Non-Selective Calcium Channel Blocker Bepridil Decreases Secondary Pathology in Mice after Photothrombotic Cortical Lesion

Experimental studies have identified a complex link between neurodegeneration, β-amyloid (Aβ) and calcium homeostasis. Here we asked whether early phase β-amyloid pathology in transgenic hAPP_SL mice exaggerates the ischemic lesion and remote secondary pathology in the thalamus, and whether a non-selective calcium channel blocker reduces these pathologies. Transgenic hAPP_SL (n = 33) and non-transgenic (n = 30) male mice (4–5 months) were subjected to unilateral cortical photothrombosis and treated with the non-selective calcium channel blocker bepridil (50 mg/kg, p.o., once a day) or vehicle for 28 days, starting administration 2 days after the operation. Animals were then perfused for histological analysis of infarct size, Aβ and calcium accumulation in the thalamus. Cortical photothrombosis resulted in a small infarct, which was associated with atypical Aβ and calcium accumulation in the ipsilateral thalamus. Transgenic mice had significantly smaller infarct volumes than non-transgenic littermates (P<0.05) and ischemia-induced rodent Aβ accumulation in the thalamus was lower in transgenic mice compared to non-transgenic mice (P<0.01). Bepridil decreased calcium load in the thalamus (P<0.01). The present data suggest less pronounced primary and secondary pathology in hAPP_SL transgenic mice after ischemic cortical injury. Bepridil particularly decreased calcium pathology in the thalamus following ischemia.     

An improved method for light- and electron microscopial studies of nematode/fungal interactions

A method is presented that enables studies to be made of single nematode-fungal interactions under conditions where fungal growth at the expense of external nutrients is prevented. The nematophagous fungus Arthrobotrys ologospora was used as a model organism in these studies. The method is based on removal of the traps from the vegetative mycelium, immediately after a nematode was captured and transfer of the trap with the captured nematode into a droplet of sterile distilled water placed in a moisture chamber. In the absence of external nutrients, such isolated traps of A. oligospora were fully effective in penetrating and subsequently digesting the captured nematode. Solely vegetative mycelium was formed at the expense of the digested nematode; this developed from the trap that originally had captured the nematode. One advantage of the present method is that studies on various stages of the nematode-fungal interaction can now be performed under conditions that exclude major influences of external nutrients which otherwise could be communicated to the trap cells by way of the vegetative mycelium.     

Bacteriophage receptors of Lactococcus lactis subsp. 'diacetylactis' F7/2 and Lactococcus lactis subsp. cremoris Wg2-1

Bacteriophage P008 revealed irreversible and uniform adsorption to cell walls of L. lactis subsp. 'diacetylactis' F7/2, whereas phage P127 adsorbed reversibly to a limited number of receptor sites on cell walls of L. lactis subsp. cremoris Wg2-1. Neither extraction of lipids, cell wall- and membrane-teichoic acids nor enzymatic degradation of proteins altered the binding efficiencies of both cell wall fractions. However, phage binding was inhibited, when cell walls were subjected to lysozyme, metaperiodate, or acid treatments. This reflects that a carbohydrate component embedded in the peptidoglycan matrix is part of the phage receptors of strains F7/2 and Wg2-1.     

Development and fate of electron-dense microbodies in trap cells of the nematophagous fungusArthrobotrys oligospora

The development of electron-dense microbodies in cells of capture organs of the nematophagous fungus Arthrobotrys oligospora was studied with different ultrastructural techniques. Kinetic experiments revealed that the synthesis of these microbodies started in a very early stage of trap formation; the organelles originated from special regions of endoplasmic reticulum by budding. Mature organelles were surrounded by a single membrane of approximately 9 nm (KMnO4-fixation) and lacked crystalline inclusions. The presence of the electron-dense microbodies was independent of the conditions during which the traps had developed. The organelles remained intact during aging of the trap cells. They were also observed in the trophic hyphae after capture and penetration of nematodes. However, the distribution patterns of these organelles in the trophic hyphae, which were identical to those observed after germination of isolated traps on different cultivation media, suggested that their presence must be explained by dilution of organelles in newly formed cells.     

High Performance Liquid Chromatography of Molecular Species from Free Sterols and Sterylglycosides Isolated from Oat Leaves and Seeds

Free sterols and sterylglycosides (SG) from oat leaves and seedswere isolated by conventional thin layer chromatography (TLC)and subjected to high performance liquid chromatography (HPLC)for resolution of molecular species. Acylsterylglycosides, isolatedby TLC, were converted to SG by mild alkaline hydrolysis anddetermined as SG. Sterols and SG were injected onto the columnwithout any chemical treatment and the separated species weredetected at 200 nm. The separation of SG-species follows exactlythe separation of free sterols. Though gas liquid chromatography still is the method of choice,advantages of HPLC is to analyse directly the SG-species withouthydrolysis and derivatization as compared to GLC. After TLCthe sterol- and the SG-fraction are injected directly onto thecolumn. This is extremely important for labile sterylglycosidesor sterols, as demonstrated for the avenasterols. ¹ Preliminary reports have been presented on the "4. Arbeitstagung,Pflanzliche Lipide", October 7–8, 1983 in M?nster (FRG)and on the "6th International Symposium on the Structure, Functionand Metabolism of Plant Lipids", Neuchatel, Switzerland, July16–20, 1984. (Received November 12, 1984; Accepted January 14, 1985)     

Postembryonic development of the parasitic amphipodHyperia galba

Hyperia galba Montagu is associated with gelatinous zooplankton as are many species of the Hyperiidea. The hosts preferred in the European seas are the large scyphomedusaeAurelia aurita, Chrysaora hysoscella, Rhizostoma pulmo, Cyanea capillata andCyanea lamarckii, which harbour the first developmental stages. The anamorphic development produces young that are incapable of swimming at the time of hatching. They are characterized by an embryonic abdomen without extremities and external segmentation; the eyes are not completely developed and the mouth is primitive lacking bristles, molar and incisor. The postembryonic development, described in detail, is subdivided into two phases: the pantochelis phase and the protopleon phase; the former comprises only one stage; the latter can be subdivided into four stages. In the course of postnatal development the larval organs are reduced and characters typical of the adult are gradually differentiated.H. galba plays an important role as obligatory endoparasite of scyphomedusae at least during the first stages of development; without a host this amphipod cannot survive, neither benthically nor in the plankton. The transition from life in the female's marsupium to endoparasitism in the jellyfish generally occurs during stage of the postembryonic development which is the first stage of the protopleon phase. The specific adaptations of its reproductive biology to a parasitic mode of life such as moult inhibition under starvation, development of larval organs and the behavioural patterns of the females as well as the young are described. Further, the influence of external factors such as temperature and food supply on the course of development is examined. Dedicated to Prof. Dr. H. Mergner on the occasion of his 70th birthday.