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1.
J Investig Allergol Clin Immunol ; 30(5): 346-357, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32554337

RESUMEN

BACKGROUND AND OBJECTIVE: Since the initial anecdotal reports of coronavirus disease 2019 (COVID-19) from China, a growing number of studies have reported on smell and/or taste dysfunction (STD). Objective: The aim of our study was to investigate the frequency and severity of STD in COVID-19 patients and to evaluate the association with demographic characteristics, hospital admission, symptoms, comorbidities, and blood biomarkers. METHODS: We performed a multicenter cross-sectional study on patients who were positive for SARS-CoV-2 (n=846) and controls (n=143) from 15 Spanish hospitals. Data on STD were collected prospectively using an in-person survey. The severity of STD was categorized using a visual analog scale. We analyzed time to onset, recovery rate, time to recovery, hospital admission, pneumonia, comorbidities, smoking, and symptoms. RESULTS: STD was at least 2-fold more common in COVID-19-positive patients than in controls. COVID-19-positive hospitalized patients were older, with a lower frequency of STD, and recovered earlier than outpatients. Analysis stratified by severity of STD showed that more than half of COVID-19 patients presented severe loss of smell (53.7%) or taste (52.2%); both senses were impaired in >90%. In the multivariate analysis, older age (>60 years), being hospitalized, and increased C-reactive protein were associated with a better sense of smell and/or taste. COVID-19-positive patients reported improvement in smell (45.6%) and taste (46.1%) at the time of the survey; in 90.6% this was within 2 weeks of infection. CONCLUSION: STD is a common symptom in COVID-19 and presents mainly in young and nonhospitalized patients. More studies are needed to evaluate follow-up of chemosensory impairment.


Asunto(s)
Betacoronavirus , Infecciones por Coronavirus/complicaciones , Infecciones por Coronavirus/epidemiología , Trastornos del Olfato/epidemiología , Trastornos del Olfato/etiología , Neumonía Viral/complicaciones , Neumonía Viral/epidemiología , Trastornos del Gusto/epidemiología , Trastornos del Gusto/etiología , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Betacoronavirus/genética , Betacoronavirus/inmunología , COVID-19 , Estudios de Casos y Controles , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/virología , Estudios Transversales , Femenino , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Trastornos del Olfato/diagnóstico , Pandemias , Neumonía Viral/diagnóstico , Neumonía Viral/virología , Reacción en Cadena de la Polimerasa , Vigilancia en Salud Pública , SARS-CoV-2 , Índice de Severidad de la Enfermedad , España/epidemiología , Evaluación de Síntomas , Trastornos del Gusto/diagnóstico , Adulto Joven
2.
J Biomol Struct Dyn ; 36(16): 4246-4254, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29187070

RESUMEN

In this review, the loading efficacies of retinoids with milk proteins are investigated. It has been shown that milk proteins ß-lactoglobulin, α-, and ß-caseins bind retinol and retinoic acid via hydrophobic, hydrophilic, and H-bonding contacts causing minor alterations of protein secondary structure. Hydrophobic contact is predominant in retinoid-protein conjugation and several amino acids are involved in complex formation, stabilized by H-bonding network. Loading efficacy of retinoid was about 30-50% with retinol forming more stable protein conjugates. Milk proteins can transport retinoid to target molecules.


Asunto(s)
Proteínas de la Leche/metabolismo , Retinoides/metabolismo , Aminoácidos/metabolismo , Animales , Enlace de Hidrógeno/efectos de los fármacos , Interacciones Hidrofóbicas e Hidrofílicas , Unión Proteica/efectos de los fármacos
3.
J Biomol Struct Dyn ; 35(11): 2497-2508, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27598545

RESUMEN

In this review, the binding and loading efficacy (LE) of anticancer drugs doxorubicin (DOX), tamoxifen (Tam) and its metabolites 4-hydroxytamoxifen (4-Hydroxytam) and endoxifen (Endox) with several synthetic polymers poly(ethylene glycol) (PEG), methoxypoly (ethylene glycol) polyamidoamine (mPEG-PAMAM-G3), and polyamidoamine (PAMAM-G4) dendrimers were compared in aqueous solution at pH 7.4. The results of multiple spectroscopic methods, transmission electron microscopy (TEM) and molecular modeling of conjugated drug-polymer were examined. Structural analysis showed that drug-polymer conjugation occurs mainly via H-bonding and hydrophobic contacts. The order of binding is PAMAM-G4 > mPEG-PAMAM-G3 > PEG-6000 with 4-hydroxttamoxifen forming more stable conjugate than tamoxifen and endoxifen. Doxorubicin shows stronger affinity for PAMAM-G4 than tamoxifen and its metabolites. The drug LE was 30-55%. TEM showed significant changes in the carrier morphology upon drug encapsulation. Modeling also showed that drug is located in the surface and in the internal cavities of PAMAM with DOX forming more stable polymer conjugates.


