In situ hybridization of semithin Epon sections with BrdU labelled oligonucleotide probes

Summary We recently described a nonradioactive method for in situ hybridization with 5-bromo-2-deoxyuridine (BrdU) labelled oligonucleotide probes. An antibody to BrdU and immunocytochemistry were used in order to detect the hybridization signal. We have now applied this method to semithin Epon sections, in order to hybridize consecutive sections through single cells with different probes and to stain them with antibodies to neuropeptides. It could be shown that Epon embedding preserves mRNA well. In the present study we used a BrdU labelled synthetic oligonucleotide probe complementary to a fragment of the vasopressin precursor and an antibody to Arg-vasopressin. Vasopressin mRNA was demonstrable in a fraction of the vasopressin immunoreactive neurons in the magnocellular nuclei. In addition some of the magnocellular neurons showed either hybridization or vasopressin immunostaining only, perhaps indicating different stages of synthetic and secretory activity. The method described seems to be a valuable tool for studying synthetic activity in peptidergic neurons on a single cell level. The method might also have potential for in situ hybridization on the electronmicroscopical level.     

Association between pygmy right whales (Caperea marginata) and areas of high marine productivity off Australia and New Zealand

Abstract

Opportunistic sightings and strandings of Caperea marginata (n=196) from the vicinity of Australia and New Zealand (1884 to early 2007) were used to relate geographic and temporal patterns to oceanographic and broad-scale climatic variability. Records were not uniformly distributed along the coast and more (69%) were from Australia than New Zealand. Seven coastal whale ‘hotspots’ were identified which accounted for 61% of records with locality data. Half of the hotspot records were from southeast (37) and northwest (20) Tasmania—others each had 9–15 events. Upwelling and/or high zooplankton abundance has been documented near all whale hotspots. Records of C. marginata occurred in all months, with 75% in spring and summer. Inter-annual variability showed broad agreement between increased whale records (usually in spring/summer) and strongly positive ‘Niño 3.4’ during 1980–1995 but not thereafter. Coastal upwelling and productivity increase during climatic phenomena such as El Niño and are likely to be quickly beneficial to plankton-feeding whales such as C. marginata.     

Zahnanomalien in der Neuropädiatrie

Dental anomalies in children with neuropediatric disorders are easy to diagnose and can be essential in the diagnosis of different entities. They are present in well-known disorders as Incontinentia pigmenti, but also in rare diseases as in Kohlschütter-Tönz syndrome or the recently described ataxia, delayed dentition and hypomyelination. Anomalies of dental shape, enamel and in this case also teeth color, dental number and eruption are all encountered. Knowledge of these abnormalities is important for both clinical geneticist and child neurologist.     

Genetik der koronaren Herzkrankheit und des Herzinfarkts

Because of their high prevalence, cases of coronary artery disease (CAD) and myocardial infarction (MI) are frequently found when asking for a patient’s family history. It is common knowledge that a positive familial history constitutes a risk factor for CAD in its own right, in addition to smoking, increased alcohol intake, diabetes, obesity, hypertension, and hyperlipidemia. Nevertheless, for correct risk assessment it is crucial to accurately distinguish between sporadic and true familial cases of CAD and MI. Familial disposition is present when at least one male first-grade relative under the age of 55 or one female first-grade relative under the age of 65 has/had been diagnosed with myocardial infarction or significant coronary artery disease. In the review presented here, we compile the relevant epidemiological and genetic studies that constitute the scientific basis of this risk assessment. Furthermore, a short overview of the state of the art of genetic CAD/MI research is given.     

Saliva samples are a viable alternative to blood samples as a source of DNA for high throughput genotyping

