Ein Kreislauforgan bei Kamptozoen

Zusammenfassung Alle koloniebildenden Kamptozoen (Pedicelliniden, Barentsiiden und Urnatelliden) besitzen in der verengten Halszone an der Kelch-Stielgrenze ein Aggregat tellerartig flacher Muskelzellen, die — in einem Stapel übereinander angeordnet — den Stiel septenartig quer durchspannen. Sie sind kelchwärts gewölbt und erscheinen in der Aufsicht sternförmig verzweigt. Im lebenden Tier führt dieser Zellkomplex ständig rhythmische Kontraktionen aus und preßt dadurch Gewebsflüssigkeit vom Kelch in den Stiel. An 5 Arten, Urnatella gracilis, Barentsia benedeni, Barentsia laxa, Barentsia discreta und Barentsia cf. gracilis, wird die Ultrastruktur dieser Muskelzellen und die Architektur von Stielhals und Sternzellgewölbe unter Berücksichtigung funktioneller Gesichtspunkte untersucht und eingehend beschrieben. Die morphologischen Befunde werden im Hinblick auf die physiologischen Bedürfnisse der Tiere und auf ihre mögliche Bedeutung diskutiert und mit den Verhältnissen bei solitär lebenden Kamptozoen verglichen. Der Sternzellapparat ist offenbar ein Herzäquivalent, welches der Zone aktivsten Baustoffwechsels, dem apikalen Stielraum, ständig nährstoffreiche Hämolymphe aus dem Kelch zuführt. Diese Zirkulation von Gewebsflüssigkeit hat wahrscheinlich nur nutritive Aufgaben. Der Austausch von Atemgasen erfolgt vermutlich über Mikrovilli der Außenepithelzellen, die überall an der Körperoberfläche durch die Cuticula hindurch mit dem Umgebungsmedium in Kontakt stehen.

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A circulatory organ in entoprocta

Summary All colonial type entoprocta (Pedicellinidae, Barentsiidae and Urnatellidae) have in the narrow zone between calyx and stalk a stack of flat star-like branched muscle cells, the uppermost of which is canopy shaped whereas the subsequent cells gradually flatten out. All these muscle cells are septum-like, being stretched out across the central hollow of the apical end of the stalk. They are attached to the body wall by their points. By rhythmical contractions they pump tissue fluid from the basal portion of the calyx into the stalk. In five different species of colony building entoprocta — Urnatetta gracilis, Barentsia benedeni, Barentsia laxa, Barentsia discreta and Barentsia cf. gracilis — the architecture of the upper end of the stalk, the ultrastructure of the so called star cells and their function has been investigated. The morphological results are discussed with respect to the physiological requirements of these animals and their possible significance, and are further compared with the conditions in solitary type entoprocta, which lack the star cell apparatus. The conclusions indicate a biological advantage in evolving of a heart-like organ to provide the stalk — which in colony type entoprocta is the budding center — with the nutrient hemolymphe. This primitive circulatory system has a nutritional function. The exchange of respiratory gases probably takes place through microvilli of the outer epithelial cells, which connect the entire body surface with the surrounding medium.

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Die Untersuchungen wurden von der Deutschen Forschungsgemeinschaft in dankenswerter Weise gefördert.     

Intermittent Chemotherapy for Tuberculosis in an Urban Community

A regimen designed for effective foolproof antituberculosis treatment, acceptable on a routine basis, was applied to all patients newly diagnosed at the Chest Clinic, Hammersmith Hospital, in 1963, 1964, and 1965. During the first three months of treatment patients received daily (six days a week) streptomycin 0.75 g. plus isoniazid 300 mg. plus sodium para-aminosalicylate (P.A.S.) 12 g. The P.A.S. was usually stopped when bacterial sensitivity reports made this possible. For a further 15 months streptomycin 1 g. plus isoniazid 600 mg. was given on three alternate days each week to complete a total of 18 months'' treatment.Of the total of 140 patients (66% sputum-positive) 112 (80%) completed the planned 18 months with intermittent streptomycin plus isoniazid and a further eight completed treatment on alternative regimens (a total of 85%). The equivalent figures for one year are 88% and 94%. Excellent clinical and radiological results, together with sputum conversion, were achieved in 138 of the 140 patients (99%). Only two patients were lost from surveillance, because of failure to co-operate, before quiescence was obtained.It is concluded that the total efficiency of supervised intermittent treatment is greater than that of unsupervised daily regimens. Since 100% arrest of tuberculosis is possible with co-operative patients, less should not be accepted in developed countries.     

Acute Abdominal Pain in Childhood,with Special Reference to Cases not due to Acute Appendicitis

Appendicitis is not the only common cause of acute abdominal pain in childhood. Almost equally common is an acute episode which in its early stages resembles acute appendicitis but which subsides without treatment in 24 to 48 hours. The clinical features of this syndrome are contrasted with those of appendicitis. The two conditions cannot always be distinguished on clinical grounds, leading to admission to hospital for observation and the finding of a normal appendix in 14% of operations for suspected appendicitis. Reasons are given for abandoning attempts to diagnose acute mesenteric adenitis at the bedside.     

