Mitoseablaufstörungen

Ohne Zusammenfassung     

Genetische Aspekte bei Spermatogenesestörungen

The cause for infertility which affects about 10–15% of all couples may be found in approximately half of the cases in the male partners who usually exhibit reduced sperm counts in the ejaculate (i.e. oligozoospermia or azoospermia). The clinically most relevant genetic causes of spermatogenic failure are chromosomal aberrations including Klinefelter’s syndrome and Y chromosomal microdeletions of the AZF loci. Aside from the full clinical picture of cystic fibrosis, mutations in the CFTR gene can cause an isolated obstructive azoospermia without spermatogenic impairment. Genetic investigations should depend on the results of andrological examinations. Chromosomal aberrations are detected more frequently with decreasing sperm counts, where autosomes (e.g. translocations) are predominantly involved in men with oligozoospermia whereas in 10–15% azoospermia is caused by Klinefelter’s syndrome. Classical AZF deletions are found only in men with severe oligospermia or azoospermia and have a prognostic value. In contrast to men with AZFc deletions, carriers of complete AZFa and AZFb deletions have virtually no chance for testicular sperm extraction and a testicular biopsy is not advised. Rare cases of male infertility may be caused by specific syndromes or sperm defects (e.g. globozoospermia and disorders of ciliary structure).     

Über Koordinationsstörungen am Schildkrötenherzen

Zusammenfassung Durch mechanische Eingriffe, vor allem Zerrungen und Dehnungen, wird der Funktionszusammenhang zwischen den einzelnen Abteilungen des Herzens von Testudo graeca L. sehr leicht gelöst. Diese Störungen weichen nach wenigen Minuten von selbst, wenn die schädigende Ursache beseitigt wird.Im Tierkörper können solche Störungen, vorzugsweise durch einen starken Blutzufluß bewirkt werden. Dadurch werden die Herzabteilungen gedehnt, vor allem die empfindlichen Überleitungsgebilde. Ein stärkerer Blutzufluß zum Herzen wird aber durch die große Menge von Blutflüssigkeit vermieden, die sich normalerweise im Perikardialsack bei Testudo graeca L. befindet.Herrn Prof. Dr. Adolf Loewy, dem Leiter des Schweizerischen Forschungsinstituts, sage ich auch an dieser Stelle meinen ergebensten Dank für seine freundliche Aufnahme und tatkräftige Unterstützung.     

Imprintingstörungen in der Reproduktionsmedizin

Stochastic, environmentally and/or genetically induced errors (epimutations) during genome reprogramming in germ cells and shortly after fertilization are an important source of phenotypic variation and disease susceptibility. Animal experiments provide convincing evidence that assisted reproductive technologies (ART) interfere with sensitive time windows for epigenetic reprogramming. Epidemiological studies in humans suggest an increased risk for Beckwith-Wiedemann and Angelman syndrome; however, the absolute risk of receiving an ART child with imprinting disorder remains small. At least some genes display statistically significant methylation differences within the normal range of methylation variation between ART and non-ART pregnancies. Thus, either ART themselves or factors associated with parental infertility affect the epigenome of the next generation. Faulty methylation patterns in imprinted genes show a significant association with abnormal semen parameters. This supports the idea that epimutations can be transferred from the germline into the embryo.     

Über Wachstumsstörungen bei Amphibienlarven

Ohne Zusammenfassung     

Über Störungen des Kernteilungsrhythmus

Ohne Zusammenfassung     

Genetisch bedingte Entwicklungsstörungen der Genitalwege

Anomalies of the female and male genital tracts can be the cause of sterility and infertility. In this review disorders of the Mullerian and Wolffian structures which are responsible for the development of male and female genital tracts will be discussed.     

X-chromosomale Entwicklungsstörungen im weiblichen Geschlecht

In recent years, an increasing number of X?chromosomal genes were found to be mutated in girls with neurodevelopmental disorders (NDDs). This has blurred the traditional line between X?recessive and X?dominant inheritance. Many X?chromosomal NDDs are now characterized by a phenotypic spectrum that encompasses both males and females. To date, the mechanisms which result in variable disease manifestations between genders but also among females are only poorly understood. Various factors such as the nature, localisation and “severity” of the respective underlying mutation, as well as X?inactivation in particular, are assumed to contribute. This article provides an overview of the current knowledge on X?chromosomal NDDs in females. Additionally, several exemplary new X?chromosomal syndromes in females caused by de novo mutations will be described and discussed in more detail.     

