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41.
Joachim -Hermann Scharf 《Cell and tissue research》1967,80(1):124-139
Zusammenfassung Eine Analyse der Meßwerte von Ronge (1943) über die Reizausnutzung durch das Tastsinnes-Nervensystem der Haut zeigt im Zusammenhang mit einer vorausgegangenen Studie (Scharf und Blumenthal, 1967), daß der Reizerfolg in einer transzendenten Fläche höherer Ordnung in Abhängigkeit vom Lebensalter (oder von der Anzahl der Meissnerschen Tastkörperchen pro Hautflächeneinheit) und vom Reizdruck dargestellt werden kann. In Druckrichtung steigt diese Fläche mit zunehmendem Reizdruck nichtlinear an, in Zeitrichtung oscilliert die Fläche dagegen träge um Normwerte, die beim 20jährigen Menschen realisiert sind. Dabei werden die Altersveränderungen der histologischen Hautstruktur offenbar zur Kompensation der altersabhängigen Verminderungen der Zahl der Tastkörperchen ausgenutzt.
Mit dankenswerter Unterstützung durch einen Forschungsauftrag des Staatssekretariates für das Hochschulwesen der DDR.
Numerische Rechnung: Tischrechner Mercedes Cellatron R 44 SM, Leitende Med. techn. Ass. Ruth Pieper (Anatomisches Institut Halle). Programmgesteuerter Digitalrechner ZRA 1, Math, techn. Ass. Friedegund Hüther (Institut für Numerische Mathematik, Halle).
Graphik: Akad. Bildhauer Hellmut Helwin. 相似文献
Summary An analysis of the observations on the Reizausnutzung by nerves of touch (Ronge, 1943) connected to a previous study (Scharf and Blumenthal, 1967) shows that the irritation result may be figured by a transcendental plane of higher order as a function of age (or number of Meissner's corpuscles per area skin) and irritation pressure. Along the pressure axis this non-linear plane is increasing non-linear in dependence on ascending pressure, but along the time axis the plane oscillates lazily round about the norm values which are realized in human beings of about 20 years of age. It seems that the age-dependent changes of histological skin structure are utilized to compensate the age-dependent diminution of touch corpuscle number.
Mit dankenswerter Unterstützung durch einen Forschungsauftrag des Staatssekretariates für das Hochschulwesen der DDR.
Numerische Rechnung: Tischrechner Mercedes Cellatron R 44 SM, Leitende Med. techn. Ass. Ruth Pieper (Anatomisches Institut Halle). Programmgesteuerter Digitalrechner ZRA 1, Math, techn. Ass. Friedegund Hüther (Institut für Numerische Mathematik, Halle).
Graphik: Akad. Bildhauer Hellmut Helwin. 相似文献
42.
Zusammenfassung Von lichtmikroskopischen Befunden der Neurosekretion bei dem Oligochaeten Enchytraeus ausgehend, haben wir an zwei elektronenmikroskopisch genau bezeichneten und festgelegten Zellen bzw. Zelltypen, die bereits lichtmikroskopisch charakterisiert worden waren, Untersuchungen über die submikroskopisch faßbare Zelldynamik durchgeführt. Die beiden Arten neurosekretorischer Zellen (Q-Zelle und P-Zellen) sind elektronen-mikroskopisch schon durch ihre Lage zu erfassen. Sie können nicht nur durch die Zellgröße, sondern auch durch ihre Elementargranula, den Aufbau des endoplasmatischen Retikulums und den Golgi-Apparat eindeutig unterschieden werden. Wie schon in den lichtmikroskopischen Untersuchungen wurde die Sekretionsaktivität mit der Amputation ausgelöst. Sowohl in der Q -als auch in der P-Zelle bewirkt die Amputation eine unmittelbare Sekretentleerung. Die darauf einsetzende Phase der Sekretproduktion ist submikroskopisch durch eine erhöhte Zahl von Golgistrukturen in diesen Zellen, durch das deutlich in Erscheinung tretende granuläre endoplasmatische Retikulum und durch eine fortschreitende Vergrößerung und Verdichtung von Lysosomen in beiden Zelltypen gekennzeichnet. Für die Q-Zelle sind weiterhin die Verstärkung des diesen Zelltyp besonders noch charakterisierenden Bereiches von Membranzisternen und die dortige Ribosomenbildung typisch. Auf Grund der Feststellungen wird die Frage der Beziehung einzelner Strukturen in diesen beiden Zelltypen zur Produktion des Neuro-sekrets diskutiert. Die elektronenmikroskopische Untersuchung führte zur Entdeckung eines weiteren Zelltyps, der im Lichtmikroskop bisher nicht erkannt worden war und der sich durch besonderen Reichtum an Mitochondrien und großen Lipoid (?)-Komplexen auszeichnet (M-Zelle). Über seine Bedeutung ist jedoch noch keine Aussage möglich.
