The role of ultrasonography in the measurement of subcutaneous and visceral fat and its correlation with hepatic steatosis

Objective To evaluate the sonographic measurement of subcutaneous and visceral fat in correlation with the grade of hepatic steatosis. Materials and Methods In the period from October 2012 to January 2013, 365 patients were evaluated. The subcutaneous and visceral fat thicknesses were measured with a convex, 3–4 MHz transducer transversely placed 1 cm above the umbilical scar. The distance between the internal aspect of the abdominal rectus muscle and the posterior aortic wall in the abdominal midline was considered for measurement of the visceral fat. Increased liver echogenicity, blurring of vascular margins and increased acoustic attenuation were the parameters considered in the quantification of hepatic steatosis. Results Steatosis was found in 38% of the study sample. In the detection of moderate to severe steatosis, the area under the ROC curve was 0.96 for women and 0.99 for men, indicating cut-off values for visceral fat thickness of 9 cm and 10 cm, respectively. Conclusion The present study evidenced the correlation between steatosis and visceral fat thickness and suggested values for visceral fat thickness to allow the differentiation of normality from risk for steatohepatitis.

Toxic and metabolic encephalopathies: iconographic essay

Generally, toxic-metabolic diseases affecting the central nervous system can hardly be differentiated just on the basis of their clinical presentation. However, some typical neuroradiological features can guide the correct diagnosis. In this context, magnetic resonance imaging is an important tool which, in association with clinical and laboratory data, can establish an early and specific treatment. The present pictorial essay with selected cases from the archives of the authors' institution describes imaging findings which might help in the etiologic diagnosis of toxic-metabolic diseases.

Comparison of GC and HPLC for quantification of organic acids in two jaboticaba (Myrciaria) fruit varieties

Gas chromatography (GC) with trimethylsilyl derivative formation was compared to high-performance liquid chromatography (HPLC) for quantification of organic acids (OAs) in two jaboticaba (Myrciaria) fruit (pulp and pericarp) varieties (Sabará and Açu Paulista). Succinic and citric acids were the major OAs found in all the samples analyzed. Besides being much more tedious, the results obtained with GC were significantly lower than HPLC (p<0.05) when the data (acids, variety, two parts and flowering days) were considered together. The presence of both acids was confirmed by gas chromatography-mass spectrometry (GC-MS).

High performance liquid chromatography method for quantification of the N-phenylpiperazine derivative LASSBio-579 in rat plasma

A rapid HPLC analytical method was developed and validated for the determination of the N-phenylpiperazine derivative LASSBio-579in plasma rat. Analyses were performed using a C18 column and elution with 20 mM sodium dihydrogen phosphate monohydrate - methanol. The analyte was monitored using a photodiode array detector (257 nm). Calibration curves in spiked plasma were linear over the concentration range of 0.3-8 mg/mL with determination coefficient > 0.99. The lower limit of quantification was 0.3 mg/mL. The applicability of the HPLC method for pharmacokinetic studies was tested using plasma samples obtained after administration of LASSBio-579 to Wistar rats, showing the specificity of the method.

Importance of the lipid peroxidation biomarkers and methodological aspects FOR malondialdehyde quantification

Free radicals induce lipid peroxidation, playing an important role in pathological processes. The injury mediated by free radicals can be measured by conjugated dienes, malondialdehyde, 4-hydroxynonenal, and others. However, malondialdehyde has been pointed out as the main product to evaluate lipid peroxidation. Most assays determine malondialdehyde by its reaction with thiobarbituric acid, which can be measured by indirect (spectrometry) and direct methodologies (chromatography). Though there is some controversy among the methodologies, the selective HPLC-based assays provide a more reliable lipid peroxidation measure. This review describes significant aspects about MDA determination, its importance in pathologies and biological samples treatment.

Determinação de enxofre em amostras vegetais por oxidação via seca em meio alcalino com detecção espectrofométrica

The sulphur take an essential role in plants and it is one of the main nutrients in several metabolic processes. The dry ash oxidation, using alkaline oxidizers agent, is the simplest and most economical form for the oxidation of Organic S to sulfate in plants. The objective of this work is to propose a method for sulfur determination in plants samples using dry ash oxidation and agent oxidizers alkaline. The quantification of S-SO4(2-) in samples was accomplished by turbidimetric method. The results demonstrated that the proposed method for oxidation alkaline was appropriate.

Comparison of USEPA 3050B and ISO 14869-1: 2001 digestion methods for sediment analysis by using FAAS and ICP-OES quantification techniques

A study of the partial USEPA 3050B and total ISO 14869-1:2001 digestion methods of sediments was performed. USEPA 3050B was recommended as the simpler method with less operational risk. However, the extraction ability of the method should be taken in account for the best environmental interpretation of the results. FAAS was used to quantify metal concentrations in sediment solutions. The alternative use of ICP-OES quantification should be conditioned by a previous detailed investigation and eventual correction of the matrix effect. For the first time, the EID method was employed for the detection and correction of the matrix effect in sediment ICP-OES analysis. Finally, some considerations were made about the level of metal contamination in the area under study.

A validated method using RP-HPLC for quantification of reserpine in the Brazilian tree Rauvolfia sellowii Müll. Arg. (Apocynaceae)

This study describes a simple, fast and reproducible method using RP-HPLC-UV, in a gradient system, for quantification of reserpine in Rauvolfia sellowii stem bark. The analysis were carried out on a C18 column; mobile phase was water and acetonitrile, and separations were carried out in 10 min, flow rate of 1.0 mL min-1, 25 ºC and 268 nm. The validation data showed that the method was specific, accurate, precise and robust. Results were linear over a range of 0.625-40.0 μg mL-1, and the mean recovery was 95.1%. The amount of reserpine found in the dried stem bark was 0.01% (m/m).

