Magnetic resonance imaging (MRI) has failed to distinguish between smaller gut regions and larger haemal sinuses in sea urchins (Echinodermata: Echinoidea)

A response to Ziegler A, Faber C, Mueller S, Bartolomaeus T: Systematic comparison and reconstruction of sea urchin (Echinoidea) internal anatomy: a novel approach using magnetic resonance imaging.BMC Biol 2008, 6: 33.     

Differences underlying EGFR and HER2 oncogene addiction

Comment on: Faber AC, et al. Differential induction of apoptosis in HER2 and EGFR addicted cancers following PI3K inhibition. Proc Natl Acad Sci USA 2009; 106:19503-8.     

Short Reviews

THE WEED FLORA OF EGYPT. Loutfy Boulos & M. Nabil el-Hadidi. Pp. 178, 163 line illustrations. The American University in Cairo Press
OF PLANTS AND PEOPLE. Charles B. Heiser Jr. Pp. 250, 68 black and white photographs. University of Oklahoma Press
FLORA OF THE CAYMAN ISLANDS. George R. Proctor. Pp. 834, 256 text figs. + 3 maps
DIAGNOSIS OF MINERAL DISORDERS IN PLANTS. J.B.D. Robinson, general editor; 2 volumes. 1 Principles, C. Bould, E.J. Hewitt and P. Needham, Pp. 176, illustrated in colour and black and white
PLANT FACTS AND FANCIES. Sylvia Woods, drawing by Yvonne Skargon. Pp. 93, with line illustrations. Faber & Faber 1985
JOHN NASH. Sir John Rothenstein. Pp. 128, with colour and black and white illustration and a few black and white photographs. Macdonald & Co. (London) 1983
FLORA OF KUWAIT, VOLUME 1: DICOTYLEDONEAE. Hazim S. Daoud
THE NAMES OF PLANTS. D. Gledhill. Pp. 159. Cambridge University Press
STUDIES ON THE TIHÃMAH - THE REPORT OF THE TIHÃMAH EXPEDITION 1982 AND RELATED PAPERS
SONORAN DESERT SPRING. John Alcock. Pp. 194, numerous photographs, mostly in black and white
FLORA OF CYPRUS, VOLUME TWO. R.D. Meikle. Pp. 1137 (Pp. 833–1970), 52 text figs. Bentham-Moxon Trust     

The development of inducer and effector immune suppressor cell function in Xenopus laevis, the South African clawed toad: the effect of metamorphosis

Thymic capacity to induce suppression of antibody production by immunized Xenopus laevis toadlet spleen fragments was tested in co-cultures for different developmental stages (Nieuwkoop, P.D. and J. Faber: Normal Table of Xenopus laevis (Daudin) (North Holland, Amsterdam) 1967). While thymuses of stages 52-54 (premetamorphosis) induced suppression, those of stages 58-62 (metamorphosis) did not. This capacity returned in metamorphic climax (stages 63-65). Tests of lectin-induced suppressor function in spleens of different developmental stages exposed the same pattern of compromised activity during metamorphosis. To test whether larval thymuses could effect suppression, rather than just induce it, antigen-activated thymuses from the different stages were co-cultured with immunized toadlet spleen fragments which had been suppressor-depleted by cyclophosphamide. Only thymuses from premetamorphic larvae suppressed. Thus, when thymic capacity to induce suppression returned in metamorphic climax, it was adult-like: it lacked effector suppressor cells.     

Localization of a nervous system-specific class II beta-tubulin gene in Xenopus laevis embryos by whole-mount in situ hybridization.

A neural-specific beta-tubulin mRNA is expressed in the developing central nervous system shown by whole-mount in situ hybridization experiments. Of special interest is the fact that from the late blastula (stage 9; Nieuwkoop and Faber, 1967; Hausen and Ribesell, 1991) until the early neurula (stage 13) the signal can be found not only in the presumptive neural plate but also in the presumptive epidermis. Later in development (from stage 13) the specific mRNA becomes restricted to the presumptive brain and spinal cord area. The results are discussed in the context of predisposition and (pre)determination.     

Flexibility in crystalline insulins.

Comparisons of atomic models for chemically identical protein molecules solved in differing crystal environments provide information on flexibility in the protein structure. The structures of five T4 lysozyme proteins in differing crystal environments showed large relative displacements of the two domains with conserved backbone conformations that are connected by a flexible hinge (H. R. Faber and B. W. Matthews. 1990. Nature (Lond.). 348:263-266). In contrast, my comparison of the positions of all the atoms in two crystal forms of insulin shows that the structural changes caused by the differing crystal contacts are contained within nearby amino acids and are not propagated through the core of the insulin molecule. Groups of atoms that are most significantly displaced are not shifted in large rigid units but are repacked into new and distinct conformations. The transmission of displacements through the single domain insulin molecule is, like the movements due to thermal vibrations (D. L. D. Caspar, J. Clarage, D. M. Salunke, M. S. Clarage. 1988. Nature (Lond.). 332:659-662), characterized by short-range interactions between small atomic groups.     

