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1.
J Neurosurg ; 134(6): 1940-1950, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32736362

RESUMO

OBJECTIVE: Acute subdural hematoma (ASDH) is a major cause of mortality and morbidity after traumatic brain injury (TBI). Surgical evacuation is the mainstay of treatment in patients with altered neurological status or significant mass effect. Nevertheless, concerns regarding surgical indication still persist. Given that clinicians often make therapeutic decisions on the basis of their prognosis assessment, to accurately evaluate the prognosis is of great significance. Unfortunately, there is a lack of specific and reliable prognostic models. In addition, the interdependence of certain well-known predictive variables usually employed to guide surgical decision-making in ASDH has been proven. Because gray matter and white matter are highly susceptible to secondary insults during the early phase after TBI, the authors aimed to assess the extent of these secondary insults with a brain parenchyma densitometric quantitative CT analysis and to evaluate its prognostic capacity. METHODS: The authors performed a retrospective analysis among their prospectively collected cohort of patients with moderate to severe TBI. Patients with surgically evacuated, isolated, unilateral ASDH admitted between 2010 and 2017 were selected. Thirty-nine patients were included. For each patient, brain parenchyma density in Hounsfield units (HUs) was measured in 10 selected slices from the supratentorial region. In each slice, different regions of interest (ROIs), including and excluding the cortical parenchyma, were defined. The injured hemisphere, the contralateral hemisphere, and the absolute differences between them were analyzed. The outcome was evaluated using the Glasgow Outcome Scale-Extended at 1 year after TBI. RESULTS: Fifteen patients (38.5%) had a favorable outcome. Collected demographic, clinical, and radiographic data did not show significant differences between favorable and unfavorable outcomes. In contrast, the densitometric analysis demonstrated that greater absolute differences between both hemispheres were associated with poor outcome. These differences were detected along the supratentorial region, but were greater at the high convexity level. Moreover, these HU differences were far more marked at the cortical parenchyma. It was also detected that these differences were more prone to ischemic and/or edematous insults than to hyperemic changes. Age was significantly correlated with the side-to-side HU differences in patients with unfavorable outcome. CONCLUSIONS: The densitometric analysis is a promising prognostic tool in patients diagnosed with ASDH. The supplementary prognostic information provided by the densitometric analysis should be evaluated in future studies.


Assuntos
Densitometria/métodos , Hematoma Subdural Agudo/diagnóstico por imagem , Hematoma Subdural Agudo/cirurgia , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Densitometria/normas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/normas , Resultado do Tratamento
2.
Sci Rep ; 10(1): 4494, 2020 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-32161284

RESUMO

We describe a new technique, high fidelity Imaging Retinal Densitometry (IRD), which probes the functional integrity of the outer retinal complex. We demonstrate the ability of the technique to map visual pigment optical density and synthesis rates in eyes with and without macular disease. A multispectral retinal imaging device obtained precise measurements of retinal reflectance over space and time. Data obtained from healthy controls and 5 patients with intermediate AMD, before and after photopigment bleaching, were used to quantify visual pigment metrics. Heat maps were plotted to summarise the topography of rod and cone pigment kinetics and descriptive statistics conducted to highlight differences between those with and without AMD. Rod and cone visual pigment synthesis rates in those with AMD (v = 0.043 SD 0.019 min-1 and v = 0.119 SD 0.046 min-1, respectively) were approximately half those observed in healthy controls (v = 0.079 SD 0.024 min-1 for rods and v = 0.206 SD 0.069 min-1 for cones). By mapping visual pigment kinetics across the central retina, high fidelity IRD provides a unique insight into outer retinal complex function. This new technique will improve the phenotypic characterisation, diagnosis and treatment monitoring of various ocular pathologies, including AMD.


Assuntos
Densitometria/métodos , Imagem Óptica/métodos , Retina/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Densitometria/normas , Humanos , Imageamento Tridimensional , Raios Infravermelhos , Degeneração Macular/diagnóstico por imagem , Degeneração Macular/patologia , Imagem Óptica/normas , Retina/patologia , Epitélio Pigmentado da Retina/diagnóstico por imagem , Epitélio Pigmentado da Retina/patologia
3.
J Clin Densitom ; 22(4): 544-553, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31327665

