ABSTRACT Vincristine sulphate has been found to be a more useful metaphase arrest agent than Colcemid. Metaphase accumulation, in isografts of a CBA mammary adenocarcinoma, was linear with time for at least 10 hr after vincristine administration and also independent of drug dose in the range 1–4 mg/kg body weight. A method for evaluating the cell production rate, in histological sections, of a cell population which forms a heterogeneous component of the tissue has been described. The percentage of each tissue component was determined using the Chalkley point count method and the mean number of metaphases in an arbitrary defined field were evaluated. Corrections for percentage composition and sectioning were applied and the cell production rate defined. This was found to be 15.8 ± 0.6 cells per 1000 cells per hour for this tumour.

Die Wirkung von Kaninchen-anti-Maus-Lymphozytenserum auf das Wachstum von Tumorallotransplantaten kann in kleineren Tiergruppen leicht bestimmt werden, indem man das immunosuppressive Potential verschiedener Serumsätze prüft. Ein gutes Verhältnis zwischen dem durchschnittlichen Durchmesser von Tumortransplantaten am 14. Tag nach dem Implantat und die entsprechende, durchschnittliche, prozentuale Zunahme der Überlebenszeit der Hauttransplantate wird demonstriert.

Malignant change in somatic cell populations may be a relatively common event (1) but the subsequent development of tumours may usually be prevented by the operation of immunological surveillance mechanisms (2,3). The immunological environment of the host may thus play an important role in the regulation of tumour growth and metastasis. Attempts to utilize immunotherapy to control the growth of tumours have, however, been unsuccessful (4,5), although recent attempts to stimulate host responses have achieved an encouraging degree of success (6,7). This has emphasized the urgent need for precise information about the immunological mechanisms and the cell populations which may influence tumour growth. We have been accumulating such information in a series of experiments in which factors affecting the growth of implants of a spontaneous murine mammary adenocarcinoma have been analysed (8,9).

British Journal of HaematologyVolume 10, Issue 2 p. 193-197 Human Foetal Haematopoiesis II. HEPATIC HAEMATOPOIESIS IN THE HUMAN FOETUS D. Brynmor Thomas, D. Brynmor Thomas Institute of Pathology, The Royal Infirmary, Cardiff, and Department of Anatomy, The University, Bristol Department of Pathology, Radclifie Infirmary, Oxford.Search for more papers by this authorJ. M. Yoffey, J. M. Yoffey Institute of Pathology, The Royal Infirmary, Cardiff, and Department of Anatomy, The University, BristolSearch for more papers by this author D. Brynmor Thomas, D. Brynmor Thomas Institute of Pathology, The Royal Infirmary, Cardiff, and Department of Anatomy, The University, Bristol Department of Pathology, Radclifie Infirmary, Oxford.Search for more papers by this authorJ. M. Yoffey, J. M. Yoffey Institute of Pathology, The Royal Infirmary, Cardiff, and Department of Anatomy, The University, BristolSearch for more papers by this author First published: April 1964 https://doi.org/10.1111/j.1365-2141.1964.tb00694.xCitations: 53 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume10, Issue2April 1964Pages 193-197 RelatedInformation

British Journal of HaematologyVolume 8, Issue 3 p. 290-295 Human Foetal Haemopoiesis I. The Cellular Composition of Foetal Blood D. Brynmor Thomas, D. Brynmor Thomas Department of Anatomy, The University, Bristol Present address: Institute of Pathology, The Royal Infirmary, CardiffSearch for more papers by this authorJ. M. Yoffey, J. M. Yoffey Department of Anatomy, The University, BristolSearch for more papers by this author D. Brynmor Thomas, D. Brynmor Thomas Department of Anatomy, The University, Bristol Present address: Institute of Pathology, The Royal Infirmary, CardiffSearch for more papers by this authorJ. M. Yoffey, J. M. Yoffey Department of Anatomy, The University, BristolSearch for more papers by this author First published: July 1962 https://doi.org/10.1111/j.1365-2141.1962.tb06523.xCitations: 55 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume8, Issue3July 1962Pages 290-295 RelatedInformation

WHILE the importance of the hæmopoietic role of the fœtal liver is universally recognized, remarkably little precise information is available about the changing cytology of this organ during the course of development. The recent interest in techniques for the transfusion of suspensions of human fœtal liver, as a source of hæmopoietic stem-cells, has, however, made it desirable to study more fully the processes of fœtal blood formation.