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1.
Forum Health Econ Policy ; 23(2): 1-23, 2020 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-33984886

RESUMO

OBJECTIVES: Quantify the value of functional status (FS) improvements consistent in magnitude with improvements due to levodopa-carbidopa intestinal gel (LCIG) treatment, among the advanced Parkinson's disease (APD) population. METHODS: The Health Economic Medical Innovation Simulation (THEMIS), a microsimulation that estimates future health conditions and medical spending, was used to quantify the health and cost burden of disability among the APD population, and the value of quality-adjusted life-years gained from FS improvement due to LCIG treatment compared to standard of care (SoC). A US-representative Parkinson's disease (PD)-comparable cohort was constructed in THEMIS based on observed PD patient characteristics in a nationally representative dataset. APD was defined from the literature and clinical expert input. The PD and APD cohorts were followed from 2010 over their remaining lifetimes. All individuals were ages 65 and over at the start of the simulation. To estimate the value of FS improvement due to LCIG treatment, decreases in activities of daily living (ADL) limitations caused by LCIG treatment were calculated using data from a randomized, controlled, double-blind, double-dummy clinical trial and applied to the APD population in THEMIS. RESULTS: Total burden of disability associated with APD was $17.7 billion (B). From clinical trial data, LCIG treatment versus SoC lowers the odds of difficulties in walking, dressing, and bathing by 76%, 42% and 39%, respectively. Among the APD population, these reductions generated $2.6B in value to patients and cost savings to payers. The added value was 15% of the burden of disability associated with APD and offsets 15% of the cost of LCIG treatment. CONCLUSIONS: FS improvements, consistent with improvements due to LCIG treatment, in the APD population created health benefits and reduced healthcare costs in the US.


Assuntos
Atividades Cotidianas/psicologia , Carbidopa/normas , Levodopa/normas , Doença de Parkinson/complicações , Doença de Parkinson/tratamento farmacológico , Valores Sociais , Idoso , Idoso de 80 Anos ou mais , Antiparkinsonianos/farmacologia , Antiparkinsonianos/normas , Carbidopa/farmacologia , Combinação de Medicamentos , Feminino , Géis/farmacologia , Géis/normas , Géis/uso terapêutico , Humanos , Levodopa/farmacologia , Masculino , Doença de Parkinson/psicologia
2.
J Ultrasound Med ; 38(4): 1069-1073, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30196569

RESUMO

Commercially produced ultrasound coupling gel is often a scarce resource in rural regions of low-income countries that use sonography as their main imaging modality and, when available, may be cost prohibitive. Various homemade gels were created and tested to assure image quality was not compromised. Glucomannan-based gel and guar gum-based gel had superior physical properties in initial testing and showed no substantial difference compared with commercially available ultrasound gel on subject and phantom imaging and analysis (P > .05 using a 1-tailed sign test). Neither gel required heating, attracted insects, damaged ultrasound transducers, stained samples of clothing, or had harmful effects to subjects.


Assuntos
Géis/normas , Interpretação de Imagem Assistida por Computador/instrumentação , Ultrassonografia/métodos , Custos e Análise de Custo , Países em Desenvolvimento , Galactanos/química , Galactanos/economia , Géis/química , Géis/economia , Humanos , Interpretação de Imagem Assistida por Computador/normas , Mananas/química , Mananas/economia , Imagens de Fantasmas , Gomas Vegetais/química , Gomas Vegetais/economia , Pobreza , Ultrassonografia/economia , Ultrassonografia/normas , Viscosidade
3.
J Ultrasound Med ; 38(2): 371-377, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30043460

