Correlazioni tra organi di senso e centri nervosi in via di sviluppo

Zusammenfassung In FÄllen, wo beiLoligo-Embryonen infolge der Einwirkung von Lithiumchlorid die Augenentwicklung asymmetrisch gehemmt ist, entspricht der gehemmten Entwicklung der Augen immer eine solche des zugehörigen Augenganglions. In seltenen FÄllen kann man auch beobachten, da\ zu einem gehemmten Ganglion ein normales Auge gehört, aber niemals das umgekehrte. Diese Korrelationen sind nicht durch Lagebeziehungen bestimmt. Bringt man diese Tatsachen mit denen zusammen, die über diese VerhÄltnisse bei Vertebraten bekannt sind, so kommt man zu dem Schlusse, da\ höchstwahrscheinlich das Cephalopodenauge die Entwicklung des zugehörigen Augenganglions leitet.     

Sulla presenza di batteri nei vari organi delle piante superiori

Summary

In close agreement with Schanderl's findings it is shown that bacterial cultures may be obtained from the most different parts of non-Leguminous plants representing several families of higher plants. These bacteria, isolated from parts of higher plants, do not seem to be identical with the ones inducing nodules in Leguminous plants.     

Formazione e maturazione delle fibre collagene nelle colture di tessuti. Significato della distribuzione reticolare o fascicolare dello stroma collageno nei vari organi

Cell and Tissue Research - In den Organen wird die Form des kollagenen Stromas durch die Anordnung der Parenchymzellen beeinflußt; wenn diese sehr dicht aneinander liegen, wirkt wahrscheinlich...     

Ricerche Sui Fenomeni di Contrazione di Mitocondri Isolati di Internodio di Pisello

Abstract

Study on the contraction phenomena of isolated mitochondria of pea internodes. — The action of the phosphorylative inhibitors atractylate and oligomycin on ATP-induced contraction of isolated pea mitochondria has been studied. Oligomycin has proved to be an efficient inhibitor of mitochondrial contraction; no effect is seen on the contrary upon addition of atractylate. Both atractylate and oligomycin inhibit completely oxygen consumption of mitochondria with succinate as substrate. On the base of these results it is postulated that the two inhibitors act upon different sites of the phosphorylative reaction sequence.     

Fenomeni di Inattivazione e di Riattivazione Enzimatica in Endospermi di semi di Ricino

Abstract

Inactivation and riactivation of enzymes in endosperms of castor bean seeds. — On the basis of previous results, the possibility has been investigated of the reversible interconversion of active and inactive form of enzymes in castor bean seeds, during their development.

The results described here indicate that:

1. the activity of some glycolytic enzymes increases greatly (81% and 400% increase of, respectively, Gl-6-P-dehydrogenase and aldolase) upon incubation of dry seeds for few hours at 4 °C.

2. The decrease of enzyme activity upon dehydration of seeds and the increase during the subsequent imbibition can be shown reproducibly.

3. This same observation is made for oxygen uptake.

These results are interpreted to indicate the reversible inactivation of enzymes caused by dehydration of seeds.     

Tecniche di Coltura di Semi di Grano Sottoposti ad Operazioni di Trapianto Embrionale

Abstract

Cultural techniques for wheat seeds submitted to embryo transplantation. — The author, on the basis of his experience coming from the work carried out on the embryo transplantation for several years, takes in consideration some aspects, at technical level, regarding the best way to cultivate wheat seeds submitted to embryo transplantation operations.

In particular, the author refers on the possibility to sow the transplants just made (while the traditional method foresees the drying of transplants for 48–96 hours under laboratory conditions) and he illustrates the results of the transplant culture in jiffypots, which allow to improve survival of materials intended for the growth in field.     

Hoc alterum auditus organi ossiculum est: Ear Ossicles in Physical Anthropology

In spite of the importance of auditory ossicles in anthropological studies, very little attention has been paid to these bones, which are only rarely recovered in archaeological excavations and in osteological collections. In this paper, we attempt to review some studies that started in the 1960 from when we first collected and prepared ossicles from the early Egyptian osteological collection of Giovanni Marro in Turin (Italy). We attempt to delineate the potential of ear bones in the study of man. In a few cases, archaeological ossicles were discussed in connection with some forms of pathology. Other studies examined the phylogeny of primates based on auditory ossicles. The function of the ossicles is to transmit sound waves to the cochlear endolymph. The energy transmitted through the ossicles is conserved by the action of two levers, which convert the relatively wide and low-energy movements of the hammer into smaller high-energy movements of the stirrup. It is a matter of argument whether the different proportions of the ossicles may imply variations in auditory perception in primates, including man. While the hammer of modern humans and that of the great apes show similar absolute sizes, nevertheless, the ape manubrium is appreciably greater than that of man. This difference, combined with stirrup proportions, causes a strong “low-gear” effect in apes and, as a consequence, probably a different auditory acuity. Although only a few fossil Neanderthal auditory ossicles are known, it may be, nevertheless, of interest studying the ossicles from the viewpoint of vibration transfer impedance function. The methodology may also be appropriate to study the few Australopithecine ossicles that are known. It is a matter of question whether the ossicles may have a meaning in distinguishing human populations; nevertheless, at least a case of clear distinction between human population has been achieved as in the case of Antinoe Roman–Egyptians.     

