A new technique for dissociation of hair follicles into single cells

Summary A method is described for the complete dissociation of mouse hair follicles into a suspension of single cells suitable for cell culture. Dermal tissue containing hair follicles is digested sequentially with trypsin and chondroitinase ABC under mild conditions.     

A new anaesthetic technique for slugs

Résumé On a étudié l'effet anesthésique de l'anhydride carbonique sur les limaces. La technique décrite permet une anesthésie totale pendant une heure avec une guérison de 100%.     

A new technique of pinealectomy for adult rats

Summary A new technique of pinealectomy for rats is described which brings the pineal into view of the experimenter facilitating its removal and also allows for completely parallel sham operations.Acknowledgments. We thank Drs J. A. Mitchell, R. R. Gala and A. Weinsieder for their cooperation in the initial phases of this work and Hedwig A. Murphy for her help with the illustrations. Supported by USPHS, grant No. RR 05384, and the Department of Anatomy.     

Epithelial supporting cells can differentiate into outer hair cells and Deiters' cells in the cultured organ of Corti

The organ of Corti is a complex structure containing a single row of inner hair cells (IHCs) and three rows of outer hair cells (OHCs), supported respectively by one row of inner phalangeal cells and three rows of Deiters' cells. When fetal rat organ of Corti explants are cultured, supernumerary OHCs and supernumerary Deiters' cells are produced, without any additional cell proliferation. Analysis of semi- and ultrathin sections revealed that supernumerary OHCs are produced at the distal edge of the organ of Corti. Quantitative analysis of cell types present in the organ of Corti demonstrates that when the number of OHCs increases: (i) the total number of cells remains constant; (ii) the number of Deiters' cells increases; (iii) the number of tectal cells decreases and of Hensen's cells decreases. Using specific HC markers, i.e. jagged2 (Jag2) and Math1, we showed that in addition to existing OHCs, supernumerary OHCs, tectal cells and Hensen's cells expressed these markers in embryonic day 19 organ of Corti explants after 5 days in vitro. The results of this study suggest that Hensen's cells retain the capacity to differentiate into either tectal cells, which differentiate into OHCs, or into undertectal cells which differentiate into Deiters' cells. Received 15 May 2002; received after revision 18 July 2002; accepted 7 August 2002 RID="*" ID="*"Corresponding author.     

Contribution to the primary tissue culture technique. A new method for mechanical cell dispersion

Summary A new technique for preparing primary tissue cultures by mechanical cell dispersion was idealized. The time required to prepare a culture by this procedure was greatly reduced and the cultures obtained are morphologically and physiologically of better quality than that obtained by the classical methods of enzymatic cell dispersion.This work was supported by the Conselho Nacional de Pesquisas, Fundo Especial de Despesas do Instituto Butantan and DivisãoNacional do Cancer. The authors wish to thank Mrs.Sibylle Heller for the translation.     

Neogenesis of functional hair follicles in adult mouse skin selectively induced by tumour-promoting phorbol esters

Neogenesis of functional hair follicles in the tail skin of adult mice can quantitatively be demonstrated after long-term treatment with tumour-promoting phorbol esters. The ability to induce the formation of new hair follicles correlates with the hyperplasiogenic and tumour-promoting capacity of the phorbol esters. Hyperplasiogenic but nonpromoting phorbol esters do not lead to the formation of new hair follicles.     

Neogenesis of functional hair follicles in adult mouse skin selectively induced by tumour-promoting phorbol esters

Summary Neogenesis of functional hair follicles in the tail skin of adult mice can quantitatively be demonstrated after long-term treatment with tumour-promoting phorbol esters. The ability to induce the formation of new hair follicles correlates with the hyperplasiogenic and tumour-promoting capacity of the phorbol esters. Hyperplasiogenic but nonpromoting phorbol esters do not lead to the formation of new hair follicles.Acknowledgment. I am grateful to Dr K. Goerttler and Dr F. Marks for helpful advice and discussions.     

Evidence for dissociation of ferrihemoglobin by poly-L-lysine.

Circular dichroism and absorption spectra of ferrihemoglobin were shown to be altered upon binding with poly-L-lysine at alkaline pH. When ferrihemoglobin immobilized to Sepharose gel was treated with poly-L-lysine, hemoglobin subunits were released from the gel. These results suggest that ferrihemoglobin was dissociated into subunits by poly-L-lysine.     

A simple technique for testing the in vitro response of rabbit lymphocytes to PHA and allogeneic cells.

