bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation by interferon of the immune response to viruses via the major histocompatibility complex antigens
Authors: Maudsley D J , Morris A G , Tomkins P T
Published: November 2023

Interferons (IFNs) are cellular proteins which have a range of effects on cells including (by definition) the induction of an antiviral state in cells. Three different types are recognized denoted as α, β γ and (for review, see Knight, 1984) with the possibility of a fourth (β2) (Billiau et al., 1987). IFNα and -β are related in terms of amino acid sequence (Knight, 1984) and in biological properties; both are produced by cells in response to virus infection, bind to a common receptor on the surface of target cells (Branca and Baglioni, 1981) and have broadly similar effects on cells. Because of their similarity IFNα and -β will not be discussed separately but referred to collectively as IFNα β. IFN-γ is a lymphokine (a non-antibody protein product oflymphocytes) produced by T cells in response to proliferative signals and, in sequence terms, is unrelated to IFNα β (Knight, 1984). It binds to a separate receptor on the surface of cells (Aguet et al., 1982; Branca and Baglioni, 1981; Shulman et al., 1984), and whilst it has many effects in common with IFNα β., it has others not exerted by IFNα β.. These additional effects are of a nature which suggests that IFN-γ may be more widely important in resistance to disease than IFNα β.. Some of the effects that IFNs have on cells may have important immunological consequences and it is now generally thought that the so-called immunomodulatory effects of IFNs may, in some circumstances, be more important than the antiviral effects which, at least to virologists, may seem more prominent. In fact, many immunomodulatory effects of IFNs have been demonstrated, at least in vitro. These include effects on almost every (known!) branch of the immune system and for a major review of this area Vilcek and De Maeyer (1984) should be consulted. Here we will be modest and restrict ourselves to a discussion of an area of the immune system which is undoubtedly central the major histocompatibility antigens. Our interest is in the control by IFNs of the expression of these antigens on host cells and the immunological consequences of altered levels of expression.
Cell-mediated immunity to Epstein – Barr virus and the pathogenesis of virus-associated B cell lymphomas
Authors: Rickinson A B , Gregory C D , Murray R J , Ulaeto D O , Rowe M
Published: November 2023

Epstein - Barr virus (EBV) can be found in two different habitats in vivo and appears to adopt a different lifestyle in each. Although this is most easily demonstrated during the acute primary infection, recent evidence suggests that the virus also remains resident in both sites during the life-long virus carrier state (Yao et al., 1985a,b). The first habitat is stratified oropharyngeal epithelium (Sixbey et al., 1984) and/or the epithelial duct cells of salivary glands (Wolf et al., 1984) where full virus replication has been shown to occur, leading to the release of infectious virions into buccal fluid. The second habitat is the B lymphocyte pool where the infection is seemingly non-productive (Nilsson et al., 1971) and where the infected cells, if left unchecked, may develop into oligoclonal foci of B cell proliferation (Cleary et al., 1986).
Induction of autoimmunity foilowing viral infection of the central nervous system
Authors: Sedgwick Jonathon D , Ter Meulen Volker
Published: November 2023

Autoimmune reactions have been observed in acute and chronic viral infections in animals and man both with RNA and DNA viruses. These reactions occur mainly as a transient production of antibodies to self constituents directed against either tissue or circulating antigens. In humans, cytotoxic (complement-fixing) antibodies to normal lymphocytes have been found after infection with rubella, measles and Epstein - Barr viruses whereas patients with influenza or recurrent herpes simplex virus infections may reveal humoral immune reactions against nuclei, smooth muscle or renal tubules (Mottironi and Tereoski, 1970; Loza-Tulimowska et al., 1976; Wutzler et al., 1978). Other examples include antibodies to platelets in patients infected with rubella virus, rheumatoid factor in congenital cytomegalovirus infections or antibodies to intermediate filaments in infectious mononucleosis (Linder et al., 1979). However, these reactions are probably not of pathogenetic significance since, with the clearance of the virus by the host defence mechanisms, the antibodies disappear. In contrast to these observations little is known about cell-mediated autoimmune (CMAI) reactions as a result of viral infections. Since virus replication is associated with major cellular changes it has been proposed that such a phenomenon may occur in an infected host and under certain conditions be perpetuated even in the absence of the infectious agent (Notkins et al., 1984).
Strain preservation, inoculum preparation and development
Authors: Parton Carol , Willis Peter
Published: November 2023

Conventional modern microbiology depends on the availability of pure, stable cultures. Unless microorganisms receive expert handling they are vulnerable to contamination, spontaneous mutation, deterioration and death. Most industria1 production strains are irreplaceable; many have been developed by empirical methods and are often inherently unstable. In cases where cultures can be re-isolated or replaced by service collections the associated costs in time and effort are undesirable, so the maintenance of adequate viable stocks is essential. The financia1 implications of operating industrial processes with strains that have deteriorated are obvious. Decrease in secondary metabolite titre, associated with deterioration of the primary culture, is well recognized. For example, seria1 sub-culture over 7-10 steps of inoculum cultures of Penicillium chrysogenum and Streptomyces niveus results in a total loss of production of penicillin and novobiocin respectively. Similar problems can result from the mishandling of organisms at later stages in a fermentation process. Losses can be avoided or minimized by employing effective systems for culture preservation, inoculum preparation and fermentation scale-up.
Maternal influences on development
Authors: Mirkes Philip E , Fantel Alan G
Published: November 2023

