bluuebunny/crossref_metadata_2025 huggingface dataset:
Cytogenetics in myeloid leukaemia
Authors: Potter M , Watmore A
Published: November 2023

In this chapter we consider three haematological disorders of myeloid cells: acute myeloid leukaemia (AML), the myelodysplastic syndromes (MDS), and myeloproliferative disease (MPD). Both MDS and MPD have a propensity to evolve to an acute leukaemia indistinguishable clinically from a de novo AML. Indeed, the differential diagnosis in these cases may be simply based on the blast count. The poorly defined boundaries between disorders is reflected in the commonality of the chromosome findings in the three conditions.
Assay and purification of protein (serine/threonine) phosphatases
Authors: Mackintosh Carol
Published: November 2023

Protein phosphatases comprise several families of enzymes that catalyse the dephosphorylation of intracellular phosphoproteins, thereby reversing the actions of protein kinases. This critical property of the reversibilityof intracellular protein phosphorylation allows for great sensitivity of control and integration of cellular regulation.
Combined approaches to experimental neuroanatomy: combined tracing and immunocytochemical techniques for the study of neuronal microcircuits
Authors: Smith Yoland , Bolam J P
Published: November 2023

Most of the chapters in this volume have so far dealt with individual techniques in experimental neuroanatomy at the electron microscopic level. From these techniques we can identify projection neurones and examine the morphology of their afferent terminals. Moreover, the structural characteristics of the post-synaptic target of a set of anterogradely labelled terminals can be analysed from material containing immunostained structures, or intracellularly labelled neurones. These approaches in themselves produce valuable information concerning neuronal elements within the microcircuits and networks of the brain. However, the amount of data obtained using such approaches is limited in the sense that the identified structure is examined ‘in isolation’. In order to establish the position of an identified neurone, or population of terminals within the neural network in relation to other neuronal elements, it is necessary to know the nature of the terminals afferent to a labelled neurone, or the nature of the post-synaptic targets of identified terminals. By this we mean that it is necessary to know the origin, neurochemical nature, and pattern of innervation of the synaptic terminals afferent to an identified neurone. Similarly, it is important to know the morphology, the chemical nature and the synaptic output of the neurones that are post-synaptic to a specific population of labelled terminals. Thus, to establish the microcircuitry or neuronal networks of a particular area of the brain it is necessary to combine the individual experimental approaches in a single experimental animal.
Analysis of protein phosphorylation in cell lines
Authors: Woodgett James R
Published: November 2023

Protein phosphorylation now is regarded as the pre-eminent mechanism of post-translational regulation. Its reversibility, rapid kinetics, and specificity of effect has resulted in its exploitation by most systems of cellular control. Hence, studies of the mechanisms by which cells transduce and respond to signals commonly involve some aspect of this covalent modification. The ability to introduce high specific activity radioisotopes into cultured cells, together with their ease of manipulation and harvest, has made cell lines the system of choice for studying the dynamic processes of protein phosphorylation. In this chapter are described basic techniques for assessing the influence and role of phosphorylation in a given process using cultured cells. Given the increasing realization of the importance and ubiquity of this form of modification, these methods should be of widespread use to researchers wishing to dissect the molecular bases of cellular controls.
Analysis of viral sequence variation by PCR
Authors: Simmonds Peter , Chan Shiu-Wan
Published: November 2023

Sequence analysis has played a fundamental part in virological research since methods for the determination of nucleotide sequences were developed in the late 1970s (1, 2). However, these techniques require relatively large amounts of template DNA which are often obtainable only by virus culture in vitro and DNA cloning. The dependence on virus isolation and the time required to construct and screen libraries have always been major impediments to such studies. The polymerase chain reaction (PCR) provides the means to amplify DNA specifically from any viral nucleotide sequence (3-6). The method is sufficiently sensitive and specific to allow direct amplification and sequence analysis of viral genetic material present in vivo, eliminating the need for prior virus isolation and cloning. The limitation of PCR for viral analysis is its dependence on detailed sequence information to specify the primers necessary for amplification. Therefore, the majority of PCR studies have been aimed at comparing large numbers of sequences over a relatively short region of the viral genome. PCR is intrinsically unsuitable for sequencing a complete viral genome; construction of libraries and screening with cloned viral DNA is likely to remain the method of choice for large sequencing projects for the foreseeable future.
Herpes simplex virus vectors
Authors: Rixon Frazer J , Mclauchlan John
Published: November 2023

As with other virus vector systems, one reason for using her pesviruses is to allow expression of proteins outside their normal environment so that their properties can be examined, either alone or in combination with other defined proteins. However, there is additional interest attached to herpes simplex viruses as vectors which relates to their ability to establish long-term latent infections in neuronal cells. This neurotropism implies that herpes simplex virus-based vectors may be used as tools to deliver genes of interest into neurones. Herpes simplex virus (HSY) is limited, as a natural infection, to man, where serological studies suggest an incidence of greater than 90%, but under laboratory conditions it has a wide host range in experimental animals and in tissue culture cells. Two serotypes of HSY are known: HSY-1 and HSY-2, which are typically associated with facial and genital lesions, respectively.
GPI membrane anchors: isolation and analysis
Authors: Ferguson Michael A J
Published: November 2023

