Influence of the glass packing on the contamination of pharmaceutical products by aluminium. Part II: Amino acids for parenteral nutrition

The presence of aluminium in amino acids parenteral nutrition solutions can be related to the affinity of the amino acids for aluminium present in glass containers used for storage. For this study solutions of 19 amino acids used in parenteral nutrition were stored individually in glass flasks and the aluminium measured at determined time intervals. Solutions of complexing agents for aluminium, as ethylene-diaminetetraacetic acid, nitrilotriacetic acid, citrate, oxalate and fluoride ions were also stored in the same flasks and the aluminium measured during the same time interval. The measurements were made by electrothermal atomic absorption spectrometry. The aluminium content of the glass containers was also measured. The results showed that the glasses have from 0.6% to 0.8% Al. Only solutions of cysteine, cystine, aspartic acid and glutamic acid became contaminated by aluminium. As the same occurred with the complexing agents, aluminum can be released from glass due to an affinity of the substances for aluminium. Comparing the action of complexing agents and amino acids for which the stability constants of aluminium complex are known, it is possible to relate the magnitude of the stability constant with the aluminium leached from glass, the higher the stability constant, the higher the aluminium released. The analysis of commercial formulations with and without cysteine, cystine, glutamic acid or aspartic acid stored in glass containers confirms that the presence of these amino acids combined with the age of the soLution are, at least partially, responsible for the aluminium contamination. The resuLts demonstrated that the contamination is an ongoing process due to the presence of aluminium in glass combined with the affinity of some amino acids for this element.     

Influence of the glass packing on the contamination of pharmaceutical products by aluminum. Part I: Salts, glucose, heparin and albumin

The presence of aluminium (Al) in pharmaceutical products used parenterally as sodium and potassium chlorides, glucose, heparin and albumin were investigated with respect to their storage in glass containers. As glasses can have aluminium in their composition, the aluminium may be released from the glass into the solution. The action of the substances above mentioned were investigated storing their solutions in glass and plastic containers, and measuring the aluminium in solution at determined time intervals. The aluminium present in the commercial pharmaceutical products, stored in both plastic and glass containers were also measured. All glass containers were analysed to determine their aluminium content. The aluminium determinations were done by atomic absorption spectrometry. The results showed that aluminium is present in all analysed glasses in a percentage of 0.6 to 3%. Although all substances already have a residual aluminium contamination, the major contribution comes from the glass containers in which their solutions were stored. The contamination arising from glass depends too much on the nature of the substance. While the salts extracted about 400 μg Al/l in 60 days, glucose extracted 150 μg Al/l, and albumin and heparin about 500 μg Al/l in the same time interval. Commercial solutions of glucose contain about 10 μg Al/l when stored in polyethylene and from 350 to 1000 μg Al/l when in glass ampules. Considering all commercial products, solutions stored in plastic containers contained no more than 20 μg Al/l whereas in glass the aluminium contamination reached 1000 μg/l, and in all of them the aluminium increases with the age of the product.     

Influence of the glass packing on the contamination of pharmaceutical products by aluminium. Part I: salts, glucose, heparin and albumin.

The presence of aluminium (Al) in pharmaceutical products used parenterally as sodium and potassium chlorides, glucose, heparin and albumin were investigated with respect to their storage in glass containers. As glasses can have aluminium in their composition, the aluminium may be released from the glass into the solution. The action of the substances above mentioned were investigated storing their solutions in glass and plastic containers, and measuring the aluminium in solution at determined time intervals. The aluminium present in the commercial pharmaceutical products, stored in both plastic and glass containers were also measured. All glass containers were analysed to determine their aluminium content. The aluminium determinations were done by atomic absorption spectrometry. The resuLts showed that aluminium is present in all analysed glasses in a percentage of 0.6 to 3%. Although all substances already have a residual aluminium contamination, the major contribution comes from the glass containers in which their solutions were stored. The contamination arising from glass depends too much on the nature of the substance. While the salts extracted about 400 microg Al/l in 60 days, glucose extracted 150 microg Al/l, and albumin and heparin about 500 microg Al/l in the same time interval. Commercial solutions of glucose contain about 10 microg Al/l when stored in polyethylene and from 350 to 1,000 microg Al/l when in glass ampules. Considering all commercial products, solutions stored in plastic containers contained no more than 20 microg Al/l whereas in glass the aluminium contamination reached 1,000 microg/l, and in all of them the aluminium increases with the age of the product.     