After approximately 50 years of teratological research, since the pioneering work of Warkany, it is abundantly clear that a wide variety of agents can disrupt normal mammalian development, resulting in malformations. Because mammalian embryos develop in utero, many teratogenic agents first interact with the maternal organism. Thus, the mother is able to modify the toxicity of potential teratogens in a variety of ways, influencing virtually every aspect of teratogenesis. ln recent years a great deal of effort has been expended in dissecting the teratogenic process into maternal and embryonic/fetal components. Because not all instances of maternal influence can be covered here, we have chosen to discuss two major areas: (a) the role of maternal versus embryonic metabolism of so-called proteratogens and (b) the role of maternal environment. In addition to presenting methodological details, we also summarize specific research areas in which investigators have made significant insights into ‘maternal influences’ on development.
Gas chromatography of lipids
Authors: Evershed Richard P
Published: November 2023

Gas chromatography is used extensively in the analysis of all the major lipid classes. In many instances GC analyses are performed on intact molecular species. However, for involatile or thermally unstable substances, such as phospholipids, chemical or enzymatic degradations must be used to release their simpler lipid moieties, as these are more amenable to GC analysis. (See Chapter 2 for accounts of degradation and derivatization methods commonly employed in the analysis of lipids.) This is a practical account of GC techniques used in lipid analysis. Wall¬ coated open tubular (WCOT) capillary columns offer substantial improvements in separation power compared to that attainable using packed GC columns. However, as packed-column GC is still used in many laboratories, reference is made to packed-column GC methods where appropriate. Theoretical treatment of GC has been more than adequately covered elsewhere (for example in ref. 1) and so will not be repeated here. Readers requiring further information on the gas chromatography of lipids are directed to a recent monograph (2) which contains an extensive bibliography covering the period up to 1989.
Methods of Structural Analysis of Proteins. Part 1—Protein Crystallography
Authors: Jones E Yvonne , Stuart David I
Published: November 2023

1. Introduction X-ray crystallography provides a method by which the detailed three dimensional structure of a protein may be revealed at or near to atomic resolution. A well-refined protein structure, at a resolution of 3 A or better, provides a wealth of information: on specific atom positions, their interactions (hydrogen bonds, etc.), solvent accessibility, and variations in flexibility/ mobility within the molecule. The constraints imposed on the protein molecule by its packing within the crystal may produce some slight perturbations in the conformation of certain flexible regions, but comparison of crystal (solved by X-ray crystallography) and solution (solved by nuclear magnetic resonance) structures of the same protein, as well as studies of the same protein in different crystal environments, clearly indicate that this is usually a minor effect. Many enzymes remain active when crystallized, and time-resolved structural studies of enzymic mechanisms will be touched on in this chapter.
Genetic Engineering of the Processing and Secretory Pathway of an Inflammatory Cytokine in Mammalian Cells: a Case Study
Authors: Kriegler Michael
Published: November 2023

1. Introduction In addition to the induction of tumour regression, tumour necrosis factor (TNF) has been implicated as the causative agent in a number of pathologies, including cachexia, septic shock, rheumatoid arthritis, autoimmunity, and induction of HIV expression. Our early studies of TNF led us to propose that this complex physiology might be manifest by different forms of TNF: the 17 kDa secretory form and a precursor 26 kDa transmembrane form we first identified and characterized (1). It was shown that TNF is first synthesized as a transmembrane molecule that is cleaved by a specialized ‘TNF convertase’ to the 17 kDa form prior to its release from the cell. In an attempt to separate the biological activities of the 17 kDa and 26 kDa forms, we genetically engineered the molecule and thus generated both an uncleavable 26 kDa mutant form and a solely secretable 17 kDa mutant form of the wild-type molecule and studied their biological activities. In these studies we found that an uncleavable mutant of TNF kills tumour cells by cell-to-cell contact, and that TNF need not be internalized by its target cell to kill (2). Thus, the 26 kDa integral transmembrane form of TNF may function in vivo to kill tumour cells and other targets locally, in contrast to the systemic bioactivity of the secretory component.
Urinalysis: review of methods
Authors: Shuker David E G
Published: November 2023

Changes in the pysical appearance of urine have long been used by the medical profession to detect some diseases of the body for which there were no other external manifestations. The subsequent development of techniques in chemical and biochemical analysis permitted the routine determination of ‘invisible’ parameters as density, pH, protein concentration, urea, etc., and these are now routinely carried out in hospital laboratories all over the world . Changes in the levels of such urinary markers outside certain normal values often accompany diseases. However, each single marker may be affected by many different diseases and it is often necessary to consider such changes in the context of other parameters. Thus, the technique of ‘urinalysis’-that is, the measurement of urinary parameters-has hada long and respectable history in medical practice.
Mass spectrometric analysis of proteincarcinogen adducts
Authors: Skipper Paul L , Naylor Stephen
Published: November 2023

