Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
1.
Vacunas ; 23: S26-S32, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-34512220

RESUMEN

Objective: The objective of this study was to assess the attitude and hesitancy toward vaccine against COVID-19 in a Pakistani Population. Materials and methods: A mix-method, prospective study was conducted and adults (aged ≥18 years) residing in Pakistan were invited to participate. The questionnaire was prepared, hosted in Google Forms and circulated through electronic platforms and was also available to be done in in-person. Data was compiled from 15th September to 30th November 2020. Results: The response rate was 80%. A total of 1003 participants were included in the final analysis. Of them, 75% completed survey questionnaire online, while remaining 25% responded in-person. The mean age of the participants was 29.62 ± 10.47 years. The majority of participants were females; 60.9% (n = 611). 57.02% (n = 572) of the participants were employed at the time of survey. Overall, 70.68% (n = 709) of the participants had previous experience of vaccines such as the flu vaccine Only 4.9% (n = 49) participants thought that they will be seriously ill from COVID-19 within six months and 39% (n = 392) participants were confident that they will get COVID-19. A total of 71.29% of the participants reported they would consider getting vaccinated once available. There was statistical association between gender and getting vaccinated (P < 0.001). Conclusion: This study demonstrated that majority of the participants showed positive attitude toward considering COVID-19 vaccine. However awareness with informed knowledge of efficacy, possible adverse effects and cost would be of added great value to increase the real response of Pakistani population toward COVID-19 vaccination.


Objetivo: El objetivo de este estudio fue evaluar la actitud y la renuencia hacia la vacuna frente a la COVID-19 en una población paquistaní. Materiales y métodos: Se realizó un estudio prospectivo de método mixto, invitándose a participar a personas adultas (edad ≥18 años) residentes en Paquistán. Se preparó el cuestionario, que se alojó en Google Forms y se hizo circular a través de plataformas electrónicas, pudiendo realizarse también de manera personal. Los datos se recopilaron desde el 15 de septiembre al 30 de noviembre de 2020. Resultados: La tasa de respuesta fue del 80%. El análisis final incluyó un total de 1.003 participantes, de los cuales el 75% completó el cuestionario-encuesta online, mientras que el 25% respondió en persona. La edad media de los participantes fue de 29,62 ± 10,47 años. La mayoría de los participantes eran mujeres: el 60,9% (n = 611). El 57,02% (n = 572) de los participantes tenía empleo en el momento de la encuesta. En general, el 70,68% (n = 709) de los participantes tenía experiencia previa sobre vacunas tales como la vacuna frente a la gripe. Solo el 4,9% (n = 49) de los participantes pensaba que padecerían la COVID-19 de forma grave en el plazo de seis meses, y el 39% (n = 392) de los participantes estaba seguro de que se contagiaría de dicha enfermedad. El 71,29% de los participantes reportó que consideraría recibir la vacuna una vez que se dispusiera de la misma. Existió una asociación estadística entre el sexo y el ser vacunado (P< 0,001). Conclusión: Este estudio demostró que la mayoría de los participantes mostró una actitud positiva hacia la consideración de la vacuna frente a la COVID-19. Sin embargo, la concienciación sobre el conocimiento informado de la vacuna, los posibles efectos adversos y el coste supondrían un gran valor añadido al incremento de la respuesta real de la población paquistaní hacia la vacuna frente a la COVID-19.