Increased UDP-glucuronyltransferase and gamma-glutamyltranspeptidase in enzyme-altered rat liver lesions produced by low doses of aflatoxin B1

Preneoplastic liver lesions were produced in female Wistar rats by low doses of aflatoxin B1 (Model 1: administration of 37.5 micrograms/kg 12 and 24 h after partial hepatectomy; Model 2: continuous application of 3.5 micrograms/kg in tap water daily for 28 days with partial hepatectomy after 14 days. The animals then received sodium phenobarbital, 0.1% in tap water, for 180 to 400 days). In both models numerous altered hepatic foci (AHF) and hyperplastic nodules (HN) were detected enzyme histochemically by their negative ATPase and positive gamma-glutamyltranspeptidase reactions. Immunohistochemically these lesions were also UDP-glucuronyltransferase positive. Increased UDP-glucuronyltransferase adds to permanent alterations of a number of drug metabolizing enzymes observed in a variety of different tumor models. These alterations are responsible for the toxin-resistant phenotype (Faber 1984b). Increased gamma-glutamyltranspeptidase was detected both enzyme histochemically and immunohistochemically; whereas gamma-glutamyltranspeptidase activity was present in both AHF/HN and in periportal areas by enzyme histochemistry, the immunohistochemical method selectively stained gamma-glutamyltranspeptidase in AHF and HN. Immunohistochemically detectable UDP-glucuronyltransferase and gamma-glutamyltranspeptidase are markers of putative precancerous liver lesions which may be useful in the analysis of the prestages of liver carcinogenesis.     

Book reviews

The Art of Primitive Peoples. J. T. Hooper and C. A. Burland. (168 pp., 68 pls. The Fountain Press, 46–47 Chancery Lane, London W.C.2. 1953. Cloth bound 42/—).

The God of the Witches. Margaret A. Murray. (2nd ed. Faber & Faber, London 1952).

Magic Books from Mexico. C. A. Burland. (31 pp., 16 colour pls. King Penguin Books, Harmondsworth, Middlesex, England 1953. Bound 4/6 d).

Outline of South American Cultures. George P. Murdock. (Behavior Science Outlines, Vol. II, Human Relations Files, New Haven 1951. Price: $ 2.50).

Kunst im Reiche der Inca. Heinrich Ubbelohde Doering. (66 pp., 240 pls., 4 colour pls., one map. Verlag Ernst Wasmuth, Tübingen 1952. Cloth bound DM. 42).

Tiahuanacu, Atacama und Araukaner. Walter Ruben. (262 pp., 70 ill., 3 maps. Otto Harrassowitz Verlag, Leipzig 1952. Paper wrapper DM 15.80, bound DM 17.20).

Kunapipi. Ronald M. Berndt. (223 pp. Melbourne 1951), and Djanggawul. (230 pp. London 1952).     

Nerve-independence of limb regeneration in larval Xenopus laevis is related to the presence of mitogenic factors in early limb tissues.

Early limbs of larval Xenopus laevis can form a regeneration blastema in the absence of nerves. The nerve-independence could be due to the synthesis of neurotrophic-like factors by the limb bud cells. To test this hypothesis, two series of experiments were performed. Series A: the right hindlimbs of stage 57 larvae (acc. to Nieuwkoop and Faber. 1956. Normal table of Xenopus laevis [Daudin]. Amsterdam: North-Holland Pub. Co.), which are nerve-dependent for regeneration, were amputated through the tarsalia. The regenerating limbs were submitted to: sham denervation; denervation; denervation and implantation of a fragment of an early limb, or a late limb, or a spinal cord. Series B: froglets were subjected to amputation of both forelimbs. The cone blastemas were transplanted into denervated hindlimbs of stage 57 larvae, together with a fragment of an early or a late limb. The results in series A showed that the implantation of early limb tissue into the denervated blastema maintained cell proliferation at levels similar to those observed after the implantation of a spinal cord fragment or in sham denervated blastemas. However, the implantation of late limb tissues were ineffective. The results of series B showed that the implantation of early limb tissue, but not of late limb tissue prevented the inhibition of cell proliferation and the regression of denervated limb blastemas of juveniles. These results indicate that the nerve-independence is related to the synthesis of diffusible mitogenic neurotrophic-like factors in early limb tissues, and that nerve-dependence is established when differentiated cells of late limb tissues stop producing these factors.     

