (ARF) promoted by the PhIO/I2 system for the preparation of new compounds with potential interest for both medicinal and synthetic chemists.


Asunto(s)
Alcoholes/química , Iminoazúcares/síntesis química , Yodo/química , Iminoazúcares/química , Estructura Molecular
12.
Rev. méd. Chile ; 140(9): 1126-1131, set. 2012. ilus
Artículo en Español | LILACS | ID: lil-660069

RESUMEN

Background: Neuropathy is a common complication of diabetic patients. Aim: To determine the prevalence of diabetic peripheral neuropathy in Type 2 diabetic patients attended at a family medicine unit. Material and Methods: Cross-sectional assessment of 348 type 2 diabetic patients aged 34-89 years (60% females) with a disease duration of 5 to 15 years. Peripheral neurological status was evaluated using The Michigan Neuropathy Screening Instrument, a tool that includes a self-assessment of symptoms and a physical examination. Results: Diabetic neuropathy was found in 240patients (69%). The prevalence in males and females was 72 and 67% respectively. The prevalence in patients with a disease duration of 5, 10 and 15 years, was 59, 69 and 77%, respectively. Fifty percent of patients with neuropathy complained of dry skin, 2% had ulcers, 43% had an abnormal perception of vibration and 29% had an abnormal monofilament test. Conclusions: The overall prevalence of peripheral neuropathy in this group of patients was 69% and was directly associated with the duration of the disease.


Asunto(s)
Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , /complicaciones , Neuropatías Diabéticas/epidemiología , Distribución por Edad , Estudios Transversales , Neuropatías Diabéticas/diagnóstico , Neuropatías Diabéticas/etiología , Prevalencia , Factores de Riesgo , Sensibilidad y Especificidad
13.
Org Lett ; 14(13): 3388-91, 2012 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-22694091

RESUMEN

The fragmentation of anomeric alkoxyl radicals (ARF) and the subsequent intramolecular cyclization promoted by hypervalent iodine reagents provide an excellent method for the synthesis of tetrazolo-sugars. This new reaction offers additional advantages for the synthesis of these compounds, including the ready availability of the starting materials, experimental simplicity, mild conditions, and good yields.


Asunto(s)
Alcoholes/química , Glicósidos/síntesis química , Tetrazoles/química , Ciclización , Glicósidos/química , Estructura Molecular
14.
Org Lett ; 10(20): 4549-52, 2008 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-18808131

RESUMEN

A method to obtain (Z)-beta,gamma-unsaturated nitriles in high or good yields and with moderate or high stereoselectivity is described. The products were achieved through the photoinduced metalation of 3-acetoxy-4-chloronitriles with SmI2. The starting compounds were readily prepared, and a mechanism is proposed to explain this stereoselective beta-elimination reaction.


Asunto(s)
Yoduros/química , Nitrilos/síntesis química , Samario/química , Estructura Molecular , Nitrilos/química , Estereoisomerismo
15.
Chemistry ; 14(22): 6704-12, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18576400

RESUMEN

A new general methodology for the synthesis of 1,1,1-trihaloalditols by starting from 1,5-anhydro-2-deoxy-hex-1-enitol derivatives (glycals) is described. The halogens are introduced sequentially in each of the three different steps of the process. The fluorine is introduced in the first step by electrophilic fluorination of the starting glycal; next, hydroxyhalogenation of the resulting vinyl fluoride allows the addition of any halogen (F, Cl, Br or I) at will, and finally, an iodine atom is inserted through an alkoxyl radical fragmentation reaction. This methodology allows the preparation of diverse types of 1,1,1-trihalogenated compounds (R--CF(2)I, R--CFI(2), R--CFClI and R--CFBrI) under mild conditions compatible with sensitive substituents. In some cases, the diastereomeric mixtures generated from R--CFClI and R--CFBrI can be chromatographically separated, and their configuration determined by X-ray crystallographic analysis. The synthetic usefulness of these compounds has been preliminarily assessed by examining the reactivity of the fluorinated radical generated by rupture of the C--I bond.


Asunto(s)
Alcoholes del Azúcar/síntesis química , Cristalografía por Rayos X , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Estructura Molecular , Espectrometría de Masa por Ionización de Electrospray , Estereoisomerismo , Alcoholes del Azúcar/química
16.
Bol. Asoc. Méd. P. R ; Bol. Asoc. Méd. P. R;99(1): 72-87, jan.-mar. 2007.
Artículo en Inglés | LILACS | ID: lil-471874

RESUMEN

Traumatic injuries of the lower extremity vary from minimal lacerations to limb threatening open fractures. Complications and morbidity associated with these injuries can be significant. With appropriate treatment from simple wound closure to complex free tissue transfer morbidity can be minimized and the threat of limb loss can be averted. We review the present treatment of traumatic soft tissue injuries of the lower extremity.


