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1.
Placenta ; 120: 73-78, 2022 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-35227983

RESUMEN

INTRODUCTION: Soluble fms-like tyrosine kinase 1 (sFLT-1), a circulating anti-angiogenic factor that binds and antagonizes placental growth factor (PlGF), appears key to preeclamptic pathophysiology. Two main sFLT-1 splice variants exist: sFLT-1 e15a and sFLT-1 i13. Total sFLT-1/PlGF ratios are increasingly used clinically; we explore whether using placental-specific sFLT-1 e15a improves test performance compared with total sFLT-1 in preeclampsia diagnosis. METHODS: Consent was obtained for serum sampling from 96 women with suspected preeclampsia. Total sFLT-1 and PlGF were quantified using the B.R.A.H.M.S Kryptor Compact Plus automated immunoassay platform, and sFLT-1 e15a by custom enzyme-linked immunosorbent assay. Test performance was then assessed by subsequent diagnosis. RESULTS: Of 96 participants, 32 did not develop preeclampsia, 32 had early-onset (<34 weeks') disease and 32 had late-onset (≥34 weeks') disease. In those with preeclampsia, median sFLT-1 and sFLT-1 e15a were significantly increased (7361.0 vs 2463.0 pg/mL, and 946.6 vs 305.4 ng/mL respectively; p < 0.001 for both), and PlGF significantly reduced (43.5 vs 154.4 pg/mL; p < 0.001) compared to those without preeclampsia. Those with early-onset, compared to late-onset, preeclampsia chiefly had lower median PlGF levels (16.0 vs 57.3; p < 0.001), which contributed to higher sFLT-1/PlGF and sFLT-1 e15a/PlGF ratios (830.1 vs 86.7, and 109258.9 vs 12608.7 respectively; p < 0.001 for both). DISCUSSION: sFLT-1 e15a performs comparably to total sFLT-1 in women with suspected preeclampsia, however with higher translational burden. Our results support the expanding clinical use of the sFLT-1/PlGF ratio in suspected preeclampsia, particularly early-onset, to assist with disease diagnosis.


Asunto(s)
Preeclampsia , Receptor 1 de Factores de Crecimiento Endotelial Vascular/sangre , Biomarcadores , Femenino , Humanos , Placenta/metabolismo , Factor de Crecimiento Placentario , Preeclampsia/metabolismo , Embarazo , Proteínas Tirosina Quinasas Receptoras/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Receptor 1 de Factores de Crecimiento Endotelial Vascular/metabolismo
2.
Reprod Sci ; 28(5): 1489-1497, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33409874

RESUMEN

Sulforaphane, an isothiocyanate found in cruciferous vegetables such as broccoli, shows promise as an adjuvant therapy for preeclampsia. To inform future clinical trials, we set out to determine the bioavailability of sulforaphane in non-pregnant and preeclamptic women. In six healthy female volunteers, we performed a crossover trial to compare the bioavailability of sulforaphane and metabolites afforded by an activated and non-activated broccoli extract preparation. We then undertook a dose escalation study of the activated broccoli extract in 12 women with pregnancy hypertension. In non-pregnant women, an equivalent dose of activated broccoli extract gave higher levels of sulforaphane and metabolites than a non-activated extract (p < 0.0001) and greater area under the curve (AUC) (3559 nM vs. 2172 nM, p = 0.03). Compared to non-pregnant women, in women with preeclampsia, the same dose of activated extract gave lower levels of total metabolites (p < 0.000) and AUC (3559 nM vs. 1653 nM, p = 0.007). Doubling the dose of the activated extract in women with preeclampsia doubled levels of sulforaphane and metabolites (p = 0.02) and AUC (1653 nM vs. 3333 nM, p = 0.02). In women with preeclampsia, activated broccoli extract was associated with modest decreases in diastolic blood pressure (p = 0.05) and circulating levels of sFlt-1 (p = 0.0002). A myrosinase-activated sulforaphane formulation affords better sulforaphane bioavailability than a non-activated formulation. Higher doses of sulforaphane are required to achieve likely effective doses in pregnant women than in non-pregnant women. Sulforaphane may improve endothelial function and blood pressure in women with pregnancy hypertension.


