Pectinases in Aqueous Extracts of Ditylenchus dipsaci

Aqueous extracts of a population of Ditylenchus dipsaci isolated from onion and maintained monoxenically on onion callus contained endo-polygalacturonase (endo-PG) and endo-pectinmethyltranseliminase (endo-PMTE). In viscometric tests pH 4.2 and 4.0 were optimal for degradation of sodium polypectate and pectin N.F., respectively, by endo-PG. Endo-PMTE reduced viscosity of pectin N.F. optimally at pH 8.5 or above. Activity was dependent on CaCl₂. Pectinmethylesterase activity was not detected in water, NaCl, or sucrose extracts of these nematodes. The extracts macerated potato tuber tissue, onion cotyledonary tissue, and strips of onion epidermis from the ventral surface of onion bulb scales at pH 4.2, 5.3, and 6.2. Pectin could not be localized with hydroxylamine-ferric chloride reagent in macerated tissues treated for 24 hr with active extract.     

A Comparison of Pectinases from Ditylenchus dipsaci and Allium cepa Callus Tissue

Ground and whole Ditylenchus dipsaci maintained on onion callus contain no culturable micro-organisms when tested with five check media. Healthy onion callus does not produce pectolytic enzymes. Pectolytic enzymes are present in infected callus. These enzymes are, however, associated with resident nematodes and not host tissues. These results suggest that D. dipsaci is the actual source of the endo-polygalacturonase and endo-pectinmethyltrans-eliminase extracted from them.     

Über bau und funktion der prosoma-drüsen von spinnmilben (Tetranychidae,Trombidiformes)

Zoomorphology - Die licht- und elektronenmikroskopische Untersuchung der Prosomadrüsen der Spinnmilben Bryobia praetiosa, Bryobia rubrioculus und Tetranychus urticae (Tetranychidae,...     

Über Aufbau und Innervation der Kopfanhänge der prosobranchen Schnecken

Zusammenfassung Das Epithel der Kopfanhänge von elf marinen und Süßwasserprosobranchiern besteht aus prismatischen bis kubischen Stützzellen mit meist dichtem Mikrovillussaum und z.T. Pigmentgranula sowie Sinneszellen, die fast immer in Form sekundärer Sinneszellen vorliegen; nur bei Patella coerulea kommen vermutlich auch primäre Sinneszellen vor. Ihr Zytoplasma ist apikal durch glattwandige E. R.-Zisternen, helle Bläschen und Mikrotubuli gekennzeichnet. Außerdem tragen diese Zellen Zilien und stehen basal mit Nervenendigungen in Kontakt, die sich in drei Gruppen einteilen lassen: 1. Vermutlich cholinerge Endigungen mit optisch leeren Bläschen (Ø 600–800 Å). 2. Endigungen mit dense core vesicles (Ø 1000–1100 Å). Die Annahme, daß diese Endigungen biogene Amine enthalten, wird durch fluoreszenzmikroskopische Befunde gestützt. 3. Endigungen mit großen (Ø 3000–4000 Å) neurosekretorischen Elementargranula.

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Structure and innervation of the cephalic tentacles of Prosobranch molluscs

Summary The epithelium of the cephalic tentacles of eleven marine and freshwater prosobranch snails consists of villus bearing supporting cells, which partly contain pigment granules, and sensory cells, which occur in form of secondary sensory cells with the exception of Patella coerulea which presumably possesses primary sensory cells. These receptor cells are characterized as chemoreceptors by apical cilia, smooth surfaced E.R., microtubulues and empty vesicles. At their bases they are in close contact with nerve endings which can be classified in three groups: 1. presumably cholinergic endings with clear vesicles (Ø 600–800 Å). 2. endings with dense core vesicles (Ø 1000–1100 Å). The assumption that these endings contain biogenic amines is supported by positive fluorescence microscopical tests. 3. Endings with big (Ø 3000–4000 Å) neurosecretory elementary granules.