Nerve-independent DNA synthesis and mitosis in regenerating hindlimbs of larval Xenopus laevis

Summary Xenopus laevis larvae at stage 52–53 (according to Nieuwkoop and Faber 1956) were subjected to amputation of both limbs at the thigh level as well as to repeated denervations of the right limb. Results obtained in larvae sacrificed during wound healing (1 after amputation), blastema formation (3 days) and blastema growth (5 and 7 days) showed that denervated right limbs have undergone the same histological modifications observed in innervated left limbs and have formed a regeneration blastema consisting of mesenchymal cells with a pattern of DNA synthesis and mitosis very similar to that in presence of nerves. Also, the patterns of cellular density in regenerating right and left limbs were very similar. On the whole, the data here reported show a highly remarkable degree of nerve-independence for regeneration in hindlimbs of larval Xenopus laevis at stage 52–53 and lend some substance to the hypothesis that, in early limbs, there would exist trophic factors capable of replacing those released by nerves, promoting DNA synthesis and mitosis in blastemal cells. Offprint requests to: S. Filoni     

Hsp56: a novel heat shock protein associated with untransformed steroid receptor complexes

The recently-described p59 protein has been shown to be associated with untransformed steroid receptors present in rabbit uterus and rat liver cytosols (Tai, P. K., Maeda, Y., Nakao, K., Wakim, N. G., Duhring, J. L., and Faber, L. E. (1986) Biochemistry 25, 5269-5275; Renoir, J.-M., Radanyi, C., Faber, L. E., and Baulieu, E.-E. (1990) J. Biol. Chem. 265, 10740-10745), while a smaller version of this protein (p56) interacts with glucocorticoid receptors in human IM-9 cell cytosols (Sanchez, E. R., Faber, L. E., Henzel, W. J., and Pratt, W. B. (1990) Biochemistry 29, 5145-5152). In addition to interacting with glucocorticoid receptors, the p56 protein of IM-9 cell cytosol is also found as part of a large heteromeric complex that contains both the 70-kDa and 90-kDa heat shock proteins (hsp70 and hsp90, respectively). Given this association of p56 with the two major stress proteins, I have speculated that p56 may itself be a heat shock protein. In this paper, the effect of heat stress on the rate of synthesis of p56 is determined. Intact IM-9 cells were exposed to 37 or 43 degrees C for 4 h, followed by pulse-labeling with [35S]methionine. Analysis of whole cytosolic extracts by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography reveal an increased rate of radiolabeling for hsp70, hsp90, hsp100, ad hsp110, but no heat-inducible protein of smaller relative molecular mass is detected. However, immune-purification of p56 from normal and heat-stressed cytosols with the EC1 monoclonal antibody results in the presence of a 56-kDa protein that exhibits an increased rate of synthesis in response to heat stress. The results of two-dimensional gel Western blots employing the EC1 antibody demonstrate that this heat-inducible protein is indeed the EC1-reactive p56 protein and that the induction effect is not due to unequal yields of p56 during immune-purification. Heat stress has no effect on the composition of the p56.hsp.70.hsp90 complex, except that the complex derived from heat shocked-cells contains both the constitutive and heat-inducible forms of hsp70. Induction of p56 also occurs in IM-9 cells subjected to chemical stress (sodium arsenite). It is proposed that p56 is a steroid receptor-associated heat shock protein which can now be termed hsp56. Like hsp90, hsp56 likely serves in some vital cellular role apart from any specific function it provides in steroid receptor action.     

Relationships between eye factors and lens-forming transformations in the cornea and pericorneal epidermis of larval Xenopus laevis

Larval Xenopus laevis at stage 56 (Nieuwkoop and Faber, '56) were subjected to various types of lentectomy: (1) simple lentectomy, from the pupillary space after incision of outer and inner cornea; (2) lentectomy from the dorsal region of the eye; (3) lentectomy from the dorsal region of the eye and simultaneous incision of the outer cornea; (4) lentectomy from the dorsal region of the eye and simultaneous incision of the outer and inner cornea. The results obtained show that the outer cornea underwent lens-forming transformations only when the inner cornea had been incised, thus permitting outer cornea (Experiments I-IV). No lens regeneration occurred when the inner cornea was left intact (Experiments II, III). It was concluded that the factor(s) allowing the lens-forming transformations of the outer cornea is not an aspecific nutritional factor(s) but a more specific factor(s) that cannot reach the outer cornea when the inner cornea is intact. Therefore, the absence of the lens and sufficient nutrient available to the outer cornea are not enough to allow lens regeneration from the outer cornea. When lens removal was carried out through the dorsal part of the eye (Experiments III-IV) the lens regenerated from the pericorneal epidermis of this region in a large number of cases.     

