Structural changes of deoxyribonucleoprotein fibres following γ-irradiation under aerobic and hypoxic conditions

Summary The DNP fibres -irradiated under aerobic condition showed a reduction of their diameter, while no remarkable changes were observed in the DNP fibres irradiated under hypoxic condition by scanning electron microscopy.     

The binding of extra histone and protamine to deoxyribonucleoprotein

Résumé La déoxyribonucléoprotéine (DNP) du thymus de veau peut lier de l'histone supplémentaire en solution physiologique. La plupart de cette protéine est très faiblement liée et s'est degagée par HCl de 3,3 mM ou moins. On suggère ainsi que l'histone supplémentaire soit combinée aux groupes carboxyl des histones originales du DNP. Néanmoins, environ 10% de la protamine, ajouté pareillement au DNP, fut liée fortement ce qui suggère qu'elle peut atteindre les groupes phosphates libres sur l'ADN. La protamine apparemment n'a pas deplacée les histones lorsqu'elle fut liée au DNP.     

The nature of viral inclusion bodies and their differentiation from non-viral inclusions

Zusammenfassung Auf Grund der vorhandenen Information wird geschlossen, dass virale Einschlusskörper zu einer gewissen Zeit ihrer Entwicklung DNP, also elementäre Virusteilchen enthalten. In nichtviralen Einschlüssen wurde DNP niemals gefunden. Es wird ein Weg für die morphologische Unterscheidung zwischen Einschlusskörpern (Virus) und Einschlüssen anderer Natur vorgeschlagen.     

Antidromic responses evoked in the central end of the phrenic nerve by stimulation of the ipsilateral dorsal column in the cat]

In 15 adult cats under nembutal anaesthesia the dorsal columns have been stimulated at the level of the first and the second cervical segments. Under these conditions antidromically evoked responses appear both on the ipsilateral radial and phrenic nerves. Some of the afferent phrenic fibres thus activated may be related to the diaphragm muscle receptors. In some experiments a group of thin fibres (conduction velocity comprised between 16-20 m/sec) were also activated.     

Relation of the character of capacitance vessel responses in spleen and small intestine elicited by electrical stimulation of the sympathetic fibres to the level of oxygen exchange in the organs

Summary There is a correlation between character and magnitude of capacitance vessel responses and venous blood oxygen saturation under electrical stimulation of sympathetic fibres in the spleen and small intestine.     

Active transport of Cl− across the isolated intestinal mucosa ofTestudo hermanni

Riassunto Nel digiuno diTestudo hermanni in assenza di gradienti elettrochimici esiste un trasporto netto di Cl^– dal mezzo serosale a quello mucosale. Il trattamento con DNP riduce significativamente il flusso sierosamucosa di Cl^–, per cui si conferma l'esistenza di un trasporto attivo di questo ione. Anche il flusso mucosasierosa di Cl^– è inibito dal DNP, per cui è probabile che anche questo flusso sia dovuto in parte a un trasporto attivo.     

Influence du glucose sur le transport intestinal de la phénylalanine en présence et en absence de dinitrophénol

Summary Glucose inhibits the accumulation ofl-phenylalanine by rat intestinal slices during 45-minute incubations. In the presence of DNP (which alone abolishes all active transport), glucose, but not galactose, significantly stimulates amino-acid uptake. However, during short incubations, glucose inhibits the entry of phenylalamine into the tissue, both in the presence and absence of DNP.

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Ce travail a été subventionné par le Fonds National Suisse. Nous tenons à remercier MllesC. Brandt etU. Pässler pour leur aide technique efficace.     

Histochemical characterization of the red fibres in pigeon pectoralis muscle.

Red fibres of the pigeon pectoralis muscle showed high ATPase reaction at pH 9.4. Veronal-acetate pretreatment completely inhibited the ATPase reaction in these red fibres but not in type I fibres of the gastrocnemius. The former are type II red muscle fibres and hence are unlike type I red, the so-called slow-twitch muscle fibres.     

Specific immunosuppression of IgE response to hapten DNP by DNP linked to monoclonal IgG1 in rats

Summary The induction of the anti-DNP IgE in rat was suppressed by pretreatment of rats with the tolerogen synthesized by coupling DNP to rat IgG, i.e.; DNP_7–10-IgG. It was found that DNP₁₀-IgG₁ was an effective tolerogen, whereas other DNP conjugates, i.e. DNP₉-IgM, DNP₉-IgA, DNP₁₀-IgE, DNP₁₀-IgG_2c and DNP₁₀-IgG_2a were ineffective.This work was partly supported by a research grant from the Medical Council of Canada to W.Y.L.     

Histochemical characterization of the red fibres in pigeon pectoralis muscle

Summary Red fibres of the pigeon pectoralis muscle showed high ATPase reaction at pH 9.4. Veronal-acetate pretreatment completely inhibited the ATPase reaction in these red fibres but not in type I fibres of the gastrocnemius. The former are type II red muscle fibres and hence are unlike type I red, the so-called slow-twitch muscle fibres.     

