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1.
Indian J Med Res ; 147(6): 567-572, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-30168488

RESUMEN

Background & objectives: Various indices are available to record different grade of severity of dental fluorosis. These indices have chances of inter- and intra- examiner variability. Therefore, study was conducted to compare three different indices for recording dental fluorosis to find out the best and most practical index of recording dental fluorosis for field studies in children living in a fluoride endemic area. Methods: The severity grades were recorded in 300 schoolchildren aged 12-15 yr having dental fluorosis of low, medium and high fluoride areas using three different indices, viz. Dean's fluorosis index (1942), tooth surface index for fluorosis (TSIF, 1984) and ICMR index (2013). Dean's index was used as gold standard. Results: The occurrence of moderate and severe cases was higher as per the Dean's index and of mild and severe cases was higher as per the TSIF and the ICMR index. The mean time required for recording dental fluorosis as per Dean's index and TSIF was similar and almost double (1.25±0.05 min) of that required for ICMR index (0.68±0.20 min). The intra-examiner variability was found to be least in the ICMR index compared to Dean's index and TSIF. Interpretation & conclusions: The ICMR index is a simple index with objective scores and takes less time in recording the dental fluorosis as compared to Dean's index and TSIF in field studies.


Asunto(s)
Caries Dental/prevención & control , Fluoruros/análisis , Fluorosis Dental/epidemiología , Adolescente , Niño , Humanos , India , Japón , Prevalencia
2.
J Emerg Med ; 52(2): 231-234, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27887758

RESUMEN

BACKGROUND: Advancements in airway management have made the practice of blind nasal intubation obsolete. We report on successful blind nasal intubation performed with the help of capnography and real-time ultrasonography in two patients with tempormandibular joint ankylosis. CASE REPORT: Blind nasal intubation was performed in a 12-year-old patient and a 17-year old patient under general anesthesia with spontaneous respiration. Capnography was used as an aid during insertion and dynamic ultrasonography was performed to guide and confirm proper tracheal tube placement. Use of capnography helps in following the correct path toward the glottic opening, with quick detection of any obstruction, and with confirmation of final placement of the tracheal tube. Ultrasonography aids with entry into the glottis and with identifying the correct placement. We recommend the use of this modified blind nasal intubation in patients with limited mouth opening when equipment, such as a fiberoptic scope, is not available or is nonfunctional in the emergency department. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Adapting this technique will add to the armamentarium available for airway management in emergency medicine, particularly in maxillofacial injuries with limited mouth opening.


Asunto(s)
Manejo de la Vía Aérea/normas , Capnografía/métodos , Intubación Intratraqueal/métodos , Ultrasonografía/métodos , Adolescente , Manejo de la Vía Aérea/métodos , Anquilosis/complicaciones , Niño , Humanos , Intubación Intratraqueal/normas , Masculino , Procedimientos Quirúrgicos Orales , Trastornos de la Articulación Temporomandibular/complicaciones
3.
Plant Mol Biol ; 87(6): 615-31, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25754733

RESUMEN

Abiotic stresses cause accumulation of reactive oxygen species (ROS), such as hydrogen peroxide (H2O2) in plants. Sophisticated mechanisms are required to maintain optimum level of H2O2 that acts as signalling molecule regulating adaptive response to salt stress. CuZn-superoxide dismutase (CuZn-SOD) and ascorbate peroxidase (APX) constitute first line of defence against oxidative stress. In the present study, PaSOD and RaAPX genes from Potentilla atrosanguinea and Rheum australe, respectively were overexpressed individually as well as in combination in Arabidopsis thaliana. Interestingly, PaSOD and dual transgenic lines exhibit enhanced lignin deposition in their vascular bundles with altered S:G ratio under salt stress. RNA-seq analysis revealed that expression of PaSOD gene in single and dual transgenics positively regulates expression of lignin biosynthesis genes and transcription factors (NACs, MYBs, C3Hs and WRKY), leading to enhanced and ectopic deposition of lignin in vascular tissues with larger xylem fibres and alters S:G ratio, as well. In addition, transgenic plants exhibit growth promotion, higher biomass production and increased yield under salt stress as compared to wild type plants. Our results suggest that in dual transgenics, ROS generated during salt stress gets converted into H2O2 by SOD and its optimum level was maintained by APX. This basal level of H2O2 acts as messenger for transcriptional activation of lignin biosynthesis in vascular tissue, which provides mechanical strength to plants. These findings reveal an important role of PaSOD and RaAPX in enhancing salt tolerance of transgenic Arabidopsis via increased accumulation of compatible solutes and by regulating lignin biosynthesis.