Mass spectrometry is a relatively mature technology encompassing a broad range of techniques and applications. It is not static, though, and the recent introduction of so-called ‘soft’ ionization techniques such as fast atom bombardment (FAB) has revolutionized our ability to investigate protein and DNA adducts of chemical carcinogens. One focus of this paper is thus the use of FAB-MS to characterize protein adducts. A second focus is on the use of more conventional techniques such as electron ionization (EI) and chemical ionization (Cl) mass spectrometry to aid in structure elucidation and confirmation of identity. The application of gas chromatography/mass spectrometry (GC-MS) to quantitative analysis is also addressed with particular reference to the issues of sample preparation.
Genetic toxicology of the human: the current status of somatic gene mutation
Authors: Mendelsohn Mortimer L
Published: November 2023

The ability to measure human somatic gene mutation in vivo is a relatively recent development. The precursors of the HPRT, HLA-A, and haemoglobin S assays are roughly a decade old, and the first application of the glycophorin A assay was in 1986. Today, while somatic mutational data are still sparse, they are accumulating briskly, and one can begin to make reasonable generalizations about the phenomenon. It is clear already that the study of human somatic mutation offers great promise: for biological dosimetry of mutagen exposure; for identification of repair defectives; for prediction of late effects, particularly carcinogenesis; and eventually as a tool for evaluating human environmental exposure and risk.
Polymer-linked guanine for the in vivo detection of carcinogens
Authors: Ashwell Mark , Bleasdale Christine , Golding Bernard T , O’Neill Ian K
Published: November 2023

A derivative of guanine, suitable for attachment to polyvinyl alcohol within magnetic microcapsules, has been synthesized. The polymer-linked guanine is to be used for the in vivo trapping and recovery of carcinogens. The linkage between the guanine and polymer contains a 1,2-diol unit, thus enabling the cleavage of modified guanine residues from the polymer, and their ultimate spectroscopic characterisation.
Ethylene/ethylene oxide and propylene/ propylene oxide: an evaluation of human biomonitoring and cancer risk
Authors: Bolt H M , Foest U , Marczynski B , Golka K , Hallier E , Peter H
Published: November 2023

Inhaled ethylene and propylene are both metabolized by rats to their epoxides ethylene oxide and propylene oxide. On the basis of pharmacokinetic data for metabolically formed ethylene oxide in rats, a first carcinogenic risk estimation for ethylene was published. Data for humans have been calculated from inhalation experiments with rats. Whereas ethylene is produced endogenously in rats and men, propylene and its reactive metabolite are only observed as anthropogenic air pollutants. For the endogenous production of ethylene, two sources are discussed.
Quantitation of tobacco-specific nitrosamineglobin adducts in humans
Authors: Hecht Stephen S , Kagan Mark , Kagan Shashi S , Carmella Steven G
Published: November 2023

This paper describes the results of our initial studies on the quantitation of tobacco-specific nitrosamine globin adducts in humans. Tobacco-specific nitrosamines are formed from nicotine and other tobacco alkaloids and are among the most important carcinogens in tobacco and tobacco smoke. 4-(Methyl-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N’ -nitrosonor-nicotine (NNN) are the strongest carcinogens in this group.
Haemoglobin adducts of aromatic amines as a dosimeter for exposure control and risk assessment
Authors: Neumann Hans-Günter , Birner Gerhard , Sabbioni Gabriele
Published: November 2023

N-substituted aryl compounds comprise a large family of industrial and environmental chemicals. This includes not only arylamines as such but also those chemicals which are convertible into arylamines (or reactive Noxidation products) such as nitroso-arenes and azo-compounds. Many of them are established or suspected carcinogens and their uptake increases the risk of developing tumours in humans. Exposure, therefore, should be controlled in order to identify major sources of hazard and to take preventive measures. Biochemical effect monitoring represents an improved procedure of exposure control, and we have proposed the analysis of a specific type of haemoglobin adducts of N-substituted aryl compounds as a specific dosimeter (cf. reviews in refs 1 and 2). This chapter summarizes more recent results indicating the general applicability of this method for exposure control and provides material indicating the difficulties in the use of this kind of information for risk assessment.
The separation and analysis of high-density lipoprotein (HDL) and low-density lipoprotein (LDL) subfractions
Authors: Skinner E Roy
Published: November 2023

Plasma HDL performs a wide variety of functions. In addition to its central role in lipoprotein metabolism (1) in which it provides a reservoir for small apoproteins and is implicated in the removal of surface material during the lipolysis of triglyceride-rich lipoproteins, HDL is intimately associated with the process of reverse cholesterol transport (2). In this pathway, it provides an acceptor for cholesterol effluxed from peripheral cells and serves as a carrier of this material to other lipoproteins for hepatic uptake and excretion. HDL provides steroidogenic and other tissues with a source of cholesterol by means of specific receptors (3). It is also reported to promote endothelial cell proliferation (4), to protect LDL against oxidation (5), and reduce the rate of post-prandial lipaemia (6). With such a diversity of functions, it is not surprising that HDL is highly speciated. The similarity in the composition of the various subspecies, however, has made their separation a task that has, until recently, largely eluded the attempts of most investigators; the current belief that the interactions of subspecies is likely to account for the protective effect of HDL against atherosclerosis (7) has provided a considerable stimulus for further analytical studies.
Lipoprotein - receptor interactions
Authors: Arnold Kay S , Innerarity Thomas L , Pitas Robert E , Mahley Robert W
Published: November 2023