Asunto(s)
Antineoplásicos/química , Doxorrubicina/química , Polímeros/química , Tamoxifeno/química , Antineoplásicos/administración & dosificación , Antineoplásicos/metabolismo , Dendrímeros/química , Dendrímeros/metabolismo , Doxorrubicina/administración & dosificación , Doxorrubicina/metabolismo , Sistemas de Liberación de Medicamentos/métodos , Microscopía Electrónica de Transmisión , Simulación del Acoplamiento Molecular , Nylons/química , Nylons/metabolismo , Polietilenglicoles/química , Polietilenglicoles/metabolismo , Polímeros/metabolismo , Tamoxifeno/administración & dosificación , Tamoxifeno/metabolismo
4.
J Biomol Struct Dyn ; 35(10): 2257-2268, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27434220

RESUMEN

The conjugation of trypsin (try) and trypsin inhibitor (tryi) with poly(ethylene glycol) (PEG) and methoxypoly(ethylene glycol) anthracene (mPEG-anthracene) was investigated in aqueous solution, using multiple spectroscopic methods, thermodynamic analysis, and molecular modeling. Thermodynamic parameters ΔS, ΔH, and ΔG showed protein-PEG bindings occur via H-bonding and van der Waals contacts with trypsin inhibitor forming more stable conjugate than trypsin. As polymer size increased more stable PEG-protein conjugate formed, while hydrophobic mPEG-anthracene forms less stable protein complexes. Modeling showed the presence of several H-bonding contacts between polymer and amino acids that stabilize protein-polymer conjugation. Polymer complexation induces more perturbations of trypsin inhibitor structure than trypsin with reduction of protein alpha-helix and major increase in random structures, indicating protein structural destabilization.


Asunto(s)
Antracenos/química , Polietilenglicoles/química , Inhibidores de Tripsina/química , Tripsina/química , Agua/química , Animales , Sitios de Unión , Bovinos , Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Cinética , Páncreas/química , Unión Proteica , Conformación Proteica en Hélice alfa , Conformación Proteica en Lámina beta , Dominios y Motivos de Interacción de Proteínas , Soluciones , Glycine max/química , Termodinámica , Tripsina/aislamiento & purificación , Inhibidores de Tripsina/aislamiento & purificación
5.
J Pharm Biomed Anal ; 134: 269-274, 2017 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-27930994

RESUMEN

The morphology of tRNA was studied upon conjugation with testosterone and its aliphatic and aromatic dimers, using multiple spectroscopic methods, transmission electron microscopy (TEM) and molecular modeling. Structural analysis showed that testosterone binds tRNA through A62, A64, C60, C61, C63, G51, U50 and U59 bases. The binding affinity was testosterone dimer-aromatic>testosterone dimer-aliphatic>testosterone. The steroid loading efficacy was 35-45%. Transmission electron microscopy showed major changes in tRNA morphology upon testosterone interaction with an increase in the diameter of the tRNA aggregate, indicating encapsulation of testosterone by tRNA.


Asunto(s)
Simulación del Acoplamiento Molecular/métodos , ARN de Transferencia/química , ARN de Transferencia/metabolismo , Testosterona/química , Testosterona/metabolismo , Sitios de Unión/fisiología , Modelos Moleculares , Estructura Terciaria de Proteína , Testosterona/análogos & derivados
6.
Int J Biol Macromol ; 95: 850-855, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27693340

RESUMEN

Conjugation of DNA with testosterone and it aliphatic dimer (alip) and aromatic dimer (arom) was investigated in aqueous solution at pH 7.4. Multiple spectroscopic methods, transmission electron microscopy (TEM) and molecular modeling were used to characterize steroid-DNA binding and DNA morphology. Spectroscopic analysis showed that testosterone binds DNA via A7, A16, A17, T8, T15 and T18 nucleobases with overall binding constants Ktest-DNA=1.8 (±0.4)×104M-1, Ktest-dimeralip-DNA=5.7 (±0.7)×104M-1 and Ktest-dimer-arom-DNA=7.3 (±0.9)×104M-1. The binding affinity increases in this order: testosterone dimer-aromatic>testosterone dimer-aliphatic>testosterone. The steroid loading efficacy was 40-50%. Transmission electron microscopy showed major changes in DNA morphology as testosterone-DNA interaction occurred with increase in the diameter of the DNA aggregate, indicating encapsulation of testosterone by DNA. Modeling showed the presence of several nucleobases attached to testosterone with the free binding energy of -4.93Kcal/mol.