Herrn Prof. Dr. W. Bargmann danke ich für die Überlassung eines Arbeitsplatzes im Anatomischen Institut Kiel.     

Comparative Study of Cultured Burkitt Tumor Cells by Immunofluorescence, Autoradiography, and Electron Microscopy

Cultured Burkitt cells were examined by immunofluorescence, autoradiography, and electron microscopy in an effort to identify the stainable cells with those harboring herpes-type virus particles. Immediately after a 2-hr pulse of (3)H-thymidine, from 30 to 60% of the cells revealed heavy nuclear labeling. In most cases the grains were evenly dispersed, but in about 3 to 5% the grains showed a focal distribution and occasionally they extended into the cytoplasm. Such nuclear foci were rarely seen at 8 hr after the pulse. When the analysis was restricted to preselected immunofluorescent cells, up to 80% showed label at 8 hr and cytoplasmic grains were prominent. To reduce cellular deoxyribonucleic acid (DNA) synthesis, cells were X-irradiated with 3,000 to 6,000 R, and the isotope pulse was applied 1, 4, or 7 days later. Whereas the total number of labeled cells decreased in roughly twofold steps at the respective intervals (from 40 to 10%), the incorporation of (3)H-thymidine into fluorescent cells was not affected by X irradiation. In each series, about 70% of the fluorescent cells contained label when they were examined at 24 and 48 hr after the pulse, whereas at 8 and 72 hr fewer were positive. At the earlier intervals, unlabeled fluorescent cells most likely represented cells which had completed viral DNA synthesis prior to the pulse; at the later intervals, unlabeled fluorescent cells were probably cells which commenced viral replication after the pulse. These data support the conclusion that the immunofluorescent cells are the ones which harbor virus, and also confirm the expectation that the virus is a DNA virus from a member of the herpes group. This conclusion was firmly established by sectioning and electron microscopic examination of individual fluorescent cells, all of which contained numerous virus particles, whereas the nonstained cells prepared in a similar manner were free of them.     

Die Ultrastruktur der Kapillarwand in der menschlichen Placenta zur Zeit der Schwangerschaftsmitte

Zusammenfassung Die Wand der Kapillaren in der menschlichen Placenta aus der Schwangerschaftsmitte wird elektronenmikroskopisch untersucht und zu der Wand des Sinusoides der reifen Placenta in Beziehung gesetzt. Bereits zur Zeit der Schwangerschaftsmitte sind vereinzelt Sinusoide nachweisbar, doch treten sie gegenüber den Kapillaren zahlenmäßig in den Hintergrund.Die Kapillaren des Zottenbinnenraumes besitzen keine Basalmembran; sie sitzen meist, nur durch einen Spalt getrennt, einer Pericytenschicht auf. Die Pericyten haben häufig fußförmige Ausläufer, die die Basalmembran des Cytotrophoblasten erreichen. Die Kapillarendothelien sind zwar einreihig angeordnet, überlappen aber einander in ausgedehnter Weise.Im Cytoplasma der Kapillarendothelien findet man häufig eine feinfilamentäre Zeichnung, jedoch nur nach Kaliumpermanganat-Kontrastierung.Die Kapillaren der unreifen Placenta sind durch das Fehlen der Basalmembran, durch die ungewöhnliche Dicke und durch die starke Überlappung ihres Endothels für eine Gefügedilatation besonders geeignet.Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Modification of tumor cells by a low dose of Newcastle disease virus