RESUMO

OBJECTIVES: Ultrasound (US) is increasingly used in settings where commercial US gel is unavailable. This study evaluated noncommercial gel recipes compared to commercial gel. METHODS: A search for US gel formulations revealed 6 recipes. Half-strength commercial gel and a modified glucomannan recipe were also tested. Nine gels, including commercial gel, were tested in Liberia and the United States. In each session, 2 physician sonologists evaluated 9 gels on 2 models, obtaining videos from the hepatorenal space with a curvilinear transducer, the cardiac parasternal long view with a phased array transducer, and the left basilic vein with a linear transducer. The sonologists and models, who were blinded to gel identity, made independent quantitative and qualitative gel evaluations comparing the test gel to commercial gel. Two physician sonologists who were blinded to the gel identities and a US operator reviewed the images and rated their quality. An analysis of variance in repeated measures was performed to test for differences in the overall score, real-time quality, and other characteristics. Post hoc pairwise comparisons to commercial gel were performed with a Tukey-Kramer adjustment. Inter- and intra-rater reliability was calculated for the image review. RESULTS: Commercial gel earned a perfect score. Compared to commercial gel, xanthine gum gel scored highest, followed by half-strength commercial gel. Hot concentrated glucomannan and cold glucomannan gel were found to be significantly worse than commercial gel. No significant difference was found between images based on the gel used on the image review. CONCLUSIONS: No significant difference in image quality was found between commercial and noncommercial gels on US image review.


Assuntos
Géis/química , Géis/normas , Ultrassonografia/instrumentação , Braço/irrigação sanguínea , Braço/diagnóstico por imagem , Países em Desenvolvimento , Recursos em Saúde , Coração/diagnóstico por imagem , Humanos , Rim/irrigação sanguínea , Rim/diagnóstico por imagem , Libéria , Fígado/irrigação sanguínea , Fígado/diagnóstico por imagem , Reprodutibilidade dos Testes , Transdutores , Ultrassonografia/métodos , Estados Unidos
5.
Wilderness Environ Med ; 29(4): 446-452, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30290983

RESUMO

INTRODUCTION: Resource and logistical constraints may limit the availability of commercial ultrasound (US) transmission gel (USTG) in austere environments. Glucomannan powder, a dietary fiber supplement, can be mixed with tap water to form a gel that may be a field-expedient substitute for USTG. We compared glucomannan gel with a commercial USTG for US image adequacy and quality. METHODS: A single clinician obtained 193 US video clips from 14 different examinations on live-tissue and simulation training models using both commercial and glucomannan USTGs. Four US fellowship-trained providers, blinded to type of gel used, independently reviewed the randomized US video clips. The primary outcome of US image adequacy was scored as "yes" or "no" and analyzed using Pearson χ2 analysis. The secondary outcome of image quality was rated on a 0 to 5 Likert scale and analyzed with the independent t test. RESULTS: For US image adequacy, commercial USTG was superior to glucomannan gel (P=0.042, 95% CI: 96.5-96.6%), with commercial USTG adequate in 96.6% of images (375 of 388 "yes"), whereas glucomannan USTG was adequate in 93.5% (359 of 384 "yes") of images. For US image quality there was no statistically significant difference between the 2 USTGs (P=0.176, 95% CI: 93.4-93.5%), with commercial USTG rated at 3.4±1.0 and glucomannan gel at 3.3±1.1. CONCLUSION: Despite a high image adequacy rate, glucomannan gel proved inferior to commercial USTG for US image adequacy but produced equivalent image quality. Glucomannan USTG may be a reasonable substitute when commercial USTG is unavailable.


Assuntos
Géis/normas , Mananas/normas , Ultrassonografia/métodos , Adolescente , Adulto , Custos e Análise de Custo , Humanos , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Estudos Prospectivos , Ultrassonografia/economia , Adulto Jovem
6.
Emerg Med J ; 34(4): 227-230, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27986838

RESUMO

OBJECTIVE: Point-of-care ultrasound is a portable, relatively low-cost imaging modality with great potential utility in low-resource settings. However, commercially produced ultrasound gel is often cost-prohibitive and unavailable. We investigated whether images obtained using an alternative cornstarch-based gel would be of comparable quality with those using commercial gel. METHODS: This was a blinded, randomised, cross-over study comparing commercially produced ultrasound gel with home-made cornstarch-based gel. Ultrasound-trained faculty obtained three video clips with each gel type from patients at one urban ED. The clips were evaluated by a radiologist and an ultrasound-trained emergency physician. Images were assessed in terms of overall adequacy (dichotomous) and quality, resolution and detail using a rating scale (0-10). All sonographers and physicians reviewing the images were blinded to the type of gel used. RESULTS: Thirty-four patients were enrolled in the study, producing 204 separate images (102 with each gel). The cornstarch gel clips were deemed accurate in 70.6% (95% CI 63.9% to 76.5%) of the scans, as compared with 65.2% (95% CI 58.4% to 71.4%) of those using commercial gel. There was no difference between the two groups with respect to image detail, resolution or quality. CONCLUSIONS: Images produced using the cornstarch-based alternative ultrasound gel were of similar quality to those using commercial gel. The low cost and easy preparation of the cornstarch-based gel make it an attractive coupling medium for use in low-resource settings.