Mit Unterstützung durch die Sächsische Akademie der Wissenschaften zu Leipzig.
Herrn Prof. Dr. F. Seidel, Marburg, zum 70. Geburtstag gewidmet. 相似文献
Summary The cytophysiology of two types of neurosecretory cells (Q and P cell) in the brain of the oligochete Enchytraeus was studied at the ultrastructural level. These cell types can be identified by their location, and particularly by the size difference of their elementary granules. Amputation of the last ten segments caused a release of secretory product followed by a phase of renewed production. This was characterized by changes in the endoplasmic reticulum, the Golgi apparatus, and the lysosomes. The role of these structures in the production of neurosecretory material was discussed. Furthermore, a cell type with extraordinarily numerous mitochondria, hitherto unknown in Enchytraeus, was described. Its function has not yet been determined.
Mit Unterstützung durch die Sächsische Akademie der Wissenschaften zu Leipzig.
Herrn Prof. Dr. F. Seidel, Marburg, zum 70. Geburtstag gewidmet. 相似文献
43.
Summary The conditions for optimum incorporation of radioactive amino acids into proteins of cultured postimplantation mouse embryos
were investigated under the aspect of using these proteins for two-dimensional electrophoretic separations and fluorography.
The aim was to obtain highly radioactively labeled proteins under conditions as physiological as possible. Mouse embryos of
Days 8, 10, and 11 of gestation were cultured in Tyrode’s solution. Incubation time and concentration of [3H (or14C)]amino acids in the culture medium were varied over a broad range. Embryos were prepared with placenta and yolk sac or without
any embryonic envelopes. After culturing, the physiologic-morphologic state of the embryos was registered on the basis of
several criteria. The radioactivity taken up by the total protein of each embryo was determined and calculated in disintegrations
per minute per milligram protein per embryo. To approach our aim, embryos of different developmental stages had to be cultured
under different conditions. A good compromise for Day-8, Day-10, and Day-11 embryos was: embryos prepared with yolk sac (opened)
and placenta, 150 μCi radioactive amino acids added per milliliter medium, incubation for 4 to 5 h. For maximum labeling of
proteins it is advisable to culture Day-10 embryos without embryonic envelopes under particular conditions.
This work was supported by grants from the Deutsche Forschungsgemeinschaft awarded to the project K1 237/3-2 (Systematic analysis
of cell proteins). 相似文献
44.
An alternating (asymmetric) bipolar staircase voltage clamppulse series was used to investigate the action potential inChara corallina. Using this protocol, we found that the actionpotential was present in the hyperpolarized region of the current-voltagerelationship of the whole cell membrane. Effects of strong hyperpolarizingvoltage steps, during the excitation process, can thus be studied. (Received August 22, 1989; Accepted October 14, 1989) 相似文献
45.
Enzymes Involved in Anaerobic Polyethylene Glycol Degradation by Pelobacter venetianus and Bacteroides Strain PG1 总被引:1,自引:0,他引:1
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In extracts of polyethylene glycol (PEG)-grown cells of the strictly anaerobically fermenting bacterium Pelobacter venetianus, two different enzyme activities were detected, a diol dehydratase and a PEG-degrading enzyme which was characterized as a PEG acetaldehyde lyase. Both enzymes were oxygen sensitive and depended on a reductant, such as titanium citrate or sulfhydryl compounds, for optimal activity. The diol dehydratase was inhibited by various corrinoids (adenosylcobalamin, cyanocobalamin, hydroxocobalamin, and methylcobalamin) by up to 37% at a concentration of 100 μM. Changes in ionic strength and the K+ ion concentration had only limited effects on this enzyme activity; glycerol inhibited the enzyme by 95%. The PEG-degrading enzyme activity was stimulated by the same corrinoids by up to 80%, exhibited optimal activity in 0.75 M potassium phosphate buffer or in the presence of 4 M KCI, and was only slightly affected by glycerol. Both enzymes were located in the cytoplasmic space. Also, another PEG-degrading bacterium, Bacteroides strain PG1, contained a PEG acetaldehyde lyase activity analogous to the corresponding enzyme of P. venetianus but no diol dehydratase. Our results confirm that corrinoid-influenced PEG degradation analogous to a diol dehydratase reaction is a common strategy among several different strictly anaerobic PEG-degrading bacteria. 相似文献
46.