RESUMO

The indications for initial and follow-up bone mineral density (BMD) in transgender and gender nonconforming (TGNC) individuals are poorly defined, and the choice of which gender database to use to calculate Z-scores is unclear. Herein, the findings of the Task Force are presented after a detailed review of the literature. As long as a TGNC individual is on standard gender-affirming hormone treatment, BMD should remain stable to increasing, so there is no indication to monitor for bone loss or osteoporosis strictly on the basis of TGNC status. TGNC individuals who experience substantial periods of hypogonadism (>1 yr) might experience bone loss or failure of bone accrual during that time, and should be considered for baseline measurement of BMD. To the extent that this hypogonadism continues over time, follow-up measurements can be appropriate. TGNC individuals who have adequate levels of endogenous or exogenous sex steroids can, of course, suffer from other illnesses that can cause osteoporosis and bone loss, such as hyperparathyroidism and steroid use; they should have measurement of BMD as would be done in the cisgender population. There are no data that TGNC individuals have a fracture risk different from that of cisgender individuals, nor any data to suggest that BMD predicts their fracture risk less well than in the cisgender population. The Z-score in transgender individuals should be calculated using the reference data (mean and standard deviation) of the gender conforming with the individual's gender identity. In gender nonconforming individuals, the reference data for the sex recorded at birth should be used. If the referring provider or the individual requests, a set of "male" and "female" Z-scores can be provided, calculating the Z-score against male and female reference data, respectively.


Assuntos
Densidade Óssea , Conferências de Consenso como Assunto , Densitometria/normas , Osteoporose/diagnóstico , Pessoas Transgênero , Feminino , Humanos , Masculino
4.
Respir Res ; 20(1): 45, 2019 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-30819163

RESUMO

BACKGROUND: We developed a method to calculate a standard score for lung tissue mass derived from CT scan images from a control group without respiratory disease. We applied the method to images from subjects with emphysema associated with alpha-1 antitrypsin deficiency (AATD) and used it to study regional patterns of differential tissue mass. METHODS: We explored different covariates in 76 controls. Standardization was applied to facilitate comparability between different CT scanners and a standard Z-score (Standard Mass Score, SMS) was developed, representing lung tissue loss compared to normal lung mass. This normative data was defined for the entire lungs and for delineated apical, central and basal regions. The agreement with DLCO%pred was explored in a data set of 180 patients with emphysema who participated in a trial of alpha-1-antitrypsin augmentation treatment (RAPID). RESULTS: Large differences between emphysematous and normal tissue of more than 10 standard deviations were found. There was reasonable agreement between SMS and DLCO%pred for the global densitometry (κ = 0.252, p < 0.001), varying from κ = 0.138 to κ = 0.219 and 0.264 (p < 0.001), in the apical, central and basal region, respectively. SMS and DLCO%pred correlated consistently across apical, central and basal regions. The SMS distribution over the different lung regions showed a distinct pattern suggesting that emphysema due to severe AATD develops from basal to central and ultimately apical regions. CONCLUSIONS: Standardization and normalization of lung densitometry is feasible and the adoption of the developed principles helps to characterize the distribution of emphysema, required for clinical decision making.


Assuntos
Densitometria/métodos , Pulmão/diagnóstico por imagem , Enfisema Pulmonar/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Deficiência de alfa 1-Antitripsina/diagnóstico por imagem , Adulto , Densitometria/normas , Feminino , Humanos , Pulmão/metabolismo , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Enfisema Pulmonar/metabolismo , Tomografia Computadorizada por Raios X/normas , Deficiência de alfa 1-Antitripsina/metabolismo
5.
Molecules ; 24(3)2019 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-30691078

RESUMO

This study reports the development and validation of a new, simple, and accurate high-performance thin-layer chromatography (HPTLC)-densitomeric method for the determination of nandrolone decanoate in a commercially available injection formulation. Chromatographic analysis was performed on glass CN modified silica gel 60F254 plates developed using n-hexane-ethyl acetate in volume ratio 42.5:7.5 as the mobile phase. Densitometric scanning was carried out at the wavelength of 245 nm. This chromatographic system gave compact spot and a symmetrical peak of nandrolone decanoate with retardation factor (RF) value at 0.57 (±0.02). The linearity of this method with the high correlation coefficient of calibration plot ranges from 0.780 to 12.500 µg/spot. The developed method is characterized by good precision (coefficient of variation CV < 2%) and high accuracy close to 100.3% (R = 99.0%). Values of limits of detection and quantification equal to 0.231 and 0.700 µg/spot, respectively, confirm the sensitivity of the developed method. The analysis of the pharmaceutical formulation of nandrolone decanoate indicates drug content of 50.5 mg/mL and 101.0% in relation to the label claim. This is in good agreement with the recommendation of the International Council for Harmonisation (ICH) guidelines as well as the pharmacopoeial requirements. The low CV value (<1%) of nandrolone decanoate content in the tested injection formulation confirms the suitability of the proposed HPTLC-densitometric method for routine control of this compound in examined pharmaceuticals.