Summary Augmented tumor-specific T cell responses were observed against the high metastatic murine lymphoma variant ESb when using as immunogen ESb tumor cells that had been modified by infection with a low dose of Newcastle disease virus (NDV). Such virus-modified inactivated tumor cells (ESb-NDV) were potent tumor vaccines when applied postoperatively for active specific immunotherapy of ESb metastases. We demonstrate here that immune spleen cells from mice immunized with ESb-NDV contain enhanced immune capacity in both the CD4⁺, CD8^– and the CD4^–, CD8⁺ T cell compartments to mount a secondary-tumor-specific cytotoxic T cell response in comparison with immune cells from mice immunized with ESb. ESb-NDV immune CD4⁺, CD8^– helper T cells also produced more interleukin 2 after antigen stimulation than the corresponding ESb immune cells. There was no participation of either CD4⁺ or CD8⁺ virus-specific cells in the augmented response. The specificity of the T cells for the tumor-associated antigen remaind unchanged. Thus, there is the paradox that the virus-mediated augmentation of the tumor-specific T cell response in this system involves increased T helper activity but does not involve the recognition of viral epitopes as potential new helper determinants.Abbreviations CTL cytolytic T lymphocytes - IL-2 interleukin 2 - rIL-2 recombinant IL-2 - mAb monoclonal antibody - NDV Newcastle disease virus - SSC syngeneic spleen cell     

Paradoxical effects of oxytocin and vasopressin on basal prolactin secretion and the estrogen-induced prolactin surge

The roles of oxytocin (OT) and vasopressin (AVP) on both basal and estrogen-induced prolactin (PRL) secretion were examined. Adult female Sprague-Dawley rats that were ovariectomized for 3 weeks and received estrogen treatment for 1 week were used. Intravenous administration of hormones and serial blood sampling were accomplished through indwelling intraatrial catheters which were implanted two days before. Plasma PRL levels were measured by radioimmunoassay. Oxytocin at a dose of 20 micrograms/rat stimulated a moderate PRL release in the morning and lower doses (5 and 10 micrograms) were without effect. Vasopressin was most effective at a dose of 5 micrograms/rat in stimulating PRL release, while consecutive injections of higher doses (10 and 20 micrograms) were less effective. In contrast, TRH, ranging from 1 to 8 micrograms/rat, induced a dose-dependent increases in PRL secretion. Using the effective dosages determined from the morning studies, repeated injections of either OT, AVP or their specific antagonists MPOMeOVT [( 1-(beta-mercapto-beta, beta-cyclopentamethylene propanoic acid), 2-(O-methyl)tyrosine, 8-ornithine]-vasotocin) and d (CH2)5Tyr(Me)AVP ([1-(beta-mercapto-beta, beta-cyclo-pentamethylene propionic acid), 2-(O-methyl)tyrosine, 8-arginine]-vasopressin), were given hourly between 1300 to 1800 h and blood samples were obtained hourly from 1100 to 1900 h. It was found that either OT or AVP significantly reduced the afternoon PRL surge, while their antagonists were not as effective. When OT or AVP were administered together with their specific antagonists, the inhibitory effects of either hormone on PRL surge were reversed. Thus it is concluded that both OT and AVP assume a non-specific stress-like effect on PRL release, in which basal secretion is stimulated and surge secretion is inhibited.     

High dose antioxidant supplementation to MS patients. Effects on glutathione peroxidase, clinical safety, and absorption of selenium.

High-dose antioxidant supplementation has recently been recommended for multiple sclerosis (MS) patients. This study tests the clinical safety, the glutathione peroxidase (GSH-px) activity, and the absorption of selenium during such supplementation. Eighteen MS patients were given 6 tablets especially made for this study, equivalent to 6 mg sodium selenite, 2 g vitamin C, and 480 mg vitamin E a day for five wk. GSH-px, which was lower than in non-MS controls before the start of treatment, increased fivefold during 5 wk of treatment. Side effects were scarce. Ten MS patients were subjected to a 24-h selenium absorption study after ingestion of 2 active tablets, equivalent to 2 mg sodium selenite. Selenium, which was low initially, increased 24% during the first 3 h and then stabilized. It is concluded that the tested antioxidant treatment seems to be safe and that MS patients have low GSH-px, which may be increased by the tested antioxidant treatment.