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  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Der Gynäkologe 33 (2000), S. 788-794 
    ISSN: 1433-0393
    Schlagwort(e): Schlüsselwörter ICSI ; Intrazytoplasmatische Spermieninjektion ; Pränataldiagnostik ; Amniozentese ; Genetische Sonographie ; Follow-up ; Keywords ICSI ; Intracytoplasmic sperm injection ; Prenatal diagnosis ; Amniocentesis ; Genetic sonography ; Follow-up
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Abstract Intracytoplasmic sperm injection (ICSI) is one of the most effective, invasive means of treating infertility. Since couples undergoing ICSI have a higher genetic risk than the general population, these genetic factors have to be taken into account (e.g., structural and numeric chromosomal aberrations or cystic fibrosis mutations). Only a small number of studies have satisfactorily evaluated the risk of de novo chromosomal aberrations in the offspring of such couples following an ICSI treatment. In these studies it was suspected that a higher risk of gonosomal aberrations was already present. This is – most likely – also a consequence of the underlying genetic risk in these couples. However, generally advising these women to submit to an invasive prenatal diagnostic procedure does not to be the correct conclusion from these data. Instead, pregnant women should be counseled about the possibilities as well as limitations of invasive and noninvasive prenatal diagnostic procedures. Counseling should be conducted on an individual basis. A noninvasive approach of prenatal diagnosis includes nuchal translucency screening towards the end of the first trimester as well as a detailed ultrasound examination in the second trimester. After critical analysis of all available data on pregnancies and births following ICSI, there does not seem to be any cause to counsel the couples about a higher rate of maior malformations in their offspring as a consequence of ICSI. Furthermore, the development of these children in the first 2 years of life is – insofar as has been evaluated – normal in comparison to the general population. However, further studies should be conducted in the future, to collect more data, which should help in counseling the prospective parents.
    Notizen: Zusammenfassung Die intrazytoplasmatische Spermieninjektion (ICSI) stellt ein Maximum der Sterilitätsbehandlung dar. Aufgrund der Ursachen der männlichen Subfertilität, für die diese Behandlung primär eingesetzt wird, müssen diverse genetische Risiken bedacht werden, die die behandelten Paare in einem erheblich höheren Maße tragen als die Allgemeinbevölkerung. Dazu gehören neben strukturellen und numerischen chromosomalen Aberrationen z. B. eine erhöhte Inzidenz an Mukoviszidosemutationen. Eine Stammbaumanalyse zur differenzierten genetischen Beratung dieser Paare ist für die Einschätzung des individuellen Risikos notwendig. Wenige Studien besitzen eine ausreichende Qualität, um das Risiko neu auftretender chromosomaler Auffälligkeiten bei den Neugeborenen nach ICSI feststellen zu können. Hier wird der Verdacht auf ein erhöhtes Risiko gonosomaler Aberrationen geäußert. Dies ist vermutlich ebenfalls eine Folge des vorliegenden Hintergrundrisikos der behandelten Paare. Eine generelle invasive Pränataldiagnostik halten wir nicht für sinnvoll. Vielmehr müssen die Schwangeren hinsichtlich invasiver und nichtinvasiver Möglichkeiten zur Abschätzung des Risikos von bedeutsamen genetischen Auffälligkeiten beraten werden. Dies beinhaltet insbesondere auch den Hinweis auf ein Screening zur Bestimmung der Nackendicke [10. bis 14. Schwangerschaftswoche (SSW)] sowie einen detaillierten Ultraschall in der 18. bis 22. SSW. Bei einer kritischen Zusammenschau der vorliegenden Daten gibt es bisher keinen Hinweis auf eine erhöhte Fehlbildungsrate durch ICSI bei der Geburt der so gezeugten Kinder. Auch hinsichtlich der postpartalen Entwicklung bis zum 2. Lebensjahr – weitere Studien liegen noch nicht vor – kann in der Aufklärung auf unauffällige Daten verwiesen werden. In jedem Falle sind weitere Studien wünschenswert, um die Beratung der prospektiven Eltern durch zusätzliche Daten noch besser absichern zu können.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Molecular and cellular biochemistry 127-128 (1993), S. 19-30 
    ISSN: 1573-4919
    Schlagwort(e): phosphorylase kinase ; calmodulin ; calmodulin-binding peptides ; Ca2+-binding