2.
BMC Geriatr ; 21(1): 415, 2021 07 06.
Artículo en Inglés | MEDLINE | ID: mdl-34229623

RESUMEN

BACKGROUND: Older age and comorbid burden are both associated with adverse outcomes in SARS-CoV-2, but it is not known whether the association between comorbid burden and adverse outcomes differs in older and younger adults. OBJECTIVE: To compare the relationship between comorbid burden and adverse outcomes in adults with SARS-CoV-2 of different ages (18-64, 65-79 and ≥ 80 years). DESIGN, SETTING, AND PARTICIPANTS: Observational longitudinal cohort study of 170,528 patients who tested positive for SARS-CoV-2 in the US Department of Veterans Affairs (VA) Health Care System between 2/28/20 and 12/31/2020 who were followed through 01/31/2021. MEASUREMENTS: Charlson Comorbidity Index (CCI); Incidence of hospitalization, intensive care unit (ICU) admission, mechanical ventilation, and death within 30 days of a positive SARS-CoV-2 test. RESULTS: The cumulative 30-day incidence of death was 0.8% in cohort members < 65 years, 7.1% in those aged 65-79 years and 20.6% in those aged ≥80 years. The respective 30-day incidences of hospitalization were 8.2, 21.7 and 29.5%, of ICU admission were 2.7, 8.6, and 11% and of mechanical ventilation were 1, 3.9 and 3.2%. Median CCI (interquartile range) ranged from 0.0 (0.0, 2.0) in the youngest, to 4 (2.0, 7.0) in the oldest age group. The adjusted association of CCI with all outcomes was attenuated at older ages such that the threshold level of CCI above which the risk for each outcome exceeded the reference group (1st quartile) was lower in younger than in older cohort members (p < 0.001 for all age group interactions). LIMITATIONS: The CCI is calculated based on diagnostic codes, which may not provide an accurate assessment of comorbid burden. CONCLUSIONS: Age differences in the distribution and prognostic significance of overall comorbid burden could inform clinical management, vaccination prioritization and population health during the pandemic and argue for more work to understand the role of age and comorbidity in shaping the care of hospitalized patients with SARS-CoV-2.


Asunto(s)
COVID-19 , SARS-CoV-2 , Anciano , Hospitalización , Humanos , Unidades de Cuidados Intensivos , Estudios Longitudinales , Persona de Mediana Edad , Pandemias
3.
Bull Entomol Res ; 111(2): 153-159, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32744195

RESUMEN

Primary pests such as Rhyzoperta dominica may increase the contents of dockage, dust, and frass in grain mass. Although it has been suggested that frass can affect the population growth of stored product pests and ecological interactions among primary and secondary pests in stored grain, this has not been validated experimentally. Therefore, this work experimentally tested the hypothesis that R. dominica wheat frass may support population increases in secondary pests such as Tribolium confusum, T. castaneum, and Oryzaephilus surinamensis for the first time. The effect of frass on secondary pest performance was compared with the effects of various physical qualities of wheat grain (i.e., intact grain kernels, grain fragments, flour, grain + frass) and an artificially enriched control diet (milled wheat kernels, oat flakes, and yeast). The results showed that the clean intact grain kernels did not support the population growth of any tested species, and the nutrient-rich control diet provided the best support. Frass was a significantly better food medium for O. surinamensis and T. castaneum than flour or cracked grain, while T. confusum performed equally well on flour and frass. Our results showed that in terms of food quality and suitability for the tested species, frass occupied an intermediate position between the optimized breeding diet and simple uniform cereal diets such as cracked grain or flour. The results suggest that (i) the wheat frass of primary pest R. dominica is a riskier food source for the development of the tested secondary pests than intact or cracked wheat grain or flour; (ii) frass has the potential to positively influence interspecific interactions between R. dominica and the tested secondary pests; and (iii) wheat grain should be cleaned if increases in R. dominica populations and/or accumulated frass are detected.


Asunto(s)
Escarabajos/fisiología , Grano Comestible , Almacenamiento de Alimentos/métodos , Animales , Conducta Alimentaria , Control de Plagas/métodos
4.
Am J Transplant ; 17(8): 2178-2185, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28489305

RESUMEN

Since the first attempt of pig-to-primate liver xenotransplantation (LXT) in 1968, survival has been limited. We evaluated a model utilizing α-1,3-galactosyltransferase knockout donors, continuous posttransplant infusion of human prothrombin concentrate complex, and immunosuppression including anti-thymocyte globulin, FK-506, methylprednisone, and costimulation blockade (belatacept, n = 3 or anti-CD40 mAb, n = 1) to extend survival. Baboon 1 remained well until postoperative day (POD) 25, when euthanasia was required because of cholestasis and plantar ulcers. Baboon 2 was euthanized following a seizure on POD 5, despite normal liver function tests (LFTs) and no apparent pathology. Baboon 3 demonstrated initial stable liver function but was euthanized on POD 8 because of worsening LFTs. Pathology revealed C4d positivity, extensive hemorrhagic necrosis, and a focal cytomegalovirus inclusion. Baboon 4 was clinically well with stable LFTs until POD29, when euthanasia was again necessitated by plantar ulcerations and rising LFTs. Final pathology was C4d negative and without evidence of rejection, inflammation, or thrombotic microangiopathy. Thus, nearly 1-mo rejection-free survival has been achieved following LXT in two of four consecutive recipients, demonstrating that the porcine liver can support life in primates for several weeks and has encouraging potential for clinical application as a bridge to allotransplantation for patients with acute-on-chronic or fulminant hepatic failure.