Identificazione di Alcuni Fattori di Crescita Nel Succo di Pomodoro

Abstract

Growth-factors in tomato juice. Raw juice of green and red tomato fruits contains 7 amines which can be separated by paper electrophoresis. These were identified as basic amino acids (arginine, lysine and ornithine) and aliphatic diamine and polyamines (putrescine, spermine and spermidine). These amines were found in tomato juice for the first time. One compound (band 6, table 1) was not identified. Putrescine, spermidine and the unidentified band, after elution, were assayed « in vitro » for the possible cellular proliferation of Jerusalem artichoke (« Helianthus tuberosus ») dormant tubers. The results show that the last three coumpounds must be considered natural growth-factors present in the raw juice of tomato fruits.     

Ricerche Sull'ultrastruttura dei Tubi Cribrosi di Piccioli di Foglie di Edera

Abstract

The ultrastructure of sieve tubes in leaf petioles of HEDERA HELIX. — The structural organization of the sieve elements in Hedera leaf petiole at the beginning of the second year of life has been studied. At this stage of life the sieve tubes are completely developed, but still in full activity.

Their plasmatic structures, though altered, show that they are still alive. The cytoplasm forms a parietal layer; mitochondria, endoplasmic reticulum and plastids are present although very peculiar in aspect. The cytoplasm is bounded externally by a plasmalemma; on the contrary no tonoplast is detectable.

The data reported in this paper are favourable to the idea of an active partecipation of the sieve tubes in the translocation of organic solutes, in agreement with the findings concerning the oat coleoptile.     

Variazioni di Metaboliti Nel Seme di Ricino in Fase di Maturazione

Abstract

Changes of glycolytic substrates level during ripening of the castor bean seed. — The changes of the concentration of carbohydrates and of the main glycolytic substrates in the castor bean seed during the ripening phase were investigated. The following results were obtained:

The level of unphosphorylated sugars and of acid hydrolysable polysaccharides remains almost unchanged, with a tendency to a rise during the ripening phase. The slight increase of these compounds, together with the transition of the R. Q. from high to low values, might be interpreted as an indication of a shift of the seed from the a metabolism of fat synthesis to one of conversion of lipids into sugars, such as is observed in the germinating castor bean seeds.

Hexose monophosphate level sharply decreases during the last period of maturation. However, the level of these substrates does not fall so low as to suggest a severe limitation for the pentose-P pathway activity.

Fructose diphosphate, DOAP, GAP, 3 PGA, 2 PGA, PEP and pyruvate levels consistently increase during the ripening process. This indicates that the drop of oxygen uptake observed in this phase cannot be due to a lack of glycolytic substrates. On the other hand, the ratios between some substrates are shifted, during ripening, from values close to the theoretical equilibrium constants to quite different values. This finding, when correlated with the one of the strong decrease of the glycolytic flow, strongly suggests a severe inactivation of the glycolyting enzymes during ripening.

The increase of pyruvate in tissues showing a decreasing respiratory activity indicates a fall of the oxidative capacity of mitochondria. This might be due to a lack of ADP, or other high energy bond acceptor, following a block of synthetic processes. However, no decrease of ADP level, and an increase of the ADP/ATP ratio during ripening is observed, Among the alternative hypothesis: a) lack or excess of oxalacetate; b) increase of concentration of some Krebs cycle inhibitor; c) inactivation of mitochondrial enzymes, the latter is thought most probable, in view of the finding of a sharp decrease of some other enzyme activities during ripening, of the above mentioned interpretation of the shift of the ratios between glycolytic substrates, and of the very low level of mitochondrial activity in preparation from the mature castor bean seed. These results when correlated with those from parallel investigations on the biochemistry of castor bean seed maturation and germination suggest, as a working hypothesis, that the respiratory metabolic inactivation accompanyng seed repening is due to a general block of the metabolism of ribonucleic acid and thus protein synthesis.     