Assuntos
Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Densitometria , Decanoato de Nandrolona/análise , Preparações Farmacêuticas/análise , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida de Alta Pressão/normas , Cromatografia em Camada Fina/métodos , Cromatografia em Camada Fina/normas , Densitometria/métodos , Densitometria/normas , Composição de Medicamentos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
6.
Pak J Pharm Sci ; 31(6 (Supplementary): 2679-2682, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30587479

RESUMO

The highly oriented modern detection techniques provide a precise and definite tool for investigation in natural medicines. Current study directed the standardization of eminent biomarker Vasicine in a natural cough syrup. A highly accurate and precise method of High-performance thin layer chromatography (HPTLC) has been developed to certify the quantity of vasicine inside the syrup. Ethyl acetate, chloroform, ethanol and ammonia (6:3:1: 1 v/v) were mobile phase for the study. The TLC plate silica gel G60F254 was used with CAMAG Scanner III and CAMAG Linomate 5. The detected Rf value was 0.51 in both sample and reference standard at 254 nm. International conference of Harmonization (ICH) guidelines were followed for the validation of the developed method. Linearity was achieved in the range of 200µg to 1600µg with co-efficient correlation r2=0.9995. Accuracy was found in between 98.9 to 101.4% however precision was good at both inter and intra-day. As per the standardization of ICH, the developed method was found to be reproducible and showed sharp similar peak with high resolution.


Assuntos
Alcaloides/análise , Antitussígenos/análise , Densitometria/normas , Compostos Fitoquímicos/análise , Quinazolinas/análise , Alcaloides/química , Antitussígenos/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida de Alta Pressão/normas , Cromatografia em Camada Fina/métodos , Cromatografia em Camada Fina/normas , Densitometria/métodos , Compostos Fitoquímicos/química , Quinazolinas/química , Padrões de Referência
7.
Aten Primaria ; 50 Suppl 2: 30-38, 2018 11.
Artigo em Espanhol | MEDLINE | ID: mdl-30563623

RESUMO

In 1994, the World Health Organisation established osteoporosis criteria based on bone mineral density (in terms of T-Score), granting a risk factor the category of disease. Given that it has a low positive predictive value of fractures when applied to low-risk populations, its use as a screening test is controversial because it favours overdiagnosis due to the false labelling of the disease it produces. In the coming years, the indication of densitometry will be made based on the absolute risk of fracture. This is the criterion adopted by the PAPPS (Programa de Actividades Preventivas y de Promoción de la Salud or Programme for Preventive Activities and the Promotion of Health), which proposes as part of its latest recommendations the use of the Z-score instead of the T-Score, as a densitometric evaluation criterion, in a clear effort to fight against overdiagnosis.


Assuntos
Densidade Óssea , Fraturas do Quadril/etiologia , Uso Excessivo dos Serviços de Saúde , Osteoporose/diagnóstico , Fraturas da Coluna Vertebral/etiologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Conservadores da Densidade Óssea/uso terapêutico , Densitometria/normas , Feminino , Humanos , Pessoa de Meia-Idade , Osteoporose/complicações , Osteoporose/tratamento farmacológico , Valor Preditivo dos Testes , Medição de Risco/métodos , Fatores de Risco , Sensibilidade e Especificidade , Espanha
8.
J Chromatogr Sci ; 54(7): 1105-14, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27406122

RESUMO

Topiramate, 2,3:4,5-bis-O-(1-methylethylidene)-ß-d-fructopyranose, is an anticonvulsant drug indicated in the treatment and control of partial seizures and severe tonic-clonic (grand mal) seizures in adults and children. An economic and rapid high-performance thin-layer chromatographic (HPTLC) method was developed and was validated for the quantitative determination of topiramate in plasma, brain homogenate and pharmaceutical formulation. The simple extraction method was used for the isolation of topiramate from formulation, plasma and brain homogenate samples. HPTLC separation was achieved on an aluminum-backed layer of silica gel 60F254 plates using toluene : acetone (5.0 : 2.0, v/v) as mobile phase. Spots of developed plates were visualized by spraying of reagent [3.0% phenol in the mixture of ethanol : sulfuric acid (95 : 5, v/v)]. Quantitation was achieved by densitometric analysis at 340 nm over the concentration range of 1,000-5,000 ng/spot. The method was found to give compact spot for the drug (Rf: 0.61 ± 0.018). The regression analysis data for the calibration plots showed good relationship with a correlation coefficient of 0.9983. The minimum detectable amount was found to be 165 ng/spot, whereas the limit of quantitation was found to be 500 ng/spot. Statistical analysis of the data showed that the method is precise, accurate, reproducible and selective for the analysis of topiramate. The developed method was successfully employed for the estimation of topiramate in samples of equilibrium solubility study, diffusion study, microemulsion formulation and suspension formulation (developed in-house), rat plasma and rat brain homogenate samples.