Asunto(s)
ADN/química , Dimerización , Testosterona/química , Testosterona/farmacología , ADN/metabolismo , Simulación del Acoplamiento Molecular , Conformación de Ácido Nucleico , Relación Estructura-Actividad , Testosterona/metabolismo
7.
Rev. med. vet. zoot ; 69(1): 19-32, ene.-abr. 2022. tab, graf
Artículo en Español | LILACS, COLNAL | ID: biblio-1389164

RESUMEN

RESUMEN En muchos países la fasciolosis y la paramfistomosis representan un grave problema para la salud del sector pecuario. En Colombia hay registros de ambas distomatosis en bovinos, la mayoría en el trópico alto andino, las cuales generan pérdidas econômicas anuales cercanas a 40 000 000 000 COP. El objetivo de esta investigación fue determinar la prevalencia de fasciolosis y paramfistomosis en vacunos de la hacienda La Candelaria, Caucasia (Colombia), y la presencia de caracoles hospederos intermediarios. Para cumplirlo, se realizó un estudio descriptivo de corte transversal con muestreo no probabilístico por conveniencia. Se recolectaron heces de los animales y se hizo el diagnóstico mediante la técnica modificada de Dennis. Se establecieron las prevalencias de los digeneos de acuerdo con el sexo, peso, edad y raza. Se recolectaron caracoles dulciacuícolas en la zona estudiada y se identificaron por morfologia. Se analizaron 466 muestras fecales de 178 bovinos, de las razas Cebú (Bos indicus), BON (blanco orejinegro) y del cruce entre ellas. Se diagnosticaron F. hepatica y Paramphistomidae con prevalencias del 2,2% y 30,9%, respectivamente. En el 1,1% de los vacunos se diagnosticó coinfección. Ambas trematodosis prevalecieron en las hembras (p = 0,03). Se identificaron moluscos dulciacuícolas Ampullariidae, Physidae y Planorbidae sin estadios larvarios de digeneos. Se concluyó que los bovinos de doble propósito de la hacienda La Candelaria están expuestos a F. hepatica y Paramphistomidae, y, probablemente, se infectan en los predios de la hacienda. Paramphistomidae es más prevalente que F. hepatica, lo cual concuerda con lo descrito en algunos estudios realizados en hatos del trópico alto andino colombiano. Paramphistomidae se encontró en todos los grupos etarios.


ABSTRACT Fasciolosis and paramphistomosis are a major health problem for the livestock economy worldwide. In Colombia, both distomatosis are reported in cattle, particularly in high Andean tropics, with annual economic losses close to COP 40 billion. The goal of this study was to determine the prevalence of fasciolosis and paramphistomosis in cattle from La Candelaria farm, Caucasia (Colombia), and the presence of intermediate host snails. A descriptive cross-sectional study was carried out with non-probability convenience sampling. Stool samples were collected from the animals and the diagnosis was made using the modified Dennis technique. Digenea prevalence were determined according to sex, weight, age, and race. Freshwater snails were collected in the studied area and were identified by morphology. 400 and 66 fecal samples from 178 bovines of the Zebu (Bos indicus), BON (white-eared white) breeds and the cross between them were analyzed. Fasciola hepatica and Paramphistomidae were diagnosed with a prevalence of 2,2% and 30,9%, respectively. Coinfection was diagnosed in 1,1% of the cattle. Both trematodosis were most frequent in females (p = 0,03). Freshwater molluscs Ampullariidae, Physidae and Planorbidae without digenea larval stages were identified. It was concluded that dual-purpose cattle from La Candelaria farm are exposed to F. hepatica and Paramphistomidae and are probably infected on the farm grounds. Paramphistomidae was more prevalent than F. hepatica, which agrees with other studies in herds from the Colombian high Andean tropics. Paramphistomidae was found in all age groups.


