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1.
J Investig Allergol Clin Immunol ; 33(4): 281-288, 2023 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-35503227

RESUMEN

BACKGROUND AND OBJECTIVE: Comorbidities can influence asthma control and promote asthma exacerbations (AEs). However, the impact of multimorbidity in AEs, assessed based on long-term follow-up of patients with asthma of different degrees of severity, has received little attention in real-life conditions. To describe the epidemiological and clinical characteristics and predictors of AEs in patients who had presented at least 1 AE in the previous year in the MEchanism of Genesis and Evolution of Asthma (MEGA) cohort. METHODS: The work-up included a detailed clinical examination, pulmonary function testing, fractional exhaled nitric oxide (FeNO), blood counts, induced sputum, skin prick-tests, asthma questionnaires, and assessment of multimorbidity. The number of moderate-severe AEs in the preceding year was registered for each patient. RESULTS: The study population comprised 486 patients with asthma (23.7% mild, 35% moderate, 41.3% severe). Disease remained uncontrolled in 41.9%, and 47.3% presented ≥1 moderate-severe AE, with a mean (SD) annual exacerbation rate of 0.47 (0.91) vs 2.11 (2.82) in mild and severe asthma, respectively. Comorbidity was detected in 56.4% (66.6% among those with severe asthma). Bronchiectasis, chronic rhinosinusitis with nasal polyps, atopy, psychiatric illnesses, hyperlipidemia, and hypertension were significantly associated with AEs. No associations were found for FeNO, blood eosinophils, or total serum IgE. Sputum eosinophilia and a high-T2 inflammatory pattern were significantly associated with AEs. Multivariable regression analysis showed a significant association with asthma severity, uncontrolled disease, and low prebronchodilator FEV1/FVC. CONCLUSION: Our study revealed a high frequency of AE in the MEGA cohort. This was strongly associated with multimorbidity, asthma severity, poor asthma control, airflow obstruction, higher sputum eosinophils, and a very high-T2 inflammatory pattern.


Asunto(s)
Asma , Eosinofilia , Humanos , Óxido Nítrico , Multimorbilidad , Asma/diagnóstico , Asma/epidemiología , Eosinófilos
2.
J Investig Allergol Clin Immunol ; 33(1): 37-44, 2023 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-35416154

RESUMEN

BACKGROUND AND OBJECTIVES: Chronic rhinosinusitis with nasal polyps (CRSwNP), which is characterized by partial loss of smell (hyposmia) or total loss of smell (anosmia), is commonly associated with asthma and/or nonsteroidal anti-inflammatory drug-exacerbated respiratory disease (N-ERD). CRSwNP worsens disease severity and quality of life. The objective of this real-world study was to determine whether biological treatments prescribed for severe asthma can improve olfaction in patients with CRSwNP. A further objective was to compare the improvement in in olfaction in N-ERD and non-N-ERD subgroups. METHODS: We performed a multicenter, noninterventional, retrospective, observational study of 206 patients with severe asthma and CRSwNP undergoing biological treatment (omalizumab, mepolizumab, benralizumab, or reslizumab). RESULTS: Olfaction improved after treatment with all 4 monoclonal antibodies (omalizumab [35.8%], mepolizumab [35.4%], reslizumab [35.7%], and benralizumab [39.1%]), with no differences between the groups. Olfaction was more likely to improve in patients with atopy, more frequent use of short-course systemic corticosteroids, and larger polyp size. The proportion of patients whose olfaction improved was similar between the N-ERD (37%) and non-N-ERD (35.7%) groups. CONCLUSIONS: This is the first real-world study to compare improvement in olfaction among patients undergoing long-term treatment with omalizumab, mepolizumab, reslizumab, or benralizumab for severe asthma and associated CRSwNP. Approximately 4 out of 10 patients reported a subjective improvement in olfaction (with nonsignificant differences between biologic drugs). No differences were found for improved olfaction between the N-ERD and non-N-ERD groups.


