The assessment of tobacco smoke toxicity in tissue and organ culture: An in vitro arrangement for exposure under defined conditions

Zusammenfassung Eine Apparatur zur Berauchung von Zell-und Organkulturen unter kontrollierten Bedingungen (Anzahl und Dauer der Puffs, Temperatur, Luftfeuchtigkeit) wird beschrieben. Das System basiert auf der Verwendung der Filtrona-Berauchungsmaschine (Cigarette Components Ltd.); die zusätzlichen Elemente können leicht aus laboreigenem Material zusammengestellt werden. Frischrauch und wasserdampfgesättigte Gasmischungen (z.B. Luft/CO₂) können in der Berauchungskammer in variablen Proportionen gemischt werden.     

The assessment of tobacco smoke toxicity in organ culture. II. Ultrastructural studies on the immediate response of foetal rabbit tracheal epithelium to short-term exposures of whole smoke.

Foetal rabbit tracheal organ cultures were exposed under defined conditions to whole cigarette smoke and fixed immediately for electron microscopy. After an exposure to 4 or 8 puffs, epithelial intercellular spaces were enlarged, the apical portion of many cells bulged out into the lumen and many cilia were swollen. An exposure to 12 puffs produced a breakdown of the epithelium.     

The caryotype of some teleostea fish obtained by tissue culture in vitro

Riassunto In questo lavoro vengono riportati dati numerici e morfologici sul cariotipo di diverse specie di Pesci Teleostei (Tinca tinca, Carassius auratus, C. carassius, Scardinius erythrophtalmus, Anguilla anguilla), ottenuti mediante culture in vitro.     

Ca2+-dependence and metabolic status of an obligate thermophile,Thermoactinomyces vulgaris,under shake culture conditions

Summary Ca²⁺ stimulates germination ofT. vulgaris spores. There is a higher mycelial yield as well as higher protein, DNA, RNA and free Pi content in cultures grown in the presence of Ca²⁺ as compared to those grown in the absence of this divalent cation.Grateful thanks are due to Professor R. P. Roy for providing the necessary facilities. V. P. S. acknowledges with thanks the receipt of a Post Doctoral Research Fellowship of the Council of Scientific and Industrial Research, New Delhi.     

Radioimmunoassay of hormonal activity of Gobius niger L. testicular interstitial tissue in organ culture: spontaneous activity and stimulation by pituitary gland]

After the interstitial tissue was cultivated, the radio-immunoassay revealed in the media very small quantities of free testosterone but much larger quantities of testosterone conjugates as glucuronids and sulfates. Association of pituitaries increases greatly the secretion. 12-13 days precultivated pituitaires retain close to 70% of their stimulating potency.     

The invasion and growth of Babesia bovis in tick tissue culture.

Erythrocytic forms of Babesia bovis inoculated into cell cultures of the tick Boophilus microplus invaded the tick cells and showed multiplication for up to 48 h after inoculation.     

Analysis of the tissue interactions responsible for the mesonephogenic determination in amphibians, by the in vitro culture technic]

The cultivation of mesonephric lateral mesoblast, in combination with the dorso-caudal endoblast, with or without cordomesoderm, leads to the differentiation of mesonephric tubules in Bufo bufo and Pleurodeles waltlii. Then, the nephric duct does not seem to be necessary to nephric differentiation under in vitro cultivation conditions.     

Costs and benefits of mycorrhizas: Implications for functioning under natural conditions

Summary It is paradoxical that most plants under natural conditions are infected with vesicular-arbuscular mycorrhizal fungi, yet that it is often difficult to demonstrate that infected plants receive any benefit from the association. The costs and benefits of infection are analysed and a hypothesis formulated that infection only yields benefits at times during the life cycle when P demand by the plant exceeds the capacity of the root system. A simulation model is described that suggests that infection density should be more or less constant below a threshold value of root P uptake rate, but that above this value roots should be non-mycorrhizal. More extensive study of mycorrhizas under field conditions is needed to test such predictions.     

The prinary tissue culture of rat adult decapsulated adrenal glands: Problems of methodology and applications

Riassunto Le colture primarie di surrene di Ratto adulto si prestano molto bene a studi morfologici e funzionali mediante tecniche di indagine diverse (microscopia ottica ed elettronica, istochimica, autoradiografia, biochimica). Sono stati effettuati studi originali sulla coltura di tessuto surrenale dopo permanenza prolungata in azoto liquido e sull'isolamento di linee cellulari differenziate di cellule corticali.

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Acknowledgment. Authors thank ProfessorV. Meneghelli, Director of this Institute, for his encouragement and interest in this work. MissLucia Bolognani and Dr.Anna Belloni provided skilful technical assistance.     

Evidence for a novel racemization process of an asparaginyl residue in mouse lysozyme under physiological conditions

We examined chemical reactions in mouse lysozyme after incubation under physiological conditions (pH 7 and 37°C). After incubation for 8 weeks, racemization was observed specifically at Asn127 among the 19 Asp/Asn residues in mouse lysozyme. Furthermore, analysis of the primary structure showed that the racemized residue was not Asp, but Asn, which demonstrates that deamidation and isomerization did not occur. These results mean that this racemization occurs without forming a succinimide intermediate. This is the first example of D-asparaginyl formation in a protein occurring during the racemization process under physiological conditions.Received 16 September 2004; received after revision 26 October 2004; accepted 12 November 2004     

The primitive ontology of quantum physics: Guidelines for an assessment of the proposals

The paper seeks to make progress from stating primitive ontology theories of quantum physics—notably Bohmian mechanics, the GRW matter density theory and the GRW flash theory—to assessing these theories. Four criteria are set out: (a) internal coherence; (b) empirical adequacy; (c) relationship to other theories; and (d) explanatory value. The paper argues that the stock objections against these theories do not withstand scrutiny. Its focus then is on their explanatory value: they pursue different strategies to ground the textbook formalism of quantum mechanics, and they develop different explanations of quantum non-locality. In conclusion, it is argued that Bohmian mechanics offers a better prospect for making quantum non-locality intelligible than the GRW matter density theory and the GRW flash theory.     

In vitro culture of chick down feather bulbi: a tool to obtain proliferating and differentiating keratinocytes in an organotypic structure

Chick down feather bulbi can be cultured in different culture systems. Morphological analysis and 3H-thymidine incorporation measurements prove that the majority of cells are viable epithelial cells.     

In vitro culture of chick down feather bulbi: A tool to obtain proliferating and differentiating keratinocytes in an organotypic structure

Summary Chick down feather bulbi can be cultured in different culture systems. Morphological analysis and³H-thymidine incorporation measurements prove that the majority of cells are viable epithelial cells.