The interaction of lipoproteins with their receptors is the first step of a homeostatic mechanism that controls plasma cholesterol levels, intracellular cholesterol metabolism, and lipoprotein catabolism. The classic studies of

M. S. Brown and J. L. Goldstein (Univ. of Texas, Dallas) have demonstrated the significance of low density lipoprotein (LDL) receptors in supplying cells and tissues with cholesterol and in removing plasma lipoproteins via the liver (1). Other less well-defined lipoprotein receptors are the chylomicron remnant receptor (apolipoprotein E receptor), the high density lipoprotein (HDL) receptor, the acetyl LDL receptor (scavenger receptor), and the immunoregulatory receptor. While each of these receptors is unique, many of the procedures developed for the characterization of the LDL receptor can be applied to study other receptors (2-4).
Isolation and characterization of proteoglycan core protein
Authors: Hascall Vincent C , Yanagishita Masaki , Calabro Anthony , Midura Ronald , Rada Jody A , Chakravarti, Shukti , Hassell John R
Published: November 2023

Proteoglycans have one or more glycosaminoglycan chains covalently bound to a core protein or glycoprotein. Normally, the glycosaminoglycans, with the exception of hyaluronic acid, contain numerous sulfate ester groups (see Chapter 9). This makes proteoglycans highly polyanionic and confers upon them distinct properties, such as large hydrodynamic volumes and, frequently, high buoyant densities. These properties can be used to advantage in purification and characterization steps. The isolation of proteoglycans first requires effective extraction from cells or tissue and then separation from other extracted macromolecules. Because of the wide diversity of core proteins, there is no universally applicable set of procedures that will be satisfactory for every proteoglycan. Thus the protocols described below, while generally useful, may require modification to adapt them for use in any particular problem. They are chosen to illustrate general principles which can help investigators choose optimal combinations for their particular needs.
Multif actorial inheritance
Authors: Young Ian d.
Published: November 2023

Many disorders show familial clustering which does not conform to any obvious pattern of Mendelian inheritance, as the incidence figures in close relatives are usually considerably less than would be anticipated if the conditions in question were caused by single genes, recessively or dominantly inherited. Examples are found in all age groups and include many relatively common congenital malformations such as spina bifida and cleft lip/palate plus disorders of adult life such as schizophrenia and epilepsy. For want of a better term these conditions are said to show multifactorial inheritance. Multifactorial inheritance is thought to involve the interaction of adverse environmental factors with an innate susceptibility determined by the additive effects of many genes. If only genetic factors are involved then the term polygenic inheritance is applied. Several ingenious hypotheses and models have been proposed to explain the likely underlying genesis of these disorders. These models are usually based on the assumption that the disorder represents the ‘visible’ tail end or extreme of an underlying characteristic believed to show a normal distribution curve in the general population. Discontinuity of the phenotype (i.e. affected or unaffected) is explained by superimposition of a threshold beyond which morphogenesis or homeostasis goes awry. The concept of multifactorial inheritance and its limitations have been discussed in a lucid and amusing review by Fraser.1
Oligoribonucleotide Synthesis
Authors: Gait Michael J , Pritchard Clare , Slim George
Published: November 2023

It is remarkable to note that, compared with a 2’-deoxyribonucleoside, the presence of a single extra hydroxyl group at the 2’-position of a ribonucleoside has given rise in recent years to so many headaches for chemists attempting to assemble oligoribonucleotide chains. For example, whereas machine-aided assembly of oligodeoxyribonucleotides has been established for some years (Chapter 1), only very recently has it been possible to assemble oligoribonucleotides satisfactorily using mechanized solid phase procedures. Part of the difficulty here has been the need to find a combination of compatible protecting groups for the ribonucleoside 2’- and 5’-hydroxyl groups. Thus in solid phase synthesis with chain assembly proceeding in a conventional 3’-to 5’-direction, 5’-terminal protecting groups must be selectively removed at every cycle of ribonucleotide addition, whereas 2’-protecting groups must remain intact throughout all steps of oligoribonucleotide assembly and must be removed specifically at the end of the synthesis without leading to chain migration or internucleotidic cleavage. Further problems stem from the less facile coupling reactions and hence slightly poorer coupling efficiences obtained hitherto in oligoribonucleotide synthesis. In addition, oligoribonucleotides are highly susceptible to degradation by ribonucleases, which are ubiquitous and difficult to remove, and therefore the utmost care must be taken during all purification steps.
Die psychologische Wirkung der Farben und Formen und der Einfluss des Label-Design auf das Marken-Image und auf die Geschmacksempfindung
Authors: Lüscher M
Published: November 2023