ABSTRACT: BACKGROUND: The increasing trend for incorporation of biological sample collection within clinical trials requires sample collection procedures which are convenient and acceptable for both patients and clinicians. This study investigated the feasibility of using saliva-extracted DNA in comparison to blood-derived DNA, across two genotyping platforms: Applied Biosystems Taqman TM and Illumina Beadchip TM genome-wide arrays. METHOD: Patients were recruited from the Pharmacogenetics of Breast Cancer Chemotherapy (PGSNPS) study. Paired blood and saliva samples were collected from 79 study participants. The Oragene DNA Self-Collection kit (DNAgenotek(R)) was used to collect and extract DNA from saliva. DNA from EDTA blood samples (median volume 8 ml) was extracted by GenProbe, Livingstone, UK. DNA yields, standard measures of DNA quality, genotype call rates and genotype concordance between paired, duplicated samples were assessed. RESULTS: Total DNA yields were lower from saliva (mean 24 ug, range 0.2-52 ug) than from blood (mean 210 ug, range 58-577 ug) and a 2-fold difference remained after adjusting for the volume of biological material collected. Protein contamination and DNA fragmentation measures were greater in saliva DNA. 78/79 saliva samples yielded sufficient DNA for use on Illumina Beadchip arrays and using Taqman assays. Four samples were randomly selected for genotyping in duplicate on the Illumina Beadchip arrays. All samples were genotyped using Taqman assays. DNA quality, as assessed by genotype call rates and genotype concordance between matched pairs of DNA was high (>97%) for each measure in both blood and saliva-derived DNA. CONCLUSION: We conclude that DNA from saliva and blood samples is comparable when genotyping using either Taqman assays or genome-wide chip arrays. Saliva sampling has the potential to increase participant recruitment within clinical trials, as well as reducing the resources and organisation required for multicentre sample collection.     

Intercellular junctions in the uterine epithelium of Salamandra salamandra (L.) (Amphibia,Urodela)

Summary Intercellular junctions in the uterine epithelium of the ovoviviparous urodele Salamandra salamandra were studied in pregnant and non-pregnant females by freeze-fracture technique. Junctional complexes consist of zonulae occludentes (tight junctions) and numerous maculae adhaerentes (desmosomes); z. adhaerentes and nexuses (gap junctions) could not be identified. Tight junctions are of the flexible type exhibiting loosely interconnected fibrils. The fibrillary network appears stretched more often in pregnant females possibly due to the mechanical stress of pregnancy. The structure and occurrence of the junctions identified, especially that of the tight junctions, is discussed with regard to the functions of the uterus during pregnancy.Zusammenfassung Mit Hilfe der Gefrierbruchtechnik wurden im Uterus-epithel trächtiger und nichtträchtiger Feuersalamanderweibchen (Salamandra salamandra) Zonulae occludentes und Maculae adhaerentes, jedoch keine Z. adhaerentes sowie Nexus identifiziert. Die Z. occludentes sind flexibel. Ihr fibrilläres Netzwerk ist bei trächtigen Weibchen öfter gestreckt; das ist möglicherweise auf die stärkere Ausdehnung des Uterusgewebes während der Trächtigkeit zurückzuführen. Das Vorkommen der verschiedenen Kontakt-strukturen, namentlich das der Z. occludentes, wird im Hinblick auf die Funktionen des Uterus während der Trächtigkeit diskutiert.We are indebted to Mrs. K. Ott for excellent technical assistance and to Miss Dr. U. Beigel for linguistic help     

Mikrozephaliesyndrome und geistige Behinderung

Clarification of the cause of mental retardation, which has a prevalence of 2–3%, is a common reason for genetic consultation. On the basis of the cardinal sign of microcephaly, which also has a prevalence of 2–3%, an overview on different conditions with developmental delay/mental retardation is given according to the mode of inheritance. The current version of the Winter–Baraitser Dysmorphology Database lists 558 conditions with the combination of microcephaly and developmental delay/mental retardation. This makes clear that the following overview gives only a limited look at the comprehensive field of clinical genetics/dysmorphology.     

Acidocalcisomen,Mitosomen und Apicoplasten. Neu entdeckte Zellorganellen

Three new, membrane‐bounded organelles were detected in the last decade. Acidocalcisomes which occur in pro‐ and eukaryotes are acidic and store calcium, and further also phosphate, oxygen, magnesium, zink, sodium, potassium, and iron. Furthermore, they are engaged in osmoregulation, pH‐ and Ca²⁺‐homeostasis. Mitosomes are strongly reduced mitochondria of different parasitic protists, which were previously grouped as primarily mitochondria‐free organisms. Apicoplasts are the strongly reduced plastids of the parasitic apicomplexans (formerly sporozoa). They are a target for the development of new drugs, e.g. against the cause of malaria, Plasmodium.