Asunto(s)
Factores de Coagulación Sanguínea/metabolismo , Supervivencia de Injerto/efectos de los fármacos , Inmunosupresores/farmacología , Trasplante de Hígado/mortalidad , Trasplante Heterólogo , Animales , Animales Modificados Genéticamente , Supervivencia de Injerto/inmunología , Papio , Tasa de Supervivencia , Porcinos
5.
Am J Transplant ; 17(7): 1778-1790, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28117931

RESUMEN

In our studies of life-supporting α-1,3-galactocyltransferase knockout (GalT-KO) pig-to-baboon kidneys, we found that some recipients developed increased serum creatinine with growth of the grafts, without histological or immunological evidence of rejection. We hypothesized that the rapid growth of orthotopic pig grafts in smaller baboon recipients may have led to deterioration of organ function. To test this hypothesis for both kidneys and lungs, we assessed whether the growth of outbred (Yorkshire) organ transplants in miniature swine was regulated by intrinsic (graft) or extrinsic (host environment) factors. Yorkshire kidneys exhibited persistent growth in miniature swine, reaching 3.7 times their initial volume over 3 mo versus 1.2 times for miniature swine kidneys over the same time period. Similar rapid early growth of lung allografts was observed and, in this case, led to organ dysfunction. For xenograft kidneys, a review of our results suggests that there is a threshold for kidney graft volume of 25 cm3 /kg of recipient body weight at which cortical ischemia is induced in transplanted GalT-KO kidneys in baboons. These results suggest that intrinsic factors are responsible, at least in part, for growth of donor organs and that this property should be taken into consideration for growth-curve-mismatched transplants, especially for life-supporting organs transplanted into a limited recipient space.


Asunto(s)
Trasplante de Riñón/métodos , Riñón/crecimiento & desarrollo , Trasplante de Pulmón/métodos , Pulmón/crecimiento & desarrollo , Animales , Galactosiltransferasas , Supervivencia de Injerto , Riñón/enzimología , Riñón/patología , Pulmón/enzimología , Pulmón/patología , Masculino , Papio , Porcinos , Porcinos Enanos , Trasplante Heterólogo
6.
Am J Transplant ; 16(6): 1715-1725, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26613235

RESUMEN

We sought to determine the effects of exogenous administration of human coagulation factors following pig-to-baboon liver xenotransplantation (LXT) using GalT-KO swine donors. After LXT, baboons received no coagulation factors (historical control, n = 1), bolus administration of a human prothrombin concentrate complex (hPCC; 2.5 mL/kg, n = 2), continuous infusion of hPCC (1.0 mL/h, n = 1) or continuous infusion of human recombinant factor VIIa (1 µg/kg per hour, n = 3). The historical control recipient demonstrated persistent thrombocytopenia despite platelet administration after transplant, along with widespread thrombotic microangiopathy (TMA). In contrast, platelet levels were maintained in bolus hPCC recipients; however, these animals quickly developed large-vessel thrombosis and TMA, leading to graft failure with shortened survival. Recipients of continuous coagulation factor administration experienced either stabilization or an increase in their circulating platelets with escalating doses. Furthermore, transfusion requirements were decreased, and hepatic TMA was noticeably absent in recipients of continuous coagulation factor infusions compared with the historical control and bolus hPCC recipients. This effect was most profound with a continuous, escalating dose of factor VIIa. Further studies are warranted because this regimen may allow for prolonged survival following LXT.