Diese Erkenntnisse werden beniitzt, urn das Corporate-Design und Label-Design farblich und formal zu definieren und zu gestalten, urn das beabsichtigte Image zu erzeugen. Jede Zielgruppe soil mit den ihr entsprechenden Farben und Formen angesprochen werden.
Plants after next: Brewing in the next century
Authors: MacLeay Alastair
Published: November 2023

Technical opportunities concern changed understanding of raw materials and their inter-relationship with processing plants; the ability to process raw materials off line and add brewing characters post fermentation; new approaches to product development; new opportunities in barley and yeast genetics; new brewing unit operations and packaging innovation. All create the background to economic benefit and greater flexibility in an increasingly volatile market place.
Novel gushing promoters derived from hops
Authors: Moir M , Dobson G , Seaton J C
Published: November 2023

Bien que 1’utilisation d’extrait de houblon isomerise soit plus economique que celle du houblon ou de pellets, de nombreux brasseurs craignent 1’introduction dans la biere en bouteilles ou en boites, de promoteurs de surmoussage.
The influence of cell wall composition of a brewer’s flocculent lager yeast on sedimentation during successive industrial fermentations
Authors: Teixeira J M , Teixeira J A , Mota M , Manuela M , Guerra B , Cruz J M Machado , Almeida A M Sa
Published: November 2023

The cell wall biochemical composition of a Saccharomvces uvarum flocculent strain before and after flocculation expression was analysed. No difference in total carbohydrate and protein content and on PAGE patterns of cell wall proteins was measured. Anyway, enzymatic treatment demonstrated that a protein must be envolved in the flocculation mechanism.
Konstruktion und Anwendung glucanolytischer Hefen
Authors: Kunze G , Schulz R , Biittner R , Barner A , Bode R
Published: November 2023

In order to transfer β-glucanase activity the bglM, bglA and bglHl genes of B. macerans, B. amvloliquefaciens and a hybrid gene containing sequences from both species were transfered into yeasts on a multicopy plasmid and also integrated into the yeast genome.
Immobilized yeast in brewing—A current perspective
Authors: Ryder David S , Masschelein Charles A
Published: November 2023

This paper describes recent advances in immobilized yeast cell technology and the current commercial options practically applicable to the brewing process, for rapid fermentation and/or maturation, in the production of malt beverages with defined organoleptic/analytical spectra.
Mash filtration difficulties caused by split barley kernels: a microbiological problem
Authors: Haikara A , Home S
Published: November 2023

The occurrence of split barley kernels is well known in different countries and leads to mash filtration problems. These are currently solved by rejecting barley lots containing too high counts of split kernels. In our studies on split barley kernels lactic acid bacteria, pseudomonads and enterobacteria multiplied heavily during pilot malting. The Tepral filtration method revealed a strong dependence of filtration difficulties on the percentage of split barley kernels in the sample. Addition of bacterial mass to the mashing and artificial contamination of squeezed barley kernels with different bacteria retarded mash filtration depending on the strain.
Enhancement of flavour in beers with reduced alcohol contents
Authors: Muller R E , Barrett J , Baxter E D
Published: November 2023

High gravity brewing is frequently accompanied by a disproportionately high synthesis of ester compounds during fermentation. Such disproportionate ester synthesis can be utilized to allow the production of beers with reduced alcohol contents while maintaining flavour active ester levels within target specifications for full strength beers. The manipulation of other fermentation parameters, including temperature, wort aeration and carbon to nitrogen ratios can be used to adjust the fusel oil content of the final beer. Manipulation of each parameter results in different changes in the fusel oil profile, and can be exploited to achieve desired flavour characteristics.
Technik und Technologic eines stromungstechnisch optimierten Würzekochers
Authors: Esslinger H M , Michel R , Salzgeber B
Published: November 2023

By increasing the turbulences in the fluid flow, the heat flux also rises. The increase of the total heat transfer coefficient is leading to a decrease of heat exchanger area for a given rate of heating up the wort or a given rate of evaporation. The smaller heating area results in lower costs of investment and a smaller local want for installing the apparatus. But the smaller volume of the apparatus leads to a smaller need of cleaning liquid, too.
Organischer Kohlenstoff im Brauereibriiden als Prozess- und Emissionskontrollparameter
Authors: Müller Dr.-Ing. Klaus
Published: November 2023

The carbon compounds in mash and wort vapours have been measured using a special flame ionisation detector. The time course of emission during brewing gives an insight into the stripping of aroma substances in various mash and wort boiling procedures.
Fracture properties of starch gels
Authors: Luyten H , G.Ramaker M , Vliet T Van
Published: November 2023

Fracture properties of starch gels are, in contrast with their small deformation properties, clearly time dependent. Fracture stress and deformation at fracture increased with increasing rate of deformation. A possible explanation for this is friction between the granules during large deformations.
Correlating instrumental measurement and non-oral sensory evaluation of texture mixed gels
Authors: Damasio H M , Costell M , Izquierdo L , Duran L
Published: November 2023