An interfacial equilibria model for the electrokinetic properties of a fat emulsion. Part III: A predictive computer model

Abstract

The semi-empirical thermodynamic model for the binding of metal ions to an emulsion (intralipid 20%) reported previously (Hall et al., 1991 ; Gaskin et al., 1993) is incorporated into a thermodynamic computer model. This permits the zeta potential and emulsion stability together with precipitate formation to be estimated for any intravenous nutrition regimen. A regimen frequently used in the intravenous nutrition of patients is considered in this modeling study. The effect of solution pH and calcium on the zeta potential of the emulsion is predicted. Calcium and magnesium are the only metal cations which are predicted to be of importance when considering stability of this emulsion.     

The effect of pressure on the glass transition of biopolymer/co-solute. Part I: The example of gelatin

High-solid materials of gelatin in the presence of co-solute were prepared and subjected to a series of hydrostatic pressures up to 700 MPa. Following this, a study was made of the relaxation properties of the mixture around the glass transition region and the melting behaviour of the gelatin network. Structural properties were monitored using differential scanning calorimetry and small-deformation dynamic oscillation on shear. Thermograms were obtained and master curves of viscoelasticity were constructed for each experimental pressure. The dependence of the empirical shift distances obtained from mechanical measurements and supplementing evidence from thermal analysis argue that the application of pressure did not alter the vitrification or melting characteristics of the gelatin/co-solute system within the experimentally accessible pressure range. Unlike the principle of the time–temperature–pressure superposition applicable to synthetic macromolecules, it may not be possible to incorporate a pressure component into the framework of thermorheological simplicity governing the glass transition of the high-sugar gelatin network.     

Comparison of different pretreatment methods for lignocellulosic materials. Part II: Influence of pretreatment on the properties of rye straw lignin

Several processes have been suggested to convert various types of lignocellulosic biomass into lignin products and saccharides. This paper evaluates the suitability of an organosolv process, a process using soda, a hydrothermal process and a process developed in this work, called the “Aquasolve process” for inclusion into a lignocellulosic biorefinery concept. Part II of this paper investigates the influence of the different pretreatment processes on the properties of rye straw lignin and evaluates their ability to produce high recoveries of high quality lignin.Specifications for high quality lignin products are defined and the isolated lignin fractions are analysed by Klason lignin, carbohydrate and ash content, elemental analysis, thermo-gravimetric analysis, ³¹P NMR, and size exclusion chromatography. The organosolv process shows the largest lignin recovery, followed by the soda and Aquasolve processes. Lignin products from the soda process, the Aquasolve process and with reservation the organosolv process show interesting properties for polymer applications.     

Influence of the spacer length on the activity of enzymes immobilised on nylon/polyGMA membranes: Part 1. Isothermal conditions

β-Galactosidase was immobilized on nylon/poly(glycidyl methacrylate) membranes through spacers of different length: hexamethylenediamine, ethylenediamine or hydrazine. The effect of the spacer length on the catalytic behavior of the three membranes was studied in isothermal bioreactors. The behavior of the soluble and insoluble enzymes was compared to know the effects of the immobilization process and of the spacer length.

The enzyme derivatives in comparison with the soluble enzyme exhibited shifts of the optimum pH values towards more acidic solutions. These shifts were found decreasing with the spacer length; while an opposite trend was observed when the optimum temperature values were considered. Also the values of the apparent K_m were found to decrease with the spacer length.

All these results indicated that a soluble enzyme could be considered as an enzyme immobilized on a solid support through a spacer of infinite length.     

The nutritive value of concentrate feedstuffs for ruminant animals: Part III. Small intestinal digestibility as measured by in vitro or mobile bag techniques

The aim of the study was to generate a database of small intestinal digestibility (SID) of different sources of concentrate ingredients commonly offered to ruminants in European countries. Test protein feeds were sunflower meal (SUN), rapeseed meal (RAP), soyabean meal (SBM) and cottonseed meal (CSM). Test energy feeds were palm kernel meal (PK), pollard (PO), barley (BA) and beet pulp (BP). Test protein+energy feeds were maize distillers grains (MDG), maize gluten feed (MGF), copra meal (CO) and malt combings (MC). The ruminal undegradable protein (RUP) portion of the test feedstuffs was obtained by ruminal incubation in four Friesian steers offered grass silage and concentrate. The RUP fraction was digested with pepsin and pancreatin enzymes (PPD) or placed into the duodenal cannula of two Friesian cows using the mobile bag technique, which were recovered in the faeces. The average in situ SID (g/kg) of CSM, RSM, SBM, SUN, BA, BP, PK, CO, MDG, MGF and MC was 834 (S.D. 61), 711 (S.D. 47), 978 (S.D. 9), 586 (S.D. 170), 427 (S.D. 80), 712 (S.D. 24), 767 (S.D. 53), 816 (S.D. 38), 860 (S.D. 73), 656 (S.D. 65) and 510 (S.D. 41), respectively. Corresponding in vitro SID values (g/kg) were 641 (S.D. 65), 620 (S.D. 45), 840 (S.D. 27), 606 (S.D. 155), 445 (S.D. 36), 601 (S.D. 17), 640 (S.D. 63), 686 (S.D. 69), 756 (S.D. 63), 634 (S.D. 84) and 504 (S.D. 16), respectively. These results show that the SID of feeds can vary substantially between different sources and indicates that different feeds should be screened for their nutritive value as a result. As the relationship between in situ (Y) and in vitro (X) SID is best described by the linear regression equation Y=−91.9+12.7X (r=0.91), indicating a close relationship between results obtained using both techniques, the in vitro PPD technique offers a quick and reliable method for SID of feeds to be screened on a regular basis.     