Glycosylphosphatidyl inositol (GPI) membrane anchors are ubiquitous among the eukaryotes and are utilized by a wide variety of cell surface glycoproteins. The GPI anchor can be thought of as an alternative to the hydrophobic transmembrane polypeptide domain for membrane proteins anchorage. Discussions of the biosynthesis and the known and possible functions of GPI anchors have been extensively reviewed elsewhere (1–3). This chapter will concentrate on structure determination.
Tat trans-activator
Authors: Peterlin B Matija , Adams Melanie , Alonso Alicia , Baur Andreas , Ghosh Subir , Lu Xiaobin , Luo Ying
Published: November 2023

Several lentiviral promoters or their 5’ long terminal repeats (LTRs) are unusual among eukaryotic promoters in that they contain an RNA structure in their leader sequences which is important for their function (for review see refs 1-10). This RNA element is called the trans-activation response element or TAR (11). Interactions between TARs and virally encoded trans-activators called Tats greatly increase levels of viral replication and expression of all viral proteins (12-15). Translated from multiply spliced mRNAs that appear early in the viral life cycle, Tat primarily affects rates of elongation of transcription (16); however, effects of Tat on initiation of transcription and translation have also been reported (17, 18). Since human immunodeficiency virus type 1 (HIV-1) lacking Tat or TAR replicates poorly and does not cause cytopathology (19, 20), approaches designed to interfere with Tat or TAR might be useful in the treatment of acquired immunodeficiency syndrome (AIDS).
Auxiliary proteins of the primate immunodeficiency viruses
Authors: Gibbs James S , Desrosiers Ronald C
Published: November 2023

All known primate lentiviruses possess the essential structural genes gag, pol, arid env and the essential regulatory genes tat and rev. However, all of them possess at least three or four additional genes that are known to encode protein products and that are apparently unique to the lentivirus subfamily of retroviruses. In general, little is known about their functions (1). However, since they are likely to be important for some aspects of the virus life cycle, it is important that their functional roles be clarified. Such auxiliary genes are often referred to as ‘non-essential’ due to the fact that in many circumstances they may be mutated or deleted with little or no effect on virus growth in vitro. However, the importance of these genes for virus growth in cell culture often depends upon the particulars of the system employed. The extent to which a mutant virus is able to replicate appears to depend in many cases upon the host cell used, the particular virus being studied, the methods used for infecting the cell, and the methods used for monitoring virus production. For example, cocultivation vs. infection or transfection, or the inoculum employed may affect the rate or extent of mutant virus replication. One major caveat of such studies is that the situation in cell culture may or may not be relevant to virus growth in vivo.
Mutational analysis: new mutations
Authors: Michaelides K , Schwaab R , Lalloz M R A , Schmidt, W , Tuddenham E G D
Published: November 2023

In the last few years the search for mutations and sequence polymorphisms has been dramatically accelerated by the use of PCR and subsequently by direct sequencing of PCR products (1, 2). In spite of these powerful new methods, direct sequencing is not always practicable in detecting mutations because they may be positioned anywhere in some of the very large genes which are being studied. For example, mutations have now been found in nearly every one of the 26 exons of the factor VIII gene. Thus a number of prescreening methods have been developed, such as discriminant oligonucleotide hybridization (3), enzymatic (4) and chemical cleavage methods (5), single stranded conformation polymorphism (SSCP) (6) and denaturing gradient gel electrophoresis (DGGE) (7). These methods are described and by way of example, some results of their application to screening the coding sequences and splice sites of the factor VIII gene for mutations amongst haemophilia A patients (8-10) are shown.
Procedures for isolating yeast DNA for different purposes
Authors: Wach Achim , Pick, Horst , Philippsen Peter
Published: November 2023

The DNA isolation procedures described in this chapter have been extensively used with Saccharomyces cerevisiae strains. However, they can be adapted for other Saccharomyces species and for other yeast genera. The demands with respect to purity, size, and amount of yeast DNA can be very different and mainly depend on the type of experiment to be performed, e.g. DNA hybridization for screening many strain isolates for rearrangements, to verify the status of transforming DNA, or to search for homologous sequences; re-isolation of recombinant yeast plasmids for transformation into Escherichia coli; PCR-type reactions; construction of gene banks with partially cleaved and size fractionated DNA; or DNA ligations on a preparative scale. (The isolation of chromosomal sized DNA for electrophoretic karyotyping is discussed in Chapter 5.)
Radiometric methods for detection in blots
Authors: Laskey R A
Published: November 2023