Asunto(s)
Factores de Coagulación Sanguínea/administración & dosificación , Rechazo de Injerto/tratamiento farmacológico , Hemorragia/tratamiento farmacológico , Trasplante de Hígado/efectos adversos , Trombocitopenia/tratamiento farmacológico , Animales , Animales Modificados Genéticamente , Rechazo de Injerto/etiología , Rechazo de Injerto/patología , Supervivencia de Injerto , Hemorragia/etiología , Hemorragia/patología , Humanos , Papio , Porcinos , Porcinos Enanos , Trombocitopenia/etiología , Trombocitopenia/patología , Trasplante Heterólogo
7.
Br J Neurosurg ; 19(3): 265-7, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16455531
8.
Neurochem Int ; 39(5-6): 427-34, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11578778

RESUMEN

Large numbers of activated glia are a common pathological feature of many neurodegenerative disorders, including Alzheimer's disease (AD). Several different stimuli, including lipopolysaccharide (LPS), dibutyryl (db)cAMP, and aged amyloid-beta 1-42 (A beta), can induce glial activation in vitro, as measured by morphological changes and the production of pro-inflammatory cytokines and oxidative stress molecules. Only A beta-induced activation is attenuated by the addition of exogenous apolipoprotein E (apoE)-containing particles. In addition, only A beta also induces an increase in the amount of endogenous apoE, the primary apolipoprotein expressed by astrocytes in the brain. The functional significance of the increase in apoE appears to be to limit the inflammatory response. Indeed, compared to wild type mice, glial cells cultured from apoE knockout mice exhibit an enhanced production of several pro-inflammatory markers in response to treatment with A beta and other activating stimuli. The mechanism for both the A beta-induced glial activation and the increase in apoE appears to involve apoE receptors, a variety of which are expressed by both neurons and glia. Experiments using receptor associated protein (RAP), an inhibitor of apoE receptors with a differential affinity for the low-density lipoprotein receptor (LDLR) and the LDLR-related protein (LRP), revealed that LRP mediates A beta-induced glial activation, while LDLR mediates the A beta-induced changes in apoE levels. In summary, both an apoE receptor agonist (apoE) and an antagonist (RAP) inhibit A beta-induced glial cell activation. Thus, apoE receptors appear to translate the presence of extracellular A beta into cellular responses, both initiating glial cell activation and limiting its scope by inducing apoE, an anti-inflammatory agent.


Asunto(s)
Péptidos beta-Amiloides/fisiología , Apolipoproteínas E/fisiología , Encefalitis/fisiopatología , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/fisiología , Neuroglía/fisiología , Animales , Humanos
9.
J Biol Chem ; 275(43): 33974-80, 2000 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-10940295

RESUMEN

We have previously shown that beta-amyloid (Abeta) induces astrocyte activation in vitro and that this reaction is attenuated by the addition of exogenous apolipoprotein E (apoE)-containing particles. However, the effects of Abeta on endogenous apoE and apoJ levels and the potential role of apoE receptors in astrocyte activation have not been addressed. Three activating stimuli (lipopolysaccharide, dibutyryl cAMP, and aged Abeta 1-42) were used to induce activation of rat astrocyte cultures, as assessed by changes in morphology and an increase in interleukin-1beta. However, only Abeta also induced approximately 50% reduction in the amount of released apoE and apoJ and an 8-fold increase in the levels of cell-associated apoE and apoJ. Experiments using two concentrations of receptor-associated protein, an inhibitor of apoE receptors with a differential affinity for the low density lipoprotein receptor (LDLR) and the LDLR-related protein (LRP), suggest that LRP mediates Abeta-induced astrocyte activation, whereas LDLR mediates the Abeta-induced changes in apoE levels. Receptor-associated protein had no effect on apoJ levels or on activation by either dibutyryl cAMP or lipopolysaccharide. These data suggest that apoE receptors translate the presence of extracellular Abeta into cellular responses, both initiating and modulating the inflammatory response induced by Abeta.