Asunto(s)
Arabidopsis/fisiología , Ascorbato Peroxidasas/genética , Peróxido de Hidrógeno/metabolismo , Potentilla/enzimología , Rheum/enzimología , Superóxido Dismutasa/genética , Antioxidantes/metabolismo , Arabidopsis/efectos de los fármacos , Arabidopsis/enzimología , Arabidopsis/genética , Ascorbato Peroxidasas/metabolismo , Vías Biosintéticas , Pared Celular/metabolismo , Expresión Génica , Regulación de la Expresión Génica de las Plantas , Lignina/metabolismo , Estrés Oxidativo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Tallos de la Planta/efectos de los fármacos , Tallos de la Planta/enzimología , Tallos de la Planta/genética , Tallos de la Planta/fisiología , Plantas Modificadas Genéticamente , Potentilla/genética , Rheum/genética , Transducción de Señal , Cloruro de Sodio/farmacología , Superóxido Dismutasa/metabolismo , Transcriptoma , Transgenes
4.
J Org Chem ; 80(11): 5912-8, 2015 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-25938581

RESUMEN

Stannous chloride catalyzed chemoselective reductive amination of a variety of carbonyl compounds with aromatic amines has been developed for the synthesis of a diverse range of tertiary amines using inexpensive polymethylhydrosiloxane as reducing agent in methanol. The present method is also applicable for the synthesis of secondary amines including heterocyclic ones.


Asunto(s)
Aminas/síntesis química , Compuestos de Estaño/química , Aminación , Catálisis , Compuestos Heterocíclicos/síntesis química , Estructura Molecular , Siloxanos/química , Estereoisomerismo
5.
AAPS PharmSciTech ; 16(6): 1270-80, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25771737

RESUMEN

Medical management of heavy metal toxicity, including radioactive ones, is a cause for concern because of their increased use in energy production, healthcare, and mining. Though chelating agents like EDTA and DTPA in parenteral form are available, no suitable oral formulation is there that can trap ingested heavy metal toxicants in the stomach itself, preventing their systemic absorption. The objective of the present study was to develop and optimize gastro-retentive controlled-release tablets of calcium-disodium edentate (Ca-Na2EDTA). Gastro-retentive tablet of Ca-Na2EDTA was prepared by direct compression method. Thirteen tablet formulations were designed using HPMC-K4M, sodium chloride, and carbopol-934 along with effervescing agents sodium bicarbonate and citric acid. Tablet swelling ability, in vitro buoyancy, and drug dissolution studies were conducted in 0.1 N HCl at 37 ± 0.5°C. Ca-Na2EDTA was radiolabeled with technetium-99m for scintigraphy-based in vivo evaluation. Formula F8 (Ca-Na2EDTA 200 mg, carbopol 100 mg, avicel 55 mg, citric acid 30 mg, NaHCO3 70 mg, NaCl 100 mg, and HPMC 95 mg) was found to be optimum in terms of excellent floating properties and sustained drug release. F8 fitted best for Korsmeyer-Peppas equation with an R (2) value of 0.993. Gamma scintigraphy in humans showed mean gastric retention period of 6 h. Stability studies carried out in accordance with ICH guidelines and analyzed at time intervals of 0, 1, 2, 4, and 6 months have indicated insignificant difference in tablet hardness, drug content, total floating duration, or matrix integrity of the optimized formulation. Gastro-retentive, controlled-release tablet of Ca-Na2EDTA was successfully developed using effervescent technique as a potential oral antidote for neutralizing ingested heavy metal toxicity.


