In vitro bioaccessibility of proteins and lipids of pH-shift processed Nannochloropsis oculata microalga.

The pH-shift process fractionates biomass into soluble proteins and insoluble fractions, followed by precipitation and recovery of the solubilized proteins. Nannochloropsis oculata in seawater was subjected to the pH-shift process, followed by digestion of various intermediates and product fractions of the process, using the Infogest in vitro digestion model (Minekus et al., 2014) with added gastric lipase. As measures for protein and lipid accessibility, degrees of protein hydrolysis and fatty acid liberation were assessed post-digestion and compared to the amounts of peptide bonds and total fatty acids present in the raw materials. Results showed that neither proteins nor lipids of intact Nannochloropsis cells were accessible to the mammalian digestive enzymes used in the digestion model. Cell disruption, and to a lesser extent, further pH-shift processing with protein solubilisation at pH 7 or pH 10, increased the accessibility of lipids. For proteins, differences amongst the pH-shift processed materials were non-significant, though pre-freezing the product prior to digestion increased the accessibility from 32% to 47%. For fatty acids, pH-shift process-products gave rise to 43% to 52% lipolysis, with higher lipolysis for products solubilised at pH 10 as opposed to pH 7. Our results indicate the importance of processing to produce an algal product that has beneficial nutritional properties when applied as food or feed.

Human rights and access to hepatitis C treatment for people who inject drugs.

BACKGROUND: People who inject drugs (PWID) achieve adherence to and outcomes from hepatitis C virus (HCV) treatment comparable to other patients. Nonetheless, this population has been excluded from treatment by regulation or practice. Approval of safer and more effective oral HCV medicines should offer greater treatment options for PWID, although high medicine prices have led to continued treatment rationing and exclusion in developed countries. In middle-income countries (MICS), treatment is largely unavailable and unaffordable for most PWID. METHODS: Human rights analysis, with its emphasis on the universal and interconnected nature of the economic, social and political spheres, offers a useful framework for HCV treatment reform. Using peer-reviewed and grey literature, as well as community case reports, we discuss barriers to treatment, correlate these barriers to rights violations, and highlight examples of community advocacy to increase treatment for PWID. RESULTS: Structural drivers of lack of treatment access for PWID include stigma in health settings; drug use status as a criterion for treatment exclusion; requirements for fees or registration by name as a drug user prior to treatment initiation; and incarceration/detention in prisons and rehabilitation centers where treatment is unavailable. High medicine prices force further exclusion of PWID, with cost containment masked as concern about treatment adherence. These barriers correlate to multiple rights violations, including of the rights to privacy; non-discrimination; health; freedom of information; fair trial; and freedom from cruel, inhuman and degrading treatment. CONCLUSIONS: Needed reforms include decriminalization of drug use, possession of drugs and drug injecting equipment; removal of exclusionary or discriminatory treatment protocols; approaches to strengthen links between health providers and increase participation of PWID in treatment design and implementation; and measures to increase transparency in government/pharmaceutical company negotiations and reduce treatment price.

Evaluation of 2 hematology analyzers in body fluid mode versus flow cytometry immunophenotyping of mainly neurosurgical cerebrospinal fluid samples.

BACKGROUND: For CSF analysis, exact knowledge of the type and amount of cells is essential, especially for detection of infection or bleeding. The chamber count has been the current reference method to date, yet it is problematic due to its subjectivity depending on the examiner's skill and experience. Therefore, as a reference method, we used an impulse cytophotometric measurement with Epics XL owing to its improved objectify ability and compared this method to the measurement of CSF samples performed with the ADVIA 2120 and XE-5000. MATERIAL AND METHODS: 101 CSF samples were measured with the ADVIA 2120, XE-5000, and Epics XL. For impulse cytophotometric measurement, CD235a was used for identification of erythrocytes; CD45 for the entire leukocyte population; CD56, CD16 and CD14 for monocytes; CD3, CD4 and CD19 for lymphocytes;and CD13, CD15 and CD33 for neutrophile granulocytes. RESULTS: Regarding leukocyte measurements, a strong correlation was obtained between Epics XL and XE-5000 (r = 0.990), with the correlation between Epics XL and ADVIA 2120 not as strong (r = 0.538). This finding is due to the fact that with blood-stained CSF samples (erythrocytes >1,500/µl), no valid results were produced by the ADVIA 2120. In measurements of blood-free CSF samples, correlations between Epics XL, XE-5000, and ADVIA 2120 were almost identical (r = 0.985 and r = 0.964). The same applies to the correlation between polymorphonuclear and mononuclear cells (range 0.920-0.972). In erythrocyte measurements, the correlation between XE-5000 and ADVIA 2120 was excellent (r = 0.945). Impulse cytophotometric measurement of erythrocytes with CD 238 antibodies did not appear to be functional. CONCLUSION: In the measurement of leukocytes in CSF with the ADVIA 2120, no valid results could be obtained in blood-stained CSF samples (erythrocytes >1,500/µl). In blood-free CSF samples (erythrocytes <1,500/µl), measurements of leukocytes, and polymorphonuclear and mononuclear cells performed with the ADVIA 2120 and XE-5000 produced almost identical good results. Determination of CSF cells with the XE-5000 is presently the best automated method for counting leukocytes of blood-stained CSF.

