bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of 6-dimethylaminopurine on microtubules and putative intermediate filaments in sea urchin embryos
Authors: Dufresne Louise , Néant Isabelle , St-Pierre Johanne , Dubé FrançOis , Guerrier Pierre 
Published: April 2021

ABSTRACT
The effects of 6-dimethylaminopurine (6-DMAP) (a putative phosphorylation inhibitor) on the state of assembly of microtubules and intermediate filaments have been studied during the first cell cycle of the sea urchin Strongylocentrotus droebachiensis. Changes in the spatial organization of cytoskeletal structures were studied by indirect immunofluorescence with anti-tubulin and anti-IFa antibodies. The rates and patterns of protein phosphorylation in control and treated eggs were also investigated.
The transfer of fertilized eggs to 600 pM 6-DMAP within 4 min following insemination inhibits pronuclear migration and syngamy. This also prevents male pronuclear decondensation, while chromatin condensation and nuclear envelope breakdown do not occur in the female pronucleus. Immunolabeling with anti-tubulin antibodies reveals the presence of cortical microtubules as early as 15 min after fertilization in both control and treated eggs. However, no sperm astral microtubules could be detected in the treated eggs. At later stages, from syngamy (40 min) up to nuclear envelope breakdown (90 min), 6-DMAP affects neither cortical microtubule organization nor the state of chromatin condensation but it precludes nuclear envelope breakdown and entry into mitosis. Treatment of the fertilized eggs after nuclear envelope breakdown induces permanent chromosome decondensation and premature disappearance of the mitotic apparatus. This last event involves disruption of the spatial organization of both microtubules and putative intermediate filaments.
Quantitative measurements of protein phosphorylation show that 6-DMAP efficiently and reversibly inhibits 32P incorporation into proteins. Qualitative analysis of the autoradiograms of 32P-labeled proteins separated by SDS-PAGE reveals that a major protein band, migrating with an apparent molecular weight of 31 × 103Mr, is specifically dephosphorylated in eggs treated with 6-DMAP.
This study suggests that protein phosphorylation is required for sperm aster microtubule growth and migration, but not for cortical microtubule polymerization. It also strengthens the hypothesis that, in sea urchin eggs, putative intermediate filaments are tightly associated with spindle microtubules. Finally, it confirms that inhibiting protein phosphorylation before nuclear envelope breakdown reversibly prevents the entry into mitosis.
The response of endothelial cells to TGFβ-1 is dependent upon cell shape, proliferative state and the nature of the substratum
Authors: Sutton A. B. , Canfield A. E. , Schor S. L. , Grant M. E. , Schor A. M. 
Published: April 2021

ABSTRACT
Endothelial cells plated on two-dimensional (2-D) substrata proliferate until they form a tightly apposed confluent monolayer of quiescent cells that display a typical ‘cobblestone’ morphology. When added to proliferating cultures TGFβ-1 (transforming growth factor β-l) inhibited cell growth and caused marked morphological changes, with the cells becoming enlarged and ragged. These effects were dose-dependent and reversible. TGFβ-1 also reduced the cloning efficiency and colony size of these cells, indicating that TGFβ-1 is cytotoxic and cytostatic for endothelial cells. By contrast, TGFβ-1 added to quiescent cobblestone cultures did not affect cell morphology or cell numbers. In the presence of 20% serum, the level of total protein synthesis per cell was significantly increased by TGFβ-1 in a dose-dependent manner when the cells were cultured on a 2-D substratum, regardless of whether the cells were proliferating or cobblestone quiescent. The level of plasminogen activator inhibitor type 1 was specifically increased in these cultures, as demonstrated by reverse fibrin zymography and immunoprecipitation. Endothelial cells embedded within a 3-D collagen gel display an elongated ‘sprouting’ morphology. Such cells self-associate to form three-dimensional cellular networks within the gel, but do not proliferate. The addition of TGFβ-1 to these quiescent sprouting cells initially induced rounding-up without altering protein synthesis, and cell death occurred later. The effects of TGFβ-1 on sprouting endothelial cells were also examined using two culture systems where both the cobblestone and the sprouting phenotypes were present. TGFβ-1 reduced the number of cells present and the extent of migration of sprouting cells embedded within a type I collagen gel, but had no effect upon sprouting cells embedded within a complex endothelial-produced extracellular matrix. Large vessel (aortic) and microvessel (retinal) endothelial cells responded in a similar way to TGFβ-1; the only difference being that an increased synthesis of PAI-1 was not observed with sub-confluent BREC cultures. Our results suggest that the effects of TGFβ-1 upon endothelial cells depend on the shape (cobblestone or sprouting), on the proliferative state of the cells, and on the nature of the matrix surrounding the cells. The response of these cells to TGFβ-1 in vivo may be similarly modulated during angiogenesis by changes in the cell phenotype and the composition of the surrounding matrix.
On the Photographic Delineation of Microscopic Objects by Artificial Illumination
Authors: Shadbolt George 
Published: April 2021