Radioisotopes are used extensively to label probes for many blotting applications. This chapter considers the best methods for detecting them efficiently. The most widely used methods involve autoradiographic detection on X ray film. Autoradiographic methods can provide a good combination of sensitivity and resolution, and they do not require investment in expensive capital equipment. In spite of claims to the contrary, accurate quantitation can be achieved easily. For direct autoradiography without intensifying screens or scintillators, the response of the film is inherently linear until it reaches saturation (1, 2). When intensifying screens or fluorographic scintillators are used to increase sensitivity, the response of film to the light they produce is non-linear but it can easily be made linear by pre-exposing the film to a flash of light (1, 2). Phosphorimagers offer a new alternative to film detection methods. Although they involve a high initial capital expense, they offer increased sensitivity for most of the radioisotopes commonly used in biological sciences, the exception being tritium (3H). They also offer linearity over a wide dynamic range.
Use of peptide ligands for the detection of binding proteins by Western blotting
Authors: Hossenlopp Paul , Binoux Michel
Published: November 2023

Western ligand blotting is a variation of the method of protein analysis first described by Towbin (1) in a pioneering article, ‘Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets’, and subsequently referred to as ‘Western blotting’. The technique involves electrophoretic separation of proteins which are then transferred to a nitrocellulose or equivalent membrane where they are recognized either by an antibody (this was the method reported by Towbin, known as immunoblotting) or by a specific ligand (known as ligand blotting). Towbin had foreseen the use of ligands, since in the conclusion to his article he predicted that his technique would become applicable not only to identification of proteins by antibodies, but, more generally, to analysis of any specific interaction between a protein and its ligand (nucleic acid, nucleotide, hormone, or another protein).
Renaturative catalytic blotting of enzyme proteins
Authors: Zhu Jia-Shi , Gray Gary M
Published: November 2023

Unlike receptor proteins (see Chapter 14) which may recover appreciable ligand-binding activity after full denaturation and renaturation, the active sites of enzyme proteins are usually more fragile, presumably because their catalytic function requires a highly restricted conformation to facilitate both high-affinity binding and subsequent catalysis of their specific substrate. Many enzymes are large membrane-associated glycoproteins having a hydrophobic anchor and are rich in glycosylated domains. Traditional biochemical studies and the cDNA-derived amino acid sequences have provided considerable information about the primary and subunit structures of the enzyme proteins, but little is known of the native conformation of many membrane-associated enzyme proteins.
Lactococcal plasmid vectors
Authors: Leenhouts K J , Venema G
Published: November 2023

Lactic acid bacteria comprise a heterologous group of organisms that are used in the fermentation of milk for the production of various types of cheese, buttermilk and yoghurts, meat, and vegetables. They are all Gram-positive bacteria and, as indicated by their name, they produce lactic acid during fermentation. An important species of this group is Lactococcus, consisting of only two subspecies: L. lactis subsp. lactis and L. lactis subsp. cremoris. This chapter will be limited to a description of a number of host vector systems and their use in the application of recombinant DNA technologies in Lactococcus, although some of these systems are also potentially useful in other bacteria, including Gram-negatives.
Use of λ-plasmid composite vectors for expression cDNA cloning
Authors: Miki Toru , Aaronson Stuart A
Published: November 2023

Plasmid vectors provide straightforward approaches to clone and analyse genes of interest. They are easily manipulated, and a number of versatile plasmid vectors have been developed. Phage vectors have also been developed and successfully applied to cDNA cloning. Use of phage vectors has several advantages. For example, gene expression by λ phage can be much more tightly regulated than with plasmids. Moreover, cell viability is required only when phages are propagating in host cells.
Molecular genetics of purple bacteria
Authors: Lee Jeong K , Kaplan samuel
Published: November 2023

In 1957 Cohen-Bazire et al. (1), noted that light intensity, as well as O2 tension could dramatically and immediately alter the cellular bacteriochlorophyll (Bchl) content of photosynthetically growing cultures of Rhodobacter sphaeroides. It became clear that the cellular levels of Bchl reflect the presence of three Bchl-carotenoid (Crt)-protein complexes (2-4) which in turn are part of the inducible photosynthetic membrane structure, referred to as the intracytoplasmic membrane (ICM) (5). Subsequent studies detailed the earliest events in light entrapment and were pioneered by many investigators, one of the earliest being Rod Clayton (3). Biochemical studies of the pathways involved in Bchl and haem were pioneered by June Lascelles and her many colleagues (6).
Solid-phase peptide synthesis
Authors: Walker Brian
Published: November 2023

The chemical synthesis of oxytocin, with biological activity indistinguishable from that of the native hormone, by du Vigneaud and co-workers in 1953, represents a landmark in the application of synthetic peptides to the study of biology (1). This pioneering work earned du Vigneaud the Nobel prize for chemistry and established unequivocally the pivotal role of synthetic chemistry in peptide structure-function studies. The synthesis of this nonapeptide hormone required many months of effort and involved the combined industry of four experienced synthetic organic chemists (2). It was this labour-intensive feature that prompted Merrifield, in 1964, to introduce the solid-phase approach for the rapid production of synthetic peptides (3). This methodology has revolutionized the synthesis of peptides and has made an inestimable impact on the study of their biological activity. Fittingly, Merrifield was also awarded the Nobel prize for chemistry in 1986.
Preparative immunoaffinity techniques
Authors: Price Michael R , Beyzavi Kami
Published: November 2023