Asunto(s)
Animales , Bovinos , Bovinos , Ecosistema Tropical , Fasciola hepatica , Ganado , Coinfección , Agua Dulce , Moluscos , Investigación , Caracoles , Registros , Estudios Transversales , Diagnóstico
8.
Int J Biol Macromol ; 85: 150-6, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26723249

RESUMEN

The conjugation of tRNA with chitosan nanoparticles of different sizes 15,100 and 200 kDa was investigated in aqueous solution using multiple spectroscopic methods and atomic force microscopy (AFM). Structural analysis showed that chitosan binds tRNA via G-C and A-U base pairs as well as backbone PO2 group, through electrostatic, hydrophilic and H-bonding contacts with overall binding constants of KCh-15-tRNA=4.1 (±0.60)×10(3)M(-1), KCh-100-tRNA=5.7 (±0.8)×10(3)M(-1) and KCh-200-tRNA=1.2 (±0.3)×10(4)M(-1). As chitosan size increases more stable polymer-tRNA conjugate is formed. AFM images showed major tRNA aggregation and particle formation occurred as chitosan concentration increased. Even though chitosan induced major biopolymer structural changes, tRNA remains in A-family structure.


Asunto(s)
Quitosano/química , Nanopartículas/química , Nanopartículas/ultraestructura , ARN de Transferencia/química , Dicroismo Circular , Microscopía de Fuerza Atómica , Espectroscopía Infrarroja por Transformada de Fourier
9.
Carbohydr Polym ; 137: 207-213, 2016 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-26686122

RESUMEN

Conjugations of DNA with chitosans 15 kD (ch-15), 100 kD (ch-100) and 200 kD (ch-200) were investigated in aqueous solution at pH 5.5-6.5. Multiple spectroscopic methods and atomic force microscopy (AFM) were used to locate the chitosan binding sites and the effect of polymer conjugation on DNA compaction and particle formation. Structural analysis showed that chitosan-DNA conjugation is mainly via electrostatic interactions through polymer cationic charged NH2 and negatively charged backbone phosphate groups. As polymer size increases major DNA compaction and particle formation occurs. At high chitosan concentration major DNA structural changes observed indicating a partial B to A-DNA conformational transition.


Asunto(s)
Quitosano/química , ADN/química , Microscopía de Fuerza Atómica , Conformación Molecular
10.
Int J Biol Macromol ; 88: 354-60, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27037051

RESUMEN

Serum proteins play an increasing role as drug carriers in the clinical settings. In this review, we have compared the binding modalities of anticancer drug doxorubicin (DOX) to three model carrier proteins, human serum albumin (HSA), bovine serum albumin (BSA) and milk beta-lactoglobulin (ß-LG) in order to determine the potential application of these model proteins in DOX delivery. Molecular modeling studies showed stronger binding of DOX with HSA than BSA and ß-LG with the free binding energies of -10.75 (DOX-HSA), -9.31 (DOX-BSA) and -8.12kcal/mol (DOX-ß-LG). Extensive H-boding network stabilizes DOX-protein conjugation and played a major role in drug-protein complex formation. DOX complexation induced major alterations of HSA and BSA conformations, while did not alter ß-LG secondary structure. The literature review shows that these proteins can potentially be used for delivery of DOX in vitro and in vivo.


Asunto(s)
Doxorrubicina/uso terapéutico , Lactoglobulinas/uso terapéutico , Neoplasias/tratamiento farmacológico , Albúmina Sérica Bovina/uso terapéutico , Animales , Proteínas Sanguíneas/química , Proteínas Sanguíneas/uso terapéutico , Proteínas Portadoras/química , Proteínas Portadoras/uso terapéutico , Bovinos , Doxorrubicina/química , Sistemas de Liberación de Medicamentos , Humanos , Lactoglobulinas/química , Albúmina Sérica Bovina/química
11.
Colloids Surf B Biointerfaces ; 145: 55-63, 2016 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-27137803