Asunto(s)
Preparaciones de Acción Retardada/química , Ácido Edético/química , Mucosa Gástrica/metabolismo , Comprimidos/química , Administración Oral , Adulto , Animales , Antídotos/administración & dosificación , Antídotos/química , Disponibilidad Biológica , Celulosa/química , Química Farmacéutica/métodos , Ácido Cítrico/química , Preparaciones de Acción Retardada/administración & dosificación , Ácido Edético/administración & dosificación , Dureza , Intoxicación por Metales Pesados , Humanos , Persona de Mediana Edad , Intoxicación/tratamiento farmacológico , Conejos , Bicarbonato de Sodio/química , Solubilidad , Comprimidos/administración & dosificación , Adulto Joven
6.
AAPS PharmSciTech ; 15(4): 810-21, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24668136

RESUMEN

The present study was aimed at synthesizing an imidazole-based ionic liquid 1-butyl-3-methylimidazolium bromide (BMIMBr) and subsequent development of a novel ionic liquid-in-oil (IL/o) microemulsion (ME) system for dermal delivery of a poorly permeating drug 5-fluorouracil (5-FU). A significant enhancement in the solubility of 5-FU was observed in BMIMBr. IL/o MEs of 5-FU were prepared using isopropyl myristate, Tween 80/Span 20, and BMIMBr. Results of ex vivo skin permeation studies through mice skin indicated that the selected IL/o ME exhibited 4-fold enhancement in percent drug permeation as compared to aqueous solution, 2.3-fold as compared to hydrophilic ointment, and 1.6-fold greater permeation than water in oil (w/o) ME. The results of in vivo studies against dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mice skin carcinogenesis demonstrated that the IL/o ME could effectively treat skin cancer in 4 weeks. In addition, the side effects such as erythema and irritation associated with the conventional formulations were not observed. Histopathological studies showed that the use of IL/o ME caused no anatomic and pathological changes in the skin structure of mice. These studies suggest that the use of IL-based ME system can efficiently enhance the solubility and permeability of 5-FU and hence its therapeutic efficacy.


Asunto(s)
Emulsiones/química , Fluorouracilo/administración & dosificación , Fluorouracilo/química , Líquidos Iónicos/química , Piel/metabolismo , Administración Cutánea , Animales , Química Farmacéutica/métodos , Portadores de Fármacos/química , Femenino , Hexosas/química , Imidazoles/química , Ratones , Miristatos/química , Aceites/química , Permeabilidad , Polisorbatos/química , Absorción Cutánea , Solubilidad , Tensoactivos/química , Agua/química
7.
BMJ Case Rep ; 17(8)2024 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-39209748

RESUMEN

The association of Robin sequence (RS) with temporomandibular joint (TMJ) ankylosis is not a common occurrence. Due to restricted mouth opening, difficult bag valve mask ventilation and difficult intubation, such cases are always challenging for anaesthesiologists.A male patient in early childhood with RS and bilateral TMJ ankylosis was scheduled for bilateral gap arthroplasty. Airway management was planned with fibreoptic intubation under sedation to preserve spontaneous ventilation. After sedating the patient, a nasopharyngeal airway modified by using an endotracheal tube connector was inserted in the left nostril and connected to the ventilator circuit with a 15 mm universal connector. Pressure support ventilation was given with continuous end-tidal CO2 monitoring. Fibreoptic intubation was done through the right nostril with maintenance of spontaneous ventilation.Nasal pressure support ventilation assembly can be made with available equipment in the operation theatre. It can be a substitute for a high-flow nasal cannula in particular cases.