The blastomere periphery ofXenopus laevis,with special reference to intercellular relationships

Summary The peripheral region of theXenopus laevis blastomere is considered to be comprised of the extracellular material, the plasma membrane and the subsurface cytoplasm. These regions were examined with the electron microscope during cleavage and blastula stages (stages one to seven, Nieuwkoop and Faber, 1967). The cell contact relationships varied according to the location of the cell in the embryo. Superficially, a dense terminal junction occurred, possessing point contacts where the membranes approached to within 30 Å. More deeply, a variety of relationships appeared: wide intercellular spaces bridged by pseudopodia, long regions of unbridged parallel membrane or complex interdigitation. Tight junctions were found in limited numbers and developed at about stage seven. Extracellular material was examined using histochemical techniques on dissociated andin situ cells. The latter had appreciable amounts of such material, but dissociated cells reacted inconsistently to different techniques. The cytoplasm subjacent to the membrane possessed a filamentous network at all stages examined, but extensive microfilament tracts and microtubules appeared only at gastrulation.     

Beziehungen zwischen Lage und Teilungsfigur der Kerne und des Protoplasmas einerseits und Wandmicellierung andererseits. Dargestellt an Rippenmeristemen und Spaltöffnungsapparaten

Ohne ZusammenfassungEs ist hier die Stelle, den Professoren Dr. v. Faber und Dr. Bergdold (München), Pilger (Berlin) und Schnarf (Wien) für die freundlichste Überlassung von Frischmaterial aus den dortigen Gewächshäusern zu danken. Zudem bin ich Herrn Professor Dr. Hoefler (Wien) zu großem Danke für die allgemeine Anregung, die Ergebnisse der Protoplasmatik mit denen meiner Kern- und Micellierungsuntersuchungen zu verbinden, verpflichtet. Diese Verbindung dürfte auch noch weiterhin manchen tiefen Einblick in das Zellgeschehen und damit der Entwicklungs- und sonstigen physiologischen Anatomie der Pflanzen zu tun gestatten.     

Eye factors and lens-forming transformations of outer cornea in Xenopus laevis larvae

Outer cornea of lensectomized Xenopus laevis tadpoles at state 50 (according to Nieuwkoop, P.D. and Faber, J., ('56) Normal Table of Xenopus laevis, Daudin, North-Holland, Amsterdam, pp. 1-243) was removed 3, 7 and 10 days after lensectomy and implanted between the outer and the inner cornea of larvae of the same species at stage 51-52. In these conditions, the implanted outer cornea remained isolated from the retinal factor of the vitreous chamber, although it received the nutritional factors normally reaching the outer cornea. Results show that lens-forming transformation process of the outer cornea is arrested, and lens-forming structures undergo regression at speed which increases with increasing precocity of the stage of lens-forming transformation undergone by the implanted cornea. These data suggest that the process of lens-forming transformation is not a single-step process, but a sequence of interactions extending over a long period of time requiring the continuous presence of the retinal factor in the vitreous chamber until complete differentiation of the lens is achieved.     

A test of Przibram's Rule

Przibram's Rule states that the ratio of the mean weights in successive instars of hemimetabolous insects is 2.09. Faber (1994) described a two-stage approach to testing Przibram's Rule when the instars of the measured individuals are unknown. In the first stage, individuals are assigned to one of the instars on the basis of their weights. In the second stage, a test of the null hypothesis that the means of logarithmic weight in the two groups differ by the logarithm of 2.09 is performed. This approach suffers from two problems. First, errors in assigning individuals to instars will exaggerate the difference between instars. Secondly, the validity of the test in the second stage is based on the implicit assumption that the variance of logarithmic weight in the two groups is equal. This note describes a test of Przibram's Rule that avoids these problems.     

Cell migration in the formation of the pronephric duct in Xenopus laevis

To determine if cell migration is involved in the formation of the pronephric duct in Xenopus, we used morphometry, ablation, and videomicroscopy of vitally stained cells to study duct formation. In St 23-24 (Nieuwkoop and Faber, 1956) embryos, a ridge of cells forms caudal to the pronephric rudiment. The ridge lengthens at approximately the same rate as the embryonic trunk from St 23 to St 31. Ablation experiments demonstrated that the ridge constitutes the pronephric duct rudiment (PDR); when the ridge was ablated at St 23-24, little or no duct formation occurred, whereas a duct formed when the pronephric rudiment was ablated and the ridge left intact. Vital dye injections showed that the PDR forms from the intermediate mesoderm ventral to myotomes IV-VIII. From St 29/30 to St 33/34, the PDR actively elongates along the ventral edge of the myotomes as far as myotome XIV, where it joins the cloaca as the pronephric duct. Videomicroscopy of vitally stained cells showed that the PDR elongates throughout its length and does not incorporate additional cells from the mesoderm over which it elongates. The results strengthen the case for a common mode of pronephric duct formation among amphibian species.