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At least 289 records · Page 16Linked to original sources
PubMedDate not supplied

[Department of sterol biochemistry].

The Department of Steroid Biochemistry headed by Professor Vendt Volodymir Petrovich, Doctor of Biological Sciences (1906-1993) was created on the basis of the Department of Photobiochemistry in 1976. At that time the Department was headed by Kokunin Vasyl Andriyovich, Candidate of biological sciences, till 1990. Professor Yu.D.Kholodovais, Doctor of biological sciences, is the head of the department today. Study of action mechanism of low-molecular-weight biologically active substances of steroid nature (cholesterol, cholecalciferol, ecdysterone) under normal and pathological conditions (atherosclerosis, rickets) as well as the development of scientific grounds of production of new drugs used both in medicine and agriculture are the basic purposes of the Department. The department is engaged in: 1) the study of biosynthetic processes of de novo cholesterol and its precursors in different tissues and cells of the organism; 2) the elucidation of the role of sterols as the components of membrane structure in different cells as well as the study of cholesterol absorption processes in the intestine and the search of a hypocholesterolemic agents; 3) the study of localization and biological properties of vitamin D-dependent proteins in order to elucidate their role in intestinal calcium transport; 4) the investigation of different classes of blood plasma composition of intestine and liver lipoproteins (LP), their structural, functional properties and frequency of occurrence; 5) the search of highly effective biostimulators of steroid nature, the elucidation of their action mechanisms and elaboration of new preparations on their basis for medicine and agriculture. Sterols are components of lipids with cyclopentanoperhydrofenantren molecular structure. Cholesterol is the basic animal and human organism sterol. A new complicated, multi-step method of cholesterol biosynthesis and participation of a number of enzymes and cofactors in it have been studied (V. Vendt, R. Morozova, I. Nikolenko, Visnyk AN URSR, 1978). Cholesterol is the major component of cell membrane structures which determines their structure and permeability. The interest to study a new method of cholesterol biosynthesis regulation arises from the reason that cholesterol pools in membranes participate in such diseases as rachitis, atherosclerosis, arterial coronal disease, different forms of cholecystitis, etc. It is established that the nature, rate and intensity of de novo cholesterol biosynthesis depend on types of cells, tissues and organs, taking into account the functional state of final compounds in these biosystems under normal conditions.(ABSTRACT TRUNCATED AT 400 WORDS)

Academies and Institutes↗
PubMedDate not supplied

[Department of the Biochemistry of Muscles].

The basic scientific achievements of the Department of Biochemistry of Muscles organized at the Academy of Sciences of Ukrainian SSR in 1944 are presented in this short historical overview. The basic guidelines for activities in the scientific field are as follows: study of biochemical processes in the working muscles as well as during misfunctions and disabilities, processes of adenine nucleotides exchange and ammonia creation, biochemical characterization of Ca2+ and H+ transport through the plasma and sarcoplasmic reticulum membranes. It is shown that creatine and creatine phosphate as well as adenine nucleotide content and metabolism affect the muscle functioning, glycogen metabolism proceeds simultaneously with the lowering of content of inorganic phosphate. The facts of glucose phosphorylation and its conversion via glycolytic pathways and the backward reaction of glycolysis (the aerobic synthesis of phosphopyruvate, glycogen synthesis from glucose in the presence of phosphorylase) were determined. After the muscle work up to tiredness adenine nucleotide depletion is not limited by its dephosphorylation, but goes up to formation of inosine acid and ammonia. Deamidation is shown to be in myofibrillar fraction and in sarcoplasmic reticulum of the skeletal muscle. Deamidation activity is not registered in myocardium myofibrillar fraction but it is registered in sarcoplasmic reticulum. AMP-phosphohydrolase and adenosine desaminase were found in membranes of the sarcoplasmic reticulum. The decrease in activity of all enzymes mentioned above is registered during myocardium hypertrophy, because of aorta narrowing. These data permit creating the methods for obtaining substance "adenosine phosphate" for treatment of cardiac pathologies. Glutaminase was found to be active in the muscles. This activity depended on the organism functioning. The ammonia usage by the muscle cells goes with glutamine synthesis and consumption of energy of ATP, e.g. protein amidation. The later is of all-biological significance and is used in the fields of medicine actualls concerned with the following fact: the velocity of hydrolysis of amidated protein is different for such pathology as epilepsia, tuberculosis, poisoning with manganese oxides. The methods for diagnostics of the above pathological states were developed on this basis. It is proved that glutamine nitrogen can be also used in the reaction of transamination, particularly during synthesis of purines, inosine acid and it is stored in a form of glutaminic acid. Changes in carbohydrate and phosphorus metabolism, in nitrogen and energetic exchanges and mitochondria overfilling with calcium were determined under E-avitaminosis dystrophy.(ABSTRACT TRUNCATED)

Academies and Institutes↗
PubMed1993

Biochemistry of the intervertebral disc.