Asunto(s)
Anquilosis , Intubación Intratraqueal , Síndrome de Pierre Robin , Respiración Artificial , Trastornos de la Articulación Temporomandibular , Humanos , Masculino , Anquilosis/complicaciones , Anquilosis/cirugía , Tecnología de Fibra Óptica , Intubación Intratraqueal/métodos , Intubación Intratraqueal/instrumentación , Nasofaringe , Síndrome de Pierre Robin/complicaciones , Síndrome de Pierre Robin/terapia , Síndrome de Pierre Robin/cirugía , Respiración Artificial/instrumentación , Respiración Artificial/métodos , Trastornos de la Articulación Temporomandibular/complicaciones , Trastornos de la Articulación Temporomandibular/cirugía
8.
Bioconjug Chem ; 24(7): 1161-73, 2013 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-23758084

RESUMEN

The therapeutic efficacy of gemcitabine is severely compromised due to its rapid plasma metabolism. Moreover, its hydrophilicity poses a challenge for its efficient entrapment in nanosized delivery systems and to provide a sustained release profile. In this study, gemcitabine was covalently conjugated to poly(ethylene glycol)-block-poly(2-methyl-2-carboxyl-propylene carbonate) (PEG-PCC) which could self-assemble into micelles of 23.6 nm. These micelles afforded protection to gemcitabine from plasma metabolism as evident by negligible amount of gemcitabine and its metabolite dFdU detected in the plasma after 24 h. A controlled release of gemcitabine from the micelles was observed with 53.89% drug release in 10 days in the presence of protease enzyme Cathepsin B. Gemcitabine conjugated micelles were cytotoxic, showed internalization, and induced cell apoptosis in MIA PaCa-2 and L3.6pl pancreatic cancer cell lines. These micelles efficiently inhibited tumor growth when injected intravenously into MIA PaCa-2 cell derived xenograft tumor bearing NSG mice at a dose of 40 mg/kg in terms of reduced tumor volume and tumor weight (0.38 g vs 0.58 g). TUNEL assay revealed that gemcitabine conjugated micelles induced a much higher extent of apoptosis in the tumor tissues compared to free gemcitabine. In conclusion, gemcitabine conjugated micelles were able to enhance the drug payload, protect it from rapid plasma metabolism, and provide a sustained release and showed enhanced antitumor activity, and thus have the potential to provide a better therapeutic alternative for treating pancreatic cancer.


Asunto(s)
Adenocarcinoma/patología , Antineoplásicos/farmacología , Desoxicitidina/análogos & derivados , Neoplasias Pancreáticas/patología , Polímeros/farmacología , Animales , Antineoplásicos/química , Apoptosis , Línea Celular Tumoral , Desoxicitidina/química , Desoxicitidina/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Ratones , Polímeros/química , Ensayos Antitumor por Modelo de Xenoinjerto , Gemcitabina
9.
Pharm Res ; 30(9): 2396-409, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23756758

RESUMEN

PURPOSE: Preparation, optimization and in vitro evaluation of core-shell nanoparticles comprising of a hydrophilic core of BSA surrounded by a hydrophobic shell of PLGA for loading water-soluble drugs. METHODS: A double emulsion method was optimized for preparation of BSA-PLGA based core-shell nanoparticles. Proof of concept for core-shell type structure was established by visual techniques like confocal microscopy and TEM. Characterization was done for particle size, encapsulation efficiency, drug loading and in vitro drug release. Cellular uptake was assessed using confocal microscopy, bio-TEM and HPLC assay, and cytotoxic activity was tested by MTT assay in MG-63 osteosarcoma cells. RESULTS: The optimized core-shell nanoparticles showed a particle size of 243 nm (PDI-0.13) and encapsulation efficiency of 40.5% with a drug loading of 8.5% w/w. In vitro drug release studies showed a sustained release for 12 h. Cellular uptake studies indicated a rapid and efficient uptake within 2 h. TEM studies indicated that the core-shell nanoparticles were localized in cytoplasm region of the cells. Gemcitabine loaded core-shell nanoparticles showed enhanced cytotoxicity against MG-63 cells as compared to marketed formulation of gemcitabine (GEMCITE®). CONCLUSION: These results indicate that core-shell nanoparticles can be a good carrier system for delivering hydrophilic drugs like gemcitabine successfully to the cells with enhanced efficacy.


