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1.
Vaccine ; 41(2): 486-495, 2023 01 09.
Artículo en Inglés | MEDLINE | ID: mdl-36481106

RESUMEN

INTRODUCTION: Supplementary immunization activities (SIAs) aim to interrupt measles transmission by reaching susceptible children, including children who have not received the recommended two routine doses of MCV before the SIA. However, both strategies may miss the same children if vaccine doses are highly correlated. How well SIAs reach children missed by routine immunization is a key metric in assessing the added value of SIAs. METHODS: Children aged 9 months to younger than 5 years were enrolled in cross-sectional household serosurveys conducted in five districts in India following the 2017-2019 measles-rubella (MR) SIA. History of measles containing vaccine (MCV) through routine services or SIA was obtained from documents and verbal recall. Receipt of a first or second MCV dose during the SIA was categorized as "added value" of the SIA in reaching un- and under-vaccinated children. RESULTS: A total of 1,675 children were enrolled in these post-SIA surveys. The percentage of children receiving a 1st or 2nd dose through the SIA ranged from 12.8% in Thiruvananthapuram District to 48.6% in Dibrugarh District. Although the number of zero-dose children prior to the SIA was small in most sites, the proportion reached by the SIA ranged from 45.8% in Thiruvananthapuram District to 94.9% in Dibrugarh District. Fewer than 7% of children remained measles zero-dose after the MR SIA (range: 1.1-6.4%) compared to up to 28% before the SIA (range: 7.3-28.1%). DISCUSSION: We demonstrated the MR SIA provided considerable added value in terms of measles vaccination coverage, although there was variability across districts due to differences in routine and SIA coverage, and which children were reached by the SIA. Metrics evaluating the added value of an SIA can help to inform the design of vaccination strategies to better reach zero-dose or undervaccinated children.


Asunto(s)
Sarampión , Rubéola (Sarampión Alemán) , Humanos , Niño , Lactante , Estudios Transversales , Programas de Inmunización , Sarampión/prevención & control , Rubéola (Sarampión Alemán)/prevención & control , Vacunación , Vacuna Antisarampión , Inmunización
2.
Diabetes Metab Syndr ; 13(1): 18-23, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30641693

RESUMEN

AIMS: The study was conducted to ascertain whether chronic stress and sense of coherence are associated with risk of type 2 diabetes mellitus. METHODS: Stress questionnaires - Presumptive Stressful Life Events Scale (PSLES), Perceived Stress Scale (PSS) and Sense of Coherence (SOC) - were administered to 500 Newly Detected Diabetes Mellitus (NDDM) cases and 500 Normal Glucose Tolerance (NGT) controls recruited following 75 g OGTT. Assessment of stress was completed before the diagnosis of diabetes was revealed to them. RESULTS: PSLES and PSS scores were significantly higher and SOC score was significantly lower in NDDM subjects compared to those with NGT. PSLES and PSS correlated positively with anthropometric parameters (waist circumference, BMI), glycemic parameters (FPG, 2 hPG, A1C) and HOMA-IR and inversely with HOMA-ß whereas SOC correlated inversely with glycemic parameters (FPG, 2 hPG, A1C) and HOMA-IR and positively with HOMA-ß. In stepwise logistic regression analysis, SOC emerged as the strongest independent predictor of diabetes (OR: 0.774) after HOMA-IR (OR: 1.621) and BMI (OR: 1.288). Other significant predictors included PSS (OR:1.153), PSLES-LT (OR: 1.005) and HOMA-ß (OR: 0.894). CONCLUSION: Chronic stress and low sense of coherence are associated with a higher risk of type 2 diabetes mellitus.