In comparison to other tissues, understanding the disc biochemistry is only in the very early stage. The few facts that are known would point to strategies for interventions to alter disc biology and maintain disc biomechanics.

Biochemical Phenomena↗
PubMed1997

The pattern of clinical advice sought by general practitioners from a medical consultant in clinical biochemistry.

Clinical biochemistry departments can be a valuable source of clinical advice for further investigations and the need for referral to specialist clinics. This paper outlines the pattern of clinical advice sought by general practitioners in a district hospital setting, and addresses some of the issues regarding seeking such advice and the implications for continuing medical education and training.

Biochemical Phenomena↗
PubMedDate not supplied

[Research of Academician O.V. Palladin and his school in the field of biochemistry and physiology of muscles].

The paper deals with the history of development of one of the basic trends in scientific activity of Academician O. V. Palladin and world-known biochemical school created by him: biochemistry and physiology of muscular activity. Retrospective analysis of the works by O. V. Palladin and his pupils, dedicated to the mentioned problem permits judging of realization of his ideas, when studying the process of training, work to fatigue by means of determining the content of energy sources in muscles (creatine, creatine phosphoric acid, carnosine cholesterin, glycogen), some redox enzymes (catalase, dehydrogenases), lactic acid, vitamins (ascorbic acid, B1). It is emphasized that the scientific legacy of O. V. Palladin's school is of great practical importance for rational substantiation of regimes of physical loads of sportsmen and physical culture men, production sphere workers. The works of this school have exerted considerable influence on the solution of labour physiology problem.

Biochemistry↗
PubMed1997

[Role of Laboratory of Biochemistry, Central Research Institute of Tuberculosis, Russian Academy of Medical Sciences in the evolution of views of tuberculosis pathogenesis and in the development of up-to-date approaches to its treatment].

The stages of the researches made by the Laboratory of Biochemistry, Central Research Institute of Tuberculosis, Russian Academy of Medical Sciences, were considered. They were divided into three periods. In the first (prewar) period it was found that the specific features of the course of tuberculosis were closely associated with metabolic and neuroendocrine regulatory changes. Based on these researches, a hygienic and dietary regimen was developed for patients with tuberculosis. The second stage refers to the advent of antibiotics. At the same time the pharmacodynamics of drugs and some other chemicals was investigated and their side effects found. Criteria for early laboratory diagnosis of adverse reactions and methods of their metabolic correction were elaborated. The homeostatic changes accompanying the bulky phthisiolosurgical interventions were studied. The third (present-day) stage of studies is associated with progress in basic science. The main line of investigations is to study the systems of humoral regulation and metabolism of the cells responsible for the development and evolution of a tuberculous process.

Academies and Institutes↗
PubMed1997

Biochemistry and physiology of carbohydrates in the renal collecting duct.

Using 13C-NMR analysis of cell extracts, enzymatic determination of metabolites and cofactors as well as enzyme assays on cell homogenates aerobic and anaerobic glycolysis, sorbitol formation by aldose reductase, the pentose phosphate shunt, and gluconeogenesis could be identified as the major pathways of D-glucose metabolism in renal inner medullary collecting ducts. In flux studies it was shown that D-glucose enters the collecting duct cells via a sodium-independent, cytochalasin- and phloretin-inhibitable transport system located at the basal-lateral cell side. At the same side sorbitol leaves the cells during regulatory volume decrease in a calcium-calmodulin-dependent fashion. From cell isolation studies it is proposed that sorbitol is taken up by adjacent (interstitial) cells, converted into fructose and then recycled to the collecting duct cells. This cycle might prevent carbohydrate wasting. Thus, IMCD cells exhibit unique aspects of carbohydrate biochemistry and physiology which enable them to function in a surrounding of low oxygen tension, low substrate supply, and extreme changes in extracellular osmolality.

Aldehyde Reductase↗
PubMed1999

Essential fatty acids are mediators of brain biochemistry and cognitive functions.

