Wyniki wyszukiwania - Biblioteka Nauki

1

Biotechnology of drugs on the verge of 21st century

100%

Chmiel A.

Biotechnologia

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2000

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nr 3

118-140

EN

At present most classical pharmaceutical technologies reach high level of industrial perfection. The best example of those achievements is the biotechnology of penicillins. Biosynthetic penicillin production using highly productive strains of Penicillium chrysogenum is followed by an enzymatic hydrolysis of the product using microbial penicillin acylase, the best sources of which are recombinant strains of Escherichia coli. The resulting aminopenicillanic acid is the starting material for chemical synthesis of a large number of semisynthetic penicillins. Research and development of the biotechnology of antibiotics created solid fundamentals for other biotechnological processes in the pharmaceutical industry, i.e. production of amino acids, organic acids, enzymes and enzyme inhibitors, vitamins, alkaloids, dextran, steroid drugs and others. In addition to the continuous improvement of the classical technology completely new bioprocesses were introduced to the pharmaceutical industry in the recent years as a result of unprecedented progress in genetic engineering, hybridoma techniques and cell cultures in vitro. The new group of polypeptide/protein biopharmaceuticals includes peptide hormones (e.g. insulin, growth hormones, gonadotropins), growth factors (e.g. insulin-like growth factors, epidermal growth factors), haematopoietic growth factors (e.g. erythropoietin, colony stimulating factors), blood proteins (e.g. clotting factors VIII, IX, XII and XIII, tissue plasminogen activator, streptokinase), cytokines (e.g. interferons, interleukines and tumor necrosis factor) and monoclonal antibodies. Another new area of genetic engineering and biotechnology is the production of nucleic acid drugs, which are proposed for both gene and antisense therapy.

2

Pharmaceutical biotechnology: The achievements of Century XX and the expectations in Century XXI

100%

Chmiel A.

Biotechnologia

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2002

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nr 4

56-78

EN

Pharmaceutical biotechnology is 60 years old. Its development one can divide into three essential periods. Two of them have proceeded in past century. The first period started during the Second Warld War with the industrial production of penicillin and was microbiology-based (microbial metabolites as drugs). The second one was genetic engineering-based and started in 1982, when human insulin synthesized in recombinant bacteria was introduced by pharmaceutical industry to health care. The third period began in 2001 with the first descriptions of the human genome, and is genome-based (also proteome-based). Molecular biology with its new areas genomics, farmacogenomics and proteomics, together with bioinformatics and other sophfisticated tools developed at the end of XX century and introduced (the pharmaceutical and medical biotechnology of the XXI century) very new ideas and new approaches to drug discovery and designin. Pharmaceutical biotechnology (as well as pharmaceutical industry as a whole and world biotechnology as a whole) is entering upon the third phase of its development, a very integrated and globalized one.

3

Secondary metabolites production in cultures of transformed plant organs

63%

Wysokinska H. , Chmiel A.

Biotechnologia

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2006

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nr 4

124-135

EN

Plant cell cultures in vitro produce secondary metabolites with varied effectiveness. Despite industrial application of only few cell suspension cultures, considerable progress in research on plant cell biotechnology has been made over the last few years. Transformed organ cultures, especially hairy roots, seem to be an interesting model for stable production of plant metabolites with high yield. In this paper, cultures of hairy roots of Salvia sclarea, S. officinalis, S. miltiorrhiza, S. przewalski, and Centaurium erythracea, as well as transformed shoots and plants of C. erythracea are presented. Also, production of secondary metabolites in these cultures is discussed.

4

Biotransformation by plant cell cultures. Part II. Process conditions

63%

Chmiel A. , Wysokinska H.

Biotechnologia

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1995

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nr 1

131-147

EN

Biological and biochemical conditions of biotransformation processes ,applications of cell suspension, immobilised cells and enzyme preparations are discussed.The nature and form of biocatalysts determine the technical parameters of the process.Bioreactor systems for plant cell biotechnology are presented.

5

Biotransformation by plant cell cultures. Part I. Reactions

63%

Wysokinska H. , Chmiel A.

Biotechnologia

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1995

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nr 1

114-130

EN

Plant enzymes are able to catalyse regio- and stereospecific reactions and can be applied to the production of pharmaceutically important compounds.This paper summarizes the results of such biotransformations in freely suspended cells.The factors affecting bioconversion capabilities of cells are also discussed.Special attention is paid to permeabilization and the problems of poorly water-soluble precursors.