Asunto(s)
Péptidos beta-Amiloides/farmacología , Astrocitos/efectos de los fármacos , Chaperonas Moleculares , Receptores de Lipoproteína/fisiología , Animales , Apolipoproteínas E/análisis , Células Cultivadas , Clusterina , Glicoproteínas/análisis , Interleucina-1/genética , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad , Ratas , Ratas Sprague-Dawley , Receptores Inmunológicos/fisiología , Receptores de LDL/fisiología
10.
J Biol Chem ; 274(42): 30001-7, 1999 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-10514484

RESUMEN

Composition of central nervous system lipoproteins affects the metabolism of lipoprotein constituents within the brain. The epsilon4 allele of apolipoprotein E (apoE) is a risk factor for Alzheimer's disease via an unknown mechanism(s). As glia are the primary central nervous system cell type that synthesize apoE, we characterized lipoproteins secreted by astrocytes from wild type (WT), apoE (-/-), and apoE transgenic mice expressing human apoE3 or apoE4 in a mouse apoE (-/-) background. Nondenaturing size exclusion chromatography demonstrates that WT, apoE3, and apoE4 astrocytes secrete particles the size of plasma high density lipoprotein (HDL) composed of phospholipid, free cholesterol, and protein, primarily apoE and apoJ. However, the lipid:apoE ratio of particles containing human apoE is significantly lower than WT. ApoE localizes across HDL-like particle sizes. ApoJ localizes to the smallest HDL-like particles. ApoE (-/-) astrocytes secrete little phospholipid or free cholesterol despite comparable apoJ expression, suggesting that apoE is required for normal secretion of astrocyte lipoproteins. Further, particles were not detected in apoE (-/-) samples by electron microscopy. Nondenaturing immunoprecipitation experiments indicate that apoE and apoJ reside predominantly on distinct particles. These studies suggest that apoE expression influences the unique structure of astrocyte lipoproteins, a process further modified by apoE species.


Asunto(s)
Apolipoproteínas E/genética , Astrocitos/metabolismo , Lipoproteínas/metabolismo , Animales , Astrocitos/ultraestructura , Células Cultivadas , Cromatografía en Gel , Electroforesis en Gel de Poliacrilamida , Humanos , Lipoproteínas/aislamiento & purificación , Lipoproteínas/ultraestructura , Ratones , Ratones Transgénicos , Microscopía Electrónica
11.
Indian J Pediatr ; 64(2): 225-30, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-10771841

RESUMEN

1,876 school children were surveyed in Baramulla district of Kashmir for the presence of goitre. There were 964 boys and 912 girls in the age group of 5-15 years. An overall goitre prevalence of 52.08 per cent was found (54.77% in boys and 49.23% in girls). Iodine content was assayed in urine samples of 44 randomly selected subjects. The mean +/- SEM urinary iodine was 41.85 +/- 2.52 micrograms/g of creatinine (Range 6.25-69.41).


Asunto(s)
Países en Desarrollo , Bocio Endémico/epidemiología , Tamizaje Masivo , Adolescente , Niño , Preescolar , Estudios Transversales , Femenino , Bocio Endémico/prevención & control , Humanos , Incidencia , India/epidemiología , Yodo/deficiencia , Masculino
13.
Ann Saudi Med ; 16(2): 144-7, 1996 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17372415

RESUMEN

Diabetes mellitus secondary to chronic nonalcoholic pancreatic calcification has been described from several tropical countries, including India. We describe the existence of this entity in the subtropical region-the Kashmir Valley of the Indian subcontinent. Fibrocalculous pancreatic diabetes constituted 2.55% of patients admitted with diabetes mellitus. Ketoacidosis was not seen in any patient, and some patients showed evidence of chronic microvascular complications. The majority of patients required insulin for control of blood glucose and none had consume cassava.