Major advances have been made in understanding the biochemistry of essential fatty acids (FA) and their interactions with metabolic pathways leading to the production of longer and more complex fatty acids and lipids. Less understood are the roles played by FA which are known to affect neurotransmitters, peptides, releasing factors, hormones, and a variety of physiological and cognitive processes. Based on empirical findings we propose that (a) FA exert a controlling function in the modulation of neuronal membrane fluidity, and (b) the critical factor in FA action and efficacy is not absolute level but rather the ratio between various groups of FA. This approach unifies the biochemical and cognitive results obtained from many different and unrelated fields of research.

Animals↗
PubMed1999

Diversity and variability of terpenoid defences in conifers: molecular genetics, biochemistry and evolution of the terpene synthase gene family in grand fir (Abies grandis).

This review focuses on the molecular genetics, biochemistry and evolution of terpenoid synthases relevant to terpenoid defences in conifers. In grand fir (Abies grandis) biosynthesis of terpenoids of the three classes of monoterpenes, sesquiterpenes and diterpenes is inducible by stem wounding at the level of gene activation and increase of enzyme activity of the respective terpene synthases. The monoterpene, sesquiterpene and diterpene synthases utilize prenyl diphosphates of appropriate size as substrates to generate the large diversity of carbon skeletons characteristic of the terpenoid resin of conifers. A large and diverse gene family of grand fir terpene synthases has been cloned and cDNAs are actively expressed in Escherichia coli for enzyme characterization. The monophyletic group of grand fir monoterpene, sesquiterpene and diterpene synthases represents both constitutively expressed and inducible genes encoding single product and multiple product enzymes. Several events of gene duplication and functional specialization of new synthases occurred during the evolution of terpenoid biosynthesis in grand fir, and gave rise to the enormous diversity and variability of this ancient and successful plant defence against herbivores and pathogens. The review concludes with a perspective of the biotechnological applications of terpenoid synthases for the genetic engineering of agricultural crops and forest trees.

Alkyl and Aryl Transferases↗
PubMedDate not supplied

Phosphorus biochemistry.

The biochemistry of phosphorus is outlined. As this element appears to have no redox reactions in biological systems phosphorus is always handled as phosphate and, as all phosphate compounds are thermodynamically unstable in water, phosphate uptake and incorporation are associated with energy consumption. The subsequent use of phosphate in metabolism and synthesis is illustrated by metabolic pathways and DNA (RNA) polymerizations, respectively. The importance and unique chemical significance of phosphorus in biology cannot be overestimated.

Adenine Nucleotides↗
PubMed1995

In vivo biochemistry: physical monitoring of recombination induced by site-specific endonucleases.

The recombinational repair of chromosomal double-strand breaks (DSBs) is of critical importance to all organisms, who devote considerable genetic resources to ensuring such repair is accomplished. In Saccharomyces cerevisiae, DSB-mediated recombination can be initiated synchronously by the conditional expression of two site-specific endonucleases, HO or I-Scel. DNA undergoing recombination can then be extracted at intervals and analyzed. Recombination initiated by meiotic-specific DSBs can be followed in a similar fashion. This type of 'in vivo biochemistry' has been used to describe several discrete steps in two different homologous recombination pathways: gene conversion and single-strand annealing. The roles of specific proteins during recombination can be established by examining DNA in strains deleted for the corresponding gene. These same approaches are now becoming available for the study of recombination in both higher plants and animals. Physical monitoring can also be used to analyze nonhomologous recombination events, whose mechanisms appear to be conserved from yeast to mammals.

DNA, Fungal↗
PubMed1983

Biochemistry of the polyamines.

The naturally-occurring polyamines exist in the free form, as N-acetyl derivatives and bound to protein. Their biosynthesis is subject to sensitive control, particularly of ornithine decarboxylase. This enzyme may be multifunctional and a key regulatory protein. Studies, principally with selective inhibitors, have elucidated the roles of polyamines in cell proliferation. Oxidized polyamines, in contrast, can be potent mitotic inhibitors. These effects are reviewed in terms of their chemistry and biochemistry. Their principal distinctions are that they can be made or degraded intracellularly, they can associate electrostatically with macromolecules by means of their spaced cationic groups, and these can be readily converted to covalent bonds.

Animals↗
PubMed2002

Biochemistry and molecular biology of receptors for biogenic amines in locusts.