Asunto(s)
Presión Sanguínea/efectos de los fármacos , Hipertensión Inducida en el Embarazo/metabolismo , Isotiocianatos/administración & dosificación , Isotiocianatos/farmacocinética , Sulfóxidos/administración & dosificación , Sulfóxidos/farmacocinética , Adulto , Disponibilidad Biológica , Estudios Cruzados , Femenino , Humanos , Preeclampsia/metabolismo , Embarazo , Adulto Joven
3.
Placenta ; 101: 242-250, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33032098

RESUMEN

INTRODUCTION: The widespread maternal endothelial dysfunction that underlies the manifestations of preeclampsia is thought to arise from excessive placental production of antiangiogenic factors and enhanced oxidative stress. Therefore, we assessed whether the natural antioxidant sulforaphane could improve vascular function. METHODS: Cell viability of human umbilical vein endothelial cells (HUVECs) was assessed after 24 or 48 h in normoxia (20% O2) or hypoxia (1% O2) with or without sulforaphane. To model vascular dysfunction associated with preeclampsia, mouse mesenteric arteries were incubated in trophoblast conditioned media (TCM), and human omental arteries incubated in preeclamptic explant media (PEM) with or without sulforaphane. Both media are rich in antiangiogenic compounds associated with preeclampsia. TCM was generated from primary cytotrophoblast cells from term placentae of normotensive, while PEM was generated from explants from preeclamptic women. Reactivity was assessed by wire myography. sulforaphane's actions as a vasodilator were also investigated. RESULTS: Under conditions of hypoxia, sulforaphane improved HUVEC viability. In mouse mesenteric arteries, sulforaphane reduced contraction evoked by potassium (p < 0.001), phenylephrine and endothelin 1 (all p < 0.001). Sulforaphane also inhibited Ca2+-induced contraction (p = 0.014). Sulforaphane prevented TCM-induced augmentation of phenylephrine and angiotensin II-mediated contraction of mouse mesenteric arteries. In human omental arteries, sulforaphane induced vasodilation (p < 0.001), and prevented PEM-induced endothelial dysfunction by restoring arterial sensitivity to the endothelium-dependent vasodilator bradykinin (p = 0.008). DISCUSSION: Sulforaphane causes relaxation in arteries and protects against arterial dysfunction induced by placental-derived antiangiogenic factors, which are known to contribute to the preeclampsia.


Asunto(s)
Anticarcinógenos/uso terapéutico , Isotiocianatos/uso terapéutico , Arterias Mesentéricas/efectos de los fármacos , Preeclampsia/tratamiento farmacológico , Sulfóxidos/uso terapéutico , Vasoconstricción/efectos de los fármacos , Animales , Anticarcinógenos/farmacología , Evaluación Preclínica de Medicamentos , Femenino , Células Endoteliales de la Vena Umbilical Humana , Humanos , Técnicas In Vitro , Isotiocianatos/farmacología , Ratones Endogámicos C57BL , Embarazo , Sulfóxidos/farmacología
5.
Placenta ; 96: 44-54, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32560857

RESUMEN

INTRODUCTION: Placental mitochondrial dysfunction contributes to the oxidative stress that underlies preeclampsia. Here, we assessed whether sulforaphane (SFN) could improve syncytiotrophoblast mitochondrial function after in vitro hypoxic and superoxide injury. METHODS: Placental cytotrophoblasts were isolated from healthy term placentae (n = 12) and incubated for 48 h in 8% O2 ± 1 µM SFN before acute (4hrs) or chronic (24hrs) hypoxic (1% O2), or superoxide (xanthine/xanthine oxidase) injury. Cytotrophoblasts were also isolated from preeclamptic placentae (n = 5) and cultured in 8% O2 ± 1 µM SFN. Mitochondrial respiration was measured using the Seahorse MitoStress XF assay. Cells were stained with mitotracker red to assess mitochondrial membrane health and mitochondrial gene expression assessed using RT-qPCR. RESULTS: SFN prevented significant reductions in syncytiotrophoblast mitochondrial maximal respiration, spare respiratory capacity, basal respiration and ATP production following acute hypoxia. Chronic hypoxia only reduced maximal and spare respiratory capacity. SFN prevented these negative changes and increased respiration overall. Alternatively, acute superoxide injury significantly increased mitochondrial maximal respiration and spare respiratory capacity. SFN treatment further increased basal respiration following superoxide injury and prevented significant decreases in ATP production and coupling efficiency. In preeclamptic placentae, SFN significantly increased mitochondrial maximal respiration, spare respiratory capacity, basal respiration and ATP production, and decreased proton leak. SFN up-regulated mRNA expression of mitochondrial complexes and corrected an up-regulation in fission gene expression observed after hypoxic-superoxide injury. Finally, preliminary results suggest SFN prevented hypoxia-induced impairment of mitochondrial membrane structure. DISCUSSION: SFN mitigated hypoxia and superoxide induced changes to syncytiotrophoblast mitochondrial function in vitro, and improved mitochondrial respiration in trophoblast cells from preeclamptic placentae.