Asunto(s)
Diabetes Mellitus/etiología , Sentido de Coherencia , Estrés Fisiológico , Adulto , Estudios de Casos y Controles , Enfermedad Crónica , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Factores de Riesgo
4.
Theriogenology ; 86(6): 1599-1606, 2016 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-27377210

RESUMEN

In the present study, a 31-kDa protein, purified from cattle bull seminal plasma heparin-binding proteins (SP-HBP), was characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometry. Raw semen of six cross-bred bulls was treated with 31-kDa HBP before cryopreservation to observe its effect on motility, viability, hypo-osmotic swelling test, acrosome integrity, in vitro capacitation/acrosome reaction, and oxidative stress at pre-freeze and frozen-thawed phases of cryopreservation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of 31-kDa protein eluted and purified from SP-HBP (separated on acrylamide gels) resulted in a single band of 40 kDa. In matrix-assisted laser desorption/ionization-time of flight analysis, 12 peptides were identified with matching significantly (P < 0.05) to interlukin-6 of bovine with a top score of 55. Addition of 25 µg/mL of fluorescein isothiocyanate-conjugated 31-kDa protein to raw semen and incubation at 37 °C for 20 minutes before cryopreservation resulted in its binding mainly to head region. Treatment of semen with 31-kDa HBP resulted in a significant (P < 0.05) average increase of 9.2%, 6.8%, and 11.7% and 5.5%, 6.5%, and 11.0% in motile, viable, hypo-osmotic swelling-responsive spermatozoa in six bulls at pre-freeze and frozen-thawed phases of cryopreservation, respectively. Percentage of spermatozoa with intact acrosomes nonsignificantly enhanced in the semen treated with 31-kDa HBP at both phases of cryopreservation. An average nonsignificant increase of 3.1% in in vitro capacitated and acrosome-reacted spermatozoa was obtained in semen supplemented with 31-kDa HBP. Addition of 31-kDa HBP also nonsignificantly reduced Malonadialdehyde (MDA) level by 10.7 and 19.3 µM/10(9) spermatozoa in prefrozen and frozen-thawed semen, respectively. The results obtained here indicate to conclude that treatment of cross-bred cattle bull semen with 31-kDa HBP protects the spermatozoa from cold shock effect by coating the sperm surface.


Asunto(s)
Proteínas Portadoras/farmacología , Bovinos , Crioprotectores , Heparina/metabolismo , Preservación de Semen/veterinaria , Proteínas de Plasma Seminal/farmacología , Reacción Acrosómica/efectos de los fármacos , Animales , Proteínas Portadoras/aislamiento & purificación , Criopreservación/veterinaria , Masculino , Peso Molecular , Estrés Oxidativo/efectos de los fármacos , Semen/química , Semen/fisiología , Proteínas de Plasma Seminal/aislamiento & purificación , Capacitación Espermática/efectos de los fármacos , Motilidad Espermática/efectos de los fármacos , Espermatozoides/efectos de los fármacos , Espermatozoides/fisiología
6.
Clin Oncol (R Coll Radiol) ; 27(6): 345-52, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25726363

RESUMEN

AIMS: To evaluate clinical outcome and the effect of malignant epidural compression (MEC) in the treatment of spine metastasis with stereotactic body radiotherapy (SBRT). MATERIALS AND METHODS: Seventy-six lesions in 52 patients with spinal metastasis received SBRT during the period July 2010 to December 2012. MEC was detected in 20 patients (38.4%) and was separately contoured. The median dose prescribed to involved vertebra (planning target volume) was 24 Gy (range 24-27 Gy) in a median of three fractions (range 1-3). Uninvolved elements were prescribed 21 Gy in three fractions. In 59 lesions (77.6%), the entire vertebra was treated and in 17 lesions (22.4%) only the anterior elements were treated. All patients were treated with volumetric modulated arc therapy with image guidance on a Novalis Tx linear accelerator with the ExacTrac system. Dosimetric and clinical outcomes were compared in patients with or without MEC. RESULTS: At a median follow-up of 8.48 months (range 3-40 months), 1 year local control and overall survival was 94 and 68%, respectively. In patients with or without epidural extension, the median dose to the gross tumour volume (GTV; 95%) was 23.48 Gy (range 13.70-25.75) and 22.99 Gy (range 13.55-26.84), the median spinal cord Dmax was 17.36 Gy (range 8.47-21.63) and 15.71 Gy (range 8.39-23.33). The median GTV epidural (D95%) was 21.16 Gy (range 15.43-23.92). Complete pain relief was seen in 90% of patients with MEC and 93.75% without MEC (P=NS) and neurological improvement was seen in 60% of patients in both groups of patients. CONCLUSION: It is feasible to deliver a high dose of radiation (∼90% of the prescription dose) to the epidural component with volumetric modulated arc therapy SBRT and image guidance. It yielded high rates of pain control and local control in patients with spine metastases with or without MEC.