Assuntos
Géis/normas , Ultrassonografia/economia , Ultrassonografia/métodos , Adulto , California , Estudos Cross-Over , Serviço Hospitalar de Emergência/economia , Serviço Hospitalar de Emergência/organização & administração , Feminino , Géis/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Testes Imediatos/economia , Testes Imediatos/normas , Amido/farmacologia , Amido/uso terapêutico
7.
Clin Imaging ; 40(6): 1104-1107, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27442344

RESUMO

PURPOSE: The aim of this study is to evaluate the utility of intravaginal ultrasound gel for the staging of cervical carcinoma on magnetic resonance imaging (MRI) and to confirm the results with pathological staging. METHODS: Nine patients were included in the study. T2-weighted images were compared without and with vaginal gel (VG). RESULTS: Five patients were evaluated as overstaged on MRI without VG. After VG, the results were compatible with the pathological stages in all patients. CONCLUSIONS: We suggest that this technique is easy, well tolerated, and effective, and it increases the accuracy rate of MRI staging in early cervical cancer.


Assuntos
Colo do Útero/diagnóstico por imagem , Géis/normas , Imageamento por Ressonância Magnética/métodos , Estadiamento de Neoplasias , Neoplasias do Colo do Útero/diagnóstico por imagem , Vagina/diagnóstico por imagem , Adulto , Colo do Útero/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Ultrassonografia/métodos , Neoplasias do Colo do Útero/patologia
8.
Neurodegener Dis Manag ; 6(3): 187-202, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27075968

RESUMO

Patients with Parkinson's disease often have a good initial response to dopaminergic therapy but later usually develop motor fluctuations and dyskinesia. In these patients, continuous infusion of levodopa-carbidopa intestinal gel (LCIG) allows for maintaining adequate dopamine levels and for improving motor and nonmotor symptoms, as well as quality of life and autonomy. Adequate candidate selection and follow-up are crucial for treatment success. Management should be multidisciplinary, and patient and caregiver education is a priority. This expert consensus document has been developed by a team of neurologists, gastroenterologists and nurses who have a vast experience in LCIG therapy, with an intention to provide knowledge and tools to facilitate patient management throughout all phases of LCIG treatment process.


Assuntos
Antiparkinsonianos/administração & dosagem , Carbidopa/administração & dosagem , Intestinos/efeitos dos fármacos , Levodopa/administração & dosagem , Doença de Parkinson/tratamento farmacológico , Resultado do Tratamento , Carbidopa/normas , Cuidadores/psicologia , Ensaios Clínicos como Assunto/métodos , Ensaios Clínicos como Assunto/normas , Bases de Dados Bibliográficas/estatística & dados numéricos , Esquema de Medicação , Combinação de Medicamentos , Feminino , Seguimentos , Géis/administração & dosagem , Géis/normas , Humanos , Intestinos/fisiologia , Levodopa/normas , Masculino
9.
Eur Phys J E Soft Matter ; 39(1): 10, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26830759

RESUMO

We present a novel elastography method for soft materials (100Pa-100kPa) based on indentation by a µm-sized water jet. We show that the jet creates a localized deformation ("cavity") of the material that can be easily visualized. We study experimentally how cavity width and depth depend on jet speed, height, incidence angle and sample elasticity. We describe how to calibrate the indenter using gels of known stiffness. We then demonstrate that the indenter yields quantitative elasticity values within 10% of those measured by shear rheometry. We corroborate our experimental findings with fluid-solid finite-element simulations that quantitatively predict the cavity profile and fluid flow lines. The water jet indenter permits in situ local stiffness measurements of 2D or 3D gels used for cell culture in physiological buffer, is able to assess stiffness heterogeneities with a lateral resolution in the range 50-500µm (at the tissue scale) and can be assembled at low cost with standard material from a biology laboratory. We therefore believe it will become a valuable method to measure the stiffness of a wide range of soft, synthetic or biological materials.


