An assessment of serum leptin levels in patients with chronic viral hepatitis: a prospective study

<p>Abstract</p> <p>Background</p> <p>The role of leptin in the course of liver disease due to chronic viral hepatitis (CVH) remains controversial. Our aims were to investigate the relationship between serum leptin concentrations and the severity of liver disease in a cohort of subjects with HBeAg negative chronic hepatitis B (CHB) and C (CHC) and to analyze the effect of body composition, the leptin system and insulin resistance together with viral factors on virologic response to antiviral treatment.</p> <p>Methods</p> <p>We studied 50 (36 men) consecutive patients suffering from biopsy-proven CVH due to HBV (n = 25) or HCV (n = 25) infection. Thirty-two (17 men) healthy volunteers served as controls. Levels of serum leptin and insulin were determined by immunoassays at baseline and at the end of the treatment.</p> <p>Results</p> <p>A significant association between serum leptin levels and the stage of hepatic fibrosis was noted; patients with cirrhosis presented higher serum leptin levels compared to those with lower fibrosis stage [CHB patients (17436 pg/ml vs 6028.5 pg/ml, p = 0.03), CHC patients (18014 pg/ml vs 4385 pg/ml, p = 0.05]. An inverse correlation between lower leptin levels and response to lamivudine monotherapy was noted in patients with CHB; those with a virologic response presented lower serum leptin levels (5334 vs 13111.5 pg/ml; p-value = 0.003) than non-responders. In genotype 1 CHC patients, insulin resistance played a significant role in the response to antiviral therapy.</p> <p>Conclusion</p> <p>Our data clearly suggest that cirrhosis due to CHB or CHC is associated with higher leptin levels. Increased serum leptin levels represent a negative prognostic factor for response to lamivudine monotherapy in patients with CHB. In CHC patients insulin resistance strongly influences the response to antiviral treatment in patients infected with genotype 1.</p

Discrimination of Anari Cheese Samples in Comparison with Halloumi Cheese Samples Regarding the Origin of the Species by FTIR Measurements and Chemometrics

Nowadays, adulteration of traditional food products is a very important field in the general food authenticity sector. Moreover, it is important to create databases with authentic traditional products. In Cyprus, research about the traditional dairy products is scarce. Anari is predominantly made from goat’s and sheep’s milk, but milk from cows can also be used. It is produced during the process of Halloumi cheese making. Classification of Halloumi and Anari cheese took place in two classes, thus per cheese type, and after that in milk species subclasses such as cow and goat-sheep origins for each cheese type. This research study aims to enlighten the field of food authenticity in terms of traditional Cypriot dairy products. The first step of the methodology is the freeze-drying process for lyophilization of samples. Forty-four samples have been analyzed thus far, including both Halloumi and Anari cheese. Measurements for each sample were obtained by using Fourier Transformed Infrared (FTIR) Spectroscopy. Interpretation of the extensive data was undertaken via Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA), and through the SIMCA chemometrics package. Characterization of Anari cheese by applying FTIR took place. In terms of cheese type, Halloumi and Anari cheese samples were classified correctly. In addition, Anari samples were classified correctly regarding the milk species’ origin. The proposed experimental procedure along with chemometrics allow the detection of the milk species’ origin of traditional Anari samples, highlighting the importance of FTIR spectroscopy in combination with chemometrics in food authenticity. Creation of a database with Anari samples from Cyprus has started, and this is a very important step towards authenticity of traditional dairy products of Cyprus

Investigation of the Synthesis and Properties of Ternary V–Cu–Ce Oxides of Composition VCuCeO

A co-precipitation method has been used to prepare ternary mixed oxides based on ceria with the general formula V x Cu x Ce 1 – 2x O 2 , where x was varied between 0.05 and 0.45. The structural and surface properties as well as the morphologies of the solids were examined by thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction studies, nitrogen adsorption isotherms, Fourier-transform infrared spectroscopy and scanning electron microscopy. For samples where the vanadium and copper content was low (x ≤ 0.3), the surface area increased and the pore distribution shifted towards the micropore range. The sample V 0.05 Cu 0.05 Ce 0.9 O 2 exhibited the highest surface area and the sample V 0.45 Cu 0.45 Ce 0.1 O 2 the smallest. The samples were calcined within the temperature range 473–1073 K. When the vanadium content was increased to x ≥ 0.3 and the calcination temperature set at 673 K, a phase with composition CeVO 4 was detected via X-ray diffractometry, in addition to a V 2 O 5 and a CeO 2 phase. The FT-IR spectra confirmed the above results

Preparation and Characterization of a Cerium(IV)-incorporated Manganese Oxide OMS-2. Effect of Cerium(IV) Template on Octahedral Molecular Sieves of Manganese Oxide and Characterization of Manganese Oxide Molecular Sieves with Cerium(IV) as Dopant