Asunto(s)
Fraccionamiento de la Dosis de Radiación , Neoplasias Epidurales/cirugía , Neoplasias/cirugía , Radiocirugia , Neoplasias de la Columna Vertebral/cirugía , Adulto , Anciano , Neoplasias Epidurales/mortalidad , Neoplasias Epidurales/secundario , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias/mortalidad , Neoplasias/patología , Pronóstico , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia de Intensidad Modulada/métodos , Neoplasias de la Columna Vertebral/mortalidad , Neoplasias de la Columna Vertebral/secundario , Tasa de Supervivencia , Tomografía Computarizada por Rayos X , Carga Tumoral
7.
Int J Tuberc Lung Dis ; 18(7): 840-2, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24902562

RESUMEN

India's Revised National Tuberculosis Control Programme (RNTCP) used the international benchmarks of 70% case detection rate and 85% treatment success rate among new smear-positive tuberculosis (TB) cases for assessing programme performance. This approach overemphasises outcomes and focuses on quantitative benchmarks without sufficient regard to developing systems to monitor appropriate programme practice to achieve a minimum standard of TB care services. The RNTCP has developed a novel composite indicator tool based on a logical framework pathway to move beyond narrow-focused outcome indicators such as case detection to encourage a broad-based analysis of programme implementation. The constituent indicators are from routinely monitored information, spanning input, process, output and outcome indicators across various thematic categories of the RNTCP.


Asunto(s)
Antituberculosos/uso terapéutico , Programas Nacionales de Salud , Indicadores de Calidad de la Atención de Salud , Tuberculosis/tratamiento farmacológico , Benchmarking , Humanos , India , Desarrollo de Programa , Evaluación de Programas y Proyectos de Salud , Esputo/microbiología , Tuberculosis/diagnóstico
8.
Phys Chem Chem Phys ; 16(20): 9556-64, 2014 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-24727793

RESUMEN

Conjugated polymer-semiconductor quantum dot (QD) composites are attracting increasing attention due to the complementary properties of the two classes of materials. We report a convenient method for in situ formation of QDs, and explore the conditions required for light emission of nanocomposite blends. In particular we explore the properties of nanocomposites of the blue emitting polymer poly[9,9-bis(3,5-di-tert-butylphenyl)-9H-fluorene] together with cadmium sulphide (CdS) and cadmium selenide (CdSe) precursors. We show the formation of emissive quantum dots of CdSe from thermally decomposed precursor. The dots are formed inside the polymer matrix and have a photoluminescence quantum yield of 7.5%. Our results show the importance of appropriate energy level alignment, and are relevant to the application of organic-inorganic systems in optoelectronic devices.

