Der Einfluß einiger Hormone auf die heteroplastische Knorpel- und Knochenbildung im Herzmuskel der Ratte

Zusammenfassung Es wird über histopathologische Untersuchungen des chronologischen Verlaufs an der durchSelyes Ventrikel-Ligatur hervorgerufenen Herzspitzennekrose bei Ratten berichtet. In dem der Nekrose verfallenen Myokard setzt alsbald Organisation ein; dann wandelt sich allmählich das Granulationsgewebe in eine zellarme und faserreiche Narbe um. In den subendokardialen Schichten des Narbengewebes entstehen erst Knorpel-, später Knochenherde. Der Prozeß der Knorpelbildung wird nicht von Verkalkung eingeleitet; vielmehr werden zuerst die Fibroblasten zu Knorpelzellen, um die sich dann sekundär Kalziumsalze ablagern; danach spielt sich eine typische endochondrale Ossifikation ab. Schließlich erscheint Knochenmarkgewebe zwischen den Knochenbalken.Triamcinolon hemmt geringgradig die Bindegewebsproliferation, Thyroxin steigert die Knorpel- und Knochenbildung, während Östradiol diese Vorgänge nicht beeinflußt.

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The effect of hormones on the heteroplastic cartilage and bone formation in the cardiac muscle of the rat

Summary A chronologic study was made of the histopathologic changes which occur in the cardiac apex of the rat following the application of Selye's ventricular ligature. Organisation in the necrotic cardiac muscle begins soon after ligature. Later, the granulationtissue is gradually replaced by scar tissue which is poor in cells but rich in fibers. In the subendocardial fibrous tissue, cartilage and bone develop. It is emphasized that cartilage formation is not initiated by calcification. Instead, the fibroblasts are converted to cartilage cells and, later, calcium salts are deposited in the matrix. This is followed by endochondral bone formation. Finally, bone marrow appears in the intertrabecular spaces.Triamcinolone mildly hindered connective-tissue proliferation, thyroxine increased cartilage and bone formation, while estradiol did not influence these processes.

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Die Versuche, die diesem Bericht zugrunde liegen, wurden durch das Ministère de la Santé, Québec, die Quebec Heart Foundation, Montreal, das Medical Research Couneil of Canada (Block Term Grant MT-1829) und das USPHS, Child Welfare (Grant HDO 2612-02) unterstützt. Die Autoren danken an dieser Stelle der Firma Lederle Laboratories Div., Pearl River, N.Y., USA für das bei diesen Versuchen verwendete Triamcinolon (Aristocort^®) und der Firma Schering Corporation Ltd., Pointe Ciaire, Quebec, für die Bereitstellung von Estradiol.     

Chromosome counts of some Mongolian plants

The paper gives the chromosome numbers of 45 species from 72 Mongolian localities, belonging to the genera:Amygdalus, Asparagus, Astragalus, Cancrinia, Caragana, Chamaerhodos, Chelidonium, Chesneya, Dianthus, Hypecoum, Lathyrus, Lilium, Oxytropis, Papaver, Potentilla, Schizonepeta, Sibbaldia, Thermopsis, Trifolium, Trigonella, Vicia. Chromosome morphology of three species ofChamaerhodos and taxonomical remarks on some other species are added. A new combinationSibbaldia sericea (Grubov) Soják is proposed.     

Antibacterially active substances

Synthesis of two hydroxy-derivatives of nalidixic acid as a result of microbial transformation was demonstrated in certain species of the genusAspergillus. Aspergillus alliaceus produced 7-hydroxy-nalidixic acid andAspergillus niger 6-hydroxy-nalidixic acid. It was demonstrated that the antibacterial activity of both hydroxy-derivatives (tested inEscherichia coli) was lower than that of the initial nalidixis acid.     

Ontogenetic development of antibody formation in response to different doses of gram-negative microorganisms in young rabbits

Rabbits at different stages of development were immunized with different doses of heatinactivated suspension ofEscherichia coli 086 andSalmonella paratyphi B. The dynamics and the site of formation of bactericidal and haemolytic antibodies during the primary reaction was investigated. An increase and an acceleration of antibody formation after increasing the dose of antigen was found in the serum and at the cellular level. The magnitude of the response and the rate of the reaction were directly proportional to the age of the experimental rabbits. The site of antibody formation depends on the character, route of administration, antigen dose and age of rabbits. After intraperitoneal and also after intravenous immunization withEscherichia coli andSalmonella paratyphi B antigens the site of antibody production in 15-day-old rabbits was the lymphatic tissue of the intestine, the appendix, and mesenteric lymph nodes. As the antigen dose was increased and the age of rabbits rose, i.e. in correlation with the increase of the antibody response, antibody formation shifted to the spleen which is the chief site of antibody production following immunization by these bacterial antigens from the first month of life of rabbits. In contrast with this type of antigen, after intraperitoneal or intravenous immunization with sheep erythrocytes of new-born or older rabbits antibody formation was concentrated in the spleen. The development of the immunological competence and the significance of intestinal lymphatic tissue as one of peripheral type is discussed.     

The ultrastructure of spores ofClaviceps purpurea (Fr.) Tul.

The ultrastructure of saprophytic and parasitic spores of the AscomyceteClaviceps purpurea (Fr.) Tul. was studied. Considerable differences were found to exist between the saprophytic and parasitic spores as to morphology and fine structure. The reason for the different ultrastructural morphology is probably connected with the intensity of cell metabolism. Whereas the parasitic spores obtained from the honeydew possess the character of a resting cell with a thick electron-dense cytoplasm, abundant lipid bodies, few mitochondria, an underdeveloped and hence little active endoplasmic reticulum and with a homogenous thick cell wall, the saprophytic spores appear as cells with higher metabolic rate, containing more numerous mitochondria, a thinner cytoplasm, a highly developed endoplasmic reticulum, fewer lipid bodies and abundant large vacuoles as well as frequently a new wall layer.