Immunoaffinity chromatography is one of the most powerful separative procedure-s for the purification of antigens or antibodies. The technique exploits the exquisite immunological specificity of their recognition and binding, which occurs even in complex mixtures. The procedure is highly empirical, but often separations resulting in purification of a product by several thousand-fold may be achieved by using simple chromatographic techniques. The technique has found application in the purification of diverse macro-molecules. This has been particularly enhanced over the last decade or so, following the development of hybridoma technology for the production of stable cell hybrids secreting homogeneous monoclonal antibodies of identical immunological and biochemical characteristics (1). Moreover, it is feasible to identify the epitopes for many monoclonal antibodies and, in the case of protein antigens, to prepare synthetic peptides corresponding to the native epitopes. This is being exploited in an attempt to enhance our understanding of the antigen-antibody interaction, and at the practical level to provide novel approaches in immunoaffinity techniques.
Non-isotopic DNA analysis
Authors: Dennis Lo Y -M , Mehal Wajahat Z
Published: November 2023

Advances in molecular biology have resulted in a rapid increase in knowledge of the human genome. To date, a large number of polymorphic systems has been described, many of which, for example the human leukocyte antigen (HLA) system, have many alleles and play an important role in human disease. The accurate and rapid genotyping of these multi-allelic systems, therefore, has important applications in research and potentially clinical diagnosis. The advent of the polymerase chain reaction (PCR) (1) has provided us with a powerful method for amplifying DNA sequences. The enormous amplification factor offered by the PCR allows the visualization of amplified products non-isotopically.
Thermal gelation of methylcellulose: mechanisms and structures
Authors: Haque A , Jones A K , Richardson R K , Morris E R
Published: November 2023

Thermogelation of methylcellulose occurs in two ‘waves’ of increase in rigidity (G’), preceded by an initial reduction at lower temperature. We attribute the reduction and first increase to progressive unfolding of bundles of chains held together by residual cellulosic structure, and the second increase to hydrophobic association of methyl groups exposed to the aqueous environment during the unfolding step. Consistent with this interpretation, the high-resolution 1H NMR signal is only partially (∼50%) visible in the solution state, and attains its maximum value towards the end of the first increase in G’, where transmission of light and strain-dependence of mechanical properties are also greatest. Optical rotation at temperatures up to this point shows sigmoidal transitions with the thermal hysteresis characteristic of formation and dissociation of aggregated assemblies. Both ‘waves’ of structure-formation are accompanied by enthalpic processes in DSC (endothermic on heating; exothermic on cooling). Dissociation of the gel network on cooling is attributed to the enthalpic advantage of re-forming the postulated cellulosic bundles. Addition of ethylene glycol increases G’ for the solution state, indicating that it destabilises the ‘bundles’ by acting as a solvent for the methyl substituents. At concentrations of ethylene glycol sufficient to eliminate the first ‘wave’ of increase in G’ (∼40% v/v), the resulting gels remain intact on cooling to 0°C.
Electrophoretic separation and characterization of barley and green malt endoproteinases
Authors: Jones B L , Wrobel R , Marinac L , Zhang N
Published: November 2023

Soluble nitrogenous compounds (amino acids, peptides and proteins) necessary for brewing quality beer are produced by proteinases during malting and mashing. These enzymes are critical to the brewing process. We have used two-dimensional electrophoretic separations to study green malt endoproteinases. We found many more endoproteinases in malt than were previously known, together with endogenous inhibitors. An understanding of these malt proteinases and their interactions with each other and with the inhibitors is essential for developing barleys having maximal malting quality and for selecting malting and mashing procedures that will yield worts containing optimal amounts of the various protein hydrolysis products.
Breeding high vigour barley—a short cut to fast maltings
Authors: Riis Preben , Pedersen Lars Haastrup , Bang-Olsen Kirsten
Published: November 2023

High seed vigour is a prerequisite for good malting barley. An investigation of the possibilities for breeding for higher vigour has been performed. Heredity studies of seed vigour and robustness in winter barley have shown significant genetic variations between varieties.
Kernel filling and malting barley quality
Authors: Duijnhouwer I D C , Grashoff C , Angelino S A G F
Published: November 2023

In order to improve malting barley quality, barley breeders need a definition of barley quality in terms of intrinsic grain quality characteristics rather than in terms of processing quality specifications. It is therefore essential to define these characteristics and provide a good translation into processing quality. Barley crops were grown under different assimilation conditions. A great variation in kernel filling and therefore in the size of mature kernels was obtained.
Total β-amylase in barley used as screening criterion for combined amylolytic activity in malt
Authors: Erdal K , Jensen M O , Kristensen M , Krogh J J , Riis P , Vaag P
Published: November 2023