Asunto(s)
Asma , Productos Biológicos , Pólipos Nasales , Rinitis , Sinusitis , Humanos , Omalizumab/uso terapéutico , Pólipos Nasales/complicaciones , Pólipos Nasales/tratamiento farmacológico , Olfato , Productos Biológicos/uso terapéutico , Anosmia/complicaciones , Anosmia/tratamiento farmacológico , Calidad de Vida , Estudios Retrospectivos , Asma/complicaciones , Asma/tratamiento farmacológico , Inmunosupresores/uso terapéutico , Sinusitis/complicaciones , Sinusitis/tratamiento farmacológico , Enfermedad Crónica , Rinitis/complicaciones , Rinitis/tratamiento farmacológico
3.
J Investig Allergol Clin Immunol ; 31(1): 58-64, 2021 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-31599726

RESUMEN

BACKGROUND AND OBJECTIVE: The Global Initiative for Asthma (GINA) recommends the concurrent use of self-report and pharmacy refill data to assess treatment adherence. However, clinical evidence to support this combined approach is limited. Objective: To determine nonadherence to inhaler medication based on a validated questionnaire (Test of Adherence to Inhalers; TAI) and prescription refill data in a community sample of patients with chronic obstructive pulmonary disease (COPD) or asthma. Secondarily, we sought to determine the degree of concordance between these two measures. METHODS: Cross-sectional, observational multicenter study in patients with asthma or COPD. Sociodemographic and clinical data were obtained from clinical records. Refill data were retrieved from electronic pharmacy databases. Participants completed the 12-item TAI during a single visit as part of routine care. Nonadherence was defined as TAI <50 or <80% pharmacy refill rate (PRR) in the previous 6 months. RESULTS: A total of 816 patients (mean age, 60) were included. Nonadherence rates were 58.1% (TAI) and 28.6% (PRR) compared with 64.6% for the combined data (P<.0001). Concordance between the 2 measures was weak (к=0.205). CONCLUSIONS: These findings confirm the GINA recommendations, indicating that concomitant use of the TAI and pharmacy refill data identifies a higher percentage of nonadherent asthma or COPD patients than either instrument alone.


Asunto(s)
Asma/tratamiento farmacológico , Cumplimiento de la Medicación/estadística & datos numéricos , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Asma/epidemiología , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nebulizadores y Vaporizadores , Prescripciones , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Autoinforme , España/epidemiología , Encuestas y Cuestionarios
8.
J. investig. allergol. clin. immunol ; 31(1): 58-64, 2021. tab, graf
Artículo en Inglés | IBECS (España) | ID: ibc-202256

RESUMEN

BACKGROUND: The Global Initiative for Asthma (GINA) recommends the concurrent use of self-report and pharmacy refill data to assess treatment adherence. However, clinical evidence to support this combined approach is limited. OBJECTIVE: To determine nonadherence to inhaler medication based on a validated questionnaire (Test of Adherence to Inhalers; TAI) and prescription refill data in a community sample of patients with chronic obstructive pulmonary disease (COPD) or asthma. Secondarily, we sought to determine the degree of concordance between these two measures. METHODS: Cross-sectional, observational multicenter study in patients with asthma or COPD. Sociodemographic and clinical data were obtained from clinical records. Refill data were retrieved from electronic pharmacy databases. Participants completed the 12-item TAI during a single visit as part of routine care. Nonadherence was defined as TAI <50 or <80% pharmacy refill rate (PRR) in the previous 6 months. RESULTS: A total of 816 patients (mean age, 60) were included. Nonadherence rates were 58.1% (TAI) and 28.6% (PRR) compared with 64.6% for the combined data (P<.0001). Concordance between the 2 measures was weak (=0.205). CONCLUSIONS: These findings confirm the GINA recommendations, indicating that concomitant use of the TAI and pharmacy refill data identifies a higher percentage of nonadherent asthma or COPD patients than either instrument alone