RESUMEN

Conjugation of antitumor drug tamoxifen and its metabolites, 4-hydroxytamxifen and ednoxifen with synthetic polymers poly(ethylene glycol) (PEG), methoxypoly (ethylene glycol) polyamidoamine (mPEG-PAMAM-G3) and polyamidoamine (PAMAM-G4) dendrimers was studied in aqueous solution at pH 7.4. Multiple spectroscopic methods, transmission electron microscopy (TEM) and molecular modeling were used to characterize the drug binding process to synthetic polymers. Structural analysis showed that drug-polymer binding occurs via both H-bonding and hydrophobic contacts. The order of binding is PAMAM-G4>mPEG-PAMAM-G3>PEG-6000 with 4-hydroxttamoxifen forming more stable conjugate than tamoxifen and endoxifen. Transmission electron microscopy showed significant changes in carrier morphology with major changes in the shape of the polymer aggregate as drug encapsulation occurred. Modeling also showed that drug is located in the surface and in the internal cavities of PAMAM with the free binding energy of -3.79 for tamoxifen, -3.70 for 4-hydroxytamoxifen and -3.69kcal/mol for endoxifen, indicating of spontaneous drug-polymer interaction at room temperature.


Asunto(s)
Polímeros/química , Tamoxifeno/química , Dendrímeros/química , Interacciones Hidrofóbicas e Hidrofílicas , Microscopía Electrónica de Transmisión , Poliaminas/química , Polietilenglicoles/química , Tamoxifeno/análogos & derivados
12.
J Photochem Photobiol B ; 158: 274-9, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26971631

RESUMEN

In this review, we have compared the results of multiple spectroscopic studies and molecular modeling of anticancer drug doxorubicin (DOX) bindings to DNA and tRNA. DOX was intercalated into DNA duplex, while tRNA binding is via major and minor grooves. DOX-DNA intercalation is close to A-7, C-5, *C-19 (H-bonding with DOX NH2 group), G-6, T-8 and T-18 with the free binding energy of -4.99kcal/mol. DOX-tRNA groove bindings are near A-29, A-31, A-38, C-25, C-27, C-28, *G-30 (H-bonding) and U-41 with the free binding energy of -4.44kcal/mol. Drug intercalation induced a partial B to A-DNA transition, while tRNA remained in A-family structure. The structural differences observed between DOX bindings to DNA and tRNA can be the main reasons for drug antitumor activity. The results of in vitro MTT assay on SKC01 colon carcinoma are consistent with the observed DNA structural changes. Future research should be focused on finding suitable nanocarriers for delivery of DOX in vivo in order to exploit the full capacity of this very important anticancer drug.


Asunto(s)
Antibióticos Antineoplásicos/metabolismo , ADN/metabolismo , Doxorrubicina/metabolismo , ARN/metabolismo , Dicroismo Circular , Conformación Molecular , Espectroscopía Infrarroja por Transformada de Fourier
14.
Colloids Surf B Biointerfaces ; 130: 141-8, 2015 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-25865167

RESUMEN

We investigated the interaction between polyethylene (glycol) (PEG) and human (HSA) and bovine serum albumin (BSA) in aqueous solution, using multiple spectroscopic methods and molecular modeling. The two important polymer characteristics, size and PEG hydrophobic end-group are studied in order to determine the effect of each one on PEG-protein interaction. The bindings of PEG and mPEG-anthracene with serum albumins occur via hydrophobic and H-bonding contacts with the binding affinity PEG-6000>mPEG-anthracene>PEG-3000 for BSA and EG-6000>PEG-3000>mPEG-anthracene for HSA. Modeling showed different protein binding sites are involved in PEG-BSA and PEG-HSA complexes. Several H-bonding systems between PEG and different amino acids are stabilizing polymer-protein complexes. The free binding energies of -6.48 (PEG-BSA) and -6.36 kcal/mol (PEG-HSA) showed that the interaction process is spontaneous at room temperature. Minor alterations of protein alpha-helix and beta-sheet structures were observed upon PEG complexation.


Asunto(s)
Interacciones Hidrofóbicas e Hidrofílicas , Polietilenglicoles/química , Polímeros/química , Animales , Antracenos/química , Antracenos/metabolismo , Unión Competitiva , Bovinos , Humanos , Enlace de Hidrógeno , Modelos Moleculares , Estructura Molecular , Peso Molecular , Polietilenglicoles/metabolismo , Polímeros/metabolismo , Unión Proteica , Estructura Terciaria de Proteína , Albúmina Sérica/química , Albúmina Sérica/metabolismo , Albúmina Sérica Bovina/química , Albúmina Sérica Bovina/metabolismo , Espectrofotometría , Espectroscopía Infrarroja por Transformada de Fourier , Termodinámica
15.
Colloids Surf B Biointerfaces ; 125: 309-17, 2015 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-25524222