15.
J Chromatogr ; 496(2): 245-54, 1989 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-2515202

RESUMEN

A reversed-phase high-performance liquid chromatographic assay with ultraviolet detection at 243 nm has been developed for the quantitative determination of methylprednisolone (MP) and methylprednisolone 21-[8-[methyl-(2-sulfoethyl)amino]-8-oxooctanoate] sodium salt (MPSO) in human urine following therapeutic doses in humans. The assay procedure involves stabilization of urine samples by addition of disodium ethylenediaminetetraacetic acid (Na2EDTA) and ion-pair extractions of MPSO using tetraethylammonium chloride (TEACl) as the counter ion. After extracting both drugs and internal standard into chloroform, the extract was evaporated to dryness under nitrogen. The resulting residue was reconstituted in 200-500 microliters of mobile phase and chromatographed on an IBM C18 reversed-phase column (5 microns). The mobile phase was a mixture of water-acetonitrile-isopropanol (71.2:18.8:10.0, v/v) containing 75 microliters of 0.1 M hydrochloric acid and 0.450 g of TEACl per liter. Propyl p-hydroxybenzoate was used as an internal standard. The extraction efficiencies of MP and MPSO were greater than 90% using the ion-pairing agent TEACl. The chromatographic responses were linear up to about 200 micrograms/ml for MP and 80 micrograms/ml for MPSO and had sufficient precision and accuracy to provide quantitative data from human urine. The assay detection limit was about 8 ng/ml for MP and 25 ng/ml for MPSO in human urine. Stability studies in urine indicated that without Na2EDTA stabilization and at room temperature, rapid degradation of MPSO occurred in urine. Addition of EDTA to the urine specimen and storage at -70 degrees C increased the stability of MPSO, and little or no degradation was observed in urine stored for more than 60 days. The method has been used in the simultaneous determination of MP and MPSO in urine specimens obtained from a single-dose tolerance study of MPSO in normal male volunteers.


Asunto(s)
Metilprednisolona/análogos & derivados , Metilprednisolona/orina , Adolescente , Adulto , Fenómenos Químicos , Química , Cromatografía Líquida de Alta Presión , Ácido Edético , Humanos , Masculino , Metilprednisolona/uso terapéutico , Persona de Mediana Edad , Espectrofotometría Ultravioleta , Tetraetilamonio , Compuestos de Tetraetilamonio
16.
J Chromatogr ; 434(1): 135-43, 1988 Dec 29.
Artículo en Inglés | MEDLINE | ID: mdl-3243808

RESUMEN

To evaluate the pharmacokinetics and drug availability from various dosage formulations, a method for the determination of guanadrel, (1,4-dioxaspiro[4,5]dec-2-ylmethyl)guanidine, in plasma and urine was required. A gas chromatographic procedure, based on formation of a hexafluoroacetylacetone derivative in a two-phase system of water and toluene, was developed. The limit of determination of the method is 5 ng/ml guanadrel in plasma and 15 ng/ml guanadrel in urine. Statistical analyses indicate average recoveries of 98.1 +/- 18.0 and 104.4 +/- 15.6% from plasma and urine, respectively. Mass spectrometric analyses, in conjunction with gas chromatography, confirmed the specificity of the method for intact drug. The procedure was applied successfully to drug absorption studies in humans.


Asunto(s)
Guanidinas/metabolismo , Fenómenos Químicos , Química , Cromatografía de Gases , Cromatografía en Capa Delgada , Guanidinas/sangre , Guanidinas/orina , Humanos , Masculino , Temperatura , Factores de Tiempo
17.
J Chromatogr ; 414(1): 1-10, 1987 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-3571374

RESUMEN

A high-performance liquid chromatographic assay method with ultraviolet detection at 243 nm has been developed for the quantitative determination of methylprednisolone (MP) and methylprednisolone 21-[8- [methyl-(2-sulfoethyl)amino]-8-oxoctanoate] sodium salt (MPSO) in human plasma. The method is simple, rapid and sensitive to detect MP and MPSO in human plasma following administration of therapeutic doses of MPSO. The assay procedure involved stabilization of plasma samples by addition of disodium ethylenediaminetetraacetic acid and ion-pair extractions of MPSO with tetraethylammonium chloride. After extracting both drugs and internal standard into chloroform, the extract was evaporated to dryness under nitrogen. The resulting residue was reconstituted in 200-500 microliter of mobile phase and chromatographed on a C18 IBM reversed-phase column (5 micron). The mobile phase was a mixture of water-actetonitrile-isopropanol (71:19.9:10) containing 50 microliter of 0.1 M hydrochloric acid and 0.497 g tetraethylammonium chloride. Propyl p-hydroxybenzoate was used as an internal standard. The chromatographic responses were linear up to about 200 micrograms/ml for MP and 80 micrograms/ml for MPSO in human plasma. The assay detection limit was approximately 7 ng/ml for MP and 25 ng/ml for MPSO in human plasma. Statistical analysis indicated an average recovery of 102.0 +/- 4.71% for MP and 75.2 +/- 2.88% for MPSO. Human plasma levels are reported for MP and MPSO following single-dose intravenous administration of 100-mg equivalents of MPSO.