Lymphocyte alloantigens of the horse. III. ELY-2.1: a lymphocyte alloantigen not coded for by the MHC

A new polymorphic locus of the horse which has several unusual properties is described. The suggested name for the locus is ELY-2 . The gene product of one allele at this locus, designated ELY-2.1 , has been identified with antisera raised as a result of pregnancy. Antibody to ELY-2.1 was first detected on day 55 after conception in the serum of a mare in first pregnancy. This early onset of antibody is similar to that seen for antibody to ELA antigens, and suggests that the source of the antigenic stimulus may be the tissue of the equine endometrial cups.
The antisera identifying ELY-2.1 are cytotoxic and kill all peripheral blood lymphocytes from horses carrying the antigen. ELY-2.1 is a cell surface molecule expressed on lymphocytes, erythrocytes, and platelets. Other cell types have not been investigated. The overall phenotypic frequency of ELY-2.1 in several horse breeds was 16 %. The ELY-2.1 antigen is controlled by an autosomal, dominant gene which is not coded by the ELA region (the major histocompatibility complex of the horse), nor is it identical to the ELY-1 locus, which codes for another cell surface alloantigen of equine lymphocytes. Stimulator cells carrying ELY-2.1 did not induce proliferation of ELY-2.1 negative responder cells in mixed cultures of horse lymphocytes. Attempts to raise alloantisera to other alleles of the ELY-2 locus through immunization with lymphocytes were unsuccessful. It is possible that the alternate allele(s) does not code for a gene product which is expressed. The function and biochemical nature of the ELY-2.1 molecule are unknown.     

Influence of petroleum contamination and biostimulation treatment on the diversity of Pseudomonas spp. in soil microcosms as evaluated by 16S rRNA based-PCR and DGGE

AIMS: The aim of this study was to apply a group specific PCR system followed by denaturing gradient gel electrophoresis (DGGE) analysis to evaluate the effect of oil contamination and the biostimulation process on the diversity of Pseudomonas populations in soil ecosystems. METHODS AND RESULTS: Direct DNA extraction from biostimulated- and oil-contaminated soil samples was performed. Primers specific for the genus Pseudomonas spp. were used to amplify 16S rRNA genes and then a semi-nested PCR reaction was applied to obtain smaller fragments for comparing the PCR products by DGGE. Whether in bulk, oil-contaminated or biostimulated soils, the DGGE profiles revealed little change in Pseudomonas community throughout the 270 days of experiment. The presence of a few additional bands observed only in treated samples indicated that a bacterial shift occurred with the addition of nutrients and with oil contamination. CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: The combination of semi-nested PCR and DGGE was found to be a rapid and sensitive technique to study the diversity within the genus Pseudomonas and may be suitable for further studies concerning the role of this bacterial group in large-scale oil-contaminated areas.     

Interaction of La (III) and Tb (III) ions with purine nucleotides: evidence for metal chelation (N-7-M-PO3) and the effect of macrochelate formation on the nucleotide sugar conformation.