Asunto(s)
Antimetabolitos Antineoplásicos/administración & dosificación , Desoxicitidina/análogos & derivados , Portadores de Fármacos/química , Ácido Láctico/química , Nanopartículas/química , Ácido Poliglicólico/química , Albúmina Sérica Bovina/química , Antimetabolitos Antineoplásicos/farmacología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Desoxicitidina/administración & dosificación , Desoxicitidina/farmacología , Humanos , Nanopartículas/ultraestructura , Osteosarcoma/tratamiento farmacológico , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Solubilidad , Agua/química , Gemcitabina
10.
J Microencapsul ; 30(6): 589-98, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23379506

RESUMEN

This work describes the preparation and evaluation of mucoadhesive microspheres, using Abelmoschus esculentus polysaccharide as a novel carrier for safe and effective delivery of rizatriptan benzoate into nasal cavity. The polysaccharide was extracted from the fruit of A. esculentus and mucoadhesive microspheres were prepared by emulsification, followed by crosslinking using epichlorohydrin. Prepared microspheres were evaluated for size, morphology, swelling properties, mucoadhesive strength, encapsulation efficiency and drug release. Microspheres were found to release 50% of drug within 15 min and rest of the drug was released within 60 min. The drug release was found to decrease with increasing concentration of polysaccharide. To determine the retention time of the microspheres in the nasal cavity of rabbits, the microspheres were radiolabelled with (99m)Tc and subjected to gamma scintigraphy. The results showed a significant improvement in the nasal retention of the microspheres as compared to the aqueous solution of radiolabelled free-drug.


Asunto(s)
Abelmoschus/química , Productos Biológicos/química , Portadores de Fármacos/química , Polisacáridos/química , Adhesivos Tisulares/química , Administración Intranasal , Animales , Microesferas , Mucosa Nasal/metabolismo , Conejos
11.
AAPS PharmSciTech ; 14(4): 1284-93, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23959702

RESUMEN

Cetirizine is a piperazine-derived second-generation antihistaminic drug recommended for treatment of pruritus associated with atopic dermatitis. The present investigation encompasses development of a nanosized novel elastic vesicle-based topical formulation of cetirizine dihydrochloride using combination of Phospholipon® 90G and edge activators with an aim to have targeted peripheral H1 antihistaminic activity. The formulation was optimized with respect to phospholipid/drug/charge inducer ratio along with type and concentration of edge activator. The optimized formulation was found to be satisfactory with respect to stability, drug content, entrapment efficiency, pH, viscosity, vesicular size, spreadability, and morphological characteristics. The ex vivo permeation studies through mice skin were performed using Franz diffusion cell assembly. It was found that the mean cumulative percentage amount permeated in 8 h was almost twice (60.001 ± 0.332) as compared to conventional cream (33.268 ± 0.795) and aqueous solution of drug (32.616 ± 0.969), suggesting better penetration and permeation of cetirizine from the novel vesicular delivery system. Further, therapeutic efficacy of optimized formulation was assessed against oxazolone-induced atopic dermatitis in mice. It was observed that the developed formulation was highly efficacious in reducing the itching score (4.75 itches per 20 min) compared to conventional cream (9.75 itches per 20 min) with profound reduction in dermal eosinophil count and erythema score. To conclude, a novel vesicular, dermally safe, and nontoxic topical formulation of cetirizine was successfully developed and may be used to treat atopic dermatitis after clinical investigation.


Asunto(s)
Antialérgicos/administración & dosificación , Antialérgicos/uso terapéutico , Cetirizina/administración & dosificación , Cetirizina/uso terapéutico , Dermatitis Atópica/tratamiento farmacológico , Administración Tópica , Animales , Química Farmacéutica , Composición de Medicamentos , Elasticidad , Electroquímica , Excipientes , Femenino , Liberación de Histamina/efectos de los fármacos , Lípidos/química , Liposomas , Masculino , Ratones , Ratones Endogámicos BALB C , Microscopía Electrónica de Transmisión , Pomadas , Tamaño de la Partícula , Soluciones Farmacéuticas , Fosfolípidos/química , Piel/metabolismo , Absorción Cutánea
12.
Int J Clin Pediatr Dent ; 16(6): 871-874, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38344376