Fissazione di CO2 da Parte di Entomocecidi di Cuscuta Australis

Abstract

Fixation of carbon dioxide by galls of CUSCUTA AUSTRALIS. — The mechanism of the carbon dioxide fixation by Cuscuta is a controversial biochemical topic. Light induced reactions are involved in MacLeod's opinion while others as Ciferri and Poma believe that mainly a dark-fixation occurs.

In this study use is made of the galls, caused by the insect Smicronyx on Cuscuta australis, that appear more green coloured than the normal tissues.

Equal weights of excised galls were kept both in light and in darkness in contact with C¹⁴O₂for different incubation times, and the magnitude of the fixation was compared under these two conditions by measuring radioactivity of both soluble and acid hydrolysed fractions.

After short exposures to the tracer the fixation in light greatly exceeds that in dark (25–19/1) while with more prolonged exposures the ratio sharply decreases (to about 5/1): these figures can be interpreted with the assumption that a strong light-induced fixation superimposes itself to a low but definite dark-fixation activity.

The ratio does not change if radioactivity is measured in the hydrolysed fractions.

These results are of course referred to as being largerly preliminar and requiring further and more extensive studies.     

Sul comportamento di alcuni innesti di occhi nelle larve di Discoglossus pictus

Zusammenfassung Werden zwei primäre Augenblasen mit angefrischten Teilen derselben in Kontakt gebracht, so ordnen sie sich derartig an, daß die Elemente der einen Netzhaut sich mit denen der andern so gleichförmig vereinigen, daß keinerlei Diskontinuität zwischen den zwei in Kontakt befindlichen Netzhautportionen noch irgendwelche Veränderung nach Zahl und Beschaffenheit der Elemente selbst wahrzunehmen ist.Wenn die beiden Linsenblasen in Kontakt kommen, dann verschmelzen die beiden Portionen, durch die die Anlagerung erfolgt, miteinander und bilden eine Scheidewand, die sich nach und nach aufzulösen scheint. Die Fasern der einen und der andern Linse vereinigen sich schließlich zu einem Ganzen, wie wenn es sich um ein einziges Gebilde handelte.Die die Hornhäute der beiden Augen bildenden Elemente konvergieren zuerst gegen einen Punkt der vorderen Linsenkapsel, wohl entsprechend der Stelle, wo die Verlötung der beiden Linsenkapseln erfolgt; dann aber löst sich diese Verwachsung und die Zellen dehnen sich in einer einzigen Linie zur Bildung einer BrÜcke, welche von der skleralen HÜlle der einen Hälfte zu der der andern Hälfte zieht.Die Ciliarkörper- und Irisbildung erfolgt auf Kosten der zwei halben Augen, die in Kontakt kommen und sich zusammen zu einem einzigen harmonischen Ganzen entwickeln, als ob es sich um die beiden symmetrischen Abschnitte einer und derselben Augenblase handelte.Der Sehnerv wird ebenfalls durch Gewebsportionen gebildet, die zur Substanz der beiden Hirnblasen gehören, welche gleichfalls in der Weise verwachsen, daß sie eine Höhle umgeben, die das Produkt der Vereinigung der zwei Höhlen der beiden in Kontakt gekommenen Blasen ist.Und die Skiera? Und die Chorioidea?Auch sie scheinen dem allgemeinen, soeben angedeuteten Entwicklungsgesetz zn folgen. Es steht außer Zweifel, daß sich in diesem Fall sagen läßt, daß die mit angefrischten Partien in Kontakt gekommenen Augenblasen sich derart zu verhalten streben, daß sie ein einziges, die Portionen sowohl der einen wie der andern Augenblase umfassendes Auge bilden und daß diese Gewebe sich zu einem einzigen Organ ausbilden, das sich in der gleichen Weise entwickelt, wie wenn die Elemente nicht zwei verschiedenen Individuen, sondern nur einem Individuum angehörten.     

Studio di Sostanze Anticrescita di Origine Vegetale

Abstract

Antigrowth substances of plant origin. 1) A method for quantitative evaluation of antigrowth activity. The antigrowth activity of various kinds of plant extracts has been quantitatively evaluated, by determining the reduction of lenghtening of the lateral radicles of wheat grains induced by them. Grains are allowed to develop on water moistened filter paper until the lateral radicles have reached a lenght of about 5 mm.; then grains, carefully selected for approximately equal redicles lenght, are uniformly distributed in Petri dishes lined with filter paper, and moistened with 10 ml of distilled water, for the controls, or of the extracts under examination. All the operations are performed as much as possible under steril conditions. After 36 hrs incubation at 28° C, in the dark, the lenght of the lateral radicles is measured and the percent inhibition determined. This, when plotted against the log of the extract concentration, gives a straight line. The method is very sensitive and its reproducibility makes it possible to follow quantitatively the purification of antigrowth principles.