Cytogenetic studies of Hynobiidae (Urodela). XIV. Analysis of the chromosome of a Chinese salamander, Batrachuperus pinchonii (David)

The chromosome number of a Chinese salamander, Batrachuperus pinchonii, was re-examined. Adults and embryonic specimens had a diploid number of 66, with 33 bivalents during meiosis, in contrast to previous reported results. Furthermore, when C-banding analysis was performed with embryos, chromosomes with banding patterns homoeologous to those of Salamandrella keyserlingii and Hynobius species were found. It appears, therefore, that Batrachuperus, Salamandrella and Hynobius might be derived from a common ancestral species in eastern Asia. Received 22 August 1997; received after revision 14 October 1997; accepted 20 November 1997     

The karyotype,C-bands and AgNO3-bands of a lungless salamander from Korea:Onychodactylus fischeri (Boulenger) (Amphibia,Urodela)

The karyotype of a lungless salamander,Onychodactylus fischeri, from Korea was analyzed and compared with that of the Japanese congeneric species,O. japonicus. In both species the diploid karyotype consists of78 chromosomes, including 6 pairs of large chromosomes, 6 pairs of medium-sized ones, and the remaining 27 pairs of microchromosomes. The chromosome number ofO. fischeri, 2n=78, is, like that ofO. japonicus, the largest so far reported in the order Urodela. C-banding showed that constitutive heterochromatin inO. fischeri was mainly in the centromeric regions and near the secondary constrictions of the large chromosomes. AgNO₃-bands were located in the secondary constrictions associated with C-band heterochromatin.     

Preparation of specific antiserum againstRana esculenta pre-α lens crystallin

Summary Specific antiserum againstRana esculenta lens pre- crystallin was prepared in a rabbit by injecting antigen-antibody precipitate of this crystallin obtained from immunoelectrophoresis ofesculenta total soluble lens proteins against homologous antiserum.Acknowledgments. We thank Mr.A. Wachter for the excellent technical help, Mr.Th. Hulskes and Mr.A. M. v. Egeraat for the illustrations and finally Dr.W. E. Hawkins for valuable discussion.     

Cytogenetic studies of Hynobiidae (Urodela). IX. Karyological characteristics ofHynobius abei Sato by means of R-and C-banding

Summary Chromosomal characteristics of the salamander speciesHynobius abei, from Ohimya (Kyoto) were revealed by the techniques of R-and C-banding. The karyotype ofH. abei was characterized by the shortness of an R-negative (C-positive) band in the terminal region of the long arm of chromosome 2 and a band encompassing the whole short arm of chromosome 10. These two bands inH. abei were the shortest among those of the variousHynobius species that have been examined. Otherwise no differences could be detected betweenH. abei and seven other pond-type species ofHynobius (2n=56) in terms of the banding patterns of 18 specifically identifiable pairs of their chromosomes.     

Na-pump sites in the oviduct ofSalamandra salamandra (L.) (Amphibia,Urodela)

Summary Using³H-ouabain autoradiography, Na⁺–K⁺-ATPase has been localized on the basolateral membranes of ciliated and nonciliated cells in the oviduct (pars recta, p. convoluta I, II, III) of the European fire salamander,Salamandra salamandra. The mucous and seromucous gland cells of the p.convoluta I, II, III, however, do not show any significant labelling. An asymmetrical distribution of ouabain binding sites is a main feature of transporting epithelia.     

Axoplasmic transport in regenerating limbs ofAmbystoma maculatum larvae

Summary Axoplasmic transport of³H-leucine labelled molecules from spinal cord segments into regenerating larval salamander limbs was observed. However, labelled molecules were not observed in cells of the regeneration blastema.This work was supported by grants No.s A-9403 and A-1208 from the National Research Council of Canada to S.R.S. and R.A.L., respectively.     

Axoplasmic transport in regenerating limbs of Ambystoma maculatum larvae.

Axoplasmic transport of 3H-leucine labelled molecules from spinal cord segments into regenerating larval salamander limbs was observed. However, labelled molecules were not observed in cells of the regeneration blastema.     