Cell differentiation and pigment composition in Anabaena cylindrica

Summary Cell differentiation in Anabaena cylindrica is accompanied with characteristic changes in the pigment composition of heterocysts and spores. In both the absence of phycocyanin is consistent with the lack of CO₂-fixing ability previously reported. The presence of chlorophyll and -carotene suggests a functional photosystem I in heterocysts. In the spores chlorophyll is largely replaced by pheophytin. The quantitative distribution of carotenoids is also affected. An increase in the proportion of -carotene is characteristic of heterocysts while spores show a larger proportion of xanthophylls compared with the intact filament.     

Beobachtungen zur fortpflanzungsbiologie und zum verhalten der geißelspinne tarantula marginemaculata C. L. Koch (Chelicerata,Amblypygi)

The social behaviour of T. m. includes ritualized fights. Sperm transfer is achieved by means of a spermatophore deposited on the ground and by the male pulling the female over it. The behaviour and the spermatophore are described and compared to those of other arachnids and the phylogenetical implications are discussed.     

Die Feinstruktur der peribronchialen Mikroparaganglien beim Meerschweinchen

Zusammenfassung Das Parenchym der peribronchialen Mikroparaganglien wird von zwei Zellarten aufgebaut: Chromaffine Zellen (Typ I-Zellen) und Hüllzellen (Typ II-Zellen).Die chromaffinen Zellen sind durch ihren reichen Gehalt an Vesikeln mit elektronendichtem Inhalt gekennzeichnet, deren Durchmesser 700–1300 Å beträgt. Markfreie Nerven ziehen an die Typ I-Zellen heran und bilden synaptische Kontakte aus. Die chromaffinen Zellen sind dabei der postsynaptische Teil der Verbindung. Die Hüllzellen entsprechen strukturell und funktionell den Schwannschen Zellen.Ein Mikroparaganglion wird von 10 bis 15 chromaffinen Zellen und deren Hüllzellen aufgebaut. Sie liegen dicht um fenestrierte Kapillaren, die von den Aa. bronchiales aus versorgt werden. Die Paraganglien sind von den Nervenzellen des peribronchialen Plexus durch dessen Perineurium getrennt. Selten findet man solitäre chromaffine Zellen innerhalb der Nervengeflechte. Es wird angenommen, daß die Paraganglien endokrine Funktionen erfüllen.

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The fine structure of the guinea pig peribronchial micro-paraganglia

Summary The parenchyma of peribronchial microparaganglia consists of two different cell types: chromaffin cells (type I-cells) and surrounding cells (type II-cells).The chromaffin cells contain numerous vesicles with electron dense content, their diameter ranging from 700 to 1,300 Å. Unmyelinated nerves form synapses with type I-cells. The surrounding cells structurally and functionally correspond to Schwann cells.A micro-paraganglion consists of ten to fifteen chromaffin cells and their satellite cells. They are situated close to fenestrated capillaries, which are supplied from the Aa. bronchiales. A perineurial sheath separates the paraganglia from the nerve cells of the peribronchial plexus. Single chromaffin cells are found seldom within the nervous plexus.The paraganglia are thought to have an endocrine function.

     

Biology of budding bacteria

Summary Budding bacteria from aquatic or terrestrial habitats were found to accumulate ferric oxide hydrate (ferric hydroxide) on their cell surfaces. Metal paper clips served as the source of oxidizable iron. Pure cultures deposited ferric hydroxide during growth on sea water medium at a pH of 7.8, but not in a mineral salts medium of normal ionic strength, of pH 7.2, and without NaCl, although some active strains came from fresh water or soil.Ferric iron deposition was found to be initiated at primary active sites on the cell surface; the hyphae and rods eventually become completely encased by the heavy coat.The presence of iron depositing, budding bacteria in fresh water, brackish water or sea water indicates an ubiquitous distribution of these microorganisms.Actively depositing isolates from marine environments are more closely related to Pedomicrobium than to Hyphomicrobium spp. because of their multiple formation of hyphae from rod-shaped swarmer cells. A taxonomic and cultural study of these new forms is in progress.     

Über die Lokalisierung der Saccharoseaufnahme bei Submersmycel von Aspergillus niger

Zusammenfassung Junges Submersmycel von Aspergillus niger ist in seiner ¹⁴C-Saccharoseinkorporation uneinheitlich. Weiterhin konnte gefunden werden, daß die Saccharoseaufnahme gleichmäßig über die Hyphen junger Pellets erfolgt. Eine verstärkte radioaktive Markierung der Hyphenspitze nach längerer Inkubation ist die Folge des Spitzenwachstums. Altes Mycel verhält sich anders. Hier sind Orte intensiven Stoffwechsels proliferierende Conidienträger.

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On the localization of the sucrose uptake by submerged Aspergillus niger mycel

Summary It was found, that joung pellets of Aspergillus niger are inhomogen in relation to the incorporation of ¹⁴C-sucrose. In joung pellets the uptake takes place uniformly over the surface of the hyphae. With extending of the incorporation time the radioactivity was localized mainly in growing tips of the hyphae. Growth centres in old pellets are not the hyphae but the proliferating conidiophores.