Ansprache bei der Feier des 80. Geburtstages von Prof. Dr. Max Nonne am 13. I. 1941

Ohne ZusammenfassungBei der Feier, die im festlich geschmückten großen Hörsaal des Universitätskrankenhauses Eppendorf stattfand, wurde Prof. Nonne in Anerkennung seiner Verdienste um die Neurologie die Goethe-Medaille für Kunst und Wissenschaft verliehen.     

Untersuchungen über die spezifische und quantitative Erfassung des Liquor-γ-Globulins mit der Zinksulfatfällung

Zusammenfassung Die Frage der quantitativen und elektiven Erfassung des Liquor--Globulins mit der vonRoboz u. Mitarb. beschriebenen Zinksulfatfällung wurde an Modellversuchen mit reinem -Globulin und Albumin und an der elektrophoretischen Auftrennung des mit Zinksulfat aus Liquor präzipitierten Proteins untersucht. Aus reinen -Globulinlösungen wurden in Abhängigkeit zu der in Ansatz gebrachten -Globulinmenge nur 18–46% gefällt. Das Elektrophoresediagramm der mit Zinksulfat gefällten Liquorproteine zeigte, daß neben einer Anreicherung des -Globulins eine Fällung sämtlicher Liquorproteine zustande kam. Die elektrophoretische Auftrennung der im Überstand der Fällung verbliebenen Eiweißkörper ließ neben den übrigen Fraktionen noch eine deutliche -Globulinbande erkennen. Eine elektive und quantitative Fällung des Liquor--Globulins mit der Zinksulfatmethode konnte demnach nicht nachgewiesen werden.Herrn Dozent Dr.H. Bauer danke ich für die Anregung und Unterstützung bei Durchführung dieser Untersuchungen.     

Buchbesprechungen

Ohne Zusammenfassung     

The time course of glycogen depletion in single fibers of chronically stimulated rabbit fast-twitch muscle

A time course study was conducted to investigate the possibility of a relationship between fiber degeneration and glycogen depletion in chronically nerve-stimulated extensor digitorum longus muscle of the rabbit. Muscles were stimulated 12 h daily at 10 Hz using alternating one-hour periods of stimulation and rest. When measured for the first time after 3 h (1 h stimulation, 1 h rest, 1 h stimulation), microphotometry revealed complete glycogen depletion of all fiber types (fast glycolytic, FG; fast oxidative glycolytic, FOG; slow oxidative, SO). Different responses were noted beginning at day 4. At this time point, all FOG and SO fibers recovered their glycogen stores with some of the FOG population attaining levels higher than the FOG fibers in the unstimulated, contralateral muscle. Approximately 28% of the FG fibers recovered to normal glycogen values, whereas 58% remained depleted and 14% displayed overshoting glycogen levels. Fifteen percent of all fibers were glycogen-depleted after 12 days of stimulation. At this time, classic fiber types could no longer be distinguished. Fiber degeneration, which was recognized by the invasion of nonmuscle cells, began after 6 days and was restricted to the glycogen-depleted fibers. By this time, there was also a significant increase in DNA content. Exhaustions of glycogen, the main fuel of the FG fibers, is believed to cause a collapse of energy-supply and ATP-driven ionic pumps. The latter could be the initial step of fiber deterioration.     

Experimentelle Untersuchungen mit dem „Virus der akuten disseminierten Encephalomyelitis des Menschen“ (Margulis,Soloviev, Shubladze)

Ohne Zusammenfassung     

Evaluation of multiple sclerosis sera against measles antigen in the complement fixation test

Summary The examination of 28 spinal fluids of MS patients and 22 spinal fluids of control persons showed no differences in the content of complement fixing antibodies against measles virus. In contrast to spinal fluid findings, higher antibody titers could be demonstrated in the serum of 70 MS patients than in 548 control persons. These differences were of biostatistical significance.Stiftung zur Erforschung der spinalen Kinderlähmung und der Multiplen Sklerose.     