ANTECEDENTES: La Global Initiative for Asthma (GINA) recomienda el uso combinado de cuestionarios autocumplimentados y el registro de la retirada de la medicación mediante la receta electrónica (RERFF) para determinar el nivel de adhesión terapéutica. Sin embargo, la evidencia para apoyar esta recomendación es limitada. OBJETIVOS: El objetivo del presente estudio fue determinar el nivel de adhesión a los inhaladores utilizando la información proporcionada mediante el Test de Adhesión a los Inhaladores (TAI-12), junto al RERFF, en un grupo de pacientes con asma o con Enfermedad Pulmonar Obstructiva Crónica (EPOC). Un objetivo secundario fue determinar el grado de concordancia entre ambos métodos. MÉTODOS: Estudio observacional, transversal y multicéntrico en pacientes diagnosticados con asma o EPOC. Se recogieron las características demográficas y clínicas de los registros clínicos. Los datos de retirada de inhaladores se recogieron en el RERFF. Los participantes cumplimentaron el TAI-12 durante una sola visita en el contexto de la atención clínica rutinaria. Se definió "baja adherencia" como TAI <50 o RERFF <80% en los 6 meses previos. RESULTADOS: Se incluyeron 816 pacientes (edad media, 60 años). Las tasas de baja adherencia fueron 58,1% (TAI) y 28,6% (RERFF) versus 64,6% para la combinación de los dos instrumentos (TAI+RERFF; p < 0,0001). La concordancia entre las dos medidas fue débil (kappa de Cohen = 0,205). CONCLUSIONES: Estos resultados confirman las recomendaciones de GINA, indicando que el uso de la combinación del TAI y la RERFF incrementa la capacidad para identificar la baja adherencia terapéutica, comparada con la del TAI o RERFF por separado


Asunto(s)
Humanos , Masculino , Femenino , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Cumplimiento de la Medicación , Nebulizadores y Vaporizadores/normas , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Asma/tratamiento farmacológico , Estudios Transversales , Ficha Clínica , Encuestas y Cuestionarios , Autocuidado/estadística & datos numéricos
9.
Br J Pharmacol ; 172(13): 3254-65, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25131623

RESUMEN

The free fatty acid receptors (FFA) 1 (previously designated GPR40) and FFA4 (previously GPR120) are two GPCRs activated by saturated and unsaturated longer-chain free fatty acids. With expression patterns and functions anticipated to directly or indirectly promote insulin secretion, provide homeostatic control of blood glucose and improve tissue insulin sensitivity, both receptors are being studied as potential therapeutic targets for the control of type 2 diabetes. Furthermore, genetic and systems biology studies in both humans and mouse models link FFA4 receptors to diabetes and obesity. Although activated by the same group of free fatty acids, FFA1 and FFA4 receptors are not closely related and, while the basis of recognition of fatty acids by FFA1 receptors is similar to that of the short-chain fatty acid receptors FFA2 and FFA3, the amino acid residues involved in endogenous ligand recognition by FFA4 receptors are more akin to those of the sphingosine 1 phosphate receptor S1P1 . Screening and subsequent medicinal chemistry programmes have developed a number of FFA1 receptor selective agonists that are effective in promoting insulin secretion in a glucose concentration-dependent manner, and in lowering blood glucose levels. However, the recent termination of Phase III clinical trials employing TAK-875/fasiglifam has caused a setback and raises important questions over the exact nature and mechanistic causes of the problems. Progress in the identification and development of highly FFA4 receptor-selective pharmacological tools has been less rapid and several issues remain to be clarified to fully validate this receptor as a therapeutic target. Despite this, the ongoing development of a range of novel ligands offers great opportunities to further unravel the contributions of these receptors.


Asunto(s)
Receptores Acoplados a Proteínas G/metabolismo , Animales , Variación Genética , Humanos , Ligandos , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/antagonistas & inhibidores , Receptores Acoplados a Proteínas G/genética
10.
Biochem Pharmacol ; 57(6): 663-72, 1999 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-10037452