The combined amylolytic activity of malt is often evaluated by Diastatic Power (DP). Using new specific colorimetric assays recently developed by McCleary B-amylase was found highly correlated to DP whereas only insignificant correlations were observed between DP and a-amylase/limit dextrinase. By modifying the extraction conditions a procedure for determination of total B-amylase in barley has been worked out.
Pulverschrot: Reaktionsgeschwindigkeiten beim Maischen und Abtrennung mit einem Dekanter
Authors: Richter K , Sommer K
Published: November 2023

During the wort preparation process finer grists allow faster reactions in mashing but they require different machines to separate the spent grains. The suitability of decanter centrifuges was examined for different types of grists.
Developments in yeast science and technology
Authors: Molzahn S W
Published: November 2023

For many years the scientific study of yeast has progressed faster than the advances in yeast technology applied to brewing. This paper considers key developments in yeast biochemistry, physiology and genetics as well as the parallel, but often unconnected advances in yeast technology. The reasons for the apparent failure to exploit fully our improved understanding of how yeast functions will be explored. Prospects for applying more of the available scientific knowledge to the benefit of the process and product will be discussed.
Neural network modeling: applications to brewing fermentations
Authors: D’Amore Tony , Celotto Guy , Austin Glen D , Stewart Graham G
Published: November 2023

Brewing fermentations are dependent on a number of initial ingredient and process variables. Neural network modeling is capable of establishing relationships between variables within sets of given input and output data. This technique is being employed to optimize and control wort composition, wort oxygen levels, and yeast pitching rates.
Optimal ester production by the application of the fed-batch principle to brewery yeast fermentations
Authors: Masschelein C A , Winkel L Van De , Debourg A
Published: November 2023

The ester synthesizing activity of alcohol acetyl transferase under batch fermentation conditions is subject to cyclic variations depending upon yeast growth and substrate availability. It is therefore clear that for achieving the full potential of brewing yeast to produce esters we need to conduct the fermentation at a single optimum condition.
The importance of being glycogen
Authors: Ryder David S , Masschelein Charles A
Published: November 2023

The energetic state of the yeast cell to produce the storage carbohydrates, glycogen and trehalose, is of profound importance to understanding the optimization of metabolic resilience under cellular “stress” conditions, as might be found at the conclusion of fermentation.
Novel differences between ale and lager brewing yeasts
Authors: Crumplen Rena , Amore Tony D’ , Slaughter Colin , Stewart Graham G
Published: November 2023

The differences between ale and lager yeast strains familiar to the brewing industry have been disregarded by the taxonomic grouping of brewing and non-brewing yeasts under the name Saccharomyces cerevisiae. Studies have been conducted to provide further evidence regarding the distinctiveness between ale and lager yeasts. In addition to the well-documented differences in growth temperatures, ability to utilize melibiose and giant colony morphology, ale and lager yeasts exhibit unique patterns of mixed carbohydrate fermentation, carbohydrate transport, flocculation, sulfite production and sensitivity to cations.
Practical experiments to improve foam stability
Authors: Haukeli A O , Wulff T O , Lie S
Published: November 2023

The following full scale experiments were performed in five plants, in order to improve the foam stability: acidification and increased mashing-in temperature, changes in the pretreatment of the yeast strains, wort aeration and fermentation temperature, and finally use of low levels of caramel malt in addition to lager malt.
Electronic measurement of beer aroma using an array of conducting polymers
Authors: Cope R , Molzahn S W , Gardner J W , P.J. Iredale
Published: November 2023

The sense of smell is a personal characteristic, with individuals differing both in their sensitivity and in their response to odours. This poses a challenge for the Brewing Industry which relies on subjective sensory profiling for monitoring beer quality and for the comparison of different beers. An instrument has been developed which contains an array of polymer sensors whose conductance changes when exposed to odorous molecules. The profile of sensor output is specific for a given beer. The instrument is designed to provide objective discrimination between beers and indicate the origin of sensory differences without recourse to complex analysis.
Carbonyl compounds during beer production and in beer
Authors: Grönqvist Anders , Virtanen Johanna Siirilä , Virtanen Hannele , Home Silja , Pajunen Esko
Published: November 2023

Aldehydes and ketones play a very important role in beer flavour. A new method for the simultaneous determination of several carbonyl compounds during beer production and in beer was developed. The method is based on direct derivatization with 0-(2,3,4,5,6-pentafluoro- benzyl)-hydroxylamine (PFBOA) and on gas chromatographic analysis with EC detection.
Untersuchungen flüchtiger Aromastoffe bei der Bieralterung mittels multidimensionaler Gaschromatographie
Authors: Lustig S , Miedaner H , Narziß L , Back W
Published: November 2023