Asunto(s)
Humanos , Traumatismos de los Tejidos Blandos/cirugía , Procedimientos de Cirugía Plástica/métodos , Traumatismos de la Pierna/cirugía , Desbridamiento , Trasplante de Piel , Colgajos Quirúrgicos
17.
Ann Oncol ; 15(4): 680-5, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15033679

RESUMEN

BACKGROUND: Countries with scarce resources have the right to appropriate essential health care but very few reports discuss how this can be achieved. We assessed the survival of a large cohort of pediatric oncological patients to provide hard data on which to base realistic evaluation and planning schemes. PATIENTS AND METHODS: This multicenter retrospective survey covered consecutively diagnosed and treated patients admitted to eight national level hospitals in seven countries in Central America and the Caribbean. The research protocol was discussed extensively, so the data to be collected and the criteria for their evaluation were clearly pre-defined. We analysed 2214 patients diagnosed between 1996 and 1999 with various cancers, classified as hemato-oncological disorders (70%) and solid tumors (30%). RESULTS: Three-year overall survival was 48.4% [standard error (SE) 1.3]. Detailed analysis of acute lymphoblastic leukemia highlighted the wide intercountry variability: 3-year survival was 62.2% (SE 5.3) in Cuba, 74.2% (SE 3.3) in Costa Rica, 61.7% (SE 4.9) in Nicaragua, and lower in the other four countries. CONCLUSIONS: The yield of diagnostic-therapeutic protocols depends largely on the context of care in which they are applied. This paper documents the importance of including epidemiological research in interventions for cooperation in complex health areas such as pediatric oncology.


Asunto(s)
Neoplasias/epidemiología , Región del Caribe/epidemiología , América Central/epidemiología , Niño , Humanos , Leucemia Mieloide Aguda/epidemiología , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiología , Estudios Retrospectivos , Análisis de Supervivencia
18.
Org Lett ; 5(22): 4171-3, 2003 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-14572277

RESUMEN

[reaction: see text]. The beta-fragmentation of 2,2-difluoro-saccharide anomeric alkoxyl radicals, generated under oxidative condition by treatment of the respective alcohols with (diacetoxyiodo)benzene (DIB) and iodine, afforded 1,1-difluoro-1-iodo alditols in high yield. The reactivity of the fluorinated radical generated by rupture of the C-I bond has been preliminarily assessed by reductive deiodination with tributyltin hydride/AIBN and intermolecular allylation using the Keck reaction.


Asunto(s)
Alcoholes/química , Hidrocarburos Halogenados/síntesis química , Monosacáridos/química , Alcoholes del Azúcar/síntesis química , Flúor/química , Yodo/química , Espectroscopía de Resonancia Magnética , Estructura Molecular
20.
Biotechnol Prog ; 15(5): 828-33, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10514252

RESUMEN

Pichia pastoris was transformed with the Trichoderma reesei cbh1 gene, and the recombinant enzyme was purified and analyzed kinetically and by circular dichroism. The P. pastoris rCBH I was recognized by MoAb raised to T. reesei CBH I but was found in multiple molecular weight species on SDS-PAGE gels. Carbohydrate content determination and SDS-PAGE western analysis indicated that the recombinant protein was hyperglycosylated, although a species very similar in molecular weight to the T. reesei enzyme could be isolated chromatographically. The P. pastoris rCBH I also demonstrated activity toward soluble and insoluble substrates (i.e., pNPL and Sigmacell), although at a level significantly lower than the wild-type enzyme. More seriously, the yeast-expressed enzyme showed non-wild-type secondary structure by circular dichroism. We conclude that P. pastoris may not serve as an adequate host for the site-directed mutagenesis of T. reesei CBH I.


Asunto(s)
Celulasa/biosíntesis , Celulasa/genética , Pichia/metabolismo , Trichoderma/enzimología , Secuencia de Aminoácidos , Secuencia de Bases , Celulosa 1,4-beta-Celobiosidasa , Dicroismo Circular , Clonación Molecular , Cinética , Datos de Secuencia Molecular , Pichia/genética , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/genética , Análisis de Secuencia de Proteína , Trichoderma/genética
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