Assuntos
Anticonvulsivantes/sangue , Cromatografia em Camada Fina/normas , Densitometria/normas , Frutose/análogos & derivados , Acetona , Animais , Anticonvulsivantes/farmacocinética , Química Encefálica , Calibragem , Frutose/sangue , Frutose/farmacocinética , Ratos , Ratos Wistar , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Solubilidade , Tolueno , Topiramato
9.
J Chromatogr Sci ; 54(7): 1115-9, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27406123

RESUMO

A rapid, sensitive and selective high-performance thin-layer chromatography (HPTLC) method was developed and validated for the determination and pharmacokinetics of pirfenidone in rat serum. One-step protein precipitation by methanol is reported, and serum samples were separated by HPTLC using a simple mobile phase of toluene-methanol in the ratio of 8:2. The retardation factor of pirfenidone in the serum sample was 0.45 with the detection performed at 315 nm. The calibration curve was linear over the range of 100-1,200 ng/spot with a lower limit of quantitation of 40 ng/spot. The mean recovery of pirfenidone in serum was in the range of 70.6-75.8%, and intra-day and inter-day precision were both <14.1%. This method was successfully applied to the pharmacokinetic study of pirfenidone in rats on oral administration of the drug at a dose of 15.0 mg/kg.


Assuntos
Analgésicos/sangue , Cromatografia em Camada Fina/normas , Densitometria/normas , Piridonas/sangue , Acetona , Administração Oral , Analgésicos/farmacocinética , Animais , Calibragem , Limite de Detecção , Masculino , Piridonas/farmacocinética , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Tolueno
10.
J Chromatogr Sci ; 54(7): 1120-8, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27406124

RESUMO

Aspirin (ASP) and dipyridamole (DIP) are widely used as a combination in pharmaceutical formulations for treatment of strokes. Many of these formulations are containing tartaric acid as an excipient (in DIP pellets formulation for sustained release), which increases the probability of formation of dipyridamole tartaric acid ester impurity (DIP-I). On the other hand, salicylic acid (SAL) is considered to be one of the synthesis impurities and a degradation product of ASP. In this work, two chromatographic methods, namely, TLC-densitometry and HPLC, have been established and validated for simultaneous determination of ASP, DIP, SAL and DIP-I. Good separation was achieved by using silica gel as stationary phase and toluene-methanol-ethyl acetate (2:3:5, by volume) as mobile phase in the case of TLC-densitometry and Zorbax ODS column with mobile phase consisting of phosphate buffer (pH 3.3)-acetonitrile-triethylamine (40:60:0.03, by volume) for HPLC. Influence of different organic solvents in mobile phase composition has been studied to optimize the separation efficiency in TLC densitometry. Moreover, factors affecting the efficiency of HPLC, like pH of the buffer used, organic solvent ratio in the mobile phase and flow rate, have been carefully studied using one variable at a time approach. Finally, the proposed methods were validated as per ICH guidelines.


Assuntos
Aspirina/isolamento & purificação , Cromatografia em Camada Fina/normas , Dipiridamol/análogos & derivados , Dipiridamol/isolamento & purificação , Ácido Salicílico/isolamento & purificação , Tartaratos/isolamento & purificação , Acetatos , Cápsulas , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida de Alta Pressão/normas , Cromatografia em Camada Fina/métodos , Densitometria/métodos , Densitometria/normas , Concentração de Íons de Hidrogênio , Metanol , Reprodutibilidade dos Testes , Solventes , Tolueno
11.
J Chromatogr Sci ; 54(3): 318-25, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26363491

RESUMO

This work was concerned with development, optimization, application and validation of reversed phase high performance liquid chromatography (RP-HPLC) and thin layer chromatography (TLC)-densitometric methods for analysis of cetylpyridinium chloride, chlorocresol and lidocaine in Canyon(®) gel. The first developed RP-HPLC method depended on chromatographic separation on a ZORBAX Eclipse Plus C8 column, with elution with a mobile phase consisting of 0.05% phosphoric acid solution : acetonitrile : methanol (15 : 24 : 61, by volume), pumping the mobile phase at a flow rate of 1.00 mL min(-1), with ultraviolet detection at 220 nm. While in the subsequently developed method, the TLC-densitometric method, complete separation of the studied mixture was achieved using methanol : acetone : acetic acid (7 : 3 : 0.2, by volume) as a mobile phase, aluminum plates precoated with silica gel 60 F254 as a stationary phase and 215 nm as the scanning wavelength. Factors affecting the developed methods were studied and optimized; moreover, methods had been validated as per the International Conference of Harmonization guideline and the results indicated that the suggested methods were reproducible, reliable and applicable for rapid routine analysis. Statistical comparison of the two developed methods with the reported HPLC ones using F- and Student's t tests showed no significant difference.