Asunto(s)
Antioxidantes/farmacología , Hipoxia de la Célula/efectos de los fármacos , Isotiocianatos/farmacología , Mitocondrias/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Sulfóxidos/farmacología , Superóxidos/farmacología , Trofoblastos/efectos de los fármacos , Adulto , Femenino , Humanos , Mitocondrias/metabolismo , Placenta/efectos de los fármacos , Placenta/metabolismo , Embarazo , Trofoblastos/metabolismo
6.
Zootaxa ; 4624(4): zootaxa.4624.4.8, 2019 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-31716202

RESUMEN

The Micropezidae species of Mauritius are reviewed on the basis of recent collections. Mimegralla splendens (Wiedemann 1830) is newly recorded from Mauritius and the new genus Paraeurybata is described for Calobata taeniata Macquart 1851. A third species, Courtoisia apicalis (Macquart 1851), remains known only from the type specimen collected in Réunion and from a single specimen collected in Mauritius in 1963.


Asunto(s)
Dípteros , Animales , Mauricio , Reunión
7.
Br J Pharmacol ; 174(10): 1002-1014, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-27590257

RESUMEN

The peptide hormone relaxin regulates the essential maternal haemodynamic adaptations in early pregnancy through direct actions on the renal and systemic vasculature. These vascular actions of relaxin occur mainly through endothelium-derived NO-mediated vasodilator pathways and improvements in arterial compliance in small resistance-size arteries. This work catalysed a plethora of studies which revealed quite heterogeneous responses across the different regions of the vasculature, and also uncovered NO-independent mechanisms of relaxin action. In this review, we first describe the role of endogenous relaxin in maintaining normal vascular function, largely referring to work in pregnant and male relaxin-deficient animals. We then discuss the diversity of mechanisms mediating relaxin action in different vascular beds, including the involvement of prostanoids, VEGF, endothelium-derived hyperpolarisation and antioxidant activity in addition to the classic NO-mediated vasodilatory pathway. We conclude the review with current perspectives on the vascular remodelling capabilities of relaxin. LINKED ARTICLES: This article is part of a themed section on Recent Progress in the Understanding of Relaxin Family Peptides and their Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.10/issuetoc.


Asunto(s)
Endotelio Vascular/metabolismo , Óxido Nítrico/metabolismo , Relaxina/metabolismo , Animales , Humanos
8.
Zootaxa ; 4132(2): 254-68, 2016 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-27395665

RESUMEN

The previously monotypic genus Pseudeurybata Hennig is revised to include seven species from Central America and Mexico and one species from South America. Pseudeurybata rufilabris (Enderlein) and Pseudeurybata compeditus (Hennig) are given as new combinations and a lectotype is designated for P. rufilabris (Enderlein). Pseudeurybata browni and P. alces from Costa Rica, P. guatemalensis from Guatemala, P. dasypogon from Mexico, and P. zeta from Colombia and Ecuador are described as new. All species are keyed and illustrated.


Asunto(s)
Dípteros/clasificación , Distribución Animal , Estructuras Animales/anatomía & histología , Estructuras Animales/crecimiento & desarrollo , Animales , Tamaño Corporal , Dípteros/anatomía & histología , Dípteros/crecimiento & desarrollo , Femenino , Masculino , Tamaño de los Órganos , América del Sur
9.
Zootaxa ; 4098(1): 1-42, 2016 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-27394573

RESUMEN

The family Nothybidae (Diptera: Schizophora) is revised. The family consists of 11 species in the single genus Nothybus Rondani, which occurs in Papua New Guinea, Nepal and much of the Oriental Region. Three species are described as new: N. absens spec. nov. (China), N. cataractus spec. nov. (Laos, Thailand) and N. procerus spec. nov. (India). Nothybus longithorax Rondani, 1875 is treated as a junior synonym of N. longicollis (Walker, 1856). Nothybus decorus Meijere, 1924 syn. nov. is included as a junior synonym of N. lineifer Enderlein, 1922.