Flux balance analysis for ethylene formation in genetically engineered Saccharomyces cerevisiae.

Biosynthesis of ethylene (ethene) is mainly performed by plants and some bacteria and fungi, via two distinct metabolic routes. Plants use two steps, starting with S-adenosylmethionine, while the ethylene-forming microbes perform an oxygen dependent reaction using 2-oxoglutarate and arginine. Introduction of these systems into Saccharomyces cerevisiae was studied in silico. The reactions were added to a metabolic network of yeast and flux over the two networks was optimised for maximal ethylene formation. The maximal ethylene yields obtained for the two systems were similar in the range of 7-8 mol ethylene/10 mol glucose. The microbial metabolic network was used for testing different strategies to increase the ethylene formation. It was suggested that supplementation of exogenous proline, using a solely NAD-coupled glutamate dehydrogenase, and using glutamate as the nitrogen source, could increase the ethylene formation. Comparison of these in silico results with published experimental data for yeast expressing the microbial system confirmed an increased ethylene formation when changing nitrogen source from ammonium to glutamate. The theoretical analysis methods indicated a much higher maximal yield per glucose for ethylene than was experimentally observed. However, such high ethylene yields could only be obtained with a concomitant very high respiration (per glucose). Accordingly, when ethylene production was optimised under the additional constraint of restricted respiratory capacity (i.e. limited to experimentally measured values) the theoretical maximal ethylene yield was much lower at 0.2/10 mol glucose, and closer to the experimentally observed values.

Determination of eflornithine enantiomers in plasma by precolumn derivatization with o-phthalaldehyde-N-acetyl-L-cysteine and liquid chromatography with UV detection.

A bioanalytical method for indirect determination of eflornithine enantiomers in 75 microL human plasma has been developed and validated. L- and D-eflornithine were derivatized with o-phthalaldehyde and N-acetyl-L-cysteine to generate diastereomers which were separated on two serially connected Chromolith Performance columns (RP-18e 100 x 4.6 mm i.d.) by a isocratic flow followed by a gradient flow for elution of endogenous compounds. The diastereomers were detected with UV (340 nm). The between-day precisions for L- and D-eflornithine in plasma were 8.4 and 2.3% at 3 microm, 4.0 and 5.1% at 400 microm, and 2.0 and 3.7% at 1000 microm. The lower limit of quantification was determined to be 1.5 microm, at which precision was 14.9 and 9.9% for L- and D-eflornithine, respectively.

Ethylene production by metabolic engineering of the yeast Saccharomyces cerevisiae.

The non-ethylene producing yeast, Saccharomyces cerevisiae, was transformed into an ethylene producer by introducing the ethylene forming enzyme from the plant pathogenic bacterium Pseudomonas syringae. Cultivation of the metabolically engineered strain was performed in well-controlled bioreactors as aerobic batch cultures with an on-line monitoring of ethylene production. The highest productivity was obtained during the respiro-fermentative growth on glucose but there was also a significant rate of formation during the subsequent phase of ethanol respiration. Furthermore, investigations were performed whether substitution of the original nitrogen source, NH(4)(+), for glutamate could improve productivity and yield of ethylene even more. The rationale being that one of the substrates for the enzyme is 2-oxoglutarate and this compound can be formed from glutamate in a single reaction. Indeed, there was a substantial improvement in the rate of production and the final yield of ethylene was almost three times higher when NH(4)(+) was replaced by glutamate.

Placental pathology casebook. Complete hydatidiform mole with coexistent term twin pregnancy.

A case of twin pregnancy consisting of a complete hydatidiform mole with a coexistent, viable fetus is presented. The case is distinctive for its presentation on ultrasound, its unusually low levels of serum hCG, its remarkable histology, and its term delivery.

Influence of the nitrogen source on Saccharomyces cerevisiae anaerobic growth and product formation.