Assuntos
Anti-Infecciosos Locais/química , Cetilpiridínio/análise , Cresóis/análise , Lidocaína/análise , Acetonitrilas , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida de Alta Pressão/normas , Cromatografia de Fase Reversa/métodos , Cromatografia de Fase Reversa/normas , Cromatografia em Camada Fina/métodos , Cromatografia em Camada Fina/normas , Densitometria/métodos , Densitometria/normas , Estabilidade de Medicamentos , Humanos , Metanol , Boca , Ácidos Fosfóricos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Solventes
12.
J Clin Microbiol ; 53(12): 3864-9, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26468500

RESUMO

Parameters like zone reading, inoculum density, and plate streaking influence the precision and accuracy of disk diffusion antibiotic susceptibility testing (AST). While improved reading precision has been demonstrated using automated imaging systems, standardization of the inoculum and of plate streaking have not been systematically investigated yet. This study analyzed whether photometrically controlled inoculum preparation and/or automated inoculation could further improve the standardization of disk diffusion. Suspensions of Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 29213 of 0.5 McFarland standard were prepared by 10 operators using both visual comparison to turbidity standards and a Densichek photometer (bioMérieux), and the resulting CFU counts were determined. Furthermore, eight experienced operators each inoculated 10 Mueller-Hinton agar plates using a single 0.5 McFarland standard bacterial suspension of E. coli ATCC 25922 using regular cotton swabs, dry flocked swabs (Copan, Brescia, Italy), or an automated streaking device (BD-Kiestra, Drachten, Netherlands). The mean CFU counts obtained from 0.5 McFarland standard E. coli ATCC 25922 suspensions were significantly different for suspensions prepared by eye and by Densichek (P < 0.001). Preparation by eye resulted in counts that were closer to the CLSI/EUCAST target of 10(8) CFU/ml than those resulting from Densichek preparation. No significant differences in the standard deviations of the CFU counts were observed. The interoperator differences in standard deviations when dry flocked swabs were used decreased significantly compared to the differences when regular cotton swabs were used, whereas the mean of the standard deviations of all operators together was not significantly altered. In contrast, automated streaking significantly reduced both interoperator differences, i.e., the individual standard deviations, compared to the standard deviations for the manual method, and the mean of the standard deviations of all operators together, i.e., total methodological variation.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão/normas , Manejo de Espécimes/métodos , Contagem de Colônia Microbiana/normas , Densitometria/normas , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
13.
Phytochem Anal ; 26(4): 237-46, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25676726

RESUMO

INTRODUCTION: Ocimum sanctum Linn (Sanskrit: Tulasi; family: Libiaceae), popularly known as holy basil or Ocimum teinufolium, is found throughout the semitropical and tropical parts of India. In Ayurveda, Tulasi has been well known for its therapeutic potentials. OBJECTIVE: To optimise and develop a standard method to quantify seven polyphenols simultaneously by HPTLC. METHODS: A three-level factor Box-Behnken statistical design was used for optimisation, where extraction time (min), temperature (°C) and methanol:water ratio (% v/v) are the independent variables with polyphenols as the dependent variable. The separation was archived on a silica-gel 60 F254 HPTLC plate using toluene:ethyl acetate:formic acid:methanol (3:3:0.8:0.2 v/v) as the mobile phase. Densitometric analysis of polyphenols was carried out in the absorbance mode at 366 nm. RESULTS: The quantification of polyphenols was carried out based on peak area with a linear calibration curve at concentration ranges of 60-240, 20-200, 100-1600, 40-200, 200-1400, 10-160, 200-1400, 100-5000 ng/band for caffeic acid, ellagic acid, rutin, kaempferol, catechin, quercetin, eupalitin and epicatechin respectively. The method was validated for peak purity, precision, accuracy, limit of detection (LOD) and quantification (LOQ). Method specificity was confirmed using the retention factor value and visible spectra correlation of marker compounds. CONCLUSIONS: A validated HPTLC method was newly developed for simultaneous quantification of seven polyphenols in an Ayurvedic preparation of O. sanctum. The proposed method is simple, precise, specific, accurate, cost-effective, less time consuming and has the ability to separate the polyphenols from other constituents.


