Morphology study of progesterone polymorphs prepared by polymer‐induced heteronucleation (PIHn)

In this article, morphology of progesterone polymorphs prepared by polymer‐induced heteronucleation (PIHn) technique was studied. Hydroxypropyl methylcellulose(HPMC), such as dextran T‐500 and gelatin G‐9382, polyisoprene (PI), and acrylonitrile/butadiene copolymer (NBR) were used as substrates. The crystallizations were performed by solvent evaporation at room temperature from 0.5, 10, and 40 mg/ml solutions in chloroform and acetone. Progesterone polymorphs were identified by X‐ray diffraction. Differential scanning calorimetry and total attenuated reflectance infrared spectroscopy were used as complementary techniques in the identification. Depending on the polymeric matrix and the concentration used, form 1, form 2, or mixture of both polymorphs were obtained. Scanning electron microscopy pictures evidenced difference in morphology and in homogeneity of the two progesterone polymorphs. These polymorphs prepared by PIHn, did not present a distinctive morphology that allows identifying polymorph by its crystal habit. Hence, polymeric matrix induced the crystallization, affecting polymorphism and morphology. SCANNING 35:213‐221, 2013. © 2012 Wiley Periodicals, Inc.     

Influence of processing on the levels of amines and proline and on the physico-chemical characteristics of concentrated orange juice

The influence of processing on the levels of bioactive amines and proline as well as on some physico-chemical characteristics of concentrated orange juice was investigated. Samples were collected at seven points of a production line on three non-consecutive days, and analysed for the levels of 12 bioactive amines, proline, and reducing and non-reducing sugars, and for some physico-chemical characteristics. Among the amines analysed, only putrescine, spermidine and synephrine were found in the samples at all processing stages. Significant differences were observed for spermidine and total amine levels throughout processing. Synephrine and putrescine were resistant to processing. Proline levels changed significantly throughout processing, as did levels of reducing and non-reducing sugars. The pH varied from 3.59 to 3.72, acidity from 0.873 to 0.918 g citric acid/100 mL, and density from 1.0378 to 1.0970 g/mL. Among these parameters, pH, acidity and density were significantly affected by processing.     

Dual-network hydrogels based on chemically and physically crosslinked chitosan/chondroitin sulfate

The formation of a novel type of hydrogel that combines chemically and physically crosslinked networks in a dual-network approach is presented here. Chitosan (CHT) and chondroitin sulfate (CS) were chemically modified with glycidyl methacrylate (GMA) and then crosslinked. The chemical hydrogels (CHT- and CS-gel) were deposited in different vials filled with CS or CHT stock solutions to form the dual-network hydrogels. FTIR, TGA and XRD analyses were used to characterize the chemical and the dual-network hydrogels. The percentages of CS or CHT complexed to the CHT- and CS-gel networks were calculated from the HPLC data. SEM images and swelling assays indicated that the formation of a secondary network by polyelectrolyte complexation changes the morphologies and liquid uptake capacities of the chemical hydrogels. Hence, the data and discussion presented here enable the formation of dual-network hydrogels with very interesting properties, such as the ability to interact with charged specimens (i.e., drugs, proteins or metal ions), a desirable feature for a wide range of applications.     

Effect of phosphate binders on oxidative stress and inflammation markers in hemodialysis patients

It has been suggested that phosphate binders may reduce the inflammatory state of hemodialysis (HD) patients. However, it is not clear whether it has any effect on oxidative stress. The objective of this study was to evaluate the effect of sevelamer hydrochloride (SH) and calcium acetate (CA) on oxidative stress and inflammation markers in HD patients. Hemodialysis patients were randomly assigned to therapy with SH (n=17) or CA (n=14) for 1 year. Before the initiation of therapy (baseline) and at 12 months, we measured in vitro reactive oxygen species (ROS) production by stimulated and unstimulated polymorphonuclear neutrophils and serum levels of tumor necrosis factor α, interleukin-10, C-reactive protein, and albumin. There was a significant reduction of spontaneous ROS production in both groups after 12 months of therapy. There was a significant decrease of Staphylococcus aureus stimulated ROS production in the SH group. There was a significant increase in albumin serum levels only in the SH group. In the SH group, there was also a decrease in the serum levels of tumor necrosis factor α and C-reactive protein. Our results suggest that compared with CA treatment, SH may lead to a reduction in oxidative stress and inflammation. Therefore, it is possible that phosphate binders exert pleiotropic effects on oxidative stress and inflammation, which could contribute toward decreasing endothelial injury in patients in HD.     