Asunto(s)
Dípteros/clasificación , Distribución Animal , Estructuras Animales/anatomía & histología , Estructuras Animales/crecimiento & desarrollo , Animales , Asia , Tamaño Corporal , Dípteros/anatomía & histología , Dípteros/crecimiento & desarrollo , Femenino , Masculino , Tamaño de los Órganos
10.
Zootaxa ; 3914(5): 525-40, 2015 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-25661960

RESUMEN

Mesoconius Enderlein, including Zelatractodes Enderlein new synonym, is revised for Central America with one described species (Mesoconius hemithorax Frey) and five new species (M. bicolor, M. dianthus, M. nigrihumeralis, M. tigrinus, and M. zadbi). The relatively large species of this entirely Neotropical genus, most of which are restricted to narrow high elevation ranges, lack the male genital fork that characterizes all other Taeniapterinae.


Asunto(s)
Dípteros/clasificación , Distribución Animal , Estructuras Animales/anatomía & histología , Estructuras Animales/crecimiento & desarrollo , Animales , Tamaño Corporal , América Central , Dípteros/anatomía & histología , Dípteros/crecimiento & desarrollo , Ecosistema , Femenino , Masculino , Tamaño de los Órganos
11.
Zootaxa ; 3887(1): 1-36, 2014 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-25543921

RESUMEN

Howickia Richards 1951 is redefined to include all wingless or strongly brachypterous Sphaeroceridae in New Zealand as well as two newly described fully winged species, H. oliveri and H. lepidostylus. Biroina Richards 1973 is newly treated as a junior subjective synonym of Howickia. The following new flightless species are described from New Zealand: H. bicolor, H. cordata, H. exasperata, H. harrisoni, H. mercurialis, H. nigrilegula, H. nigriventer, H. nudistylus, H. omamari, H. palmai, H. regalis, H. tangata, H. wahaika and H. zonula.


Asunto(s)
Dípteros/anatomía & histología , Dípteros/clasificación , Distribución Animal , Animales , Dípteros/fisiología , Femenino , Masculino , Nueva Zelanda , Especificidad de la Especie
12.
Zootaxa ; 3682: 45-84, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-25243275

RESUMEN

The Caribbean and North American species of the large, otherwise neotropical genus Grallipeza Rondani (Diptera: Micropezidae: Taeniapterinae) are revised and keyed. One species, G. nebulosa (Loew), is endemic to the southeastern United States and eighteen species are endemic to single Caribbean islands. Of these, the following nine are described as new: Grallipeza abeja, G. albiterga, G. cliffi, G. grenada, G marleyi, G. mellea, G. paraplacida, G. perezi and G. turba.


Asunto(s)
Dípteros/anatomía & histología , Dípteros/clasificación , Distribución Animal , Animales , Femenino , Masculino , América del Norte , Filogenia , Especificidad de la Especie , Indias Occidentales
13.
Alcohol ; 44(1): 89-98, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20113877

RESUMEN

Alcohol use during adolescence leads to increased risk of developing an alcohol use disorder (AUD) during adulthood. Converging evidence suggests that this period of enhanced vulnerability for developing an AUD may be due to the adolescent's unique sensitivity and response to alcohol. Adolescent rats have been shown to be less sensitive to alcohol intoxication and withdrawal susceptibility; however, age differences in ethanol pharmacokinetics may underlie these effects. Therefore, this study investigated alcohol intoxication behavior and withdrawal severity using a modified Majchrowicz model of alcohol dependence that has been shown to result in similar blood ethanol concentrations (BECs) despite age differences. Adolescent (postnatal day, PND, 35) and adult rats (PND 70+) received ethanol according to this 4-day binge paradigm and were observed for withdrawal behavior for 17h. As expected, adolescents showed decreased sensitivity to alcohol-induced CNS depression as evidenced by significantly lower intoxication scores. Thus, adolescents received significantly more ethanol each day (12.3+/-0.1g/kg/day) than adults (9.2+/-0.2g/kg/day). Despite greater ethanol dosing in adolescent rats, both adolescent and adult groups had comparable peak BECs (344.5+/-10.2 and 338.5+/-7.8mg/dL, respectively). Strikingly, withdrawal severity was similar quantitatively and qualitatively between adolescent and adult rats. Further, this is the first time that withdrawal behavior has been reported for adolescent rats using this model of alcohol dependence. A second experiment confirmed the similarity in BECs at various time points across the binge. These results demonstrate that after consideration of ethanol pharmacokinetics between adults and adolescents by using a model that produces similar BECs, withdrawal severity is nearly identical. This study, in combination with previous reports on ethanol withdrawal in adolescents and adults, suggests only a BEC-dependent effect of ethanol on withdrawal severity regardless of age.