The biochemistry and molecular biology of biogenic amines and their metabotropic receptors in insects, with a focus on locusts, is reviewed. These compounds are known to be responsible for the control of a huge variety of different behaviours. Receptors for these amines usually belong to the class of G-protein coupled receptors (GPCR) and transmit all known functions of these compounds. The physiological significance of biogenic amine neurotransmission in insects, especially in locusts is briefly summarised. Regarding the corresponding receptors, their pharmacological features and the molecular properties are described in detail.

Animals↗
PubMed2002

Combined biochemistry and histocytochemistry as a tool to investigate Ecto-ATPase in the cardiac muscle.

Ecto-ATPase (ecto-adenosine triphosphatase), a key enzyme of cardiac metabolism, is responsible for modulation of the concentration of extracellular nucleotides in the heart. We present methodology consisting of the combined use of biochemical and histocytochemical techniques to study its properties. Using samples from essentially the same preparation, we applied biochemistry and histocytochemistry to determine biochemical characteristics of ecto-ATPase and an in situ localization of its reactivity. Our results indicated that detected enzyme resists fixation, depends on divalent ions, and hydrolyzes ATP, but not AMP or ADP-beta-S. Reaction product of the enzyme activity was found confined to the extracellular surface of the plasma membrane of cardiac myocytes and endothelial cells due to the corresponding orientation of the enzyme active sites. Experiments using an inhibitor justified specificity of the reaction. When used together with molecular biological and immunocytochemical techniques, the present methodological approach should be capable of yielding important information about the actual ability of ecto-ATPase to operate.

Adenosine Diphosphate↗
PubMed1985

Topographical variations in the morphology and biochemistry of adult canine tibial plateau articular cartilage.

Topographically, there are both morphological and biochemical differences in the articular cartilage of the tibial plateau of normal adult dogs when the cartilage covered by the meniscus is compared with that more centrally placed and not covered by meniscus. Histologically, differences are present in the surface morphology, in intra- and extracellular lipid content, and in the morphology of the mineralization front. Electron microscopy shows, in the covered cartilage, variability in collagen fiber size, with evenly spaced fibers apparently randomly distributed and an orderly relationship between the proteoglycans and collagen, whereas in the uncovered area, the collagen is aggregated into bundles and appears to be dissociated in large part from the proteoglycans. The most striking feature in the biochemistry of the two regions is an increased water content in the uncovered cartilage, as compared with the covered. In addition, there is an increased amount of proteoglycans that can be extracted in the uncovered cartilage. The heterogeneity of the cartilage on the tibial plateau should be taken into account when considering both the histologic and biochemical variations found in osteoarthritic cartilage; and when reflecting on the pathogenesis of osteoarthritis.

Animals↗
PubMed1988

Biochemistry of fusion mass consolidation in the sheep spine.

We report here the biochemistry of fusion mass consolidation in sheep spines during a 1-year period following autogenous cortical-cancellous bone grafting and stabilization with Harrington distraction rods. Biochemical analysis of vertebral fusion mass included determination of wet weight and dry weight and quantification of glycosaminoglycan, collagen, calcium, and phosphate following extraction with neutral EDTA and proteolytic hydrolysis with papain. Our results showed that at 1 week after surgery, the fusion mass consisted of original cortical and cancellous bone graft material. The cortical bone graft was partially resistant to EDTA-papain treatment, resulting in a residue containing hydroxyproline and mineral. At 12 weeks after surgery, the fusion mass had become a homogeneous material, which, like cancellous bone graft, was completely susceptible to treatment by EDTA-papain. Collagen content of consolidating fusion mass was highest at 16 weeks after surgery when normalized to dry weight; glycosaminoglycan content was highest within 6 weeks after surgery. Mineral content was lowest at the 6-week stage but by 12 weeks after surgery, it was comparable with original bone grafting material. At 24 and 52 weeks after surgery, fusion mass consolidation was characterized by an increase in the proportion of organic and mineral components resistant to EDTA-papain. The appearance of the EDTA-papain-resistant material in the fusion mass coincided with formation of lamellar bone and successful consolidation.

Animals↗
PubMedDate not supplied

The biochemistry of living tissues: examination by MRS.

MRS defines the molecular state of water, the chemical environment of cells and tissues and the qualitative and quantitative state of intermediary metabolism. Because cancer has disordered physiology, obvious differences in MR spectra can be observed. However, the detailed understanding of the biochemistry of cancer will also emerge from careful, quantitative multinuclear MR. The intermediary metabolism of ATP, the Krebs cycle, creatine, cholines and lipids, is discussed. Finally, the biochemical challenge posed by oncogenes may be amenable to MR analyses.

Body Water↗