RESUMEN

To discover safe and effective topical skin-lightening agents, we have evaluated alkyl esters of the natural product gentisic acid (GA), which is related to our lead compound methyl gentisate (MG), and four putative tyrosinase inhibitors, utilizing mammalian melanocyte cell cultures and cell-free extracts. Desirable characteristics include the ability to inhibit melanogenesis in cells (IC50 < 100 microg/mL) without cytotoxicity, preferably due to tyrosinase inhibition. Of the six esters synthesized, the smaller esters (e.g. methyl and ethyl) were more effective enzyme inhibitors (IC50 approximately 11 and 20 microg/mL, respectively). For comparison, hydroquinone (HQ), a commercial skin "bleaching" agent, was a less effective enzyme inhibitor (IC50 approximately 72 microg/mL), and was highly cytotoxic to melanocytes in vitro at concentrations substantially lower than the IC50 for enzymatic inhibition. Kojic acid was a potent inhibitor of the mammalian enzyme (IC50 approximately 6 microg/mL), but did not reduce pigmentation in cells. Both arbutin and magnesium ascorbyl phosphate were ineffective in the cell-free and cell-based assays. MG at 100 microg/mL exhibited a minimal inhibitory effect on DHICA oxidase (TRP 1) and no effect on DOPAchrome tautomerase (TRP-2), suggesting that MG inhibits melanogenesis primarily via tyrosinase inhibition. MG and GA were non-mutagenic at the hprt locus in V79 Chinese hamster cells, whereas HQ was highly mutagenic and cytotoxic. The properties of MG in vitro, including (1) pigmentation inhibition in melanocytes, (2) tyrosinase inhibition and selectivity, (3) reduced cytotoxicity relative to HQ, and (4) lack of mutagenic potential in mammalian cells, establish MG as a superior candidate skin-lightening agent.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Ésteres/farmacología , Gentisatos , Hidroxibenzoatos/farmacología , Melanocitos/efectos de los fármacos , Glicoproteínas de Membrana , Monofenol Monooxigenasa/antagonistas & inhibidores , Oxidorreductasas , Animales , Línea Celular , Ésteres/síntesis química , Hidroxibenzoatos/toxicidad , Oxidorreductasas Intramoleculares/antagonistas & inhibidores , Melaninas/análisis , Melanocitos/enzimología , Ratones , Pruebas de Mutagenicidad , Proteínas/antagonistas & inhibidores , Pigmentación de la Piel/efectos de los fármacos , Relación Estructura-Actividad
11.
Pediatr Med Chir ; 11(5): 541-2, 1989.
Artículo en Italiano | MEDLINE | ID: mdl-2631062

RESUMEN

Case report of a iatrogenic benign intracranial hypertension in a 7 months old infant. Unlike in the child and the adult, this syndrome has a peculiar non specific clinical pattern in the infant. Having ruled out other specific acute diseases of the central nervous system, it seems reasonable not to start any treatment since the outcome of this condition is always benign.


Asunto(s)
Analgésicos/efectos adversos , Antipirina/análogos & derivados , Seudotumor Cerebral/inducido químicamente , Sulfametoxipiridazina/análogos & derivados , Antipirina/efectos adversos , Humanos , Lactante , Masculino , Sulfametoxipiridazina/efectos adversos
12.
Pediatr Med Chir ; 9(4): 487-8, 1987.
Artículo en Italiano | MEDLINE | ID: mdl-3697329

RESUMEN

One case of a 13-months-old-female infant with transient idiopathic hyperphosphatasemia is described. This syndrome is characterized by: 1) increased serum alkaline phosphatase activity not associate with an organic disease; 2) normalization of the enzyme activity within 12 weeks. Familial hyperphosphatasemia, a permanens disease, is also excluded because of ALP normal values in both parents. Rickets, hepatic and biliary diseases are excluded by clinical, radiologic and laboratory data.


Asunto(s)
Fosfatasa Alcalina/sangre , Desarrollo Infantil/fisiología , Humanos , Lactante , Masculino
14.
Immunomethods ; 5(2): 98-106, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7874443

RESUMEN

From the original observation that the codons for the hydrophobic and hydrophilic amino acids on one strand of the DNA may be complemented by the codons for the hydrophilic and hydrophobic amino acids, respectively, on the complementary strand, arose the molecular recognition theory which forms the basis for much of the work involving complementary peptides. A number of examples have been documented where peptides with inverted hydropathic profiles have been shown to form complexes in high-affinity chromatography and solid matrix binding assays. Nevertheless, our current understanding of the molecular forces leading to the formation of these complexes is rather rudimentary, and it is highly desirable to have a detailed three-dimensional structure of a complex of interacting complementary peptides. In this article, we provide a brief review of the solution NMR work done by different laboratories in an attempt to study these interactions.


Asunto(s)
Espectroscopía de Resonancia Magnética/métodos , Péptidos/análisis , Proteínas/química , Secuencia de Aminoácidos , Humanos , Datos de Secuencia Molecular , Péptidos/metabolismo
15.
Minerva Pediatr ; 44(12): 593-4, 1992 Dec.
Artículo en Italiano | MEDLINE | ID: mdl-1301483

RESUMEN

The paper reports the case of a neonate suffering from autoimmune neonatal thrombocytopenia whose mother had suffered from previous idiopathic thrombocytopenia purpura. Although asymptomatic, the baby received early treatment with high doses of immunoglobulin G (1 g/kg) in a single dose. Treatment was repeated on day 12 using the same method. No other treatment was associated with IgG. The Authors confirm the good level of tolerability and efficacy of IgG in the treatment of autoimmune neonatal thrombocytopenia without complications.