Strukturelle Chromosomenstörungen bei Intelligenzminderung

Anomalies of chromosome number and structure are among frequent causes of intellectual disability (ID) and psychomotor developmental delay. The great heterogeneity of ID is reflected in the diversity of the possible aberration types and causative chromosomal regions. In this context, conventional cytogenetics using light microscopy detect—amongst others—structural aberrations of sizes above 5–10 megabases (Mb), and also in the form of small mosaics, and locates them within the genome. Clinically suspected microdeletion and microduplication syndromes of much smaller aberration sizes can be detected by fluorescence in situ hybridization. Chromosomal microarrays (CMAs) can identify submicroscopic microdeletions and -duplications in the entire genome owing to their much superior resolution, which can reach significantly less than 0.1 Mb; however, CMAs cannot give evidence about the location of the duplications and usually barely detect low-grade mosaics of less than 20%. Because of their varying abilities, conventional cytogenetics and CMAs complement each other and detect causative chromosomal aberrations in approximately 15% each of patients with ID, including Down syndrome. Together with modern sequencing techniques, they constitute an important element of the etiological analysis of ID in human genetics. Typical chromosome aberration types are discussed with examples and are categorized in an overview of the present-day situation.     

Behandlung depressiver Störungen bei Diabetes mellitus

Approximately 25% of all diabetes patients suffer from symptoms of clinical depression. This comorbidity of depression and diabetes is associated with hypoglycaemia, microvascular and microvascular complications and a clearly increased mortality. With regard to psychosocial outcome depression is related to impaired generic and diabetes-specific quality of life and poor treatment adherence. Despite this life endangering interaction depression is under-diagnosed and under-treated in diabetes patients. Therefore a screening for depression should be an integral part of routine care. Treatment for depression is aimed not only towards improvement of depression but should focus on physical aspects of diabetes as well. Depression can be treated with antidepressant medication, psychotherapy or a flexible combination of both. These approaches demonstrate relatively good results that are comparable to those patients with depression without diabetes. Up to now no single treatment that consistently leads to better medical outcome in patients with depression and diabetes could be identified. The management of diagnosis and treatment of comorbid depression in diabetes can be enhanced by following algorithms that are grounded on evidence-based treatment guidelines.     

Anpassungsstörungen im Sinne einer reaktiven Depression

There is an overlap between adjustment disorders and (sub-)threshold depression. Thereby, adjustment disorders correspond with the concept of reactive depression, a concept recently discussed as being worth reintroducing as a subcategory of depression. However, there is a lack of prevalence rates for adjustment disorders in terms of reactive depression. The present study estimates prevalence rates and characteristics of subjects with reactive compared with other types of depression. Data from the German National Health and Examination Survey (GHS) were used. The sample consists of 4181 subjects of the German population. Subthreshold and threshold depression were assessed by means of the M-CIDI, including a question about life events, which were considered as causal for the depressive symptoms. The 4-week prevalence rates of reactive and other subthreshold depression were 0.7% and 0.2%, while the 12-month prevalence rates were 1.7% and 0.5%, respectively. The corresponding threshold rates were 1.9% and 0.7% for the 4-week prevalence rates and were 4.1% and 1.3%, respectively, for the 12-month prevalence rates. With regard to the sociodemographic and medical characteristics of subjects with reactive and other depression, no significant differences were found except for the number of inpatient days (mean: 1.9 vs. 0) and the number of mental disorders (1.5 vs. 0.9). Persons with subthreshold reactive depression reported more often “suicidal ideations” compared with person with other subthreshold depression. The results of the present study emphasize the importance of adjustment disorders in terms of reactive depression. Considering the high clinical relevance of adjustment disorders and the scientific neglect of this category, a revision within the forthcoming classification systems is necessary.