Asunto(s)
Metilprednisolona/análogos & derivados , Metilprednisolona/sangre , Adolescente , Adulto , Disponibilidad Biológica , Cromatografía Líquida de Alta Presión , Estabilidad de Medicamentos , Humanos , Indicadores y Reactivos , Cinética , Masculino , Persona de Mediana Edad , Espectrofotometría Ultravioleta
18.
J Chromatogr ; 344: 41-9, 1985 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-3910669

RESUMEN

A high-performance liquid chromatographic method with ultraviolet detection (lambda max = 243 nm) has been developed for the simultaneous determination of methylprednisolone (MP) and its water-soluble prodrug esters methylprednisolone hemisuccinate (MPS) and N,N,N'-triethylethylenediamine amide of 6 alpha-methylprednisolone-21-hemisuberate hydrochloride (TMPS) in dog plasma. A reversed-phase liquid chromatographic separation was performed on a Microsorb C8 (3 microns) column equipped with a C8 5-microns guard column. The mobile phase composition was water--acetonitrile--methanol--dimethyloctylamine--acetic acid (65.5:34:0.4:0.04:0.04). The methyl ester of phenethylcarbamate was employed as an internal standard. The chromatographic responses were linear up to 25 micrograms/ml for MP, 70 micrograms/ml for MPS, and 95 micrograms/ml for TMPS. The sensitivity of the assay by ultraviolet detection is approximately 4, 8, and 12 ng/ml of plasma for MP, MPS and TMPS, respectively. The assay variability in terms of 95% confidence limit for each steroid is less than 4.5%. Plasma concentration--time curves are reported for MP, MPS, and TMPS after intravenous administration of MPS and TMPS equivalent to 3, 10 and 30 mg MP per kg body weight of dog. The assay methodology is simple, selective and reproducible for the quantitative determination of MP, MPS and TMPS in dog plasma.


Asunto(s)
Hemisuccinato de Metilprednisolona/análogos & derivados , Metilprednisolona/análogos & derivados , Metilprednisolona/sangre , Animales , Fenómenos Químicos , Química , Cromatografía Líquida de Alta Presión , Perros , Cinética , Hemisuccinato de Metilprednisolona/sangre , Espectrofotometría Ultravioleta
19.
J Chromatogr ; 309(1): 95-105, 1984 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-6480775

RESUMEN

A reversed-phase high-performance liquid chromatographic (HPLC) assay method has been developed for determining pirlimycin in human serum and urine. The method involves chloroform extraction of pirlimycin free base followed by derivatization with 9-fluorenylmethylchloroformate to form a carbamate ester. The reaction is rapid, reproducible, and quantitative. 9-Fluorenylmethylchloroformate reacts with amines to form derivatives sensitive to both ultraviolet and fluorescence detection. Human serum and urine samples following 50-mg and 500-mg single oral doses of pirlimycin were analyzed. The samples were chromatographed on an RP-18 Spherisorb 5-micron, 250 X 4.6 mm I.D. reversed-phase HPLC column. The eluent for the serum assay was acetonitrile-water (58:42) containing 0.02% acetic acid, and for the urine assay was acetonitrile-methanol-tetrahydrofuran-water (48:2:1:49). Fluoranthene was used as an internal standard. The assay sensitivity by ultraviolet detection (lambda max = 264) was about 5 ng/ml and by fluorescence detection (lambda excitation = 270 nm, lambda emission = 300 nm) was 0.1 ng/ml. Statistical analysis indicates an average drug recovery of 101 +/- 4.2% from serum and 102.0 +/- 2.62% from urine.


Asunto(s)
Clindamicina/análogos & derivados , Fenómenos Químicos , Química , Cromatografía Líquida de Alta Presión/métodos , Cromatografía en Capa Delgada , Clindamicina/análisis , Clindamicina/sangre , Clindamicina/orina , Humanos , Factores de Tiempo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...