Stretch activation and isoforms of myosin heavy chain and troponin-T of rat skeletal muscle fibres

Recent studies on single mammalian skeletal muscle fibres revealed a correlation between the kinetics of stretch-induced delayed force increase (stretch activation) and the isoforms of the myosin heavy chain. This observation suggests a causal relation between stretch activation and myosin heavy chain. However, the assumption is weakened by the fact that isoforms of other myofibrillar proteins tend to be coexpressed with myosin heavy chain isoforms. The relation between the isoforms of the tropomyosin-binding troponin subunit and myosin heavy chain is unknown. For a variety of reasons, tropomyosin-binding troponin subunit is a possible candidate for being involved in stretch activation. Therefore, we measured stretch activation of single, maximally Ca2+-activated skinned rat skeletal muscle fibres and characterized them by their myosin heavy chain composition, as well as by the isoform species of tropomyosin-binding troponin subunit. Four myosin heavy chain isoforms (I, IIa, IId or IIx and IIb) and six tropomyosin-binding troponin subunit isoforms (TnT1s, TnT2s, TnT1f, TnT2f, TnT3f, TnT4f) were distinguis hed. The following preferential coexpression patterns of the myosin heavy chain and tropomyosin-binding troponin subunit isoforms were observed: MHCI-TnT1s, MHCIIa-TnT3f, MHCIId-TnT1f, and MHCIIb-TnT4f. Stretch activation kinetics was found to be correlated with the myosin heavy chain isoform complement also in fibres not displaying one of the preferential MHC-TnTf isoform coexpression patterns. This corroborates the assumption of a causal relation between myosin heavy chain and stretch activation This revised version was published online in July 2006 with corrections to the Cover Date.     

Relations between chronic stimulation-induced changes in contractile properties and the Ca2+-sequestering system of rat and rabbit fast-twitch muscles

This study compares changes in contractile properties, Parvalbumin content, and Ca²⁺-uptake by the sarcoplasmic reticulum (SR) of low-frequency stimulated rat and rabbit tibialis anterior (TA) muscles. Time to peak tension increased 1.8-fold in 35-day stimulated rabbit TA, while no change occurred in rat TA. Isometric twitch tension increased 2-fold in rabbit TA, but was unaltered in rat TA. Parvalbumin (PA) content was more than 90% reduced in rabbit TA, but only 60% in rat TA after 35 days. At this time, PA content of the stimulated rat TA was still higher than that of normal rabbit TA. Taking into account the suggested role of PA as a cytosolic Ca²⁺ buffer, its decrease could lead to an impaired free Ca²⁺-decay with a prolonged active state and a higher tension output during a single twitch. This would explain why chronic stimulation led to an increase in isometric twitch tension in rabbit TA, but not in rat TA. The 1.6-fold rise in half-relaxation time of 35-day stimulated rat and rabbit TA most likely resulted from a 50% reduced Ca²⁺-uptake by the SR, due to a still unknown modification of the Ca²⁺-transport ATPase.     

Buchbesprechungen

Ohne Zusammenfassung     

Expression and functional implications of troponin T isoforms in soleus muscle fibers of rat after unloading

The expression pattern of troponin T (TnT) isoforms was studied in rat soleus muscle fibers in control and after hindlimb unloading (HU) conditions. To determine the functional consequence of TnT expression, the fibers were also examined for their calcium activation characteristics. With regard to TnT expression, four populations of fibers were distinguished in control muscle. Slow fibers expressing only slow isoforms of TnT (TnT1s, 2s, 3s ) were predominant (54%). Hybrid slow fibers (16%) differed from slow fibers by the additional expression of two TnTf isoforms. Hybrid fast fibers (22%) expressed slow and fast isoforms of TnT while fast fibers (8%) expressed only fast TnT isoforms. The expression of the other regulatory protein isoforms was checked for each population. The contractile experiments revealed steeper slopes of the tension/pCa relationship from hybrid slow fibers expressing fast TnT in a completely slow molecular environment. The expression of TnTs in hybrid fast fibers did not modulate the intrinsic co-operativity. After HU, the fast population was increased and reached 55%. The slow population decreased to 41% and a very small amount of hybrid slow fibers remained (4%). These data demonstrated the implication of TnT isoforms in the calcium activation properties and, more particularly, in the modulation of co-operativity within the myofibrillar lattice. Regulation of TnT expression appeared as a very fast and complete process compared to moderate changes of TnC and TnI.