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.     

Serum Enzyme Activity of Newborn Calves,Pigs, and Lambs

Serum activities of aspartate aminotransferase (AspAT = GOT), alanine aminotransferase (AlAT = GPT), and total lactate dehydrogenase (LDH) have been investigated in newborn calves, pigs, and lambs. In the two latter species the LDH isoenzyme distribution in serum was also studied. Blood samples were taken at frequent intervals from birth to 48–72 hrs. post partum. Calves and pigs were born with very low serum enzyme values, whereas lambs showed a picture more similar to what has been reported in human infants. In all species a marked temporary enzyme increase occurred during the first 24–48 hrs. This elevation was found not to be due to colostrum feeding, since a parallel increase was found in starved animals. Possible regulating mechanisms are discussed. The LDH isoenzyme pattern proved to be more stable than total LDH in the early post-natal period. The percentage isoenzyme distribution, however, showed characteristic differences from that found in adult animals of the same species.     

Carotenoids of Thiorhodaceae

Summary The isolation, morphology and growth chracteristics of pure cultures of a Thiothece, Lamprocystis and Thiodictyon strain are described.Their carotenoid composition is reported. The Thiothece strain produced in addition to okenone (1), several related ketocarotenoids, among which a demethylated okenone (6) was identified by a small scale total synthesis. Thiodictyon and Lamprocystis produced carotenoids of the rhodopinal (previously warmingone) series, the latter organism contained as major carotenoids a lycopenol (4), not previously found in Nature, and a cross-conjugated lycopenal (2), previously called anhydro-warmingone.Part 7. Acta chem. scand. 21, 2185 (1967).     

Photoadaptation in marine Arctic diatoms

Summary Photoadaptation in some marine Arctic diatoms has been studied. Thalassiosira antarctica, Nitzschia delicatissima and Chaetoceros furcellatus were grown at-0.5°C and various irradiances and continuous light. Growth and cellular chlorophyll were followed during transitional phase after the algae had been transferred from one irradiance to another. Adaptation time for cellular chlorophyll was linearly related to the gradient in irradiance, and adaptation to transfer from high to low light was faster than from low to high light. Adaptation time was found to be species dependent, and Arctic diatoms growing at low temperature seemed to adapt as fast as temperate species.Contribution No. 243 from Trondhjem Biological Station     

Plasminogen activator inhibitor (type-1) in rat adrenal medulla

Summary Plasminogen activator inhibitor type-1 (PAI-1) was identified in extracts of rat adrenal medulla, and its immunohistochemical localization was studied together with that of tissue-type plasminogen activator (t-PA). By staining of adjacent sections and by doublestaining of the same section we demonstrate that the same cells of the adrenal medulla contain both PAI-1 and t-PA immunoreactivity in the cytoplasm. In addition a few ganglion cells of the adrenal medulla were found to contain PAI-1 but not t-PA. Neither of the components were found in the adrenal cortex. Analysis of extracts from isolated adrenal medulla using reverse zymography showed the presence of a plasminogen activator inhibitor with M _r46000. The inhibitory activity disappeared when the extract was passed through a column with sepharose-coupled anti-PAI-1 IgG, while the run-through from a similar column coupled with preimmune IgG still contained the inhibitor. The present findings suggest that PAI-1 could play a role in the regulation of t-PA activity in the rat adrenal gland medullary cells.     

Rabbit distal colon epithelium: III. Ca2+-activated K+ channels in basolateral plasma membrane vesicles of surface and crypt cells

Summary In the mammalian distal colon, the surface epithelium is responsible for electrolyte absorption, while the crypts are the site of secretion. This study examines the properties of electrical potential-driven⁸⁶Rb⁺ fluxes through K⁺ channels in basolateral membrane vesicles of surface and crypt cells of the rabbit distal colon epithelium. We show that Ba²⁺-sensitive, Ca²⁺-activated K⁺ channels are present in both surface and crypt cell derived vesicles with half-maximal activation at 5×10^–7 m free Ca²⁺. This suggests an important role of cytoplasmic Ca²⁺ in the regulation of the bidirectional ion fluxes in the colon epithelium.The properties of K⁺ channels in the surface cell membrane fraction differ from those of the channels in the crypt cell derived membranes. The peptide toxin apamin inhibits Ca²⁺-activated K⁺ channels exclusively in surface cell vesicles, while charybdotoxin inhibits predominantely in the crypt cell membrane fraction. Titrations with H⁺ and tetraethylammonium show that both high-and low-sensitive⁸⁶Rb⁺ flux components are present in surface cell vesicles, while the high-sensitive component is absent in the crypt cell membrane fraction. The Ba²⁺-sensitive, Ca²⁺-activated K⁺ channels can be solubilized in CHAPS and reconstituted into phospholipid vesicles. This is an essential step for further characterization of channel properties and for identification of the channel proteins in purification procedures.     

Unbalanced translocation between chromosomes 2 and 7 with de novo deletion of band 35 on the long arm of chromosme 2

Summary Clinical and cytogenetical findings are described in an infant with a de novo deletion of the long arm of chromosome 2. The boy's karyotype is 46,XY, rec(2)delq,t(2;7) (2pter2q34::7p217pter) (7qter7p21::2q362qter). He showed developmental retardation, low-set ears, micrognathia, short neck, abundant skin of the neck, tetralogy of Fallot, bipartite labialike scrotum, clitorislike penis, cryptorchism, and deformities of the hands and feet.