The interaction of the La (III) and Tb (III) ions with adenosine-5'-monophosphate (5'-AMP), guanosine-5'-monophosphate (5'-GMP), and 2'-deoxyguanosine-5'-monophosphate (5'-dGMP) anions with metal/nucleotide ratios of 1 and 2 has been studied in aqueous solution in acidic and neutral pHs. The solid complexes were isolated and characterized by Fourier transform ir and 1H-nmr spectroscopy. The lanthanide (III)-nucleotide complexes are polymeric in nature both in the solid and aqueous solutions. In the metal-nucleotide complexes isolated from acidic solution, the nucleotide binding is via the phosphate group (inner sphere) and an indirect metal-N-7 interaction (outer-sphere) with the adenine N-1 site protonated. In the complexes obtained from neutral solution, metal chelation through the N-7 and the PO3(2-) group is prevailing. In aqueous solution, an equilibrium between the inner and outer sphere metal-nucleotide interaction has been observed. The ribose moiety shows C2'-endo/anti pucker in the free AMP anion and in the lanthanide (III)-AMP complexes, whereas the GMP anion with C2'-endo/anti sugar conformation exhibits a mixture of the C2'-endo/anti and C3'-endo/anti sugar puckers in the lanthanide (III)-GMP salts. The deoxyribose has O4'-endo/anti sugar pucker in the free dGMP anion and a C3'-endo/anti, in the lanthanide (III)-dGMP complexes.     

Procedures for the characterisation of bioaerosol particles. Part II: Effects of environment on culturability

The behaviour of bioaerosol particles in industrial and health-careapplications may be most effectively understood once they have beenquantitatively assessed using well-characterised sampling and assaytechniques. However, the large number of different conditions possiblein this wide range of applications makes the assessment of bioaerosolparticles very difficult. In addition to the effects of differentsampling and assay technologies, the mechanism of aerosolisation andenvironmental conditions can influence bioaerosol behaviour. The effectsof sampler selection and suspension aerosolisation on bioaerosolviability were reported earlier as ``Part I' of two papers, and theeffects of the environment on the culturability of three different typesof microorganism are reported here as ``Part II'. The environmentalrelative factors considered in the present study are: relativehumidity (RH), aerosol-age, and a number of gaseous pollutants. A smallnumber of additional tests, examining the effects of aerosolisationmethod on culturability, are also reported. A combination of anenvironmentally controlled Bioaerosol Test Chamber and Goldberg RotatingDrum were shown to be an appropriate facility to carry out the study.Changing RH was shown to have a considerable effect on the culturablefraction of aerosolised Sacharomyces cerevisiae cells but notPenicillium expansum spores or Bacillus subtilis var.niger spores. In this text, ``culturable fraction' is definedas the fraction of the total number of microorganisms in a sample thatwill form colonies (i.e. grow and reproduce) on a suitably preparedculture plate under optimum conditions for the species of microorganismunder consideration. After the initial shock of aerosolisation, theculturable fraction of S. cerevisiae cells and P.expansum spores is not further affected by increasing aerosol age.Results from an earlier study have shown spray suspension and collectedaerosol age also have no effect on culturability of P. expansumspores. The effects of gaseous pollutants are reflected in the reductionin culturability of P. expansum spores following exposure tosulphur dioxide, ozone and ozone hydrocarbon cocktail. This reductionwas never to less than 30% of the unpolluted control. All thetests show that P. expansum spores are fairly robust andbiologically stable. Examination of the effects of aerosolisationtechnique on the culturability of S. cerevisiae shows theCollison nebuliser produces aerosols with the highest culturabilitycompared with either a plain glass atomiser or a Unimed nebuliser usedin these tests.     

Preliminary experiments on the potential of hoverflies [Dipt.: Syrphidae] for the control of aphids under glass

Control ofAphis gossypii Glover populations on isolated cucumber plants grown at 21°C was achieved on days 2, 3, or 4 by larvae ofMetasyrphus corollae (F.) hatched from eggs laid on the plants on day 0. With 45% of hoverfly eggs viable, greater than 9 aphids per egg at the end of oviposition resulted in a failure of control. Larvae 1, 2, or 3 days old prevented aphid increase unless there were more than 15, 26 or 41 aphids per larva respectively. Continuous control on single caged cucumber plants was possible providing that the presence of 1 gravid hoverfly was maintained in the cage, but elimination of the aphid population was observed in only 1 instance. A possible role for hoverflies in crop protection under glass is discussed.

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Résumé On parvenait à réduire des populations d'Aphis gossypii Glover fixés sur plants isolés de concombres, croissant à 21°C, au moyen de larves deMetasyrphus corollae (F.) écloses d'œufs pondus sur les plantes au tout début de l'expérience (jour 0) en 2, 3 ou 4 jours. Avec 45% d'œufs viables de Syrphes, une proportion supérieure à 9 pucerons/œuf en fin de ponte, entraine l'échec du “control”. Les larves agées de 1, 2 ou 3 jours empêchaient l'accroissement des populations à moins qu'il y eut plus de 15, 26 ou 41 Aphides/larve respectivement. Le “control” continu sous cage sur de simples plants de concombres était possible pourvu que la présence d'une seule ♂ gravide de Syrphe soit maintenue en cage, mais l'élimination de la population de pucerons n'était observée que dans 1 seul cas. Le róle possible des Syrphes dans la protection des cultures protégées est discutée.