9.
Drug Dev Ind Pharm ; 40(1): 92-101, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23301771

RESUMEN

OBJECTIVE: This study aimed to evaluate kinetic solubility advantage of amorphous etoricoxib solid dispersions prepared with three water soluble polymers and correlate it with solid state and supersaturated drug solution stabilization potential of these polymers. METHODS: Amorphous solid dispersions (ASDs) of etoricoxib were prepared with polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP) and hydroxyethyl cellulose (HEC) at 70:30w/w ratio and characterized for glass transition temperature (Tg), miscibility and intermolecular interactions. Kinetic solubility profiles of amorphous etoricoxib and its ASDs were determined in water at 37 °C. Solid-state stability was assessed by enthalpy relaxation studies at a common degree of undercooling of around 19.0 °C at 0% RH. Recrystallization behavior of supersaturated drug solution was evaluated in the absence and presence of pre-dissolved polymer at 37 °C. RESULTS: Amorphous etoricoxib exhibited rapid solid-to-solid transition to yield a solubility advantage of merely 1.5-fold in water. Among the ASDs, etoricoxib-PVP dispersion exhibited maximal "peak" (2-fold) and "plateau" (1.8-fold) solubility enhancement, while etoricoxib-PVA dispersion could only sustain the "peak" solubility achieved by amorphous etoricoxib. In contrast, etoricoxib-HEC dispersion displayed no solubility advantage. The rank order for solid state and supersaturated solution stabilization followed a similar trend of amorphous etoricoxib < HEC < PVA < PVP. CONCLUSION: Dissolution behavior of ASDs is influenced by concomitantly occurring solid phase changes, thus understanding these processes independently can enable assessment of the predominant route of drug crystallization and stabilization by the polymer.


Asunto(s)
Portadores de Fármacos/química , Polímeros/química , Piridinas/administración & dosificación , Sulfonas/administración & dosificación , Celulosa/análogos & derivados , Celulosa/química , Química Farmacéutica/métodos , Cristalización , Composición de Medicamentos , Estabilidad de Medicamentos , Etoricoxib , Transición de Fase , Alcohol Polivinílico/química , Povidona/química , Piridinas/química , Solubilidad , Sulfonas/química , Termodinámica , Temperatura de Transición
10.
Artículo en Inglés | MEDLINE | ID: mdl-23277180

RESUMEN

Clopidogrel hydrogen sulfate (+)-(S)-(2-chlorophenyl)-6,7-dihydrothieno[3,2-c]pyridine-5(4H)-acetate sulfate (1:1), is a selective adenosine diphosphate (ADP) receptor antagonist often used in the treatment of coronary artery, peripheral vascular and cerebrovascular diseases. In the present communication, a comparative study of two polymorphic forms (forms 1 and 2) of clopidogrel hydrogen sulfate (CLP) has been reported. There is difference in conformation and intermolecular hydrogen bonding pattern of two forms. These differences are nicely reflected in the vibrational spectra. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands of CLP form 1 are interpreted with the aid of structure optimizations and normal mode analysis based on ab initio HF and DFT method employing 6-311++G(d,p) basis. Polymorphism in CLP have been studied using various characterization tools like FT-Raman, FT-IR spectroscopy and DSC in combination with the quantum chemical calculations. UV-vis spectroscopic studies along with HOMO-LUMO analysis of both polymorphs were performed. The solvent effect calculated by TD-DFT/IEF-PCM/6-31G model results complements with the experimental findings. Stability of the molecule arising from hyper conjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis.


Asunto(s)
Electrones , Modelos Moleculares , Teoría Cuántica , Espectrometría Raman , Ticlopidina/análogos & derivados , Vibración , Absorción , Rastreo Diferencial de Calorimetría , Clopidogrel , Cinética , Conformación Molecular , Solventes/química , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier , Termodinámica , Ticlopidina/química
11.
Spectrochim Acta A Mol Biomol Spectrosc ; 103: 325-32, 2013 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-23261630