Assuntos
Dimetilpolisiloxanos/química , Elasticidade , Géis/química , Microfluídica/métodos , Nylons/química , Dimetilpolisiloxanos/normas , Géis/normas , Nylons/normas
10.
J Cardiothorac Vasc Anesth ; 28(5): 1208-10, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25027104

RESUMO

OBJECTIVE: Ultrasound transmission gel (USTG) is used routinely to enhance the image quality during transesophageal echocardiogram examinations. Ultrasound gel is manufactured in both sterile and non-sterile preparations, and both preparations have been used during transesophageal echocardiograms in the United States. The United States Food and Drug Administration (FDA) currently recommends that all transesophageal echocardiogram (TEE) examinations be performed using sterile ultrasound gel. The authors sought to identify if anesthesiology departments with cardiothoracic fellowship programs follow current FDA recommendations of using sterile ultrasound gel during TEE examination. DESIGN: Survey. SETTING: Survey of cardiothoracic fellowship directors. The majority of fellowship directors practice in academic hospitals although the practice site was not addressed in the survey. PARTICIPANTS: Fellowship directors volunteered to participate in the study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Survey responses were tallied using the website, www.surveymonkey.com, and 56% of respondents do not currently follow the current FDA recommendations. CONCLUSIONS: A majority of cardiothoracic program director respondents to the authors' survey do not utilize single-use sterile packets of USTG for TEE examinations. While the infectious risk of USTG used for TEE examinations from multiple-use containers versus single-use sterile containers has not been established clearly, a change in practice to follow the current FDA recommendations may be advised.


Assuntos
Anestesiologia/normas , Ecocardiografia Transesofagiana/normas , Géis/normas , Anestesiologia/métodos , Ecocardiografia Transesofagiana/métodos , Contaminação de Equipamentos/prevenção & controle , Feminino , Humanos , Internato e Residência , Masculino , Diretores Médicos , Médicos/normas , Inquéritos e Questionários
11.
Food Sci Technol Int ; 20(4): 253-63, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23751542

RESUMO

The potential of using the unwashed mince of farmed meagre as raw material for the preparation of heat-induced gel products was assessed taking into account the effect of age (small size <1 kg meagre vs commercial size > 2kg meagre), lower salt levels (1.0%, w/w, vs 2.5%, w/w), and microbial transglutaminase (MTGase) incorporation (0.0%, w/w, vs 0.5%, w/w). Heat-induced gel products from > 2 kg fish were of superior quality. Salt reduction from 2.5% to 1.0% (w/w) was detrimental for textural quality, particularly, of gels prepared from >2 kg meagre mince. MTGase addition improved texture. Moreover, MTGase incorporation led to a greater importance of non-covalent hydrophobic bonding.


Assuntos
Produtos Pesqueiros/análise , Peixes , Qualidade dos Alimentos , Géis/normas , Cloreto de Sódio/farmacologia , Transglutaminases/farmacologia , Fatores Etários , Análise de Variância , Animais , Aquicultura/métodos , Fenômenos Químicos , Eletroforese em Gel de Poliacrilamida/métodos , Manipulação de Alimentos/métodos , Géis/análise , Temperatura Alta , Interações Hidrofóbicas e Hidrofílicas
12.
Reg Anesth Pain Med ; 38(5): 415-24, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23974866