Thomas Harriot’s optics,between experiment and imagination: the case of Mr Bulkeley’s glass

Some time in the late 1590s, the Welsh amateur mathematician John Bulkeley wrote to Thomas Harriot asking his opinion about the properties of a truly gargantuan (but totally imaginary) plano-spherical convex lens, 48 feet in diameter. While Bulkeley’s original letter is lost, Harriot devoted several pages to the optical properties of “Mr Bulkeley his Glasse” in his optical papers (now in British Library MS Add. 6789), paying particular attention to the place of its burning point. Harriot’s calculational methods in these papers are almost unique in Harriot’s optical remains, in that he uses both the sine law of refraction and interpolation from Witelo’s refraction tables in order to analyze the passage of light through the glass. For this and other reasons, it is very likely that Harriot wrote his papers on Bulkeley’s glass very shortly after his discovery of the law and while still working closely with Witelo’s great Optics; the papers represent, perhaps, his very first application of the law. His and Bulkeley’s interest in this giant glass conform to a long English tradition of curiosity about the optical and burning properties of large glasses, which grew more intense in late sixteenth-century England. In particular, Thomas Digges’s bold and widely known assertions about his father’s glasses that could see things several miles distant and could burn objects a half-mile or further away may have attracted Harriot and Bulkeley’s skeptical attention; for Harriot’s analysis of the burning distance and the intensity of Bulkeley’s fantastic lens, it shows that Digges’s claims could never have been true about any real lens (and this, I propose, was what Bulkeley had asked about in his original letter to Harriot). There was also a deeper, mathematical relevance to the problem that may have caught Harriot’s attention. His most recent source on refraction—Giambattista della Porta’s De refractione of 1593—identified a mathematical flaw in Witelo’s cursory suggestion about the optics of a lens (the only place that lenses appear, however fleetingly, in the writings of the thirteenth-century Perspectivist authors). In his early notes on optics, in a copy of Witelo’s optics, Harriot highlighted Witelo’s remarks on the lens and della Porta’s criticism (which he found unsatisfactory). The most significant problem with Witelo’s theorem would disappear as the radius of curvature of the lens approached infinity. Bulkeley’s gigantic glass, then, may have provided Harriot an opportunity to test out Witelo’s claims about a plano-spherical glass, at a time when he was still intensely concerned with the problems and methods of the Perspectivist school.     

The significance of the Barrovian Case

The Barrovian Case is a technical problem, hitherto unsolved, involving either a double convex lens or a concave mirror. The problem, due to Isaac Barrow and reported by Berkeley in his New theory of vision, is that what is seen in certain instances with these devices seems to violate historically important principles of optics. One is the ‘ancient principle’ of Euclid that the object should be seen at the intersection of the refracted (or reflected) ray with the perpendicular of incidence; the other is the principle attributed to Kepler that the perceived distance of an object varies indirectly with the divergence of the rays it sends to the eye. The most obvious difficulty is that the object should appear, impossibly, behind the eye. As it happens, despite some strong claims that have been made about the significance of the problem, the principles generating it no longer have the centrality in optics they were once thought to have. But even accepting them, the problem can be solved by viewing it as an instance, albeit a very complicated one, of the classical problem of the relativity of sense perception.     

Inhibition of aldose reductase by dihydroflavonols inEngelhardtia chrysolepis and effects on other enzymes

Astilbin and neoastilbin, dihydroflavonol rhamnosides fromEngelhardtia chrysolepis, showed potent inhibition of lens aldose reductase. Kinetic analysis showed astilbin exhibited uncompetitive inhibition against bothdl-glyceraldehyde and NADPH. These taxifolin glycosides were selective inhibitors of aldose reductase with no inhibition of NADH oxidase.     

Eye lens development and γ crystallins in Discoglossus pictus (Anura)

Summary The ontogeny and localization of the crystallins in Discoglossus pictus lens development has been determined. Using antibody specific for amphibian crystallins in the immunofluorescence technique, it was found that crystallins first appear in primary lens fibre cells in the lens rudiment, and continue to be restricted to the fibre area as lens development progresses. Thus the role of crystallins as indicators of a differentiated state remains constant in amphibian evolution, having been demonstrated in the most archaic anuran superfamily, as well as in others more recently evolved.This research was largely accomplished during the tenure of a fellowship from the European Molecular Biology Organization to D. S. McDevitt, and was partially supported by Biomedical Research Support Grant RR 546414 to D. S. McDevitt.The authors are grateful to Prof. W. J. van Doorenmaalen for use of the laboratory facilities; and to the Hubrecht Laboratory, International Embryological Institute, Utrecht, The Netherlands, for the gift of live D. pictus eggs. We thank Miss C. M. J. Stuifsand for the normal histology and Mr Th. Hulskes for the illustrations.     