RESUMEN

We present a comprehensive study of the interactions between chitosan nanoparticles (15, 100 and 200 kDa with the same degree of deacetylation 90%) and two model proteins, i.e., bovine (BSA) and human serum albumins (HSA), with the aim of correlating chitosan molecular weight (Mw) and the binding affinity of these naturally occurring polymers to protein. The effect of chitosan on the protein secondary structure and the influence of protein complexation on the shape of chitosan nanoparticles are discussed. A combination of multiple spectroscopic methods, transmission electron microscopy (TEM) and thermodynamic analysis were used to assess the polymer-protein complex formation. Results revealed that the three chitosan nanoparticles interact with BSA to form chitosan-BSA complexes, mainly through hydrophobic contacts with the affinity order: 200>100>15 kDa. However, HSA-chitosan complexation is mainly via electrostatic interactions with the stability order: 100>200>15 kDa. Furthermore, the association between polymer and protein causes a partial protein conformational change by a major reduction of α-helix from 63% (free BSA) to 57% (chitosan-BSA) and 57% (free HSA) to 51% (chitosan-HSA). Finally, TEM micrographs clearly revealed that the binding of serum albumins with chitosan nanoparticles induces a significant change in protein morphology and the shape of the polymer.


Asunto(s)
Quitosano/química , Nanopartículas/química , Albúmina Sérica/química , Animales , Sitios de Unión , Bovinos , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Cinética , Modelos Moleculares , Peso Molecular , Nanopartículas/ultraestructura , Tamaño de la Partícula , Unión Proteica , Estructura Secundaria de Proteína , Especificidad de la Especie , Electricidad Estática , Termodinámica
16.
Colloids Surf B Biointerfaces ; 135: 175-182, 2015 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-26255162

RESUMEN

Synthetic polymers poly(ethylene glycol) (PEG), methoxypoly (ethylene glycol) polyamidoamine (mPEG-PAMAM-G3) and polyamidoamine (PAMAM-G4) dendrimers were used for encapsulation of antibiotic drug doxorubicin (Dox) and its analogue N-(trifluoroacetyl) doxorubicin (FDox) in aqueous solution at pH 7.4. Multiple spectroscopic methods, transmission electron microscopy (TEM) and molecular modeling were used to characterize the drug binding process to synthetic polymers. Structural analysis showed that drug-polymer binding occurs via both H-bonding and hydrophobic contacts. The order of binding is PAMAM-G4>mPEG-PAMAM-G3>PEG-6000 with Dox forming more stable conjugate than FDox. Transmission electron microscopy showed significant changes in carrier morphology with major changes in the shape of the polymer aggregate as drug encapsulation occurred. Modeling also showed that drug is located in the surface and in the internal cavities of PAMAM with the free binding energy of -4.14 kcal/mol for Dox and -3.93 kcal/mol for FDox, indicating of spontaneous drug-polymer interaction at room temperature.


Asunto(s)
Antibióticos Antineoplásicos/química , Doxorrubicina/química , Antibióticos Antineoplásicos/síntesis química , Dendrímeros , Doxorrubicina/síntesis química , Composición de Medicamentos , Enlace de Hidrógeno , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Simulación del Acoplamiento Molecular , Nylons , Polietilenglicoles , Polímeros/síntesis química , Polímeros/química , Soluciones
17.
Ann Otol Rhinol Laryngol ; 107(2): 164-9, 1998 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9486912

RESUMEN

The constant increase in human life expectancy has led to a higher proportion of oncologic patients of advanced age. The clinical characteristics of 272 patients with laryngeal carcinoma diagnosed when they were 70 or older are compared with those of a group of younger patients with the same kind of tumor. The advanced age group showed a higher proportion of women, less tobacco and alcohol use, a predominance of glottic location, and a higher previous morbidity. The T category was similar in both groups, but the advanced age group had a higher proportion of N0 tumors. The planning of treatment was similar in the two groups of patients, except for less use of both chemotherapy and partial larynx surgery in the advanced age group. Results in terms of local and regional control, distant metastasis, and 5-year adjusted survival were similar in both groups of patients. The results suggest that advanced age is not a determining factor when considering radical treatment in a patient with laryngeal carcinoma.