Asunto(s)
Envejecimiento , Trastornos Relacionados con Alcohol/etiología , Conducta Animal/efectos de los fármacos , Depresores del Sistema Nervioso Central/toxicidad , Etanol/toxicidad , Síndrome de Abstinencia a Sustancias/etiología , Factores de Edad , Trastornos Relacionados con Alcohol/fisiopatología , Trastornos Relacionados con Alcohol/psicología , Animales , Nivel de Alerta/efectos de los fármacos , Depresores del Sistema Nervioso Central/sangre , Depresores del Sistema Nervioso Central/farmacocinética , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Etanol/sangre , Etanol/farmacocinética , Masculino , Modelos Biológicos , Actividad Motora/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Factores de Riesgo , Índice de Severidad de la Enfermedad , Desarrollo Sexual , Síndrome de Abstinencia a Sustancias/fisiopatología , Síndrome de Abstinencia a Sustancias/psicología
14.
Clin Pharmacol Ther ; 82(1): 21-32, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17522597

RESUMEN

The low productivity and escalating costs of drug development have been well documented over the past several years. Less than 10% of new compounds that enter clinical trials ultimately make it to the market, and many more fail in the preclinical stages of development. These challenges in the "critical path" of drug development are discussed in a 2004 publication by the US Food and Drug Administration. The document emphasizes new tools and various opportunities to improve drug development. One of the opportunities recommended is the application of "model-based drug development (MBDD)." This paper discusses what constitutes the key elements of MBDD and how these elements should fit together to inform drug development strategy and decision-making.


Asunto(s)
Ensayos Clínicos como Asunto/métodos , Relación Dosis-Respuesta a Droga , Aprobación de Drogas , Diseño de Fármacos , Modelos Biológicos , Farmacología , Proyectos de Investigación , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/psicología , Aminas/farmacología , Aminas/uso terapéutico , Analgésicos/farmacología , Analgésicos/uso terapéutico , Animales , Anticolesterolemiantes/farmacología , Anticolesterolemiantes/uso terapéutico , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes/uso terapéutico , Caproatos/farmacología , Caproatos/uso terapéutico , Colesterol/sangre , Ensayos Clínicos como Asunto/legislación & jurisprudencia , Ensayos Clínicos como Asunto/estadística & datos numéricos , Cognición/efectos de los fármacos , Simulación por Computador , Ácidos Ciclohexanocarboxílicos/farmacología , Ácidos Ciclohexanocarboxílicos/uso terapéutico , Gabapentina , Glicoproteínas/farmacología , Glicoproteínas/uso terapéutico , Guías como Asunto , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Hipercolesterolemia/sangre , Hipercolesterolemia/tratamiento farmacológico , Factores Inmunológicos/farmacología , Factores Inmunológicos/uso terapéutico , Metaanálisis como Asunto , Modelos Estadísticos , Agonistas Muscarínicos/farmacología , Agonistas Muscarínicos/uso terapéutico , Neuralgia Posherpética/tratamiento farmacológico , Infiltración Neutrófila/efectos de los fármacos , Oximas/farmacología , Oximas/uso terapéutico , Farmacocinética , Reproducibilidad de los Resultados , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/inmunología , Estados Unidos , United States Food and Drug Administration , Ácido gamma-Aminobutírico/farmacología , Ácido gamma-Aminobutírico/uso terapéutico
15.
Diagn Microbiol Infect Dis ; 39(4): 257-60, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11404070