Assuntos
Cromatografia em Camada Fina/métodos , Densitometria/métodos , Ocimum/química , Polifenóis/análise , Calibragem , Cromatografia em Camada Fina/normas , Densitometria/normas , Limite de Detecção , Sensibilidade e Especificidade
14.
AAPS PharmSciTech ; 16(1): 165-70, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25233802

RESUMO

Bulk density can be a key indicator of performance, and may influence choice of formulation route of materials in pharmaceutical development. During early development, the cost of API's can be expensive and the availability of material for powder property analysis is limited. The aim of this work was to investigate a suitable small-scale, low material requirement, bulk density test which would provide comparable data to the recommended large volume USP test. Materials with a range of morphological characteristics typically seen in the pharmaceutical industry were assessed to ensure that methods were suitably robust. It was found that the USP II "low volume" test does not give equivalent results to other tests in the USP, across the range of materials. An alternative test based on the FT4 powder rheometer at a scale of 25 mL gave results equivalent to the large volume USP I standard test. The use of smaller 10-mL methods was also found to give acceptable results for materials that were considered well-behaved but were more variable with difficult to handle materials with low bulk density.


Assuntos
Densitometria/normas , Teste de Materiais/normas , Tamanho da Partícula , Preparações Farmacêuticas/análise , Preparações Farmacêuticas/química , Tecnologia Farmacêutica/normas , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estados Unidos
15.
J Clin Densitom ; 17(2): 219-24, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24657108

RESUMO

The International Society for Clinical Densitometry (ISCD) convened its second Pediatric Position Development Conference (PDC) on October 2-3, 2013 in Baltimore, MD. The conference was co-sponsored by the American Society for Bone and Mineral Research (ASBMR) and was held immediately before their annual meeting. The aim of a PDC is to make recommendations for standards in the field of bone densitometry. The recommendations address issues such as quality control, data acquisition and analysis, and the interpretation and reporting of bone densitometric results. In 2007, ISCD convened its first Pediatric PDC to address issues specific to skeletal health assessments in children and adolescents. The 2013 Pediatric PDC focused on advances in the field since that initial conference that would lead to revisions of the original positions. Topics for consideration were developed by the ISCD and its Scientific Advisory Committee. Clinically relevant questions related to each topic were assigned to task forces for a comprehensive review of the medical literature and subsequent presentation of reports to an international panel of experts. Expert panelists included representatives from both the ISCD and ASBMR. The recommendations of the PDC Expert Panel were subsequently reviewed by the ISCD Board of Directors and positions accepted by majority vote. The approved recommendations became the Official Positions of the ISCD. The positions are to be submitted to the ASBMR for its consideration for endorsement. Topics considered at the Pediatric PDC included fracture prediction and definition of osteoporosis, dual-energy X-ray absorptiometry assessment in chronic diseases that may affect the skeleton, dual-energy X-ray absorptiometry interpretation and reporting, quantitative computed tomography measurements, and densitometry in infants and young children. We discuss potential implications of the new recommendations and factors leading to a change in the wording of these positions, considering the science that has evolved over the past 6yr.


Assuntos
Densitometria/normas , Absorciometria de Fóton/normas , Criança , Humanos , Pediatria/normas
16.
J Clin Endocrinol Metab ; 99(1): 142-50, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24384018

RESUMO

CONTEXT: There is little consensus regarding which individuals should be recommended for bone mineral density (BMD) testing, a situation that could eventually affect the appropriateness of routine clinical practice. OBJECTIVES: The aim of this study was to estimate the impact on the population of the application of the BMD testing criteria provided by the National Osteoporosis Guideline Group (NOGG), National Osteoporosis Foundation (NOF), and Osteoporosis Canada and to assess the appropriateness of the BMD tests currently performed. DESIGN: A cross-sectional study was conducted using the baseline data of the ESOSVAL cohort. PARTICIPANTS: Participants included 11 035 men and women aged 50 years old and over attending primary health care centers in the Valencia region, Spain (2009-2010). MAIN OUTCOME AND MEASURES: BMD testing by dual-energy X-ray absorptiometry was recorded. RESULTS: Of the 10 710 people included in the study, 1617 (15.1%; 95% confidence interval [CI]: 14.4-15.8) received a BMD test. When applying the NOGG criteria, BMD testing would be recommended in 17.4% (95% CI: 16.7-18.1) of individuals, whereas this percentage would rise to 74.6% (95% CI: 73.7-75.4) and 80.1% (95% CI: 79.4-80.9) when using the Osteoporosis Canada and the NOF criteria, respectively. Regarding the appropriateness of the BMD tests performed in the ESOSVAL cohort, 40.7% (95% CI: 38.3-43.1), 86.0% (95% CI: 84.3-87.7), and 82.2% (95% CI: 80.3-84.1) of individuals having a BMD test met the NOGG, NOF, and the Canadian guidelines criteria, respectively. Of the tests performed, 40.7% would be deemed as appropriate, whereas 10.7% would be considered inappropriate. CONCLUSIONS: The impact on the population of the different recommendations is enormous, varying from 17% to 80% of the population over 50 who would be tested. Although in men it seems that a clinical rationale exists between the presence of risk factors and the rates of BMD testing, this pattern does not seem to exist in women. One in 10 of the densitometric tests performed were inappropriate according to all the guidelines.