6

Mycobacteria in current genetic research

51%

Golanska E. , Sasiak A. , Jaworski A. , Chmiel A.

Biotechnologia

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1998

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nr 3

72-88

EN

The article reviews the development of molecular investigations of the genus Mycobacterium. Achievements and difficulties of the genetics of mycobacteria are presented. Vectors and selectable markers commonly used in genetic manipulations and methods of introduction of foreign DNA into mycobacteria are described. The stress is laid not only on the research of the virulent mycobacteria, but also on molecular investigations of the non-pathogenic strains used in steroid drugs industry.

7

The conditions of transformed roots growth in bioreactors

51%

Pawlowska B. , Ledakowicz S. , Chmiel A.

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2005

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nr 2

88-102

EN

Transformed roots are also called transgenic roots or due to their appearance ? hairy roots. Transformed roots are obtained by infection of plants or parts of them with soil bacteria, Agrobacterium rhizogenes. Genetically transformed roots are characterised by rapid and stable growth of biomass, genetic stability, and stable biosynthesis of metabolites. Hairy roots can be an alternative source of many economically important chemicals like enzymes, pigments, flavours and especially bioactive pharmaceuticals. Cultures of transformed roots are comparatively easy to cultivate in shaking flasks. Application of flasks does not allow to obtain great amount of biomass. There is a necessity of scaling up the culture using bioreactors. The first attempts of scaling up the culture were connected with bioreactors designed for microbiological processes. However, these bioreactors are inadequate for hairy roots cultures. Some promising results were achieved in the case of using mist bioreactor. This paper is a review of bioreactors employed in cultures of hairy roots and mathematical modelling of hairy root growth.

8

Ginsenosides contents in Panax quinquefolium cultures

51%

Kochan E. , Gadomska G. , Wysokinska H. , Chmiel A.

Biotechnologia

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2004

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nr 1

236-243

EN

Contents of six main saponins (Rb1, Rb2, Rc i Rd ? protopanaxadiols, Rg1 i Re - protopanaxatriols) were investigated in callus and suspension cultures of Panax quinquefolium. HPLC method was used to indicate saponins quantatively. Qualitative composition and the amount of individual ginsenosides varied depending on culture age and light conditions. The younger calli, grown in dark, produced all indicated metabolites, and protopanaxatriols were dominant. In older callus cultures, only 3 of the saponins (Rg1, Re, Rb1) were present. The calli grown in light did not synthesize protopanaxadiols at all. Although suspension cultures contained all of the 6 above indicated metabolites, ginsenosides Re and Rd were predominant and reached the highest level, 2,7 mg/g d.w. and 1,2 mg/g d.w. respectively.

9

Emotional Agents at the Square Lattice

51%

Czaplicka A. , Chmiel A. , Hołyst J.

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tom 117

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nr 4

688-694

EN

We introduce and investigate by numerical simulations a number of models of emotional agents at the square lattice. Our models describe the most general features of emotions such as the spontaneous emotional arousal, emotional relaxation, and transfers of emotions between different agents. Group emotions in the considered models are periodically fluctuating between two opposite valency levels and as result the mean value of such group emotions is zero. The oscillations amplitude depends strongly on probability p_{s} of the individual spontaneous arousal. For small values of relaxation times τ we observed a stochastic resonance, i.e. the signal to noise ratio SNR is maximal for a non-zero p_{s} parameter. The amplitude increases with the probability p of local affective interactions while the mean oscillations period increases with the relaxation time τ and is only weakly dependent on other system parameters. Presence of emotional antenna can enhance positive or negative emotions and for the optimal transition probability the antenna can change agents emotions at longer distances. The stochastic resonance was also observed for the influence of emotions on task execution efficiency.

10

Enzymatic chitosan membranes for L-aspartic acid biosynthesis

45%

Modrzejwska Z. , Chmiel A. , Sobierajski B. , Platak D. , Kaminski W.

Biotechnologia

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1998

|

nr 3

121-133

EN

A new method for the formation of enzymatic chitosan membranes containing active cells of E. coli mutant producing L-aspartic acid was developed. Trisodium orto-phosphate as a gelation agent for the chitosan membrane formation was proposed. The highest productivity, with near 100% conversion of ammonium fumarate to L-aspartic acid, has been shown by the membranes characterized by a low permeate stream flow of 5-10 dm3/m2h at an overpressure of 0,05 MPa.