RESUMEN

Antimicrobial susceptibility testing of cystic fibrosis (CF) isolates of Pseudomonas aeruginosa is difficult because the organisms are often mucoid and slow-growing. This study of 498 CF strains examined the correlation of results derived from two commonly used commercial systems (Vitek, MicroScan-WalkAway) with a reference method for 10 antimicrobials. Correlation to reference results was unacceptably low for all agents and both commercial systems had a high rate of very major (false-susceptible) errors. Although mucoid strains produced a 4.8% greater intermethod error, it was not markedly different than non-mucoid strains for the Vitek System. Overall, these tested commercial systems performed poorly for CF isolates in contrast to earlier reported, high correlations with the reference methods (broth microdilution frozen panels and agar dilution) of the National Committee for Clinical Laboratory Standards, the standardized disk diffusion test, and the Etest (AB BIODISK, Solna, Sweden).


Asunto(s)
Antibacterianos/farmacología , Fibrosis Quística/microbiología , Pseudomonas aeruginosa/efectos de los fármacos , Aminoglicósidos , Medios de Cultivo , Farmacorresistencia Microbiana , Fluoroquinolonas , Humanos , Lactamas , Pruebas de Sensibilidad Microbiana/métodos , Fenotipo , Valor Predictivo de las Pruebas , Pseudomonas aeruginosa/aislamiento & purificación , Juego de Reactivos para Diagnóstico/normas , Estándares de Referencia
16.
J Mol Biol ; 305(3): 619-31, 2001 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-11152617

RESUMEN

We have developed a method to determine the optimal binary pattern (arrangement of hydrophobic and polar amino acids) of a target protein fold prior to amino acid sequence selection in protein design studies. A solvent accessible surface is generated for a target fold using its backbone coordinates and "generic" side-chains, which are constructs whose size and shape are similar to an average amino acid. Each position is classified as hydrophobic or polar according to the solvent exposure of its generic side-chain. The method was tested by analyzing a set of proteins in the Protein Data Bank and by experimentally constructing and analyzing a set of engrailed homeodomain variants whose binary patterns were systematically varied. Selection of the optimal binary pattern results in a designed protein that is monomeric, well-folded, and hyperthermophilic. Homeodomain variants with fewer hydrophobic residues are destabilized, while additional hydrophobic residues induce aggregation. Binary patterning, in conjunction with a force field that models folded state energies, appears sufficient to satisfy two basic goals of protein design: stability and conformational specificity.


Asunto(s)
Proteínas de Homeodominio/química , Ingeniería de Proteínas , Pliegue de Proteína , Factores de Transcripción , Animales , Rastreo Diferencial de Calorimetría , Dicroismo Circular , Bases de Datos como Asunto , Guanidina/farmacología , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Luz , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Mutación/genética , Conformación Proteica/efectos de los fármacos , Desnaturalización Proteica/efectos de los fármacos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Reproducibilidad de los Resultados , Dispersión de Radiación , Solventes , Termodinámica
17.
J Clin Microbiol ; 39(1): 53-6, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11136748

RESUMEN

The Vitek automated susceptibility testing system with a modified Gram-Positive Susceptibility (GPS) 106 Card (bioMerieux Vitek, Inc., Hazelwood, Mo.) and a rapid slide latex agglutination test (MRSA-Screen; Denka Seiken Co., Ltd., Tokyo, Japan) were evaluated for their ability to detect oxacillin resistance in Staphylococcus aureus. The oxacillin-salt agar screen (OS) test, the reference broth microdilution method, and the detection of the mecA gene by PCR were compared with the commercial products. A total of 200 contemporary (1999) bloodstream infection isolates were collected from the SENTRY Antimicrobial Surveillance Program, representing diverse geographic areas throughout the world. Among the 99 mecA-positive isolates, 3 isolates were found negative by the MRSA-Screen. Another two isolates did not grow on OS plates and had MICs of 0.5 and 2 microg/ml with the Vitek GPS card. All 101 mecA-negative isolates were also found negative by the MRSA-Screen and were categorized as susceptible by the GPS card. Overall, the MRSA-Screen, GPS card, and OS test had sensitivities of 96.9, 98.0, and 98.0% and specificities of 100.0, 100.0, and 98.0%, respectively. MRSA-Screen was a rapid (