Assuntos
Absorciometria de Fóton/métodos , Densidade Óssea , Osso e Ossos/efeitos da radiação , Densitometria/métodos , Programas de Rastreamento/métodos , Osteoporose/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Estudos Transversais , Densitometria/normas , Feminino , Humanos , Masculino , Programas de Rastreamento/normas , Pessoa de Meia-Idade , Valores de Referência , Espanha/epidemiologia
17.
PLoS One ; 9(1): e85146, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24465496

RESUMO

Current software applications for densitometric analysis, such as ImageJ, QuantityOne (BioRad) and the Intelligent or Advanced Quantifier (Bio Image) do not allow to take the non-linearity of autoradiographic films into account during calibration. As a consequence, quantification of autoradiographs is often regarded as problematic, and phosphorimaging is the preferred alternative. However, the non-linear behaviour of autoradiographs can be described mathematically, so it can be accounted for. Therefore, the 'Densitometric Image Analysis Software' has been developed, which allows to quantify electrophoretic bands in autoradiographs, as well as in gels and phosphorimages, while providing optimized band selection support to the user. Moreover, the program can determine protein-DNA binding constants from Electrophoretic Mobility Shift Assays (EMSAs). For this purpose, the software calculates a chosen stepwise equilibrium constant for each migration lane within the EMSA, and estimates the errors due to non-uniformity of the background noise, smear caused by complex dissociation or denaturation of double-stranded DNA, and technical errors such as pipetting inaccuracies. Thereby, the program helps the user to optimize experimental parameters and to choose the best lanes for estimating an average equilibrium constant. This process can reduce the inaccuracy of equilibrium constants from the usual factor of 2 to about 20%, which is particularly useful when determining position weight matrices and cooperative binding constants to predict genomic binding sites. The MATLAB source code, platform-dependent software and installation instructions are available via the website http://micr.vub.ac.be.


Assuntos
Proteínas Arqueais/química , DNA de Cadeia Simples/química , Proteínas de Ligação a DNA/química , DNA/química , Densitometria/normas , Software , Archaea/química , Sítios de Ligação , Calibragem , Densitometria/estatística & dados numéricos , Ensaio de Desvio de Mobilidade Eletroforética , Cinética , Ligação Proteica , Multimerização Proteica
18.
Rev. esp. med. nucl. imagen mol. (Ed. impr.) ; 32(5): 281-285, sept.-oct. 2013.
Artigo em Espanhol | IBECS | ID: ibc-115141

RESUMO

El índice de masa corporal (IMC) es utilizado para valorar el estado nutricional. En los deportistas su resultado puede estar sobreestimado por un aumento de la masa muscular. Objetivo. Valorar la utilidad de la determinación mediante densitometría de los índices de masa grasa (IMG) y magra (IMM) como indicadores del estado nutricional, comparando los resultados con el IMC. Material y métodos. Se estudiaron 28 deportistas aficionados, jugadores de rugby, de sexo masculino. Tras ser sometidos a una densitometría de cuerpo entero mediante absorciometría dual de rayos X se determinaron, entre otros parámetros, la masa grasa y magra del cuerpo. Se calcularon los IMG (grasa en kg/talla en metros2), IMM (magra en kg/talla en metros2) y el índice de masa muscular apendicular (IMMA, musculatura en brazos y piernas en kg/talla en metros2). Resultados. Utilizando el IMC, 18 jugadores presentaban sobrepeso y 4 obesidad de tipo i . Al considerar el IMG, 7 de estos deportistas presentaban valores normales con IMM e IMMA elevados, uno pasaba de obesidad a sobrepeso y otro de sobrepeso a obesidad. De los 6 jugadores con IMC normal, uno de ellos mostraba exceso de grasa y otro defecto. Los resultados cambiaron la valoración del estado nutricional en el 39% de los jugadores estudiados. Conclusiones. Aunque para la población general el IMC es un parámetro adecuado para la valoración del estado nutricional, en los deportistas debe tenerse en cuenta el porcentaje de grasa y de musculatura determinando sus índices correspondientes. La densitometría de cuerpo entero resulta ser una técnica fiable y sencilla para este propósito(AU)