The manganese oxide material K-OMS-2 was synthesized both via a redox reaction between potassium permanganate and manganese nitrate in an acidic medium (nitric acid) under reflux conditions and by the sol–gel reaction between KMnO 4 and maleic acid employed in a 3:1 molar ratio. Cerium(IV) was then added by an ion-exchange method. The structures, morphologies, chemical compositions and thermal stabilities of the resulting materials were studied by X-ray diffraction (XRD), N 2 adsorption/desorption, scanning electron microscopy (SEM), Fourier-transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) and TGA techniques. Both the morphologies and the surface properties of the materials synthesized by these two methods were different. Thus, the material prepared via the sol–gel process possessed a higher surface area and exhibited both a different type of adsorption isotherm and smaller crystallite sizes than the material synthesized by redox reaction under reflux conditions. The physical and chemical properties of the Ce–K-OMS-2 materials were similar to those of pure cryptomelane. TGA and XRD studies showed that the K-OMS-2 and Ce–K-OMS-2 materials exhibited a greater thermal stability in O 2 rather than N 2 atmospheres. In fact, the Ce(IV) derivatives were more stable thermally than the pure material. For Ce–K-OMS-2 R , the data obtained showed that part of the manganese in the framework was substituted by Ce(IV) ions. In contrast, the data for Ce–K-OMS-2 S indicated that not only did Ce(IV) ions substitute part of the manganese in the framework but that Ce(IV) ions also replaced the K + ions in the tunnel structure of the material

Synthesis and Characterization of Mesoporous Cerium Oxide Prepared Using an Organic Base and a Templating Agent

This paper discusses the effect on the surface properties of precipitated cerium oxide of using a mixed alcohol–water solvent as well as an organic base instead of the ammonia solution used hitherto. It further discusses the influence of the presence of a templating agent, such as CTAB, on the pore structure of ceria. It was found that the use of a template leads to a more well-defined pore system. Furthermore, in addition to any mesopores, an interesting network of secondary macropores was developed

Uranium Isotope (U-232) Removal from Waters by Biochar Fibers: An Adsorption Study in the Sub-Picomolar Concentration Range

The adsorption of the U-232 radionuclide by biochar fibers in the sub-picomolar concentration range has been investigated in laboratory aqueous solutions and seawater samples. The adsorption efficiency (Kd values and % relative removal) of untreated and oxidized biochar samples towards U-232 has been investigated as a function of pH, adsorbent mass, ionic strength and temperature by means of batch-type experiments. According to the experimental data, the solution pH determines to a large degree the adsorption efficiency, and adsorbent mass and surface oxidation lead to significantly higher Kd values. The ionic strength and temperature effect indicate that the adsorption is based on the formation of inner-sphere complexes, and is an endothermic and entropy-driven process (&Delta;H&deg; and &Delta;S&deg; &gt; 0), respectively. Regarding the sorption kinetics, the diffusion of U-232 from the solution to the biochar surface seems to be the rate-determining step. The application of biochar-based adsorbents to treat radioactively (U-232) contaminated waters reveals that these materials are very effective adsorbents, even in the sub-picomolar concentration range

Chemometric analysis combined with FTIR spectroscopy of milk and Halloumi cheese samples according to species’ origin

Abstract Food adulteration is an issue of major concern, as numerous foodstuffs and beverages do not follow their labeling. Our research interest is in the field of authenticity of dairy products and particularly cheese. Adulteration of dairy products is a well‐known phenomenon, and there are numerous published studies specifically on the authenticity of cheese. In fact, substitution of a portion of fat and/or proteins, adulteration with milk of other species’ origin, and mislabeling of ingredients are some of the main issues that the science of dairy products’ authenticity is regularly facing. Discrimination of dairy products can be determined through several chemical or microbiological methods as presented in the literature. In addition, chemometric analysis is an important tool for interpretation of a huge load of measurements. The aim of this study is to discriminate between various milk samples, which is the primary ingredient of dairy products. Milk samples with different trademarks were analyzed. That data was combined with Halloumi cheese samples for chemometric discrimination of species’ origin. The innovative point of this study is the fact that it is the first time that a research study related to dairy products includes Halloumi cheese which is a traditional Cypriot cheese, not well‐studied until now. The first step of the methodology was the freeze‐drying via lyophilization of the samples. Fourier transformed infrared spectroscopy (FTIR) was chosen for their chemical characterization. Moreover, interpretation of the measurements was carried out by chemometric analysis using SIMCA software. For this study, FTIR data combined with chemometrics have given a very good discrimination of the samples according to their species’ origin. Chemometric methods such as PCA and OPLS‐DA have been used with great success. In the future, this model will be studied regarding geographical origin of the samples

Using Statistical Analysis as an Additional Tool in Porous Solid Characterization

Analytical chemists have long used statistical methods to help them organize and interpret experimental data — especially where large numbers of these are generated — as well as to help them design new experiments. Recently, chemometrics has found applications in wider fields, such as the determination of the geographical origin of food and other products. During the past several years, we have carried out a systematic study of the factors affecting the pore structure and surface chemistry of cerium oxide and of mixed oxides of cerium with various transition metal or alkaline earth metal ions

Structural mimicry and the photoreactivity of organic solids

Molecules that are photostable in the solid state can be rendered photoactive if, by burial within crystals of closely analogous monomers, they can be made to mimic the molecular conformation of the latter; this fact is demonstrated for a pair of cyclopentanone derivatives, and the general significance of this result in solid-state synthesis is discussed

An unusual photo-induced conformational polymorphism: a crystallographic study of bis(p-methoxy)-trans-stilbene

A novel example of a photo-induced single-crystal to single-crystal phase transformation is described for title compound; the accompanying change in molecular conformation is rationalised in terms of an intermediate excimeric state