Lymphocytes of rabbits can be separated from small quantities of heparinized whole blood using a simple density gradient of Ficoll-Ronpacon 1.09. This separation technique yields a pure suspension of viable cells allowing reproducible results from cultures stimulated either with PHA or allogeneic lymphocytes isolated by the same technique.     

A new device for electron microscope autoradiography of whole cultured cells

Summary A new procedure which enables us to observe whole cultured cells autoradiographically by electron microscopy is described. By this method, only a relatively small amount of radioisotope and a relatively short exposure period are needed to get a large enough number of silver grains over the cell. The location of radioactive substances can be examined in relation to internal cell structures, especially the nucleus.     

A new insight into combining forecasts for elections: The role of social media

This study is devoted to gain insight into a timely, accurate, and relevant combining forecast by considering social media (Facebook), opinion polls, and prediction markets. We transformed each type of raw data into the possibility of victory as a forecasting model. Besides the four single forecasts, namely Facebook fans, Facebook “people talking about this” (PTAT) statistics, opinion polls, and prediction markets, we generated three combined forecasts by associating various combinations of the four components. Then, we examined the predictive performance of each forecast on vote shares and the elected/non‐elected outcome across the election period. Our findings, based on the evidence of Taiwan's 2018 county and city elections, showed that incorporating the Facebook PTAT statistic with polls and prediction markets generates the most powerful forecast. Moreover, we recognized the matter of the time horizons where the best proposed model has better accuracy gains in prediction—in the “late of election,” but not in “approaching election”. The patterns of the trend of accuracy across time for each forecasting model also differ from one another. We also highlighted the complementarity of various types of data in the paper because each forecast makes important contributions to forecasting elections.     

Cephalothin-treated normal red cells: A new type of PNH-like cells

Riassunto Emazie umane normali trattate con cefalotina, in opportune condizioni sperimentali, si comportano in alcuni test di emolisi in vitro (test di emolisi acida, test di sensibilità agli isoanticorpi freddi) in modo simile alle emazie della emoglobinuria parossistica notturna (EPN) (emazie simil-EPN). A differenza di altri tipi di emazie simil-EPN, queste emazie danno anche un test di Coombs diretto positivo, di tipo non. Viene avanzata l'ipotesi che la lesione responsabile del comportamento simil-EPN di queste emazie sia da ricercare in una alterazione delle proteine stromali.     

Preparation of isolated single cardiac cells from adult frog atrial tissue.

Isolated cardiac cells from bullfrog atrial tissue can be readily prepared by digestion of intact fragments of atrial tissue with trypsin and collagenase. These isolated cells have dimensions of about 5 mum in width and range in length from 300 mum to over 500 mum. Such isolated cells may prove useful for the investigation of contractile activity of cardiac muscle at the single cell level and at the sarcomere level within the single cell.     

A new technique of recording cortical blood flow in cats,suitable for measurement of arterio-venous concentration differences

Zusammenfassung Der Blutstrom in der Hirnrinde der Katze wurde mit einer neuen Methode quantitativ gemessen und die Resultate mit früheren Untersuchungen über die Durchblutung eines nervös isolierten Rindenlappens verglichen. Bei normalen Druckverhältnissen war die Strömungsgeschwindigkeit 0,17 bis 0,50 ml/g/min. Selbststeuerung des Strömungswiderstandes war deutlich vorhanden. Die Aufnahme von Glykose, die aus Durchblutung und arteriovenöser Differenz berechnet wurde, betrug 30 bis 70 µg/g Hirngewebe/min.     

A simple technique for testing the in vitro response of rabbit lymphocytes to PHA and allogeneic cells

Summary Lymphocytes of rabbits can be separated from small quantities of heparinized whole blood using a simple density gradient of Ficoll-Ronpacon 1.09. This separation technique yields a pure suspension of viable cells allowing reproducible results from cultures stimulated either with PHA or allogeneic lymphocytes isolated by the same technique.Supported by the Swiss Science Foundation No. 3.890-0.77.     

Evidence for dissociation of ferrihemoglobin by poly-L-lysine

Summary Circular dichroism and absorption spectra of ferrihemoglobin were shown to be altered upon binding with poly-L-lysine at alkaline pH. When ferrihemoglobin immobilized to Sepharose gel was treated with poly-L-lysine, hemoglobin subunits were released from the gel. These results suggest that ferrihemoglobin was dissociated into subunits by poly-L-lysine.We thank Dr A. Ichihara and K. Aki for their valuable discussions and encouragement during the course of these studies.