The behaviour of beer volatiles during the staling process is still not fully understood. Therefore fresh and extremely aged beers were investigated by means of multidimensional gaschromatography. About 350 substances were identified, of which about 30 were of greater relevance for the aging process. Some of these compounds were quantified. The increase in concentration of these components shows a strong correlation to the appearence of stale flavour. Thus a good analytical criteria is given to evaluate flavour stability of beer.
Fermentation studies with pyruvate decarboxylase mutants of Saccharomyces cerevisiae
Authors: Hodgson J A , Woodward N A , Welsh L , Moir M , Brown J D
Published: November 2023

Acetate esters of higher alcohols formed during fermentation of worts by Saccharomyces cerevisiae have an important influence on beer character and flavour. The availability of specific higher alcohols for metabolic esterification is a factor controlling the levels of isopentyl acetate and isobutyl acetate formed. Fermentation and growth studies were performed on genetic constructs of yeast which have been deleted for the genes encoding pyruvate decarboxylase. This allowed the direct demonstration of a specific branched-chain oxo-acid decarboxylase responsible for higher alcohol synthesis.
Instrumente des Prozessmanagements im Dienste der Qualitätssicherung
Authors: Werzinger K , Krüger E , Golz H J , Högel J , Dombrowski D
Published: November 2023

In the process of establishing an open market within the European Community, companies are being subjected to extensive additional tasks and obligations within the framework to quality assurance. In the production area, the brewer must guarantee a correct, secure and documented process. For this purpose, a concept was developed for process analysis, documentation, optimization and security (PADOS). The essential features of PADOS are the production of flow and action charts for the production process together with the determination and evaluation of all possible risk factors involved.
Video/Image analysis system for the calcofluor malt modification method
Authors: Wackerbauer Karl , Camielo Michel , Hardt Rolf
Published: November 2023

Sample preparation is decisive for the quality of the results in the analysis of malt modification. The sanding and staining procedures have been optimized in order to get best contrast between fluorescent and non¬ fluorescent parts of the malt grains. By this the evaluation of the prepared clayblocks becomes much easier and the analysis results show better reproducibility.
Application of a radiofrequency permittivity biomass probe to the control of yeast cone cropping
Authors: Boulton C A , Clutterbuck V J
Published: November 2023

It has been demonstrated previously that a commercially available biomass sensor, which utilises the passive dielectrical properties of microbial cells, can be used to control yeast pitching rate. Presented here are the results of trials in which the sensor was used to determine the yeast content of process streams issuing from cylindroconical fermenters during cone cropping. Simultaneous off-line analyses confirmed that the probe detected viable yeast but did not respond to non-viable cells and trub. It is concluded that an in-line biomass probe can be applied to control automatically, yeast removal during fermenter run-down.
Sinebrychoff Kerava - a brewery for the 90’s
Authors: Pajunen Esko , Jääskeläinen Kimmo
Published: November 2023

Sinebrychoff’s new brewery on greenfield site in Kerava started brewing on December 1st 1992. Most modern and proven technology has been applied in planning and construction. Brewery lay-out is one level solution with central control room from malt to bright beer. The process is controlled an integrated automation system. The brewhouse has a capacity of 10 tons grist/brew and is equipped with mash filtration system and external wort boiling. In fermentation cylindro conical vessels up to 5,000 hl are installed combined immobilized yeast maturation and lagering system. All wort and treatment processes and operations are gathered to one processing area.
On-line measurement of dissolved nitrogen, oxygen in beer
Authors: Buttrick P , Ellicott M R T , Grant A P , Maule D R , Pyne N S
Published: November 2023

In the UK nitrogen is increasingly being added to filtered draught beer, to improve head performance. To facilitate control of the process of addition, an on-line gas chromatographic system, incorporating a novel sampling system, has been developed which has proved reliable in production use in measuring dissolved nitrogen (with an accuracy of± 1 mg/1) and oxygen. Two alternative systems were also evaluated. Both were based on gas separation foll_owed by thermal conductivity measurements. One was off-line and gave variable results, possibly due to the complication of the sampling system. The other was in-line and shows considerable promise once problems of flow variation are overcome.
Colloidal stabilization of lager beer
Authors: McMurrough I , Kelly R , Madigan D
Published: November 2023

Improvements in methods for determining the effects of pilot-scale dosage of beer with polyvinylpolypyrrolidone (PVPP) and silica hydrogel (SHG) on the removal of polyphenols and proteins, in relation to the colloidal stabilization of beer, were sought with the objectives of: 1) optimization of dosage rates 2) accurate shelf-life prediction 3) understanding better the influences of raw materials and their processing on colloidal stability.
Electron microscopical analysis of ion channels
Authors: Holzenburg Andreas
Published: November 2023