Analysis of passion fruit rinds (Passiflora edulis): isoorientin quantification by HPTLC and evaluation of antioxidant (radical scavenging) capacity

The content of isoorientin in passion fruit rinds (Passiflora edulis fo. flavicarpa O. Degener) was determined by HPTLC (high performance thin layer chromatography) with densitometric analysis. The results revealed a higher amount of isoorientin in healthy rinds of P. edulis (92.275 ± 0.610 mg L-1) than in rinds with typical symptoms of PWV (Passion fruit Woodiness Virus) infection (28.931 ± 0.346 mg L-1). The HPTLC data, allied to assays of radical scavenging activity, suggest the potential of P. edulis rinds as a natural source of flavonoids or as a possible functional food.

Quantification of tryptophan in plasma by high performance liquid chromatography

A simple, rapid and selective method using high-performance liquid chromatography with ultraviolet detection (267 nm) was applied for the determination of tryptophan in plasma. Separation was carried out on a C18 column (150 x 4.6 mm internal diameter) in 6 min. The mobile phase consisted of 5 mM the sodium acetate and acetonitrile (92:8, v/v). The method was shown to be precise and accurate, and good recovery of analyte was achieved, characterizing the method as efficient and reliable for use in laboratory analysis.

Quantification of the uranium concentration in human urine by inductively coupled plasma-sector field mass spectrometry (ICP-SFMS)

In this study, the validation of a method for analyzing the uranium (U) concentration in human urine samples by inductively coupled plasma-sector field mass spectrometry (ICP-SFMS) was conducted. PROCORAD (the Association for the Promotion of Quality Control in Radiotoxicological Analysis) provided two urine samples spiked with unknown contents of U (Sample A = 33.6 ± 1.0 µg/L and Sample B = 3.3 ± 0.1 µg/L) and one unspiked sample as a blank. The analyses were directly performed on the diluted urine samples (dilution factor = 1:20) in 5% v/v HNO3. The results obtained by ICP-SFMS corresponded well with the reference values, and the limits of detection were 235U = 0.049 × 10-3 µg/L and 238U = 7.37 × 10-3 µg/L. The ICP-SFMS technique has been shown to be successful in the analysis of the U concentration in human urine samples and for the quantification of isotopic ratios.

Metabolic response induced by endophytic fungi and bacteria in H. marrubioides Epling in vitro microplants

Hyptis marrubioides Epling is a native plant from Brazilian Cerrado. In this paper, the response of in vitro microplants of this species to inoculation with bacterial and fungal endophytic isolates is evaluated. HPLC-DAD analysis showed the presence of 3,4-O-(Z)-dicaffeoylquinic acid and quercetin-7-O-glucoside as the main components. GC/MS analysis demonstrated that the sesquiterpenes τ-cadinol and caryophyllene oxide were only produced in microplants inoculated with endophytic bacteria, while methyl hexadecanoate, methyl heptadecanoate and methyl (Z,Z,Z) 9,12,15-octadecatrienoate and the triterpene methyl 3β-hydroxy-urs-12-en-28-oate were overexpressed only when the microplant was treated with endophytic fungi.

A reliable method of quantification of trace copper in beverages with and without alcohol by spectrophotometry after cloud point extraction

A new cloud point extraction (CPE) method was developed for the separation and preconcentration of copper (II) prior to spectrophotometric analysis. For this purpose, 1-(2,4-dimethylphenyl) azonapthalen-2-ol (Sudan II) was used as a chelating agent and the solution pH was adjusted to 10.0 with borate buffer. Polyethylene glycol tert-octylphenyl ether (Triton X-114) was used as an extracting agent in the presence of sodium dodecylsulphate (SDS). After phase separation, based on the cloud point of the mixture, the surfactant-rich phase was diluted with acetone, and the enriched analyte was spectrophotometrically determined at 537 nm. The variables affecting CPE efficiency were optimized. The calibration curve was linear within the range 0.285-20 µg L-1 with a detection limit of 0.085 µg L-1. The method was successfully applied to the quantification of copper in different beverage samples.

Quantification of beta-lactam antibiotics in veterinary drugs: amoxicillin and ampicillin determination by high performance liquid chromatography

This work focused on the development and validation of an RP-HPLC-UV method for quantification of beta-lactam antibiotics in three pharmaceutical samples. Active principles analyzed were amoxicillin and ampicillin, in 3 veterinary drugs. Mobile phase comprised 5 mmol L-1 phosphoric acid solution at pH 2.00, acetonitrile with gradient elution mode and detection wavelength at 220 nm. The method was validated according to the Brazilian National Health Surveillance regulation, where linear range and linearity, selectivity, precision, accuracy and ruggedness were evaluated. Inter day precision and accuracy for pharmaceutical samples 1, 2 and 3 were: 1.43 and 1.43%; 4.71 and 3.74%; 2.72 and 1.72%, respectively, while regression coefficients for analytical curves exceeded 0.99. The method had acceptable merit figure values, indicating reliable quantification. Analyzed samples had active principle concentrations varying from -12 to +21% compared to manufacturer label claims, rendering the medicine unsafe for administration to animals.