RESUMO

BACKGROUND AND OBJECTIVES: Ultrasound coupling gel may serve as a vector for the spread of bacteria and has been the causative agent for significant health care-associated infections. The purpose of this study was to document existing infection-control procedures and level of contamination present within nonsterile ultrasound gel from several clinical departments at a single institution. A second purpose was to examine the effectiveness of clinician education and manufacturer-based ultrasound additives on ultrasound gel contamination and in vitro bacterial proliferation, respectively. METHODS: Compliance with Health Canada recommended infection-control policies were determined by survey. Contamination of in-use ultrasound gel bottles was determined by inspecting cultures after 72 hours of incubation. After infection-control education, a 28-day interval assessment was used to examine contamination rates in newly provided ultrasound gel. The ability of ultrasound gel containing parabens to prevent bacterial growth was examined in cultures grown with and without ultrasound gel. RESULTS: Practitioners were not compliant with Health Canada recommendations, but the baseline ultrasound gel contamination rate within these departments was only 2.5%. Education in infection control did not improve the contamination rate over 28 days. Contamination was discovered in ultrasound gel supplied directly from the manufacturer. Ultrasound gel suppressed but did not prevent bacterial growth in a species- and time-specific manner. CONCLUSIONS: The source of contamination for in-use ultrasound gel may be of manufacturer or human origin. Because additives to the ultrasound gel are not bactericidal, sterile ultrasound gel should be used for invasive and high-risk cases, and improving infection-control policies is warranted.


Assuntos
Competência Clínica/normas , Infecção Hospitalar/prevenção & controle , Contaminação de Equipamentos/prevenção & controle , Géis/normas , Controle de Infecções/normas , Ultrassonografia de Intervenção/normas , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/transmissão , Coleta de Dados/métodos , Embalagem de Medicamentos/normas , Humanos , Controle de Infecções/métodos , Ultrassonografia de Intervenção/métodos
13.
Acta Cytol ; 56(2): 146-54, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22378076

RESUMO

OBJECTIVES: Ultrasound-guided fine needle aspiration (FNA) is a commonly employed tool in cytopathologic practice. Artifacts resulting in misinterpretation of specimens have been noted with various ultrasound gel media. Our purpose was to perform a prospective human cadaveric study of this phenomenon to identify a low-cost solution that eliminates the artifact. STUDY DESIGN: Three separate ultrasound-guided FNAs were performed on the thyroid and parotid glands in situ of a fresh human cadaver using three different types of ultrasound gel media. Slides were prepared in standard fashion (Quik-Diff and Papanicolaou stains). Two cytopathologists subsequently analyzed the slides for the presence of any artifact interfering with their ability to visualize and interpret the cellular aspirate material. RESULTS: Two of the three gel media revealed significant artifacts mimicking apoptosis, necrosis or colloid, making it difficult to visualize the cellular components and differentiate the artifact from the thyroid colloid. One gel medium did not show any significant artifact, and there was no discernable difference in its quality with regard to the ultrasound image during FNA procedures. CONCLUSIONS: Ultrasound gels can be associated with a significant artifact in FNA specimens. To eliminate this artifact, which may alter the adequacy, diagnosis or cytologic appearance, we confirm a specific gel type that is useful for ultrasound-guided FNAs.


Assuntos
Artefatos , Biópsia por Agulha Fina/métodos , Erros de Diagnóstico/prevenção & controle , Ultrassonografia/métodos , Cadáver , Géis/química , Géis/normas , Humanos , Compostos Orgânicos/química , Compostos Orgânicos/normas , Doenças Parotídeas/diagnóstico por imagem , Doenças Parotídeas/patologia , Glândula Parótida/diagnóstico por imagem , Glândula Parótida/patologia , Compostos de Fenilmercúrio/química , Compostos de Fenilmercúrio/normas , Valor Preditivo dos Testes , Doenças da Glândula Tireoide/diagnóstico por imagem , Doenças da Glândula Tireoide/patologia , Glândula Tireoide/diagnóstico por imagem , Glândula Tireoide/patologia , Ultrassonografia/normas
14.
AAPS PharmSciTech ; 12(2): 496-506, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21479748

RESUMO

Upon topical administration, a high penetration rate of antifungal drug into the infected site is desirable to reduce treatment length and systemic side effects which occur especially after a prolonged peroral administration. Thermogelling formulations composed of poloxamer 407, medium chain triglycerides, isopropyl alcohol, dimethyl isosorbide, and water for topical application were developed, and a lipophilic drug terbinafine HCl (TBF) was incorporated. Previously, a remarkable high permeation rate of a hydrophilic drug 5-aminolevulinic acid from this vehicle was evident compared to different creams from German Pharmacopoeia. By varying the composition of vehicle constituents, a broad range of consistencies and appearances was obtained. Up to 4% TBF could be solubilized in the vehicle. TBF fluxes at steady state across human stratum corneum from these formulations were higher than those from the German Pharmacopoeia Basiscreme Deutscher Arzneimittel Codex and a marketed product at similar concentration of 1%. TBF fluxes increased along with a higher content of TBF in the formulation. The amount of TBF retained in stratum corneum was higher compared to those from both standards of comparison (p < 0.01). The thermodynamic activity of TBF in the thermogelling formulation was lower compared to those in other formulations. Therefore, the nature of the vehicle and its interaction with TBF are suggested to play a significant role in explaining higher fluxes along with higher TBF content. Differential scanning calorimetry measurements revealed comparable T2 and T3 endothermic shifts from all examined formulations suggesting equal influences to the skin lipids.