The initial steps in approaching the structural determination of ion channels should always include electron microscopical studies, which The latter criterion makes electron microscopy especially suitable for structural studies of proteins which are only available in small amounts (< 1 mg). 50 µl of a sample containing a total of 5 µg protein is, in principle, sufficient to elucidate the 3D structure of a protein! The instruments with the widest range of applications for structural studies of integral membrane proteins are the transmission electron microscopes (TEM). While the scanning TEM (STEM) is mainly used to determine the mass of biological macromolecules and/or macromolecular complexes by recording elastic annular dark-field images (an angular detector specifically retrieves elastically scattered electrons at large angles, i.e. dark-field images) which represent two-dimensional distributions of the projected mass (1, 2), the conventional TEM (CTEM) can be considered the main workhorse in structural molecular biology.
Cerebellar Granule cells
Authors: Cambray-Deakin Martin A
Published: November 2023

From a casual scan of the literature, it appears that rodent cerebellar granule cell cultures are being used in increasing numbers to address different questions in neurobiology. There are good reasons for this: the cultures are relatively easy to prepare, the starting material is neonatal rat pup thus avoiding the use of pregnant females to provide embryos, the resulting cultures are almost entirely of one cell type, and the cells produced are of relatively high yield for a neuronal culture. Granule cell cultures clearly constitute an excellent model system for studies of structural, biochemical, and electrophysiological devel opment (1,2). In some cases the highly ordered structure of the cerebellum allows parallel studies to be performed in vivo or in slice preparations.
Cerebellar Purkinje neurons
Authors: Cohen-Cory Susana
Published: November 2023

Cultured Purkinje neurons provide a good model for studying the roles of intrinsic neuronal properties, environmental signals, and cell-cell interactions during development and differentiation. Some of the cellular events that lead to the morphological and functional differentiation of Purkinje neurons, as well as the ontogeny and organization of the cerebellar circuitry are known. Moreover, due to the feasibility of electrophysiological and pharmacological manipulations in culture, Purkinje neurons have provided an excellent system for studying the development of neuronal electrical activity and transmitter sensitivity (1,2). The roles that neural activity, hormones, neurotrophic factors, and cell-cell interactions play during Purkinje cell development are now beginning to be elucidated (3—6).
Proliferation and differentiation in retinal cell cultures
Authors: Lillien Laura
Published: November 2023

The vertebrate retina consists of seven major types of cells arranged in three layers that contain cell bodies, alternating with two layers that contain fibres and synapses (Figure 1). Different types of retinal cells can be distinguished by their morphology, expression of antigenic markers, and laminar position. For example, the cell bodies of rod and cone photoreceptor cells are found in the outer nuclear layer (ONL), bipolar, horizontal, amacrine, and Muller cells in the inner nuclear layer (INL), and ganglion cells in the layer closest to the vitreous. This complex structure develops from a small number of neuroepithelial cells that arise from an out-pocketing of the neural tube. During embryonic development, retinal progenitor cells divide extensively, and in some species, progenitor cells continue to divide during the postnatal period (1,2). Populations of progenitor cells that give rise to different types of retinal cells stop dividing at characteristic times during development, differentiate, and migrate to appropriate cell layers (2).
Oligodendrocyte lineage cells from neonatal rat brain
Authors: Collarini Ellen J
Published: November 2023

Oligodendrocytes, the myelinating cells of the central nervous system, develop from precursor cells also known as 0-2A progenitors because they can also be induced to develop into type-2 astrocytes in vitro (see Chp 7) (1). Although much is known about factors that influence the survival, proliferation, and differentiation of oligodendrocyte precursor cells (2–4), biochemical analyses of intracellular events that occur during the differentiation process have been hampered by the need for relatively large numbers of purified cells at various stages of development. In the last few years, however, several methods have been published that overcome this problem. Oligodendrocyte lineage cells have been obtained with varying degrees of purity from optic nerve (3), from neonatal rat brain (5,6), or from mixed glial cultures established from neonatal rat brain (7,8), using either density gradient separation (5) or variations on an immunoselective technique known as ‘panning’ (3,6–8), first described for isolating lymphocytes (9). In this technique, dishes are coated with antibodies against a particular cell/surface antigen, then the cell suspension is added to the dish to allow selective binding of cells that express that antigen.
Enteric ganglion cells
Authors: Saffrey M Jill
Published: November 2023

The enteric nervous system (ENS), the intrinsic nervous system of the gut, is the largest part of the peripheral nervous system (PNS) and is responsible for the co-ordination of intestinal functions. Intestinal reflexes occur largely independently of input from the central nervous system (CNS) or other parts of the PNS, hence the ENS is a highly complex system, containing several types of motoneurons, interneurons, and sensory neurons. This functional heterogeneity is reflected in the great diversity of neurotransmitters employed by enteric neurons (see ref. 1). The ENS also differs considerably from other parts of the PNS in its organization. Unlike other peripheral ganglia, enteric ganglia contain no connective tissue or blood vessels; a major part of enteric ganglia consists of synaptic neuropil. Enteric glial cells are also distinctive, but show a number of similarities to astrocytes. In terms of neuronal diversity, ganglion organization, ultrastructural features, and glial cell characteristics, the ganglia of the ENS have therefore been likened to the CNS (2,3).
Detection of HIV entry into cells
Authors: Mcknight Aine , ClaPham Paul R , Schulz Thomas F
Published: November 2023