To prevent the loss of raw material in ethanol production by anaerobic yeast cultures, glycerol formation has to be reduced. In theory, this may be done by providing the yeast with amino acids, since the de novo cell synthesis of amino acids from glucose and ammonia gives rise to a surplus of NADH, which has to be reoxidized by the formation of glycerol. An industrial strain of Saccharomyces cerevisiae was cultivated in batch cultures with different nitrogen sources, i.e., ammonium salt, glutamic acid, and a mixture of amino acids, with 20 g of glucose per liter as the carbon and energy source. The effects of the nitrogen source on metabolite formation, growth, and cell composition were measured. The glycerol yields obtained with glutamic acid (0.17 mol/mol of glucose) or with the mixture of amino acids (0.10 mol/mol) as a nitrogen source were clearly lower than those for ammonium-grown cultures (0.21 mol/mol). In addition, the ethanol yield increased for growth on both glutamic acid (by 9%) and the mixture of amino acids (by 14%). Glutamic acid has a large influence on the formation of products; the production of, for example, alpha-ketoglutaric acid, succinic acid, and acetic acid, increased compared with their production with the other nitrogen sources. Cultures grown on amino acids have a higher specific growth rate (0.52 h-1) than cultures of both ammonium-grown (0.45 h-1) and glutamic acid-grown (0.33 h-1) cells. Although the product yields differed, similar compositions of the cells were attained. The NADH produced in the amino acid, RNA, and extracellular metabolite syntheses was calculated together with the corresponding glycerol formation. The lower-range values of the theoretically calculated yields of glycerol were in good agreement with the experimental yields, which may indicate that the regulation of metabolism succeeds in the most efficient balancing of the redox potential.

Cyclodextrin derivatives in pharmaceutics.

The current cyclodextrin (CD) literature is reviewed concerning synthesis, characterization, and pharmaceutical relevant applications of CD derivatives. Although natural CDs have been used extensively to improve pharmaceutical properties, the effects of chemically modified CDs on the solubility, dissolution rate, and stability of drugs are overproportional. Concerning the parenteral application, the major interest is focussed on highly water-soluble, randomly substituted hydroxyalkyl derivatives of beta- and gamma-CD such as 2-hydroxypropyl-beta-cyclodextrin (2-HP-beta-CD). Although the heptakis-(2,6-di-O-methyl)-beta-cyclodextrin is applied in the pharmaceutical field, 2-HP-beta-CD is predestined as a parenteral drug carrier owing to its weak hemolytic activity and intrinsically amorphous character. A minimal average degree of substitution is especially preferred when 2-HP-beta-CD is used as solubilizer of pharmaceuticals for the use in parenteral applications. The influence of the type, degree, and pattern of substitution of the CDs, as well as substituent effects of the guest molecule is elucidated.

Complexation of steroid hormones with cyclodextrin derivatives: substituent effects of the guest molecule on solubility and stability in aqueous solution.

The inclusion complexation of homologous derivatives of steroid hormones with cyclodextrins and 2-hydroxypropyl-beta-cyclodextrin (2-HP-beta-CD) was investigated with regard to underlying structure-interaction relationship. The interaction was studied by phase solubility analysis and stabilization effects of complex formation with 2-HP-beta-CD. The solubilizing and stabilizing abilities of 2-HP-beta-CD were generally more effective for testosterone derivatives than for estradiol esters. Within a homologous series of steroid hormones, the steepest linear solubility isotherms were found for 17-methyl and 3-methyl derivatives. The solubilization of steroid esters by 2-HP-beta-CD depended on the structure and length of the ester side chain. The interaction of 2-HP-beta-CD with the steroids was hindered by long-chain fatty acid ester groups. With increasing length of the side chain, a decline of the isotherms occurred and the phase solubility behavior changed from linear to exponential. Contrary to expectations, benzoylation of steroids considerably decreased the guest-host interaction. The observed rates of degradation of the steroid esters were significantly reduced by 2-HP-beta-CD, depending on the chain length, and correlated well with the order found in phase solubility analysis. The degradation showed no deviations from pseudo-first-order kinetics, and the degradation mechanism was not changed because of complexation. The results suggest that interaction of 2-HP-beta-CD with steroid esters involves the ester functions of the prodrugs and is more suitable for unsubstituted guest molecules.

Effect of hydrotropic substances on the complexation of sparingly soluble drugs with cyclodextrin derivatives and the influence of cyclodextrin complexation on the pharmacokinetics of the drugs.

The influence of hydrotropic compounds on complex formation by 2-hydroxypropyl-beta-cyclodextrin (2-HP-beta-CD) was investigated with methyltestosterone (MeT). Various representatives of the lyotropic series were used for this purpose. Additive hydrotropic effects were observed for nicotinamide and urea, which disrupt the water structure, while structure formers such as sorbitol exerted negative effects. The effects of hydrotropic substances on the phase solubility relationship of MeT showed that inclusion complex formation with 2-HP-beta-CD depends on the degree of ordering of the solvent and is apparently subject to entropy effects. Combined systems comprising 2-HP-beta-CD and auxiliary substances with various underlying solubilizing principles were also investigated. Combination of 2-HP-beta-CD with conventional solubilizers, such as 1,2-propylene glycol or sodium deoxycholate, reduced the solubilization capacity of 2-HP-beta-CD. Competitive displacement of the inclusion molecule from its 2-HP-beta-CD complex by sodium deoxycholate suggested that cholesterol participates in the release mechanism of the inclusion molecule under in vivo conditions. The spontaneous release of complexed drug molecules could indirectly be shown on the basis of the spontaneous action of a complexed dihydropyridine derivative after iv administration in rats. The bioavailability of an investigational drug in cynomolgus monkeys could be enhanced sevenfold by inclusion complexation with 2-HP-beta-CD.