Asunto(s)
Carcinoma de Células Escamosas/etiología , Neoplasias Laríngeas , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Envejecimiento , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/secundario , Carcinoma de Células Escamosas/terapia , Femenino , Humanos , Neoplasias Laríngeas/etiología , Neoplasias Laríngeas/mortalidad , Neoplasias Laríngeas/patología , Neoplasias Laríngeas/terapia , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Factores de Riesgo , Tasa de Supervivencia
18.
Methods Mol Biol ; 1141: 165-84, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24567139

RESUMEN

We have reviewed the binding affinities of several antitumor drugs doxorubicin (Dox), N-(trifluoroacetyl) doxorubicin (FDox), tamoxifen (Tam), 4-hydroxytamoxifen (4-Hydroxytam), and endoxifen (Endox) with chitosan nanoparticles of different sizes (chitosan-15, chitosan-100, and chitosan-200 KD) in order to evaluate the efficacy of chitosan nanocarriers in drug delivery systems. Spectroscopic and molecular modeling studies showed the binding sites and the stability of drug-polymer complexes. Drug-chitosan complexation occurred via hydrophobic and hydrophilic contacts as well as H-bonding network. Chitosan-100 KD was the more effective drug carrier than the chitosan-15 and chitosan-200 KD.


Asunto(s)
Antineoplásicos/química , Quitosano/química , Portadores de Fármacos , Nanopartículas/química , Sitios de Unión , Doxorrubicina/química , Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Cinética , Porosidad , Tamoxifeno/análogos & derivados , Tamoxifeno/química , Termodinámica
19.
Actas Esp Psiquiatr ; 33(6): 374-82, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16292721

RESUMEN

INTRODUCTION: This article reports data on the convergent and divergent validity of the Spanish adaptation of Spielberger's State-Trait Depression Questionnaire (ST-DEP). This questionnaire is a new tool because it offers an alternative to the obstacles found in most of the depression assessment scales that are differentiated in the content they evaluate and their estimation of depression levels. METHODOLOGY: The present study was carried out with a sample of 300 participants (103 males and 197 females), with mean age of 21.82 (2.74 s.d.) for males and 22.26 (3.66 s.d.) for females. All participants received information about the investigation and participated voluntarily. RESULTS AND CONCLUSIONS: The results indicate high and significant correlations of the Spanish ST-DEP scales with other depression measures (BDI, BDQ-R), thus showing the convergent validity of this questionnaire. Highly significant correlations between the Spanish ST-DEP and the State-Trait Anxiety Inventory (STAI) also appear, confirming that reported about the comorbidity between both disorders and the high scores in anxiety that subjects with depression have. In contrast, correlations with the State-Trait Anger Expression Inventory (STAXI-2) were low and non-significant in most cases, which demonstrated the divergent validity of the ST-DEP.


Asunto(s)
Depresión/diagnóstico , Lenguaje , Encuestas y Cuestionarios , Adulto , Ira , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , España , Traducciones
20.
Head Neck ; 19(3): 200-4, 1997 May.
Artículo en Inglés | MEDLINE | ID: mdl-9142519

RESUMEN

BACKGROUND: The medical literature on laryngeal carcinomas in patients without a history of tobacco and alcohol use is sparse. METHODS: A retrospective review of 933 laryngeal carcinomas treated in our center between January 1984 and December 1993 was made. Characteristics and results of patients with history of tobacco and alcohol use were compared with those who used neither. RESULTS: Of all patients with laryngeal carcinomas, 31 (3.3%) had no history of tobacco and alcohol use. In this group of patients, distribution between sexes was similar, and the mean age of patients was 70 years, compared with 63 years in the group with a history of tobacco and alcohol use. The survival rate was better in the former group. CONCLUSIONS: Patients without a history of tobacco and alcohol use who developed laryngeal cancer showed different characteristics compared with smokers or drinkers; they were an average of 10 years older, they showed no male predominance, and their lesions were mainly located in the glottis, which permitted early diagnosis and a higher survival rate.


Asunto(s)
Alcoholismo , Carcinoma de Células Escamosas/etiología , Neoplasias Laríngeas/etiología , Nicotiana , Plantas Tóxicas , Adulto , Distribución por Edad , Anciano , Análisis de Varianza , Carcinoma de Células Escamosas/epidemiología , Carcinoma de Células Escamosas/fisiopatología , Distribución de Chi-Cuadrado , Supervivencia sin Enfermedad , Femenino , Humanos , Incidencia , Neoplasias Laríngeas/epidemiología , Neoplasias Laríngeas/fisiopatología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Distribución por Sexo , Tasa de Supervivencia
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