The body mass index (BMI) is used to assess nutritional status. The result in athletes may be overestimated due to increase in muscle mass. Objective. To assess the usefulness of fat mass index (FMI) and lean mass index (LMI) determination as indicators of nutritional status and to compare the results with BMI. Material and methods. We studied 28 amateur rugby players, male. After being subjected to whole body densitometry by dual X-ray absorptiometry, we determined fat and lean body mass together with other parameters. FMI (fat in kg/height in meters2), LMI (lean in kg/height in meters2) and appendicular muscle mass index (AMMI, arms and legs musculature in kg/height in meters2) were calculated. Results. Using BMI, 18 players were overweight and 4 obese type I. Considering FMI, 7 of them had normal values and high LMI and AMMI, one of them changed from overweight to obese and another one from obese to overweight. Of the 6 players with normal BMI, one of them showed fat excess and another one fat defect. The results changed the assessment of nutritional status in 39% of players. Conclusions. Although BMI is an appropriate parameter in general population for the assessment of nutritional status, in athletes should be taken into account fat and muscle body percentage and their corresponding indexes. The whole body densitometry appears to be a simple and reliable technique for this purpose(AU)


Assuntos
Humanos , Masculino , Adulto , Densitometria/instrumentação , Densitometria/métodos , Desempenho Atlético/fisiologia , Índice de Massa Corporal , Antropometria/instrumentação , Antropometria/métodos , Densitometria/estatística & dados numéricos , Densitometria/normas , Densitometria/tendências , Absorciometria de Fóton/métodos , Absorciometria de Fóton , Obesidade/dietoterapia , Sobrepeso/dietoterapia
19.
J Clin Densitom ; 16(4): 482-8, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24063846

RESUMO

Vertebral fracture assessment (VFA) is a low-cost method of accurately identifying individuals who have clinically unrecognized or undocumented vertebral fractures at the time of bone density test. Because prevalent vertebral fractures predict subsequent fractures independent of bone mineral density and other clinical risk factors, their recognition is an important part of strategies to identify those who are at high risk of fracture, so that prevention therapies for those individuals can be implemented. The 2007 Position Development Conference developed detailed guidelines regarding the indications for acquisition of, and interpretation and reporting of densitometric VFA tests. The purpose of the 2013 VFA Task Force was to simplify the indications for VFA yet keep them evidence based. The Task Force reviewed the literature published since the 2007 Position Development Conference and developed prediction models based on 2 large cohort studies (the Study of Osteoporotic Fractures and the Osteoporotic Fractures in Men Study) and the densitometry database of the University of Chicago. Based on these prediction models, indications for VFA were reduced to a simplified set of criteria based on age, historical height loss, use of systemic glucocorticoid therapy, and self-reported but undocumented prior vertebral fracture.


Assuntos
Densitometria/normas , Guias de Prática Clínica como Assunto , Sociedades Médicas , Fraturas da Coluna Vertebral/diagnóstico por imagem , Densidade Óssea , Humanos , Radiografia , Fatores de Risco , Fraturas da Coluna Vertebral/etiologia
20.
Acta Pol Pharm ; 70(4): 611-20, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23923385

RESUMO

Flavonoids, substances present in foods of plant origin, play an important role in many metabolic processes. Numerous properties of these substances were described, including their anti-allergic, antitumor and antioxidant properties. Therefore, an increased intake of these nutrients may play a beneficial role in human health. The aim of the presented study was to estimate the daily intake of specific flavonoid compounds using thin layer chromatography (TLC) combined with densitometric qualitative and quantitative analysis. Performed investigations revealed the presence of two flavonoids in the extracts from daily food rations--naringenin and hesperidin. Naringenin content in the daily food ration of women was calculated to be 179-537 mg, whereas in the group of men it ranged around 181-550 mg, depending on the conducted method of extraction and solvent system used. Daily dietary intake of hesperidin was calculated to be 193-534 mg in the group of women and 194-562 mg in the group of men. The highest degree of extraction of these flavonoids was obtained for the mixture of acetone and water (7 : 3, v/v) by means of accelerated solvent extraction (ASE).


Assuntos
Cromatografia em Camada Fina , Densitometria , Dieta , Flavanonas/análise , Análise de Alimentos/métodos , Hesperidina/análise , Acetona/química , Cromatografia em Camada Fina/normas , Densitometria/normas , Feminino , Análise de Alimentos/normas , Humanos , Masculino , Padrões de Referência , Solventes/química , Espectrofotometria Ultravioleta , Água/química
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