RESUMEN

Imatinib mesylate, 4-(4-methyl-piperazin-1-ylmethyl)-N-u[4-methyl-3-(4-pyridin-3-yl)pyrimidine-2-ylamino)phenyl]benzamide methanesulfonate is a therapeutic drug that is approved for the treatment of chronic myelogeneous leukemia (CML) and gastrointestinal stromal tumors (GIST). It is known that imatinib mesylate exists in two polymorphic forms α and ß. However, ß-form is more stable than the α-form. In this work, we present a detailed vibrational spectroscopic investigation of ß-form by using FT-IR and FT-Raman spectra. These data are supported by quantum mechanical calculations using DFT employing 6-311G(d,p) basis set, which allow us to characterize completely the vibrational spectra of this compound. The FT-IR spectrum of α-form has also been discussed. The importance of hydrogen-bond formation in the molecular packing arrangements of both forms has been examined with the vibrational shifts observed due to polymorphic changes. The red shift of the NH stretching bands in the infrared spectrum from the computed wavenumber indicates the weakening of the NH bond. The UV-vis spectroscopic studies along with the HOMO-LUMO analysis of both polymorphs (α and ß) were performed and their chemical activity has been discussed. The TD-DFT method was used to calculate the electronic absorption spectra in the gas phase as well as in the solvent environment using IEF-PCM model and 6-31G basis set. Finally, the results obtained complements to the experimental findings.


Asunto(s)
Antineoplásicos/química , Benzamidas/química , Piperazinas/química , Pirimidinas/química , Cristalización , Electrones , Mesilato de Imatinib , Modelos Moleculares , Teoría Cuántica , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría Raman
12.
Arzneimittelforschung ; 62(2): 88-93, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22344553

RESUMEN

Curcumin (CRM) (CAS number 458-37-07), a naturally-occurring molecule, has diverse pharmacological actions. Recently our research group demonstrated that poor permeability also contributes to its poor oral bioavailability. A self nano-emulsifying drug delivery system (CRM SNEDDS) consisting of Labrasol, Gelucire 44/14, Vitamin E TPGS and PEG 400 was designed and provided 16 times improvement in oral bioavailability in rats, at a dose of 250 mg/kg body weight. Caco-2 cell transport studies were conducted for CRM SNEDDS and CRM in the presence of individual excipients, to determine the extent of improvement in permeability. Papp values for CRM, CRM SNEDDS and CRM in combination with 4 individual excipients were calculated. Transepithelial electrical resistance value was assessed to evaluate the cell morphology and the cellular tight junctions. Permeation of a transcellular marker, Lucifer Yellow was used as a marker to assess monolayer integrity. The tested excipient concentrations were found to be non-toxic to the cell monolayer in 2 h incubation. Results showed that the Papp increased 6.35 times for curcumin in CRM SNEDDS as compared to CRM. Individual excipients enhanced permeation from 1.97 to 6.35 times, with Labrasol showing the highest enhancement of 6.35 times.


Asunto(s)
Antineoplásicos Fitogénicos/farmacocinética , Curcumina/administración & dosificación , Curcumina/farmacocinética , Algoritmos , Antineoplásicos Fitogénicos/administración & dosificación , Disponibilidad Biológica , Transporte Biológico Activo , Células CACO-2 , Permeabilidad de la Membrana Celular , Supervivencia Celular , Química Farmacéutica , Citocromo P-450 CYP3A/biosíntesis , Impedancia Eléctrica , Excipientes , Humanos , Isoquinolinas , Microscopía Electrónica de Rastreo , Uniones Estrechas/metabolismo
14.
Indian Pediatr ; 47(9): 743-8, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21048254

RESUMEN

The methods of survival analysis are required to analyze duration data but their use is restricted possibly due to lack of awareness and the intricacies involved. We explain common methods of survival analysis, namely, life table, Kaplan Meier, log rank and Cox model, in a simple and friendly language so that the medical fraternity can use them with confidence where applicable.


Asunto(s)
Tablas de Vida , Análisis de Supervivencia , Humanos
15.
Pharmazie ; 63(11): 812-4, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19069241

RESUMEN

Physical stability studies of valdecoxib (VLB) and its solid dispersions with PVP (1, 2, 5, 10, 15 and 20% w/w) were carried out by Differential Scanning Calorimetry (DSC). Change in specific heat with time was measured to determine the degree of crystallinity of amorphous drug and its binary dispersions after storage at 40 degrees C and 75% RH. The rate of crystallization was found to decrease with increasing PVP concentration and time for 10% crystallization (t90%) was found to increase significantly for the amorphous drug when formulated as PVP dispersions. Enthalpy relaxation was found to be inversely correlated with t90% (min) values and was found to be a good predictor of devitrification tendency and hence stability of amorphous VLB.