Influence of the final ethanol concentration on the acetification and production rate in the wine vinegar process

BACKGROUND: The acetification process needs an overall study of the variables influencing it in order to establish their optimum values. Based on industrial experience and available literature, including a recently proposed model by the authors, among the variables most strongly influencing the acetification process are the ethanol concentration at the time the reactor is unloaded, the unloaded volume and the loading rate. To ensure economically efficient industrial production of vinegar, and to check the predictions of the aforementioned model, the influence of the final ethanol concentration at unloading time on the mean acetification rate and on productivity has been studied in this work. RESULTS: An increase in the final ethanol concentration from 0.5 to 3.5% (v/v) increased the mean overall acetification rate and acetic acid production by 38 and 26%, respectively. The increase was established mainly during the loading phase. CONCLUSIONS: The final ethanol concentration is a key variable for process optimization. If a high rate is desired then a product containing much unused substrate will be obtained, which may be industrially unacceptable. These results suggest the necessity to investigate other possibilities when high values for yield and productivity must to be achieved. Copyright © 2010 Society of Chemical Industry     

A Novel Function of the Triterpene Squalene in a Tritrophic System

Changes in apple leaf chemistry after infestation by leafminers and their effect on both host location and host habitat location of the generalist parasitoid Pholetesor bicolor were investigated. Chemical analysis of leaf solvent extracts from healthy and leafminer-damaged leaves revealed that herbivory increased the amount of the triterpene squalene (C₃₀H₅₀), whereas quantities of all other identified compounds were similar in both plant treatments. To assess the response of parasitoids to host location cues, contact bioassays were conducted with naïve females. Results showed that parasitoids performed a characteristic ovipositional probing more often on the mine-damaged than on the healthy leaf. This behavior was triggered by a hexane extract of the mine-damaged leaf, but not by a healthy leaf extract. A synthetic mixture of the compounds identified in the extract triggered a similar response. A mixture devoid of squalene was not active, whereas squalene alone elicited the probing behavior. To assess the use of the identified compounds in habitat location, Y-tube olfactometer experiments were conducted with naïve and experienced females. Results showed that squalene is not involved in habitat location and has no priming effect on P. bicolor. While other triterpenes are known to mediate habitat location of parasitoids, this is the first report in which a plant triterpene is shown to mediate host location of a parasitoid. The biological and ecological functions of squalene on all three trophic levels are discussed.     

Comparison of electromyographic pattern of sensory experts and untrained subjects during chewing of Mahon cheese

Use of electromyography (EMG) to monitor mastication is a relatively new concept in assessing food physical and sensory properties. Although expert assessment of cheese characteristics is widely used, the effect of training in sensory analysis on mastication patterns, as assessed using EMG is not well known. Nine samples of the same Mahon cheese (60 days ripening) were given to 24 subjects (8 experts, 16 untrained) and EMG recorded for each chewing sequence. Three samples were tested in a single session by each subject, and three sessions carried out on different days. EMG was recorded from four masticatory muscles for each subject. From EMG records the following was extracted: number of chews, chewing time, mean and maximum voltage of EMG bursts (i.e. chews) across chewing sequence, chewing work and chewing rate. No gender bias was found for the EMG parameters considered, therefore, as regards gender, each group was considered to be homogeneous. Variability within-subjects across samples was greater for experts than untrained subjects. Significant differences in chewing time, chewing work and chewing rate were found between the expert and untrained groups. Data analysis of the three sessions showed an influence of cognitive constructs, mediating states, on the chewing process. The experts were found to be goal driven as to their mastication process. Experts showed no significant differences between sessions, untrained subjects were found to vary their EMG output in successive sessions for number of chews, chewing time, mean voltage, and chewing work.     

Imbalance diets in preschool children: study in a day-care center in the Province of Buenos Aires,Argentina

The purpose of this study was to investigate the impact of low fat diets in children aged 2 to 5. Eighty two children (40 females and 42 males) attending a school cafeteria (Province of Buenos Aires, Argentina), in a cross sectional study, were evaluated. Body weight (W), height (H) and body composition (BC) by bioimpedance were recorded. The anthropometric raw data were processed as Z-score of the weight-for-age (WEZ) and of the height-for-age (HAZ). Serum insulin-like growth factor 1 (IGF-1) and Zinc/haemoglobin ratio (Zn/Hb) were also measured. Results showed that 73.2% of the children were adequate (A) according WEZ, 13.4% were lean (L) and 13.4% overweight (O). 8.5% presented simultaneously impairment in WEZ and HAZ. Body fat percentage and energy metabolism were higher in O than in L and A (p < 0.05). Serum IGF-1's children--aged 4 to 5 years--with HAZ deficit were low than adequate HAZ ones. No statistical differences in Zn/Hb ratio between A, L and O were found. This cross sectional study suggests metabolic disorders in young children attending school cafeterias. These conclusions will allow to design balanced diets in order to optimize the resources, promote optimal growth and development and prevent adult diseases through dietary practices in childhood.