This work deals with the study of the relationships between instrumental measurements and non-oral texture of Kappa carrageenan (C)locust bean gum (LBG) gels and C-LBG-guar gum (GG) gels. The study was performed in two series of 7 samples of 0.5 and 0.75% total hydrocolloids concentration, the proportion of gum varying from O to 60%. Instrumental ( 8 parameters) and sensory ( 10 parameters) data were examined by multidimensional scaling and two similar bi dimensional maps were obtained. Good correlations were obtained by multiple linear regression between each of the t n sensory parameters and two or more instrumental parameters ( R ) 0. 90). Good correlations were also found by simple linear regression between seven sensory and seven instrumental parameters (0.65 r 0.92).
The rheology of thin liquids
Authors: Schenz Timothy W , Fugitt Mitchel
Published: November 2023

The instrumental measurement of the rheology of low viscosity liquids has been a difficult task. With the advent of controlled stress rheometers, however, it is now possible to characterize the rheology of fluids with viscosities as low as 1 mPa · s. This sensitivity is especially useful in applications in the food and beverage industry. This paper will discuss a few such applications to low viscosity food systems stabilized with hydrocolloids and proteins. The effect of these stabilizers on the structure of low viscosity food will be explored not only in terms of its viscosity but also in terms of its viscoelastic properties.
Rheology of iota-carrageenan gels containing small amounts of kappa-carrageenan
Authors: Piculell Lennart
Published: November 2023

Measurements of the temperature-dependent rheology of the sodium and potassium forms of native and kappa-carrageen’s treated iota-carrageenan, with or without small additions of kappa-carrageenan, were performed. In the presence of potassium, which promotes gelation of kappa-carrageenan, samples containing a sufficient concentration of kappa-carrageenan (either added or present as impurities) show a substantial enhancement of the elasticity, whereas no ion specificity was seen for pure iota-carrageenan.
The functional properties of food proteins
Authors: Tolstoguzov Vladimir B
Published: November 2023

The effect of the thermodynamic incompatibility of proteins and polysaccharides on protein functional properties such as solubility and protein behaviuor at the water oil interface has been discussed. Incompatibility of chemically or structurally dissimilar biopolymers leads to an increase in their thermodynamic activity in mixed solutions. The influence of the addition of polysaccharides on the stability of protein-stabilized emulsions can not be only attributed to an increase in the continuous phase viscosity. The incompatibility of biopolymers in the aqueous continuous phase of emulsions manifests itself in an increased density of the monolayer coverage of dispersed particles and in a decreased critical protein concentration required for the formation of multilayer coverage of dispersed particles, it also has a strong impact on emulsion flocculation.
Gelling temperature of model gels and industrially produced fruit jellies made with HM- and LM-pectin
Authors: Soderberg Jorgen R , Krag-Andersen Sven
Published: November 2023

A new method for determining the gelling temperature, based on the change in thermal conductivity when gelation starts, was used to characterize HMand LM pectin gels. The basic model gel system was the socalled IPPA gel, i. e. an imitation of fruit juice gel with pH 3.1, soluble solids 65%. The system was modified regarding soluble solids and calcium-ion concentration. Comparison is made between gelling temperatures determined in model systems and in industrially produced jellies.
On the characterisation of food emulsions and dispersed hydrocolloid particles by optical methods
Authors: Lips A , M.Hart P , D.Evans I , Debet M
Published: November 2023

Instruments based on static light scattering with simultaneous multi-angle detection hold promise for both fundamental and applied studies on food systems. We have considered the quantitative reliability of the Malvern Mastersizer technique for characterising size distributions and disperse phase volume in model food emulsions and dispersions of swollen hydrocolloid gel particles with complicated refractive index behaviour. We have also examined systems containing non-spherical particles including dispersions in which there is ramified aggregation of particles. Theoretical reasoning is presented which draws attention to the relative insensitivity of the Mastersizer measurement of disperse phase volume to particle shape. Measurements on a range of model food systems bear out this prediction. Attention to the optical measurement of disperse phase volume is therefore recommended as a general priority in studies based on the Mastersizer not least as a check for internal consistency of the light scattering interpretation. Direct use of this measurement in studies of swelling of hydrocolloid particles has been shown to be feasible. For ungelatinised starch granules and model Sephadex beads, the swelling ratios inferred by the optical method are in satisfactory agreement with estimates obtained by the conventional method of exclusion of Blue Dextran.
Mechanisms of flocculation in oil-in-water emulsions. Differentiation by creaming behaviour
Authors: Fillery-Travis Annette J , Gunning Paul A , Hibberd David J , Robins Margaret M
Published: November 2023

Experimental data are reported on the creaming behaviour of two oil-in-water emulsion systems, containing polysaccharide. It is demonstrated that flocculation of the droplets occurs in both systems, but that the detailed behaviour differs. Type A emulsions exhibit rapid formation of coexistent phases at certain polymer concentrations, and the behaviour is consistent with a volume restriction (depletion) mechanism. Type B emulsions exhibit very slow flocculation which is consistent with bridging of droplets by adsorbed polymer.
The production of heat stable gels at low protein concentration by the use of the Maillard reaction
Authors: E.Hill S , R.Mitchell J , J.Armstrong H
Published: November 2023