Etude de l'activité adénosinetriphosphatasique et hexokinasique de cristallins de lapins soumis à une irradiation locale par les rayons X

Summary The irradiation of the lens by a simple dose of 1400 r, gives a very important and lasting reduction of its hexokinase activity. Its ATPase activity shows an increase during the first four days and a return to normal again. The variations observed here (that isin vivo) are different from the ones noted after irradiation of these enzymesin vitro.

---

---

Travail effectué avec le concours matériel de l'Institut National d'Hygiène.     

Eye lens development and gamma crystallins in Discoglossus pictus (Anura).

The ontogeny and localization of the gamma crystallins in Discoglossus pictus lens development has been determined. Using antibody specific for amphibian gamma crystallins in the immunofluorescence technique, it was found that gamma crystallins first appear in primary lens fibre cells in the lens rudiment, and continue to be restricted to the fibre area as lens development progresses. Thus the role of gamma crystallins as indicators of a differentiated state remains constant in amphibian evolution, having been demonstrated in the most archaic anuran superfamily, as well as in others more recently evolved.     

Preparation of specific antiserum against Rana esculenta pre-alpha lens crystallin.

Specific antiserum against Rana esculenta lens pre-alpha crystallin was prepared in a rabbit by injecting antigen-antibody precipitate of this crystallin obtained from immunoelectrophoresis of esculenta total soluble lens proteins against homologous antiserum.     

Theophrastus on Lyngurium: Medieval and Early Modern Lore from the Classical Lapidary Tradition

The ancient philosopher Theophrastus (c. 371-285 BC) described a gemstone called lyngurium, purported to be solidified lynx urine, in his work De lapidibus ('On Stones'). Knowledge of the stone passed from him to other classical authors and into the medieval lapidary tradition, but there it was almost always linked to the 'learned master Theophrastus'. Although no physical example of the stone appears to have been seen or touched in ancient, medieval, or early modern times, its physical and medicinal properties were continually reiterated and elaborated as if it did 'exist'. By the seventeenth century, it began to disappear from lapidaries, but with no attempt to explain previous authors' errors since it had never 'existed' anyway. In tracing the career of lyngurium, this study sheds some light on the transmission of knowledge from the classical world to the Renaissance and the changing criteria by which such knowledge was judged.     

Filaments of the vertebrate lens

Summary Filaments of an average diameter of 10–12 nm have been identified in the eye lens fibre cells of representative species of each vertebrate order. These filaments presumably serve a cytoskeletal role in the lens fibre cells.This study was supported by research grant Ey 0141 of the National Institutes of Health, Bethesda, Maryland, USA.     

Polyclinal,a new sulfated polyhydroxy benzaldehyde from the marine ascidianPolyclinum planum

Summary A new sulfated polyhydroxy benzaldehyde has been isolated from extracts of the temperate colonial ascidianPolyclinum planum. The structure of the new metabolite was solved by an X-ray crystallographic study. The highest concentration of this metabolite was found in the zooid-rich outer layers of this ascidian suggesting that it may represent a potential chemical defense against predators.     

Carbohydrate composition of the human cataractous lenses

Summary Specific chemical assays, including carbohydrate, hexosamines and hexuronic acid, were determined on the lens insoluble albumoid. It was noticed that the carbohydrate composition varies with age. The significance of carbohydrate in the lens in discussed.This work was supported by the College of Medicine of the University of Lagos, and financed by the British Council. The work was undertaken at the Department of Chemistry and Applied Chemistry, University of Salford, Salford (England).Special thanks are expressed to Dr L. R. Croft and Prof. G. I. Phillip for their help, support and encouragement throughout this study.     

The decrease in seed germination ofStriga hermonthica in Benin in the course of the rainy season is due to a dying-off process

Germination rate and viability ofStriga hermonthica seeds in the field in the Republic of Benin decreased steadily in the course of the rainy season. The percentage of germinating seeds decreased from 82% on April 13, 1993 to 16% on October 13, 1993. The percentage of viable seeds, according to the tetrazolium colour test, decreased in the same period from 90% to 15%. In the subsequent rainy season these values further decreased and it was concluded that the seeds do not enter a stage of secondary dormancy. This implies that if host plants (including wild hosts) are consistently kept away from infested fields for one or two year periods, this will lead to a dramatic decrease in the number of viableS. hermonthica seeds in the soil.     

The effect of chloroquine upon the developing lens

Summary Applied to the developing lens of the 14-day-old chick embryo, in organ culture conditions, chloquine prevented the elongation of the primary lens fibres, destroyed the equatorial ones and provoked vacuolisation and/or destruction in the epithelial cells.This work was supported by a grant from the office of the Chief Scientist, Ministry of Health, Israel