     

Implications of a non-lamellar lipid phase for the tight junction stability. Part I: Influence of basic amino acids, pH and protamine on the bilayer-hexagonal II phase behaviour of PS-containing PE membranes.

Inverted lipid micelles have been proposed, among other biological functions, to constitute the structural basis of the so-called tight junctions, a special cell cell contact found in epithelia and endothelial, which act as a barrier for the paracellular solute passage. As a model system for the opening and closing of this gate, we investigated the formation of the inverted hexagonal phase (HII phase) in lipid bilayer systems consisting of egg phosphatidylethanolamine (egg PE) and mixed egg PE/bovine brain phosphatidylserine (BBPS) membranes. The formation of the HII phase was modulated by Ca2+ ions, pH, basic amino acids and protamine. The lamellar-HII phase transition temperature TH of pure egg PE membranes at pH 7.0 was lowered with increasing Ca2+ concentration. This effect was attenuated by the presence of 50 mM lysine methyl ester. In the mixed lipid system, this effect was also observed, but even more pronounced. However this effect could be compensated for by raising the Ca2+ concentration from 2 to 10 mM. This was not observed in the pure PE system. In the absence of Ca2+, lysine methyl ester and protamine lowered TH in both monocomponent and mixed lipid systems, whereas lysine caused the opposite effect. The pH-dependence of mixed lipid systems, which were investigated up to a BBPS content of 20 mol%, clearly shows that increasing PS content stabilizes the lamellar phase even at low pH. The results obtained with model membranes are discussed with respect to biological implications of the lamellar-HII phase transition for the modulation of tight junction stability.     

The effect of diet on the nitrogenous end products excreted by larval Tribolium confusum: With notes on correction of A.D. and E.C.D. for fecal urine

Tribolium confusum duVal larvae were reared from hatching to the larval-pupal ecdysis on cracked wheat, finely ground wheat, finely ground wheat plus 5% brewer's yeast, or wheat germ. Feces were collected quantitatively and analyzed for nitrogenous end products by thin layer chromatography, the enzymatic-spectrophotometric method, and colorimetric methods. Larvae fed cracked wheat or wheat germ excreted a larger total of nitrogenous metabolites than did the others. The relative quantities of hypoxanthine, xanthine, uric acid, and allantoin which made up the total varied with diet. Calculated on the basis of the total, the percent allantoin remained relatively constant, but the proportions of the other end products varied considerably. Feces derived from cracked wheat or finely ground wheat contained about 25% uric acid, while feces derived from wheat germ or ground wheat with brewer's yeast contained about 61% and 45% uric acid respectively and correspondingly reduced quantities of hypoxanthine and xanthine. Urea and ammonia were also present.Correction for the estimated urine content of the feces results in an increase in the calculated approximate digestibility and a decrease in the calculated efficiency of conversion of digested food. The changes are small, but significant. The size of the change varies with the diet.

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Zusammenfassung Tribolium confusum-Larven wurden vom Schlüpfen bis zur Larven-Puppen-Häutung an geschrotetem Weizen, fein gemahlenem Weizen, fein gemahlenem Weizen + 5% Bierhefe oder Weizenkeimlingen aufgezogen. Der Kot wurde quantitativ gesammelt und mittels Dünnschichtchromatographie, der enzymatisch-spektrophotometrischen Methode und colorimetrischen Methoden auf Stickstoff-Endprodukte analysiert. Mit geschrotetem Weizen oder Weizenkeimlingen gefütterte Larven hatten einen größeren Gesamtgehalt an Stickstoff-Metaboliten als die anderen. Die relativen Mengen von Hypoxanthin, Xanthin, Harnsäure und Allantoin, welche diesen Gesamtgehalt ergaben, wechselten mit der Diät. Auf den Gesamtgehalt bezogen blieb Allantoin prozentual relativ konstant, aber die Anteile der übrigen End-produkte variierten beträchtlich. Kot nach Ernährung mit geschrotetem oder fein gemahlenem Weizen enthielt etwa 30% Harnsäure, während Kot von mit Weizenkeimlingen oder mit gemahlenem Weizen + Bierhefe ernährten Tieren etwa 68 bzw. 50% Harnsäure und entsprechend geringere Mengen Hypoxanthin und Xanthin enthielt. Harnstoff und Ammoniak waren ebenfalls vorhanden jedoch vermutlich durch die Mikroorganismen des Kots gebildet worden.