Assuntos
Química Farmacêutica/métodos , Epiderme/metabolismo , Ácido Clorídrico/farmacocinética , Naftalenos/farmacocinética , Poloxâmero/farmacocinética , Administração Tópica , Adulto , Química Farmacêutica/normas , Epiderme/efeitos dos fármacos , Feminino , Géis/normas , Humanos , Ácido Clorídrico/administração & dosagem , Ácido Clorídrico/química , Pessoa de Meia-Idade , Naftalenos/administração & dosagem , Naftalenos/química , Permeabilidade/efeitos dos fármacos , Poloxâmero/administração & dosagem , Poloxâmero/química , Terbinafina
15.
AAPS PharmSciTech ; 12(2): 453-60, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21437788

RESUMO

The purpose of this study is to determine whether sodium alginate solutions' rheological parameters are meaningful relative to sodium alginate's use in the formulation of calcium alginate gels. Calcium alginate gels were prepared from six different grades of sodium alginate (FMC Biopolymer), one of which was available in ten batches. Cylindrical gel samples were prepared from each of the gels and subjected to compression to fracture on an Instron Universal Testing Machine, equipped with a 1-kN load cell, at a cross-head speed of 120 mm/min. Among the grades with similar % G, (grades 1, 3, and 4), there is a significant correlation between deformation work (L(E)) and apparent viscosity (η(app)). However, the results for the partial correlation analysis for all six grades of sodium alginate show that L(E) is significantly correlated with % G, but not with the rheological properties of the sodium alginate solutions. Studies of the ten batches of one grade of sodium alginate show that η(app) of their solutions did not correlate with L(E) while tan δ was significantly, but minimally, correlated to L(E). These results suggest that other factors--polydispersity and the randomness of guluronic acid sequencing--are likely to influence the mechanical properties of the resultant gels. In summary, the rheological properties of solutions for different grades of sodium alginate are not indicative of the resultant gel properties. Inter-batch differences in the rheological behavior for one specific grade of sodium alginate were insufficient to predict the corresponding calcium alginate gel's mechanical properties.


Assuntos
Alginatos/química , Reologia/métodos , Estresse Mecânico , Alginatos/normas , Géis/normas , Ácido Glucurônico/química , Ácido Glucurônico/normas , Ácidos Hexurônicos/química , Ácidos Hexurônicos/normas , Soluções Farmacêuticas/química , Soluções Farmacêuticas/normas , Distribuição Aleatória , Reologia/normas
16.
J Dairy Sci ; 91(4): 1317-24, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18349224

RESUMO

An innovative packaging system has been developed, based on natural gels, that has shown the peculiar characteristic to strongly increase the shelf life of water buffalo Mozzarella cheese. To explain the mechanism of action of the gel, measurements of Ca and Na in the cheese and in the storage liquid were carried out, together with pH determination. A correlation has been found between the constant level of Ca and pH in the cheese and the prolongation of nutritional characteristics; in fact, both parameters diminish significantly in the absence of gel. At the same time, the weight of the cheese in gel remained constant for as long as 30 d. Confocal laser microscopy gave direct evidence of the persistent physical structure of proteins and lipids of Mozzarella when stored in gel.