Asunto(s)
Inmunoglobulina G/uso terapéutico , Trombocitopenia/tratamiento farmacológico , Autoinmunidad , Desarrollo Embrionario y Fetal , Femenino , Humanos , Inmunoglobulina G/administración & dosificación , Recién Nacido , Inyecciones Intravenosas , Masculino , Intercambio Materno-Fetal , Embarazo , Trombocitopenia/inmunología
16.
Minerva Pediatr ; 45(3): 123-6, 1993 Mar.
Artículo en Italiano | MEDLINE | ID: mdl-8341226

RESUMEN

The paper describes a case of meningococcal sepsis and septic shock treated with Ceftriazone, Dexamethosone, plasma and heparin. It was observed that contrary to other hematological parameters, ESR levels remained high for one month after the suspension of antibiotic therapy and complete clinical recovery. The authors relate this alteration of ESR values to the administration of plasma during the acute phase of the disease.


Asunto(s)
Infecciones Meningocócicas/sangre , Choque Séptico/sangre , Sedimentación Sanguínea , Terapia Combinada , Quimioterapia Combinada , Femenino , Fluidoterapia , Humanos , Lactante , Infecciones Meningocócicas/terapia , Plasma , Inducción de Remisión , Choque Séptico/terapia , Factores de Tiempo
17.
J Comput Aided Mol Des ; 10(5): 361-71, 1996 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8951648

RESUMEN

We report a theoretical characterization of the intermolecular transferred NOESY (inter-TrNOESY) between ligands and receptor macromolecules that bind reversibly, using a COmplete Relaxation and Conformational Exchange MAtrix (CORCEMA) theory developed in our laboratory. We examine the dependence of inter-TrNOESY on the dissociation constant, off-rate, ligand-to-receptor ratio, and distance variations between protons of interacting species within the complex. These factors are analyzed from simulations on two model systems: (i) neuraminidase complexed to a transition-state analogue; and (ii) thermolysin complexed to a leucine-based inhibitor. The latter case utilizes a three-state model of interaction to simulate the effect of hinge-bending motions on the inter-TrNOESY. Our calculations suggest a potential role for inter-TrNOESY (when observable) and CORCEMA analysis in properly docking the ligand within the active site, and in refining the conformation of the ligand-receptor (active-site) complex. These findings have implications on the structure-based design of ligands (e.g., inhibitors) reversibly binding to receptors (e.g., enzymes).


Asunto(s)
Espectroscopía de Resonancia Magnética/métodos , Modelos Químicos , Receptores de Superficie Celular/química , Programas Informáticos , Sitios de Unión , Simulación por Computador , Diseño Asistido por Computadora , Diseño de Fármacos , Ligandos , Sustancias Macromoleculares , Estructura Molecular , Neuraminidasa/química , Protones , Termolisina/antagonistas & inhibidores , Termolisina/química
18.
J Magn Reson B ; 108(3): 243-61, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7670757

