摘要:

AbstractEarly morphogenesis of mouse submandibular gland provides an excellent model for the formation of epithelial lobules as a consequence of epithelial‐mesenchymal interactions. Both proteoglycans and a glycosaminoglycan, high molecular weight components which contain amino‐sugars and hexuronic acids, seem to be important in maintaining the lobular structure through the formation of epithelial basal lamina. Collagen also appears to play a crucial role in this morphogenesis. By visualizing the distribution of collagen fibrils and by changing the concentration of collagen in the gland, we have developed a new hypothesis which emphasizes the mechanical role of mesenchyme in epithelial cleft formation. Precise mechanisms for the involvement of these molecules have not been elucidated, yet it is now clear that knowledge of the function of the extracellular matrix components is a prerequisite for understanding the epithelial‐mesenchymal interac

ISSN:0265-9247    

DOI:10.1002/bies.950110602

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThe identification of cellular deficiences in the ability to repair damage in DNA in individuals with several cancer‐prone genetic disorders, has led to the idea that defective DNA repair results in cancer. In patients with trichothiodystrophy, however, a recently discovered defect in the repair of ultraviolet damage in DNA is not associated with cancer‐proneness. Thus our previous ideas about the connections between DNA repair capacity and cancer susceptibility need to be reevalua

ISSN:0265-9247    

DOI:10.1002/bies.950110603

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractRecent studies of early development in a number of ivertebrate and vertebrate species have suggested that growth factors and their receptors may play important roles in differentiation as well as cell proliferation. In the mouse embryo, the expression of the receptors for insulin and insulin‐like growth factors I and II (IGF‐I and ‐II) are temporally regulated. The ontogeny of receptor and ligand expression within the insulin and IGF gene family suggests that the very earliest stages of mammalian embryogenesis may be subject to regulation by autocrine and paracrine factors from maternal and embryonic so

ISSN:0265-9247    

DOI:10.1002/bies.950110604

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractRetroviruses encode a small, basic nucleocapsid (NC) protein that is found complexed to genomic RNA within the viral particle. The NC protein appears to function not only in a histone‐like manner in packaging the RNA into the particle but also in specifically selecting the viral genomic RNA for packaging. A cysteine‐histidine (cys‐his) region, usually composed of 14 amino acids and reminiscent of the ‘zinc fingers’ of transcription factors, is the only highly conserved sequence element among the retroviral NC proteins. This review discusses the biochemical properties of NC, and its possible role(s) in retroviral replication. We also speculate on how the biochemical properties may relate to its function in RNA recognition and

ISSN:0265-9247    

DOI:10.1002/bies.950110605

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThe immune surveillance theory postulates that spontaneous tumors are normally rejected by the immune system and appear only when they override host‐immune recognition and rejection mechanisms. The present mini‐review describes a spontaneous tumor system, the reticulum cell sarcomas (RCS) in SJL/J mice, that is dependent on host tumor‐specific immune lymphocytes for growth. This continuous tumor‐specific response results in tumor progression and death of the host. This tumor system contradicts the basic concept of immune surveillance. We propose as an explanation that some highly antigenic tumors, like the RCS, may have evolved in a non‐autonomous fashion but, nevertheless, have lost regulatory controls of cell proliferation. In the RCS system, the tumor expresses Class II MHC I‐E like specificities that are not expressed on the host cells and which selectively stimulate a subpopulation of I‐E specific T cells, the Vβ17a+clonotype, leading to their expansion and continuous nurturing of the tumor via secreted lymphokines. This neoantigenic stimulation bypasses the tumor regulatory response that might have resulted if the tumor had not expressed neo‐antigens. Furthermore, passive administration of anti‐clonotypic antibody to tumor‐bearing mice results in tumor regression and long‐term survival through removal of the tumor reactive T cells. Thus, in this tumor system, immunosuppressive treatments are the prescripti

ISSN:0265-9247    

DOI:10.1002/bies.950110606

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

ISSN:0265-9247    

DOI:10.1002/bies.950110607

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThe subject of (ir)reducibility in biochemistry has resurfaced recently in the literature. Along with it comes a renewed emphasis on the organizational complexity of the living state and, more broadly, concern over the unity of the sciences.

ISSN:0265-9247    

DOI:10.1002/bies.950110608

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

ISSN:0265-9247    

DOI:10.1002/bies.950110609

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

ISSN:0265-9247    

DOI:10.1002/bies.950110610

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

ISSN:0265-9247    

DOI:10.1002/bies.950110612

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY