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Studienmaterial zur Weiterbildung medizinische-technischer Laborassistenten Zeitschrisft für medizinische Laboratoriumsdiagnostik, ISSN 0323-5637 25. Band, Heft 6, 1984

15 s. : grafy ; 22 cm

MeSH
Isoenzymes MeSH

Book

Enzymes and isoenzymes in pathogenesis and diagnosis : 5th international congress on clinical enzymology, Jerusalem, September 3-6, 1985

Basel : Karger, 1987

Advances in clinical enzymology ; Vol. 5

1st ed. viii, 162 s.

Conspectus
Biochemie. Molekulární biologie. Biofyzika
NML Fields
biochemie

Thesis etc.

Human amylase isoenzymes

Oslo : Universitetsforlaget, 1977

Scandinavian journal of gastroenterology, ISSN 0085-5928 vol. 12, suppl. 44, 1977

37 s. : il. ; 24 cm

Article

Autotetraploids of Vicia cracca show a higher allelic richness in natural populations and a higher seed set after artificial selfing than diploids

In this study allozymes were employed to investigate the origin, population genetic diversity and mating ...

Annals of botany. 2014 ; 113 (1) : 159-70.

Ann. bot. (Print)
ISSN 1095-8290
Medvik
Source

BACKGROUND AND AIMS: Despite the great importance of autopolyploidy in the evolution of angiosperms, relatively little attention has been devoted to autopolyploids in natural polyploid systems. Several hypotheses have been proposed to explain why autopolyploids are so common and successful, for example increased genetic diversity and heterozygosity and the transition towards selfing. However, case studies on patterns of genetic diversity and on mating systems in autopolyploids are scarce. In this study allozymes were employed to investigate the origin, population genetic diversity and mating system in the contact zone between diploid and assumed autotetraploid cytotypes of Vicia cracca in Central Europe. METHODS: Four enzyme systems resolved in six putative loci were investigated in ten diploid, ten tetraploid and five mixed-ploidy populations. Genetic diversity and heterozygosity, partitioning of genetic diversity among populations and cytotypes, spatial genetic structure and fixed heterozygosity were analysed. These studies were supplemented by a pollination experiment and meiotic chromosome observation. KEY RESULTS AND CONCLUSIONS: Weak evidence of fixed heterozygosity, a low proportion of unique alleles and genetic variation between cytotypes similar to the variation among populations within cytotypes supported the autopolyploid origin of tetraploids, although no multivalent formation was observed. Tetraploids possessed more alleles than diploids and showed higher observed zygotic heterozygosity than diploids, but the observed gametic heterozygosity was similar to the value observed in diploids and smaller than expected under panmixis. Values of the inbreeding coefficient and differentiation among populations (ρST) suggested that the breeding system in both cytotypes of V. cracca is mixed mating with prevailing outcrossing. The reduction in seed production of tetraploids after selfing was less than that in diploids. An absence of correlation between genetic and geographic distances and high differentiation among neighbouring tetraploid populations supports the secondary contact hypothesis with tetraploids of several independent origins in Central Europe. Nevertheless, the possibility of a recent in situ origin of tetraploids through a triploid bridge in some regions is also discussed.

Book

Clinical significance of amylase isoenzyme determination

Praha : Univerzita Karlova, 1987

Acta Universitatis Carolinae. Medica. Monographia ; 1987/120

81 s. : obr.,tab.,bibliogr.

Total amylase activity in serum and urine is formed by pancreatic (P) and salivary (S) isoenzymes. The evaluation of isoamylases provides better information on enzyme changes during the disease than total activities alone. The resolution of pancreatic from extrapancreatic origin of hyperamylasemia may be clinically important. The experience obtained from the analysis of isoamylases in more than 1500 patients with different clinical diagnoses we compare with a contemporary knowledge of disturbances in amylase activities. We developed a method separating quantitatively both isoamylases on the mini-columns of ion-exchanger which we used in routine clinical investigation. In the first section we selected the findings on physiology and biochemistry of isoamylases. We described for the first time a significant decrease of P-isoamylase activity in serum during the intravenous infusions of hypertonic glucose, amino acids and during acute hypercalcaemia. We suggested that hypertonic glucose, amino acids and calcium may regulate directly or indirectly the amylase flux from acinar cells in the pancreas across basolateral membrane into blood. This endocrine secretion of amylase may be important in different clinical conditions in which changes of neurohumoral and/or hormonal regulation are developed. The isoamylase activities in patients with different diagnosis are analyzed in the clinical section. The results may be correctly evaluated only in connection with the pathogenesis of isoamylase changes. Disorders of the organs producing amylase (i.e. pancreas or salivary glands) may induce changes of isoamylases depending on their functional status. A progressive loss of amylase producing cells may be accompanied by a decrease of enzyme activity in serum as was described in chronic pancreatitis with exocrine insufficiency. However, the amylase activity in serum is significantly influenced by clearance mechanisms, too. Disorders of the liver or kidneys are accompanied predominantly with hyperamylasemia caused by the disturbed clearance mechanisms. The amylase activity in serum is a consequence of the result between input and output of the enzyme within the blood stream. Some humoral and hormonal regulations are able to modulate both processes in vivo. We suppose that pathogenetic standpoint has the main role for correct interpretation of isoamylase activities. The pathogenesis of hyperamylasemia is therefore discussed in single chapters. In conclusion, the isoamylase activities in serum and urine are influenced beside genetic background by many factors in health and disease which may be respected during the evaluation of the results.