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract Holophosphorylase kinase was digested with Glu-C specific protease; from the peptide mixture calmodulin binding peptides were isolated by affinity chromatography and identified by N-terminal sequence analysis. Two peptides originating from the α subunit, having a high tendency to form a positively charged amphiphilic helix and containing tryptophane, were synthesized. Additionally, a homologous region of the β subunit and a peptide from the α subunit present in a region deleted in the α′ isoform were also selected for synthesis. Binding stoichiometry and affinity were determined by following the enhancement in tryptophane fluorescence occurring upon 1:1 complex formation between these peptides and calmodulin. Finally, Ca2+ binding to calmodulin in presence of peptides was measured. By this way, the peptides α 542–566, α 547–571, α 660–677 and β 597–614 have been found to bind specifically to calmodulin. Together with previously predicted and synthesized calmodulin binding peptides four calmodulin binding regions have been characterized on each the α and β subunits. It can be concluded that endogenous calmodulin can bind to two calmodulin binding regions in γ as well as to two regions in α and β. Exogenous calmodulin can bind to two regions in α and in β. A binding stoichiometry of 0.8mol of calmodulin/αβγδ protomer of phosphorylase kinase has been determined by inhibiting the ubiquitination of calmodulin with phosphorylase kinase. Phosphorylase kinase is half maximally activated by 23nM calmodulin which is in the affinity range of calmodulin binding peptides from β to calmodulin. Therefore, binding of exogenous calmodulin to β activates the enzyme. A model for switching endogenous calmodulin between α, β and γ and modulation of ATP binding to α as well as Mg2+/ADP binding to β by calmodulin is presented.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Biochemical genetics 18 (1980), S. 247-261 
    ISSN: 1573-4927
    Schlagwort(e): phosphorylase kinase ; mice ; X-linked deficiency ; dominant inheritance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract A new mouse strain, the V strain, with a partial deficiency of phosphorylase kinase has been established. The deficiency is caused by an X-linked dominant gene (Phk c ). Muscle extracts of homozygous and heterozygous females and hemizygous males have about 25% of the activity found in extracts of normal (C3H/HeHan) mice. This dominant phosphorylase kinase deficiency of the new V strain is different from that of the I-strain mice with the X-linked recessive deficiency of skeletal muscle phosphorylase kinase. The muscle extracts of V-strain and normal mice contain the same phosphorylase phosphatase activity of about 1 U/mg. Heart and liver extracts from V mice contained about 50% and 66%, respectively, of the phosphorylase kinase activity compared to that found in the same organs from the normal mice. The glycogen content of the skeletal muscle of the V strain was normal, i.e., 0.9 mg/g. Phosphorylase kinase was purified from the skeletal muscle of the V strain by (a) hydrophobic chromatography on methylamine Sepharose, (b) ammonium sulfate precipitation, and (c) gel filtration of Sepharose 4B. The enzyme has a similar structure to the normal murine and rabbit skeletal muscle enzyme, except that the proportion of the subunits differs. The molar ratio of the subunits of the V strain mice is (α+α′):β:γ=0.54:1:1.169, in comparison with that of the rabbit (α+α′):β:γ=1.1:1.0:1.0 and that of normal murine enzyme 0.9:1.0:0.7.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    ISSN: 0749-1581
    Schlagwort(e): NMR ; 103Rh ; 31P ; 13C ; rhodoximes ; organobis(dimethylglyoximato) rhodium ; complexes ; trans influence ; coupling constants ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The 103Rh NMR chemical shifts of rhodoximes [Rh(dmgH)2(PPh3)X] (1) and organorhodoximes [Rh(dmgH)2(L)R] (2, L = PPh3; 3, L = PMe3; 4, L = P(OPh)3; 5, L = SMe2; 6, L = py) were measured with a wide range of anionic ligands X, organo groups R and axial ligands L. The chemical shifts δ(103Rh) in the halide complexes 1 show the ‘normal halogen dependence’ (Cl 〉 Br 〉 I). δ(103Rh) in 2-6 depends on the axial base L in the order py 〉 SMe2 〉 PPh3 〉 P(OPh)3 ≍ PMe3 and in 2 on the organo group R in the order Et ≍ Me 〈 nPr 〈 CH2Ph ≍ CH2OMe 〈 CH2Br 〈 CH2Cl 〈 iPr 〈 Cy 〈 CH=CH2 〈 CH2SiMe3 〈 tBu 〈 cis-CH=CHPh ≍ cis-CH=CHPr 〈 Ph ≍ C≡CPh 〈 CPr=CH2. The coupling constants 1J(103Rh,31P) in 2 reflect the (NMR) trans influence of R. There is a strong correspondence between the NMR trans influence and the structural trans influence, as indicated by the bond lengths d(Rh - P).
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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