RESUMEN

Aim: To describe the successful eruption of an unerupted premolar associated with a dentigerous cyst without the use of any appliances. Background: Inflammatory dentigerous cyst is a variant of dentigerous cyst occurring in the mixed dentition due to stimulation of the reduced enamel epithelium of a developing permanent tooth by periapical inflammation from its carious, nonvital deciduous precursor. Marsupialization is the preferred treatment to preserve the permanent tooth. Case description: A 10-year-old patient presented to us with a well-defined, tender swelling involving the left mandibular body with buccal cortical expansion. Following imaging, marsupialization was performed involving wide excision of the alveolar mucosa overlying the region along with the cystic lining. At follow-up, spontaneous eruption of permanent teeth into occlusion was noted. Conclusion: This suggests that marsupialization along the crest may allow for successful eruption of the associated permanent teeth with the resolution of the cyst. Clinical significance: Marsupialization along the crest provides a conservative option that allows spontaneous, unassisted eruption of permanent teeth in cases of inflammatory dentigerous cysts. Careful preoperative assessments must be used to make treatment decisions. The successful eruption of permanent teeth and the total resolution of the disease both depend on adequate follow-up. How to cite this article: Jayam C, Yerragudi N, Kumar N, et al. Inflammatory Dentigerous Cyst in a 10-year-old Child Treated by Marsupialization: A Case Report. Int J Clin Pediatr Dent 2023;16(6):871-874.

13.
Pharm Pat Anal ; 12(1): 27-35, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36722320

RESUMEN

Photoresponsive liposome development is needed to serve as a facile alternative to ELISA which is ineffective for detecting small levels of biomarkers due to low detection sensitivity. The US20210396744 patent application outlines novel photoresponsive liposomes for the detection of target substances with the aid of light. Although versatile, there may be possible stability issues that can be avoided with the appropriate selection of liposome components. Furthermore, the clinical success of this technology depends on many parameters like plasma stability, efficient loading of photosensitive components in the membrane and immobilization of molecular recognition elements to the membrane. Despite several challenges, they possess enormous potential to become a non-invasive tool for the detection of target substances.


Asunto(s)
Portadores de Fármacos , Liposomas , Ensayo de Inmunoadsorción Enzimática
14.
J Stomatol Oral Maxillofac Surg ; 123(6): e962-e972, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35803558

RESUMEN

Over the recent years, Artificial Intelligence (AI) has been progressing rapidly with its ability to mimic human cognitive functions. The potential applications of AI technology in diagnosis, treatment planning, and prognosis prediction have been demonstrated in various studies. The present scoping review aimed to provide an overview of AI and Machine Learning (ML) algorithms and their applications in orthognathic surgery. A comprehensive search was conducted in databases including PubMed, Embase, Scopus, Web of Science and OVID Medline until November 2021. This scoping review was conducted following the PRISMA-ScR guidelines. After applying the inclusion and exclusion criteria, a total of 19 studies were included for final review. AI has profoundly impacted the diagnosis and prediction of orthognathic surgeries with a clinically acceptable accuracy range. Furthermore, AI reduces the work burden of the clinician by eliminating the tedious registration procedures, thereby helping in efficient and automated planning. However, focussing on the research gaps, there is a need to foster the AI models/algorithms to contemporize their efficiency in clinical decision making, diagnosis and surgical planning in future studies.


Asunto(s)
Cirugía Ortognática , Procedimientos Quirúrgicos Ortognáticos , Humanos , Inteligencia Artificial , Aprendizaje Automático
15.
Opt Express ; 19(27): 26106-16, 2011 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-22274199

RESUMEN

In this work anisotropic porous silicon is investigated as a material for optical sensing. Birefringence and sensitivity of the anisotropic porous silicon membranes are thoroughly studied in the framework of Bruggeman model which is extended to incorporate the influence of environment effects, such as silicon oxidation. The membranes were also characterized optically demonstrating sensitivity as high as 1245 nm/RIU at 1500 nm. This experimental value only agrees with the theory when it takes into consideration the effect of silicon oxidation. Furthermore we demonstrate that oxidized porous silicon membranes have optical parameters with long term stability. Finally, we developed a new model to determine the contribution of the main depolarization sources to the overall depolarization process, and how it influences the measured spectra and the resolution of birefringence measurements.