RESUMEN

A very general procedure entitled complete relaxation and conformational exchange matrix (CORCEMA) analysis has been developed to analyze the 2D-NOESY spectra of interacting systems undergoing multistate conformational exchange. This is an extension of earlier work from this laboratory on the methodological treatment of multistate conformational exchange [Krishna et al., Biopolymers 19, 2003 (1980)] and the theory of transferred NOESY for finite exchange off-rates [Lee and Krishna, J. Magn. Reson. 98, 36 (1992)]. The current theory is based on generalized rate matrices for relaxation and conformational exchange. The CORCEMA algorithm explicitly incorporates intermolecular dipolar cross relaxation between the molecules when they are complexed. It permits an analysis of NOESY intensities for the intra- as well as intermolecular contacts between the interacting molecules under a variety of binding conditions. Its application is illustrated on two examples of transferred NOESY simulations: (1) a two-state system involving a ligand and an enzyme forming a ligand-enzyme complex, and (2) a three-state system in which the ligand-enzyme complex can undergo a conformational transition from an "open state" to a "closed state," and can include conformational changes in both the complexed ligand and the complexed enzyme, such as hinge-bending motions. Simplifying expressions for generalized matrix analyses are derived for three limiting cases of the three-state system. This three-state example is illustrated using a hypothetical model of the hinge-bending motion in a thermolysin-inhibitor complex. It is shown that: (1) The neglect of cross relaxation between the interacting species in their complexed forms can lead to misleading conclusions on the "bound" conformation of the ligand. (2) If protein-mediated spin diffusion is dominant, caution is needed in analyses based on initial slopes alone due to one's inability to identify the exact range of the initial growth curve under poor signal/noise situations. (3) The neglect of conformational changes upon complexation, e.g., hinge-bending motions of the ligand-enzyme complex, can lead to erroneous results on the nature of "bound" conformations of the ligand. In this case, attempts to analyze the transferred NOESY data with a two-state model will result in a "virtual" conformation for the bound ligand. (4) When the hinge-bending rate is slower than the cross relaxation and enzyme off-rates, the bound conformation of a ligand deduced from the transferred NOESY experiment is more likely to represent nonspecific or weak binding in an open state of the enzyme.(ABSTRACT TRUNCATED AT 400 WORDS)


Asunto(s)
Espectroscopía de Resonancia Magnética , Conformación Proteica , Proteínas/química , Algoritmos , Artefactos , Quelantes/química , Enzimas/metabolismo , Aumento de la Imagen/métodos , Ligandos , Espectroscopía de Resonancia Magnética/métodos , Modelos Químicos , Unión Proteica , Procesamiento de Señales Asistido por Computador , Termolisina/antagonistas & inhibidores , Termolisina/metabolismo
19.
Med Vet Entomol ; 14(3): 272-6, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11016434

RESUMEN

A study was carried out to assess the resistance of pure and cross-bred groups of cattle to the horn fly Haematobia irritans (Linnaeus) (Diptera: Muscidae) in northern Argentina. Pure-bred cattle were Criolla, Iberian Bos taurus Linnaeus (Artiodactyla: Bovidae) and Nellore, Bos indicus Linnaeus (Artiodactyla: Bovidae). Cross-bred cattle were Hereford, British B. taurus (34%) X Nellore (66%) and Hereford (66%) X Nellore (34%). All were heifers and animals were maintained in two groups, each containing a mixture of pure and cross-breeds. The lowest fly numbers were found on Criolla heifers and the highest on Hereford X Nellore cross-breeds. However, it could not be determined from this study whether this was a consequence of breed and/or size, as Criolla heifers were lighter than the corresponding Hereford X Nellore heifers. Fly numbers on the heifers followed an approximately negative binomial distribution. However, the ranking of individual animals in their level of infestation within subgroups was not consistent. Hence, culling the most infested heifers on any given date would at best give only a small improvement in H. irritans control.


Asunto(s)
Enfermedades de los Bovinos/epidemiología , Miasis/veterinaria , Animales , Argentina/epidemiología , Peso Corporal , Bovinos/clasificación , Susceptibilidad a Enfermedades/veterinaria , Miasis/epidemiología
20.
Biochem Biophys Res Commun ; 193(2): 688-93, 1993 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-8512567

RESUMEN

The solution structure of trypsin modulating oostatic factor (TMOF), a decapeptide (H-YDPAPPPPPP-OH) hormone that signals the termination of trypsin-like biosynthesis in mosquito midgut epithelial cells, was determined by 2-D 1H nuclear magnetic resonance spectroscopy and molecular modeling. The peptide forms a rod-shaped left-handed helix about 30 A long. No evidence was found to support a poly-L-proline beta-turn model. Hydrophobic contacts between the rings of tyrosine 1 and proline 3 may enhance the stability of the N-terminal segment. This peptide provides an interesting exception to the normal chemical shift index (csi) rules. Our results suggest that a sequence of positive csi indices, normally expected for a beta-strand structure, could also describe a left-handed poly-L-proline-like helix.


Asunto(s)
Oligopéptidos/química , Estructura Secundaria de Proteína , Secuencia de Aminoácidos , Hidrógeno , Espectroscopía de Resonancia Magnética , Modelos Estructurales , Datos de Secuencia Molecular , Oligopéptidos/síntesis química , Soluciones
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