HIV-l, HIV-2, and SIV belong to the group of primate lentiviruses which use the CD4 molecule as their main port of entry. Binding of HIV virions to CD4 results in conformational changes in the virus envelope glycoproteins, gpl20 and gp41. These structural alterations are likely to be essential for virion and cell membranes to fuse. Many studies indicate that a second, still undefined, cell surface component is needed in addition to CD4, for fusion. HIV-1 is able to bind to other cell surface molecules, including the glycolipid galactocereboside but these mediate viral entry very inefficiently at best. Some strains of HIV-2 have been isolated which can fuse and infect cells independently of CD4 but the alternative receptor used by this virus has not been identified yet. CD4-independent entry of HIV-1 in vitro has also been reported to occur via Fc receptors (of antibody coated virions) or the complement receptors CR2 and CR3 (of virions coated with the C3b/C3d fragments of the complement component C3). However, it is unknown whether these routes of entry are of any significance in vivo.
Platelet preparation and estimation of functional responses
Authors: Mcnicol Archie
Published: November 2023

Human platelets are amongst the most widely studied cells in the body with a conservatively estimated 4000 articles published in 1993 alone. Clearly a vast number of investigators are presently isolating and successfully using platelets although the methods employed in many of these publications vary radically. The purpose of the present chapter is not to compare and contrast these multiple techniques but to provide reproducible protocols for the preparation of platelets and for assays of their functional responses. It should be noted that many of the more specialized techniques described in later chapters have particular requirements (e.g. specific buffers) not covered in this chapter.
Cellular model systems to study megakaryocyte differentiation
Authors: Erusalimsky Jorge D , Martin John F
Published: November 2023

In recent years the study of megakaryocyte (MK) differentiation has generated considerable interest. This is due to the fact that it is now widely recognized that changes in platelet reactivity are determined in the MK during thrombopoiesis and that MKs change in pathological conditions (1). For a long time substantial progress in the study of MK differentiation has been hampered by both the unavailability of specific megakaryocyte colonystimulating factors (MK-CSF) and by the difficulties in obtaining pure populations of both mature MKs and their progenitors in ample supply. The latter problem has been partially circumvented by the application of techniques which do not require a large number of cells, such as flow cytometry, dynamic video imaging, in situ hybridization, and the polymerase chain reaction. In addition, the use of megakaryoblastic cell lines, although not the real thing, provide enough homogeneous material for biochemical analysis. Most of the techniques described here may not necessarily apply directly to the study of signal transduction during MK differentiation. However they have an integral role in any approach to identifying and characterizing molecular mechanisms related to the biology of this lineage.
Preparation and uses of semi-permeabilized platelets
Authors: Scrutton Michael C , Knight Derek E , Authi Kalwant S
Published: November 2023

Permeabilized cells have been widely used over many years to examine various aspects of cellular function which are not readily studied in the intact cell (1). Recently these preparations have been primarily employed to characterize cellular signal transduction mechanisms; and the current development of permeabilization methodology has occurred primarily in this context. The preparations can however be used for other purposes although less effort has been devoted to such aspects.
Monoclonal antibodies to platelet cell surface antigens and their use
Authors: Wilkinson J Michael
Published: November 2023

The introduction of the technique of monoclonal antibody (mAb) preparation in 1975 revolutionized the study of cell surface molecules, and this has been as true for platelets as for any other type of cell. mAb have been used both to characterize molecules previously defined by other methods and also to identify new molecules, by immunization of mice with whole platelets or platelet plasma membrane fractions. Like any other cell type, platelets express a wide variety of cell surface proteins whose surface density may vary from tens to tens of thousands of molecules per cell. Many of the major surface glycoproteins are involved in the wide variety of adhesive interactions which platelets are able to undergo (1) and whose activity is tightly controlled during platelet activation. This control may be by conformational changes in existing cell surface molecules, notably in GPilb-Illa to reveal its fibrinogen (Fg) binding site, or by modulation of the level of cell surface expression, as for the platelet selectin, GMP 140. Other major surface glycoproteins, such as the CD9 antigen, have, as yet, no known or well defined function. There are in addition many minor surface proteins, which include receptors of various types and many other molecules of unknown function. mAb may thus be used for the definition of those proteins which are present on the surface of either resting or activated platelets, both in qualitative or quantitative terms. They may also be used for affinity purification, as described in Chapter 7, for further structural and functional characterization. In addition, the exquisite specificity of mAb for a single epitope on a particular protein means that they can be used as probes for particular structures or functions. A variety of mAb has been described, some of which are able to inhibit aggregation and activation while others are able to promote these functions. Hence they are ideal reagents for the characterization of the activities which are responsible for the transformation of resting discoid platelets into multicellular aggregates.