Subtypes of non-transformed human mammary epithelial cells cultured in vitro: histo-blood group antigen H type 2 defines basal cell-derived cells

Abstract. Normal (non-transformed) human mammary epithelial cell lines derived from reduction mammoplasties were analyzed by immunocytochemistry with more than 80 monoclonal antibodies (mAbs) and other specific reagents to tissue-specific and developmentally regulated antigens at different passage levels. A subpopulation of poorly differentiated, proliferating epithelial cells, corresponding to the 'selected' cell type of late passages, is shown to be characterized by a new marker, the histo-blood group antigen H type 2, probably carried on a membrane-bound glycolipid. These cells also express a number of other onco-developmental carbohydrate antigens [Le^y, Le^x, sialosyl-Le^a, precursor of Thomsen Friedenreich antigen (T_n), but not Thomsen-Friedenreich antigen and sialosyl-T_n). Their cytokeratin (CK) phenotype, as assessed by reactivity with monospecific mAbs and two-dimensional gel electrophoresis, is CK 5, 6, 14 and 17, with CK 19 being consistently absent, and varying minor amounts of CK 7, 8 and 18, as well as 15 and 16. The reactivity of these cells with a panel of 11 mAbs specific for CK 18 varies considerably even after cloning, indicating heterogeneity of epitope expression or accessibility. Our data strongly suggest that the H type 2⁺ cells develop from the basal cell layer of the mammary gland.     

Elasmobranch qPCR reference genes: a case study of hypoxia preconditioned epaulette sharks

Background  

Elasmobranch fishes are an ancient group of vertebrates which have high potential as model species for research into evolutionary physiology and genomics. However, no comparative studies have established suitable reference genes for quantitative PCR (qPCR) in elasmobranchs for any physiological conditions. Oxygen availability has been a major force shaping the physiological evolution of vertebrates, especially fishes. Here we examined the suitability of 9 reference candidates from various functional categories after a single hypoxic insult or after hypoxia preconditioning in epaulette shark (Hemiscyllium ocellatum).     

Temperaturabhängigkeit und Aktivierungsenergie bei der direkten Strahlenwirkung

Zusammenfassung Die Temperaturabhängigkeit von trocken bestrahlten Enzymen wird mit Hilfe der statistischen Theorie der Reaktionsgeschwindigkeit vonEyeing erklärt. Dabei zeigt sich, daß man eine von der Umgebungstemperatur verschiedene und oft sehr hohe Reaktionstemperatur sowie eine Reaktionszeit einführen muß. Aus diesem Grunde ist im allgemeinen eine Berechnung der Aktivierungsenergie nicht möglich.Auszugsweise vorgetragen auf dem XI. Internationalen Kongreß für Radiologie, Rom, September 1965.     

Importance of acyl-CoA availability in interpretation of carnitine palmitoyltransferase I kinetics

Bovine serum albumin is generally employed as a substrate depot for the delivery of acyl units to lipid metabolizing enzymes in vitro. Here we test the possibility that albumin alters the availability of substrate to mitochondrial carnitine palmitoyltransferase I and thereby alters its apparent kinetics. Binding competition with palmitoyl-CoA indicates that albumin has 5-6 high affinity sites which avidly bind the substrate, while isolated mitochondria compete favorably for substrate only as the albumin sites become saturated. In contrast to albumin, artificial phospholipid vesicles bind palmitoyl-CoA uniformly. Palmitoyl-CoA distribution between vesicles and mitochondrial membranes appears simply to be a function of the relative size of the two lipid compartments. Both albumin and artificial vesicles reduce the effective concentration of substrate available to the enzyme and in this way reduce apparent affinity. Direct measurement of mitochondrially bound substrate removes this effect and brings the results into agreement with an affinity constant of 6-7 nmol/mg. Changes in gross mitochondrial structure, as indicated by decreased optical density and increased nonpelleting protein, do not begin occurring until levels of mitochondrially bound palmitoyl-CoA are 15 times greater than this. The highly sigmoidal activity profile of carnitine palmitoyltransferase with respect to palmitoyl-CoA (apparent Hill coefficient = 3.0 +/- 0.3) is lost when vesicles are substituted for albumin, suggesting that albumin binding sites contribute to the sigmoidal kinetics in the range of palmitoyl-CoA studied.     

Development of sequence amplified characterized region (SCAR) markers of helicoverpa armigera: a new polymerase chain reaction-based technique for predator gut analysis

A method is described for the development of DNA markers for detection of Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) in predator gut analysis, based on sequence characterized amplified regions (SCARs) derived from a randomly amplified polymorphic DNA (RAPD) band. A 1200-bp DNA fragment of H. armigera, absent in the predator band pattern and in other closely related prey species, was identified by RAPD analysis. This fragment was cloned and its extremes sequenced to design extended strand-specific 20-mer oligonucleotide primers. Three pairs of SCAR primers, which amplified three different DNA fragments, were used to study the effect of fragment length on detection of prey in the predator gut. Using the pair of primers that amplified the longest fragment of H. armigera DNA, a single band of 1100 bp was obtained, but its detection was not possible in the predator gut. Detection of the ingested prey was possible with the other two pairs of SCAR primers, obtaining bands of 600 and 254 bp, respectively. Detection of H. armigera DNA in the gut of the predator Dicyphus tamaninii was evaluated immediately after ingestion (t = 0) and after 4 h. Detection of H. armigera DNA after 4 h was only possible using the pair of primers that amplified the shortest fragment (254 bp). The test for specificity, using these last pair of primers, showed that H. armigera was the only species detected. The detection threshold was defined at a 1:8192 dilution of a H. armigera whole egg in all samples.     

Explaining Darwin’s Corollary to Haldane’s Rule: The Role of Mitonuclear Interactions in Asymmetric Postzygotic Isolation Among Toads

We examine the basis of Darwin’s corollary to Haldane’s rule, which describes viability and fertility differences between F₁ produced from reciprocal crosses. We analyzed asymmetries in hybrid viability from >100 reciprocal crosses involving 36 toad species to test whether relatively high rates of mitochondrial vs. nuclear evolution produce dams with systematically less viable F₁ hybrid progeny. We find no such effect, suggesting a predominant role for stochastic accumulation of asymmetric epistatic incompatibilities.     

Progressive Erblindung und Nierenerkrankung in Zusammenhang mit einer periartikulären Hyperostose bei einem männlichen Mohrenmaki (Eulemur macaco macaco) im Tierpark Berlin

Until now there were no publications about periarticular hyperostosis in black lemurs at an European zoo. The author described a case of this disease connected with a growing blindness and a progressive renal disfunction in a male black lemur at Tierpark Berlin. Clinical symptoms, diagnosis and therapy are explained in detail.