Asunto(s)
Inhibidores de la Ciclooxigenasa 2/administración & dosificación , Isoxazoles/administración & dosificación , Sulfonamidas/administración & dosificación , Algoritmos , Rastreo Diferencial de Calorimetría , Cristalización , Inhibidores de la Ciclooxigenasa 2/química , Estabilidad de Medicamentos , Almacenaje de Medicamentos , Isoxazoles/química , Excipientes Farmacéuticos/química , Povidona/química , Sulfonamidas/química , Temperatura , Termodinámica
16.
Pharmazie ; 63(2): 136-43, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18380400

RESUMEN

This study deals with the generation and characterization of various solid-state forms of mebendazole (MBZ), a benzimidazole antihelmentic. The drug was subjected to polymorphic screen using different solvents to explore the possibility of existence of different solid forms. Different reported polymorphic forms of MBZ, i.e. form A, B and C were found to be recrystallized from acetic acid:methanol mixture (1:1), ethyl acetate and methanol, respectively. N,N-Dimethyl acetamide (DMA) and N,N-dimethyl formamide (DMF) yielded two new solvates of MBZ. These solid-state forms were characterized by thermoanalytical (DSC, TGA, HSM), crystallographic (XRD), microscopic (optical, polarized), and spectroscopic (FTIR) techniques. Solubility studies were carried out for the solvates to identify the solubility advantage. Molecular modeling studies revealed moderately strong hydrogen bonding between the solvent molecules and MBZ.


Asunto(s)
Antinematodos/química , Mebendazol/química , Rastreo Diferencial de Calorimetría , Química Farmacéutica , Modelos Moleculares , Solubilidad , Solventes , Espectroscopía Infrarroja por Transformada de Fourier , Termogravimetría , Difracción de Rayos X
17.
Animal ; 2(1): 100-4, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22444968

RESUMEN

Numerous factors influence male fertility, one of these being the oxidative stress, which has elicited enormous interest recently. In sperm, induction of oxidation decreases motility and viability but increases lipid peroxidation (LPO). The optimum dose of ferrous ascorbate (FeAA: FeSO4 + ascorbic acid) for inducing oxidative stress by affecting motility, viability and LPO has been ascertained in local crossbred cattle bull spermatozoa. The fractions of spermatozoa suspended in 2.9% sodium citrate were subjected to three doses of FeAA (100 : 500, 150 : 750, 200 : 1000; µmol/l FeSO4 : µmol/l ascorbic acid). These fractions were assessed for various parameters. Increase in the incubation period and promoter concentration induced a decrease in motility and viability, but an increase in LPO. Among three doses of FeAA, 150 : 750 µmol/l ascorbic acid is suggested to be the optimum/best dose as it induces the oxidative stress/LPO to a significant extent and also maintains better motility and viability as compared with the other two doses, and such conditions may enhance the fertilising potential of bull spermatozoa.

18.
J Indian Med Assoc ; 105(1): 42, 44-5, 48, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17802977

RESUMEN

Vertebral haemangiomas constitute an infrequently encounterd entity in clinical practice. Although x-ray, computerised tomography scan and magnetic resonance Imaging scan provide a pathognomic picture confirming the diagnosis of vertebral haemangiomas, angiography constitutes an important tool for diagnosis and helps in deciding and execution of treatment. Various treatment modalities like surgery, radiotherapy, pre-operative embolisation, percutaneous vertebroplasty and intralesional ethanol have been discussed in the setting of asymptomatic vertebral haemangiomas to those presenting with features of cord compression.