Rolf Wichmann Christian Wandreg Joachim Große-Wiesmann 《Applied microbiology and biotechnology》1990,32(4):373-379
Summary Continuous production ofl-leucine was carried out withCorynebacterium glutamicum, strain ATCC 13032 starting from-ketoisocaproic acid as the precursor, glucose as the carbon source and ammonium sulphate as the nitrogen source, with biotin in a mineral medium. By means of cross-flow microfiltration or centrifugal separation for cell retention in continuous fermentation an increase in cell density was achieved and the product solution was obtained cell-free. The cells were concentrated to over 70 g cell dry mass/1. In experiments of up to 42 days, conversion rates of 85%–99% andl-leucine yields of 85%–93% were achieved. With a substrate residence time of 3.6 h, 114 mmol/1l-leucine was produced with a space-time yield of 97 g/1 per day. A scale-up of the fermentation volume from 4 to 1001 provided comparable results. 相似文献
47.
Hoch Brigitte Lutsch Gudrun Schlegel Wolfgang-Peter Stahl Joachim Wallukat Gerd Bartel Sabine Krause Ernst-Georg Benndorf Rainer Karczewski Peter 《Molecular and cellular biochemistry》1996,160(1):231-239
Recent investigations concentrate on the correlation between the myocardial expression of the inducible 70-kDa heat shock protein (HSP70i) by different stress conditions and its possible protective effects. Only few studies have focused on the involvement of small heat shock proteins in this process. We analyzed the location of the small heat shock protein HSP25 in isolated cardiomyocytes as well as its location and induction in isolated perfused hearts of rats. By immunofluorescence microscopy HSP25 was found to colocalize with actin in the I-band of myofibrils in cardiomyocytes of isolated perfused hearts as well as in isolated neonatal and adult cardiomyocytes. Hyperthermic perfusion of isolated hearts for 45 min resulted in modulation of different parameters of heart function and in induction of HSP25 and HSP70i. Temperatures higher than 43°C (44–46°C) were lethal with respect to the contractile function of the hearts. Compared to control hearts perfused at 37°C, significant increases during hyperthermic perfusion at 42°C and 43°C were obtained for heart rate, contraction velocity and relaxation velocity. In response to hyperthermia at 43°C and after subsequent normothermic perfusion for 135 min at 37°C, left ventricular pressure, contraction velocity and relaxation velocity remained significantly elevated. However, heart rate returned to control values immediately after the period of heat treatment. HSP25 is constitutively expressed even in normothermic perfused hearts as shown by Western blotting. Hyperthermia increased the content of HSP25 only in the left ventricular tissue. In contrast, HSP70i was strongly induced in all analyzed parts of the myocardium (left ventricle, right ventricle, septum). Our findings suggest a differential regulation of HSP25 and HSP70i expression in response to hyperthermia in isolated perfused hearts. The constitutively expressed HSP25 seems to be located adjacent to the myofibrils which implies a specific role of this protein even under unstressed conditions for the contractile function of the myocardium. 相似文献
48.
49.
R. Kempken A Preißmann W. Berthold 《Journal of industrial microbiology & biotechnology》1995,14(1):52-57
Summary Animal cells from 80-L and 2000-L fed batch fermentations were removed by a prototype disc stack centrifuge in order to achieve a fast and reliable separation of solids from large quantities of cell culture fluids. The clarification capacity was excellent for animal cells but particles remained in the liquid phase and affected further downstream processing of the cell-free harvest fluid. No significant loss of product was observed. A number of parameters were monitored to optimize process conditions for use with animal cells. 相似文献
50.
Sabine Kloth Joachim Aigner Anita Schmidbauer Will W. Minuth 《Cell and tissue research》1994,277(2):247-257
Within the cortex region of the neonatal rabbit kidney the developing microvasculature was investigated by means of two endothelium-detecting antibodies (EnPo 1 and EC1). Rows of antibody-labelled cells were found within tissue regions that had previously been described as avascular. We conclude that these vessel-like structures detected by EnPo 1 and EC1 are capillary precursors without lumina. Furthermore, beneath the fibrous capsule within the morphologically homogeneous mesenchyme two cell populations can be discriminated by use of differential antigen expression. The EnPo 1 antigen, which is abundant on endothelial cells and podocytes at different developmental stages, was detected on a subpopulation of mesenchymal cells. These cells were exclusively detected surrounding the tip of the collecting duct ampulla. Due to the unique specificity of EC1 and EnPo 1 the process of microvascular development can be readily followed on serial optical sections gained by laser scan microscopy. (1) Adjacent to EnPo 1-positive mesenchymal cell islets vessel-like structures are found that are in contact with the differentiated vasculature. (2) The renal vesicle is enclosed by a network of vessel-like structures establishing contact with differentiated vessels. (3) No guidance of invading capillary sprouts toward the developing glomerulus and nephron is required, since vascular elements already accompany the earliest detectable nephron stage. 相似文献