Modifications in the type distribution of muscle fibers induced by repeated local freezings the rat sciatic nerve]

In the Rat, after a localized freezing of the sciatic nerve inducing a complete denervation of the medial head of the gastrocnemius muscle, the reinnervation took place within 16-18 days under our experimental conditions. After only one freezing, a limited and stable "type-grouping" of muscle fibres is observed from 30 to 360 days. After 2 to 5 freezing repeated every three weeks, the muscular changes observed one month after the last freezing are much more pronounced than when only one freezing is performed. These changes consist of a progressive increase in the number of type I and type II C fibres. This transformation is not stable: 3 months after the 3rd freezing, the muscle pattern does not differ from that which is noted after a single freezing.     

Some additional characteristics of methionine transport in the chicken intestine

Zusammenfassung Aufnahme und Abgabe von Methionin wurden an Darmstücken des Huhnes gemessen und die Wirkung von Äthionin sowie von DNP studiert. Ferner wurde der Einfluss des kalten Methionins in der Aussenlösung auf die Abgabe von markiertem Methionin untersucht.     

Immunocytologic differentiation of hypophyseal innervation in carp using anti met-enkephalin and anti-alpha-endorphin serums]

The immunocytological reactions with anti-met-enkephalin and anti-alpha-endorphin reveal two types of fibres in the intermediate lobe of the Carp. Their pathways through the adenohypophysis and the localization of their terminals are different. The anti-met-enkephalin positive fibres terminate mainly in a zone close to the proximal pars distalis; however some fibres terminate deeper in the intermediate lobe. The anti-alpha-endorphin positive fibres penetrate mainly in the central and ventral part where thye are more numerous than the former. It seems that the anti-met-enkephalin positive fibres belong to the gomori positive preoptico-hypophyseal tract, whereas the anti-alpha-endorphin positive fibres are gomori negative.     

Degeneration of unmyelinated axons in the dental root canal induced by 6-OH-dopamine

Summary The pulpal nerve fibres of feline incisors were examined ultrastructurally after i.v. administration of 6-OH-dopamine. The presence of degenerating unmyelinated fibres at this site provides conclusive morphological evidence that sympathetic fibres enter the dental pulp.     

Variation in the number and size of myelinated nerve fibers regenerated after repeated localized freezing of the sciatic nerve of rats]

The number and size of myelinated fibres have been determined in the nerve to medial head of the gastrocnemius muscle of Rats in which the sciatic nerve had been frozen locally 1 to 5 times at monthly intervals. The contralateral nerve was used as a control. When the measurements were made one month after the last freezing, the number of fibres increased progressively until the 3rd freezing, reaching about 220% of the normal value. No higher values were observed after 4 or 5 freezings. The mean diameter of fibres decreased with the number of operations. When the measurements were made 3, 6, 12 or 18 months after the 3rd freezing, the number of fibres decreased by about 30% between the 1st and the 3rd month and then stabilized. The mean diameter of fibres increased progressively. However, at the 18th month, the size of the myelinated fibres had not reached the normal value.     

The process of survival of denervated and freely autotransplantated skeletal muscle.

The study shows that two distinct processes occur in free autografts of denervated intact muscle during the early critical phase of the transplantation: survival of transplanted fibres at the periphery of the graft, and regeneration of new muscle fibres following breakdown of the originally transplanted fibres in the central areas.     

Elaunin fibres in the basement membrane of sweat gland secretory coil are rich in disulfide-groups.

Disulfide-groups of elaunin fibres of sweat gland basement membrane are demonstrated a) by thiosulfation/aldehyde-fuchsin staining or thiosulfation/Alcian Blue + 0.8 M MgCl2 staining, and b) by identifying SH-groups after reduction with sodiumthioglycollate. Elaunin fibres share this staining behaviour with "elastic fibre microfibrils" and with oxytalan fibres.     

A histochemical study of the pectoralis muscle of the south indian flying lizard,Draco dussumieri

Résumé Le muscle pectoral duDraco dussumieri comprend des fibres de trois sortes: minces, intermédiaires et épaisses. Les fibres minces sont adaptées à un métabolisme glycolytique et les fibres épaisses au lipolytique. L'activité des fibres minces révèle la présence de phosphorylase et de synthétase glycogénique.     

Coordinated activation of muscle fibres by different conduction velocities in branches of a crustacean motor axon

Summary Higher conduction velocities in branches of the fast excitor axon to distal muscle fibres ensure that these fibres are activated almost simultaneously with proximal fibres in the claw closer muscle of lobsters, producing a contraction of maximal force.Supported by Muscular Dystrophy Association and National Research Council of Canada.Supported by National Institute of Health and Muscular Dystrophy Association of America.     

On the heterogeneity of skeletal muscle fibers: The intermediate fibers

Résumé Les mesures d'intensité de la réaction à la succino-déshydrogénase et de la surface des fibres des muscles quadriceps et soléaire chez le rat nous ont permis d'individualiser un groupe de fibres intermédiaires qui se situe entre les fibres rouges (type I) et blanches (type II). Les fibres intermédiaires ont une activité enzymatique et une population mitochondriale distinctes, une taille moyenne et une teneur élevée en glycogène.