Asunto(s)
Pruebas de Fijación de Látex , Pruebas de Sensibilidad Microbiana/métodos , Oxacilina/farmacología , Penicilinas/farmacología , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/efectos de los fármacos , Bacteriemia/microbiología , Farmacorresistencia Microbiana , Humanos , Resistencia a la Meticilina/genética , Resistencia a las Penicilinas , Staphylococcus aureus/aislamiento & purificación
18.
Int J Antimicrob Agents ; 15(4): 291-7, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10929879

RESUMEN

In response to conflicting reports on the chemical stability of quinupristin/dalfopristin, a study was designed to assess the in vitro longevity and effects of media and storage conditions on this streptogramin combination. Broth microdilution trays containing parenteral (quinupristin/dalfopristin) and oral (RPR 106972) streptogramin combinations as well as pristinomycin components (P-I and P-II) were preincubated at 35 degrees C for 12-72 h before inoculation with control strains (Streptococcus pneumoniae ATCC 49619, Haemophilus influenzae ATCC 49247, Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 29213) and five clinical isolates with various drug resistance phenotypes. Overall, the mean quinupristin/dalfopristin activity loss was 24%/12 h, 41%/18 h, 43%/24 h, 69%/48 h and 79%/72 h with no detected loss of potency when measured by E. faecalis until 18 h. RPR 106972 mean activity loss was 6%/12 h, 19%/18 h, 19%/24 h, 56%/48 h and 71%/72 h with no loss of potency as measured by S. aureus until 48 h. Overall, P-I components had greater stability as compared with P-II for both drug combinations. Bioassays showed similar trends in decreased activity. Bioassay differences among media types were only significant (> 3 mm; greater loss of potency) for haemophilus test media for both P-II components at 72 h. The presence of an organism in the medium had no effect on stability assay results. The effect of storage temperature (4, 25 degrees C) on quinupristin/dalfopristin and RPR 106972 stability was also detrimental to drug potency indicating the requirement for rigid quality assurance for streptogramin diagnostic reagents when determining activity by reference or standardized susceptibility tests.


Asunto(s)
Antibacterianos/farmacología , Quimioterapia Combinada/farmacología , Pruebas de Sensibilidad Microbiana , Virginiamicina/farmacología , Medios de Cultivo
20.
J Clin Microbiol ; 38(5): 1818-22, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10790106

RESUMEN

Pseudomonas aeruginosa is the most common pathogen infecting the lungs of patients with cystic fibrosis (CF). Improved antimicrobial chemotherapy has significantly increased the life expectancy of these patients. However, accurate susceptibility testing of P. aeruginosa isolates from CF sputum may be difficult because the organisms are often mucoid and slow growing. This study of 597 CF isolates of P. aeruginosa examined the correlation of disk diffusion and Etest (AB BIODISK, Solna, Sweden) results with a reference broth microdilution method. The rates of interpretive errors for 12 commonly used antipseudomonal antimicrobials were determined. The disk diffusion method correlated well (zone diameter versus MIC) for all of the agents tested. However, for mucoid isolates, correlation coefficients (r values) for piperacillin, piperacillin-tazobactam, and meropenem were <0.80. The Etest correlation with reference broth microdilution results (MIC versus MIC) was acceptable for all of the agents tested, for both mucoid and nonmucoid isolates. Category interpretation errors were similar for the disk diffusion and Etest methods with 0.4 and 0.1%, respectively, very major errors (false susceptibility) and 1.1 and 2.2% major errors (false resistance). Overall, both agar diffusion methods appear to be broadly acceptable for routine clinical use in susceptibility testing of CF isolates of P. aeruginosa.


Asunto(s)
Antibacterianos/farmacología , Fibrosis Quística/microbiología , Enfermedades Pulmonares/microbiología , Pulmón/microbiología , Infecciones por Pseudomonas/etiología , Pseudomonas aeruginosa/efectos de los fármacos , Agar , Niño , Fibrosis Quística/complicaciones , Humanos , Enfermedades Pulmonares/diagnóstico , Pruebas de Sensibilidad Microbiana/métodos , Infecciones por Pseudomonas/diagnóstico , Pseudomonas aeruginosa/crecimiento & desarrollo , Pseudomonas aeruginosa/aislamiento & purificación , Reproducibilidad de los Resultados , Esputo/microbiología
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