Asunto(s)
Membranas Artificiales , Dispositivos Ópticos , Refractometría/instrumentación , Silicio/química , Transductores , Birrefringencia , Diseño de Equipo , Porosidad
16.
Mol Pharm ; 8(2): 466-78, 2011 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-21288047

RESUMEN

This study is focused on the preparation of doxorubicin-loaded nanopolymersomes (PolyDoxSome) and assessment of the effects of various solvents and process variables on the size and drug loading during preparation of formulation. PolyDoxSome was prepared by nanoprecipitation method using amphiphilic (PEG)3-PLA copolymer, and the formation of polymersomes was assessed by dynamic light scattering and optical and transmission electron microscopy and evaluated for in vitro release profile and in vitro cytotoxicity. A systematic investigation indicated that solvent composition, order of addition, aqueous phase, copolymer concentration, and external energy input have significant influence on size and dispersity of PolyDoxSome. Under optimized conditions, PolyDoxSome had a size range of 130-180 nm with PDI < 0.2, a zeta potential ∼-8 mV, and a drug loading at ∼11% w/w with an encapsulation efficiency at ∼53% w/w. In vitro release profile of PolyDoxSome at 37 °C demonstrated that doxorubicin release was pH dependent and gave higher release at pH 5.5 in comparison to the release at pH 7.4 (similarity factor, f2 < 50). PolyDoxSome exhibited enhanced cellular uptake of doxorubicin compared to free doxorubicin solution in MCF-7 cell line and showed a better cytotoxicity of doxorubicin at equivalent dose in nanopolymersomes. In conclusion, size and dispersity were strongly influenced by duration of magnetic stirring and overall composition of organic/aqueous media; however, size and dispersity were retained against different degrees of dilution. PolyDoxSome was able to control the release of doxorubicin in pH dependent manner and effectively deliver the drug in active form to MCF-7 breast cancer cells.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Doxorrubicina/química , Sistemas de Liberación de Medicamentos , Nanoestructuras/administración & dosificación , Polietilenglicoles/química , Polímeros/química , Solventes/química , Línea Celular Tumoral , Química Farmacéutica , Doxorrubicina/administración & dosificación , Doxorrubicina/farmacología , Portadores de Fármacos , Femenino , Humanos , Técnicas In Vitro , Microscopía Electrónica de Transmisión , Nanoestructuras/química , Tamaño de la Partícula
17.
Mol Pharm ; 8(1): 204-12, 2011 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-21138276

RESUMEN

This paper deals with in vivo evaluation of a new amphotericin-B-loaded polymersomes (PAMBO) formulation in terms of pharmacokinetics, toxicity, tissue distribution profile, and its efficacy in a murine model of disseminated candidiasis. Pharmacokinetic and tissue distribution studies of the PAMBO showed sustained levels of the drug in plasma as well as in target organs which harbor fungal and leishmanial infection. PAMBO was found to be much less toxic than Fungizone. It was observed that 700% increment in the dose is tolerated without observable toxicity which is supported by survival, biochemical, and histopathological results. PAMBO showed a significant improvement in the survival rate of immunosuppressed mice infected with Candida albicans as compared to control. It also showed better dose to dose (1 mg/kg) efficacy as compared to Fungizone and a significant improvement in the life expectancy at 3 and 5 mg/kg dose levels in the animals. Colony forming unit (CFU) counts in the target organs revealed significant reduction in Candida burden with PAMBO treatment. Kidney, spleen, and lung were cleared of infection, although liver was carrying a very low level of infection. Overall, PAMBO formulation is found to be more efficacious and less toxic in a fungal mice model.