Assuntos
Búfalos , Queijo/análise , Manipulação de Alimentos/métodos , Embalagem de Alimentos/normas , Animais , Cálcio/análise , Queijo/normas , Manipulação de Alimentos/normas , Géis/análise , Géis/normas , Concentração de Íons de Hidrogênio , Microscopia Confocal/métodos , Proteínas do Leite/análise , Sódio/análise , Fatores de Tempo
17.
J Food Sci ; 72(2): E73-8, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17995836

RESUMO

Tilapia meat pastes were subjected to pretreatments of hydrostatic pressure (50 to 300 MPa/4 degrees C/60 min) followed by setting (50 degrees C/60 min) with or without subsequent cooking (90 degrees C/20 min) to investigate the changes of rheological properties, gel-forming ability, whiteness, and protein solubility of gels. The gel by setting only as the control was elastic, rigid, and mainly constituted by covalent bonds. The gel by pretreatments of 50 MPa was similar to the control. A 100-MPa pretreatment induced a viscous and soft gel with mainly noncovalent bonds. The 200-MPa pretreatment produced a gel with strongest breaking force and strain compared with all the treatments in this study; moreover, the gel was mainly constituted by hydrogen bonds. A gel induced by a 300-MPa pretreatment was the most viscous. Via subsequent cooking (90 degrees C/20 min), all the gels became more rigid and elastic except that induced by a 100-MPa pretreatment.


Assuntos
Produtos Pesqueiros/análise , Produtos Pesqueiros/normas , Proteínas de Peixes/análise , Géis/química , Pressão Hidrostática , Animais , Géis/análise , Géis/normas , Humanos , Ligação de Hidrogênio , Reologia , Tilápia , Viscosidade
18.
Biosci Biotechnol Biochem ; 71(8): 2083-6, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17690447

RESUMO

The aim of this study was to improve the performance of affinity gels containing glycyl-D-phenylalanine (Gly-D-Phe) as a ligand to thermolysin. Gly-D-Phe was immobilized to the resin through spacers of varying chain lengths. The resulting affinity gels had spacer chain lengths of 2 carbon atoms and 11 and 13 carbon-and-oxygen atoms (designated T2, T11, and T13), and were characterized for their binding abilities to thermolysin. Measurement of adsorption isotherms showed that the association constants to thermolysin were in the order T13 > T11 > T2. In affinity column chromatography, in which 5 mg thermolysin was applied onto 1-ml volumes of the gels, the adsorption ratios of thermolysin were also in the order T13 > T11 > T2. These results indicate that the performance of affinity gels is improved by increasing the spacer chain length to 13 carbon-and-oxygen atoms.


Assuntos
Cromatografia de Afinidade/métodos , Géis/química , Termolisina/isolamento & purificação , Cromatografia de Afinidade/normas , Reagentes de Ligações Cruzadas/química , Dipeptídeos , Géis/normas , Ligantes , Ligação Proteica , Resinas Sintéticas , Temperatura
19.
Zhong Yao Cai ; 28(7): 605-6, 2005 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-16252733

RESUMO

OBJECTIVE: To introduce the preparation and quality control of Solanum lyratum Extract Thunb gel. METHODS: The gel was prepared with Solanum lyratum Thunb Extract as main component and carbopol 940 as base material, and Solasodine was determined by TLCS. RESULTS: The preparation of this gel was feasible, its quality was reliable, its detection method was rapid, stable, and could be used to control the quality of Solanum lyratum Thunb Extract gel. CONCLUSIONS: Studies on Solanum lyratum Thunb Extract gel will find a new path for the treatment of eczema with mono traditional Chinese medicine.


Assuntos
Medicamentos de Ervas Chinesas/química , Géis/isolamento & purificação , Plantas Medicinais/química , Alcaloides de Solanáceas/análise , Solanum/química , Tecnologia Farmacêutica/métodos , Resinas Acrílicas , Cromatografia em Camada Delgada , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/normas , Géis/normas , Controle de Qualidade
20.
Biotechnol Lett ; 27(10): 737-9, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-16049744

RESUMO

A method for the preparation of uniform gel-disks for enzyme and cell immobilisation, as well as for characterisation of gel mechanical stability, is described. The apparatus comprises a stainless steel base unit and glass parallel plates, designed to permit easy and fast production of multiple homogeneous gel sheets of variable thickness.


Assuntos
Técnicas de Química Analítica/instrumentação , Géis/química , Carragenina/química , Técnicas de Química Analítica/métodos , Géis/normas , Vidro , Polietilenoimina/química , Aço Inoxidável
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