Asunto(s)
Angiografía , Hemangioma/radioterapia , Vértebras Lumbares/patología , Neoplasias de la Columna Vertebral/radioterapia , Adulto , Femenino , Hemangioma/diagnóstico por imagen , Humanos , Dolor de la Región Lumbar/diagnóstico , Dolor de la Región Lumbar/etiología , Vértebras Lumbares/diagnóstico por imagen , Neoplasias de la Columna Vertebral/diagnóstico por imagen
19.
Pharmazie ; 60(11): 830-6, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16320944

RESUMEN

The present study highlights the development of ternary amorphous composites to enhance the solubility of a poorly soluble crystalline drug, celecoxib (CEL). These systems comprised of an 'amorphous drug,' and its 'stabilizer' and 'solubilizer.' The ternary amorphous system of CEL, poly(vinyl pyrrolidone) (PVP) and meglumine (MEG) (7:2:1 w/w) enhanced CEL solubility by approximately equal to 10.2-fold over that for the crystalline drug, and maintained the thermodynamic stability of the amorphous drug. However, MEG alone was unable to stabilize the amorphous CEL against thermally-induced crystallization, and so gave no solubility advantage. The PVP-MEG combination provided a 'synergistic' enhancement of CEL solubility, as compared to their use alone in the amorphous systems. Phase-solubility studies provided greater insight into molecular mechanisms underlying stability and solubility of these amorphous systems. MEG exhibited phase-specific interaction with CEL molecules, when stabilized by PVP in the amorphous state. The higher solubility of CEL from ternary amorphous systems was also thermodynamically favored, as analyzed by van't Hoff plots. A possible molecular level interaction of MEG with PVP-stabilized amorphous CEL seems to be responsible for the solubility advantage of the CEL-PVP-MEG ternary amorphous system.


Asunto(s)
Inhibidores de la Ciclooxigenasa 2/análisis , Meglumina/análisis , Povidona/análisis , Pirazoles/análisis , Sulfonamidas/análisis , Rastreo Diferencial de Calorimetría , Celecoxib , Semivida , Microscopía de Polarización , Dinámicas no Lineales , Excipientes Farmacéuticos , Solubilidad , Temperatura , Termodinámica , Agua
20.
Biochemistry ; 44(34): 11458-65, 2005 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-16114882

RESUMEN

Based largely upon analysis of ribosomal RNA, a third domain of life, called archaea, had been proposed in addition to bacteria and eukaryotes. However, quantitative analysis of 73 whole genomes shows only a two-domain division of life: into eukaryotes and prokaryotes. Thousands of orthologous genes in archaea and bacteria show an essentially unimodal distribution of sequence identities. Thus, whole genome analyses indicate that archaea are a phylum of bacteria rather than a separate domain of life. In contrast, archaeal rRNA and that of hyperthermophilic bacteria differ from the rRNA of mesophilic bacteria. Thus, there is a bimodal distribution of rRNA sequence identities which differ by 12%. This discrepancy in rRNA and gene content based analyses of whole genomes is likely due to a 15% elevated C:G content of the rRNA of archaea and hyperthermophilic bacteria. The elevated C:G content is consistent with stabilization against thermal denaturation caused by additional hydrogen bonding (3 bonds) in C:G pairs compared to A:U pairs (2 bonds). Based upon this premise, there is no reliable way to correct rRNA for such differences in base composition and it is not possible to quantitatively compare hyperthermophiles with mesophiles by the rRNA method. Furthermore, quantitative study of whole genomes shows that the extent of change in both bacterial and archaeal genes, including rRNA, has reached a limit. Thus, direct sequence comparisons work with closely related genomes, but it is not possible to differentiate the most divergent prokaryotic species, which are currently designated as separate phyla. We believe that the differences in characteristics of archaeal species is based primarily upon selection of genes and pathways compatible with the extreme environmental lifestyle, i.e., hyperthermophily.


Asunto(s)
Bacterias/genética , Genoma Bacteriano , ARN Bacteriano/química , ARN Ribosómico 16S/química , Animales , Bacterias/clasificación , Desnaturalización de Ácido Nucleico , Termodinámica
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