A range of globular proteins show gelation when aqueous solutions are heated at temperatures above 100°c in the presence of reducing sugars. The phenomena has been studied in some detail for bovine serum albumin. The gel strength follows the Maillard series for sugar reactivity (xylose > sorbose > mannose >fructose> lactose) and correlates with the degree of browning which develops. It is shown that the primary mechanism is a pH fall, however a change in the net protein charge due to the Maillard reaction is suggested from reduction in the pH at which the denatured protein precipitates from solution. In contrast to gels prepared at a similar pH by the use of glucono-.s-lactone and heat, the Maillard gels are not completely solubilised in mixtures of sodium dodecyl sulphate and B-mercaptoethanol suggesting that Maillard cross-linking is also important. Gel formation in this way is compared with heating in the presence of glucono-li-lactone.
Characterisation of gelation of konjac mannan using lyotropic salts and rheological measurements
Authors: Case Suzanne E , Knopp James A , Hamann Donald D , Schwartz Steven J
Published: November 2023

The rheological response of konjac mannan (KM) resembles that of a rubber elastic, in spite of the fact that no covalent links are present in gel stabilization. However, the presence of hydrophobic interactions were identified in the KM gel. Four polymers (gelatine, methylcellulose, pectin and acrylamide) which form gel networks of known bonding stabilization (i. e. hydrogen, hydrophobic, etc.) were surveyed for their rheological response (change in rigidity, G’) to thermal gradient scans. These curves were compared to the thermal gradient scan obtained for the KM gel. The KM gel had a similar rheological response to that of the rubber elastic covalently bonded acrylamide gel. Yet it showed the beginning of melting as it approached 100°C, as did the gel stabilized by a mixture of hydrophobic interactions and hydrogen bonds (pectin).
The heat-induced aggregation of β-lactoglobulin A: photon correlation spectroscopy studies
Authors: Griffin M C A , C.Price J , G.Griffin W
Published: November 2023

The heat-induced aggregation of P-lacto globulin A <P-LG-A) has been investigated using photon correlation spectroscopy (PCS). A quench technique will be described which makes it possible to ‘freeze’ the aggregation process after a chosen time interval. PCS measurements on the quenched samples of heat-aggregated P-LG-A reveal that a maximum in hydrodynamic radius occurs at a critical temperature which is itself dependent on the ionic environment of the protein. Kinetic studies using the quench technique indicate that two aggregation processes may be brought into play by heat-treatment of P-LG-A solutions and the role of temperature in controlling the predominance of one process over the other results in the observed maximum.
Use of protein (serine/threonine) kinase activators and inhibitors to study protein phosphorylation in intact cells
Authors: Hidaka Hiroyoshi , Kobayashi Ryoji
Published: November 2023

A complete understanding of the organization and functioning of a protein phosphorylation system requires the co-operation of several different approaches, such as molecular pharmacology, genetic manipulation, bio¬ chemistry, and cell biology. The advent of a new class of effective pharmacological agents is always an event of considerable interest, in particular for new types of antagonists, i.e. potentially important groups of compounds that act by specifically blocking one or more of the steps in intracellular signalling systems (1). There is now convincing evidence that intracellular protein phosphorylation systems are common mechanisms of fundamental importance in biological regulation. A large number of cellular mechanisms involving protein phosphorylation have been revealed over the past decade. However, interrelationships among each signal cascade are complex and uncertainties concerning the cellular responses in these systems remain. In order to better understand these events, improved and sophisticated methods for estimating changes in the activities of cellular response elements after extracellular stimulation have to be designed. While the biochemistry and molecular biology of protein kinases has progressed, it has been much more difficult to understand their function in intact cells. For this reason researchers studying second messenger systems and protein phosphorylation have long sought the development of specific and effective inhibitors that would permit the definitive determination of the physiological role of the protein kinases (2). Protein kinase inhibitors can be used to determine the physiological role of protein phosphorylation systems in various types of cells.
Fluorescent in situ hybridization
Authors: Buckle V J , Rack K A
Published: November 2023

The hybridization of RNA in situ to the DNA of a cytological preparation was first described by Gall and Pardue in 1969 (1) and the general principles of the technique they developed remain the basis of contemporary studies. During the 1970s this procedure was used to localize repeated sequences within the human genome by autoradiographic detection of radioactively labelled probes, and during the 1980s the sensitivity of this approach was refined sufficiently to permit detection of unique sequences of only 500 base pairs in length. At the same time non-isotopic detection procedures were being developed, which have several advantages over autoradiography including speed, safety, and resolution of signal. Advances in this area in recent years have revolutionized the applications for in situ hybridization as a tool in genome research. In particular the use of competitive hybridization means an enormous size range of cloned DNA sequences are now available for use as probes, and fluorescent detection systems now permit the concurrent visualization of multiple probes. These powerful new techniques provide a tool not only for examining the location and distribution of sequences on metaphase chromosomes but also for investigating organization within the interphase nucleus.
Fine mapping of genes: the characterization of the transcriptional unit
Authors: Antoniou M , Grosveld F , Deboer E
Published: November 2023