Asunto(s)
Anfotericina B/farmacocinética , Anfotericina B/uso terapéutico , Antifúngicos/farmacocinética , Antifúngicos/uso terapéutico , Polietilenglicoles/química , Polímeros/química , Anfotericina B/efectos adversos , Anfotericina B/química , Animales , Antifúngicos/efectos adversos , Antifúngicos/química , Candida albicans/efectos de los fármacos , Candida albicans/patogenicidad , Riñón/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos BALB C , Ratas , Ratas Sprague-Dawley , Bazo/efectos de los fármacos
19.
J Pharm Bioallied Sci ; 13(Suppl 1): S440-S443, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34447129

RESUMEN

BACKGROUND: Among the vital functions, respiration can be claimed to be one of the most important. A thorough understanding of the patient should be an important aspect a prosthodontist should dwell into so as to predispose patients to acknowledge the kind of prosthesis they require. Hence, the present study was conducted for assessing the effect of complete dentures on respiratory performance. MATERIALS AND METHODS: Fifty patients with the presence of complete edentulous arch and who had a history of complete denture usage for at least 5 years were enrolled. All the spirometric procedures were performed by trained technicians. A diagnostic spirometer was employed for performing the spirometric test. Testing was carried out in the following steps: Stage 1: testing in the absence of denture, Stage 2: testing in the presence of both dentures, Stage 3: testing in the presence of maxillary denture only, and Stage 4: testing in the presence of mandibular dentures only. Forced vital capacity (FVC) value, peak expiratory flow (PEF) value, forced expiratory volume in 1 s (FEV1) value, and forced expiratory flow 25%-75% (FEF25-75) value were recorded with the spirometric test. Analysis of all the results was done by SPSS software. RESULTS: The spirometric value of FVC, PEF, FEV1, and FEF25-75 in the absence of both maxillary and mandibular dentures (Stage 1) was found to be 3.18, 5.83, 2.44, and 2.80, respectively. The spirometric value of FVC, PEF, FEV1, and FEF25-75 in the presence of both maxillary and mandibular dentures (Stage 2) was found to be 3.09, 5.67, 2.41, and 2.67, respectively. While analyzing statistically, it was seen that there was a significant decrease in the value of spirometric variables in the presence of dentures. CONCLUSION: Chronic denture wearer edentulous patients are subjected to the risk of development of spirometric alterations. Hence, these patients should be given timely instructions about the various respiratory exercise protocols.

20.
Biomacromolecules ; 11(4): 1027-35, 2010 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-20178378

RESUMEN

(PEG)(3)-PLA copolymer has been explored for the formation of polymersomes. For this, three chains of methoxy-PEG(1100) were directly attached to citric acid by esterification. (Methoxy-PEG(1100))(3)-citrate was then reacted at its hydroxyl terminal with different moles of d,l-lactide by ring-opening polymerization to obtain polymers with five different PEG-to-PLA ratios ranging from 10:90 to 90:10. Polymers were characterized by GPC, FTIR, (1)H NMR, and DSC, films were characterized for hydrophilicity by contact angle, and surface topography was observed by SEM and AFM. All five polymers were evaluated for the formation of polymersomes. Among these, polymers with PEG content of 10-30% were able to self-assemble into polymersomes. To affirm their self-arrangement and drug carrier properties, hydrophilic and hydrophobic dyes were simultaneously encapsulated in these structures. SEM and TEM analysis of the blank polymersomes confirmed the vesicular nature of the polymersomes, whereas CLSM analysis of dye-loaded polymersomes demonstrated the presence of two separate regions viz. hydrophilic core and hydrophobic wall. Hydrophobic dye, fluorescein was released relatively faster from the wall of polymersomes, whereas hydrophilic dye, propidium iodide, was released in controlled fashion up to 18 days. It is expected that these systems may serve as a suitable carrier for simultaneous or separate delivery of drug molecules with varying physicochemical properties.


Asunto(s)
Portadores de Fármacos/química , Portadores de Fármacos/síntesis química , Polietilenglicoles/química , Polímeros/química , Polímeros/síntesis química , Biopelículas , Portadores de Fármacos/metabolismo , Sistemas de Liberación de Medicamentos , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Polímeros/metabolismo
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