The fine mapping of genes includes a number of different techniques at several different levels of analysis. To include all these steps, to progress from a (partial) protein sequence or some detection method of the gene in question, to a complete determination of the transcriptional unit of that gene is beyond the scope of this chapter. The first part will, therefore, briefly indicate the various methods used to obtain cDNA and genomic DNA clones from a particular gene and will refer to a number of reviews on these topics. The second part will describe in more detail how to use such cDNA and/or genomic clones to analyse the transcriptional unit of the gene. The third part will indicate how to use this information to start the analysis of potential control regions of the gene.
Preparation of central nervous system tissue for light and electron microscopy
Authors: Bolam J P
Published: November 2023

Techniques of experimental neuroanatomy are those that enable one to characterize the position of neurones in the microcircuits of the nervous system on the basis of their morphology, chemistry, and connections. The essence of the techniques are that the morphology, chemistry, and output region of neurones are identified first at the light microscopic level and then the chemistry, origin, and pattern of afferent synaptic input are identified at the electron microscopic level. Information of this nature is a pre-requisite to the characterization of the microcircuitry or neuronal networks of a region and provides a framework within which functional data can be interpreted. For the analysis of individual neuronal elements or populations of neurones in the microcircuitry of an area it is necessary to examine the tissue at the light microscopic level. For the analysis of synaptic interactions of individual neurones or populations of neurones, it is necessary to examine the tissue at the ultrastructural level with an electron microscope. The object of this chapter is to introduce to the reader the basic techniques used in the preparation of tissue from neuroanatomical experiments for light and electron microscopy.
Anterograde tracing with PHA-L and biocytin at the electron microscopic level
Authors: Smith Yoland
Published: November 2023

The neuronal circuitry of the mammalian brain is an extremely complex meshwork of highly ordered interconnections between billions of neurones. In order to be able to analyse and understand the organization of the circuitry of the central nervous system (CNS) it is essential to label a particular population of axonal structures to differentiate them from the unlabelled elements and study their connections.
Immunocytochemistry I: pre-embedding staining
Authors: Totterdell S , Ingham C A , Bolam J P
Published: November 2023

Immunocytochemistry is a technique which has become widely used in experimental neuroanatomy. It enables one to morphologically characterize neurones containing a specific chemical moiety, and since the major means of communication between neurones in the nervous system is by chemical transmission, immunocytochemistry represents one of the most powerful techniques available to the experimental neuroanatomist in the study of the nervous system. The approach relies on the fact that an antibody directed against a specific substance will bind avidly to that substance. With antibodies directed against neurotransmitters or an enzyme related to the neurotransmitter it is possible to morphologically characterize those neurones expressing the transmitter (or enzyme), to analyse their afferent synaptic input, and by analysis of terminals that are immunostained, to analyse their synaptic output. Furthermore, immunocytochemistry can be used to detect exogenous substances, for instance the anterograde axonal tracers Phaseolus vulgaris-Ieucoagglutinin (PHA-L).
Intracellular Lucifer Yellow injection in fixed brain slices
Authors: Buhl Eberhard H
Published: November 2023

Intracellular filling of neurones with Lucifer Yellow (LY) in fixed brain slices is a relatively novel anatomical tool to determine neuronal geometry (1, 2). In the absence of electrical activity, the procedure is based on direct visual guidance of the dye injections, therefore providing an inherently high degree of staining selectivity. Moreover, being highly compatible with a variety of other neuroanatomical protocols, intracellular filling in fixed tissue is an attractive technique to unravel neuronal microcircuitry (3, 4).
Analysis of Calcium Involvement in Host-Pathogen Interactions
Authors: Drobak Bjorn K , Bush Douglas S , Jones Russell L , Dawson Alan P , Ferguson Ian b.
Published: November 2023

Calcium has often been associated with pathogenic infections in a variety of plant tissues; but the processes involved are still poorly understood. However, present evidence suggests that Ca2+ is likely to be involved in three major areas of the host-pathogen interaction (see Sections 1.1-1.3). Maintenance of relatively high concentrations of Ca2+ in the plant cell wall may reduce cell wall breakdown induced by fungal attack. For instance, in bulky tissues such as potato tubers and carrot roots, increased concentrations of Ca2+ have been associated with reduced levels of infection of pathogens such as Sclerotium rolfsii (1). The soft-rot symptoms found in many storage organs are associated with pectinases, whose activity may be modified by the Ca2+ status of the cell walls. The role of Ca2+ generally in cell wall breakdown has still not been fully elucidated (2, 3), and there are difficulties in measuring fractions of Ca2+ in the cell wall which have any physiological meaning. The pectic lyases of Erwinia sp. are Ca2+ dependent (4). Phospholipases A, C, and D, which are all involved in the degradation of membrane lipids, all have degrees of Ca2+-dependence, which may influence the effectiveness of such pathogens as the blast fungus. The other major groups of enzymes which show Ca2+-dependence are the Ca2+-ATPases and protein kinases, which in many cases are additionally stimulated by the Ca2+-binding protein calmodulin.