ABSTRACT
The application of Photography to the purpose of delineating microscopic forms I have for some years entertained as a favourite project; but some practical difficulties of mani-lation deterred me from putting it to the test until quite recently, when a sufficient stimulus was applied in the beautiful specimens both on paper and glass exhibited in the month of October last, at the Microscopical Society of London, by Mr. Joseph Delves, of Tonbridge Wells. Of the excellent promise for a highly valuable adjunct to microscopic science, the proofs in the present Number of the Journal will afford your readers an opportunity of judging.
Excess of the Colourless Corpuscles of the Blood (Leucoeythemia) occurring in Cases of Goitre
Authors: Holland Thomas S. 
Published: April 2021

ABSTRACT
The impulse which the researches of Professors Bennett and Virchow have given to the study of the histological alterations in the Blood will be, I presume, sufficient excuse for the publication of these observations ; and by confining myself to a simple narration of facts I hope to secure the attention of those who live in districts in which Goître is of frequent occurrence, and perhaps induce them to make, in all such cases, a microscopical examination of the blood.
On the Practical Application of Photography to the Illustration of Works on Microscopy, Natural History, Anatomy, &c
Authors: Highley jun Samuel 
Published: April 2021

ABSTRACT
Many scientific phenomena, when first discovered, either from their remarkability or beauty, have excited much interest in the popular mind, but have only been regarded by it as pleasing toys, till in the course of time their practical value has been discovered, and they have been arranged thereafter in the list of applied sciences.
On the Psorospekmia and Gregarinæ
Authors: Leydig D. F. 
Published: April 2021

ABSTRACT
The Psorospermia are microscopical corpuscles of a peculiar kind, which may be generally characterized, in the full-grown condition, as rounded organisms, having a sharply-defined outline, with or without a tail-like appendage. They are flattened and lenticular in figure, and one pole is usually acuminute; and towards this pole several internal vesicles converge in a symmetrical manner. These creatures were discovered by Joh. Miiller in 1841 (Mull. Arch., 1841, p. 477). He found in a young Pike minute round cysts in the cellular tissue of the muscles of the eye, in the substance of the sclerotica, and between this and the choroid coat. The contents of the cysts was a whitish substance, which, when examined microscopically, was found to consist of peculiar elements—the “ Psorospermia.” [A detailed notice of these observations is given in the ‘ Microscop. Journal,’ vol. ii. p. 123, and in the ‘ Brit, and Foreign Med. Rev.,’ January, 1842.] In the following year the same observer (Müller’s Arch., 1842, p. 193) discovered parasitic corpuscles in the swimming bladder of a Gadus callarius, which, although specifically distinct from the Psorospermia, approached very near the latter in their organization. They resembled in general a smooth ventricose Navicula, and consisted of two elongated cases applied to each other at the cavity, and with an elliptical outline and convex outer surface. They were in part free, in part enclosed in masses within a tunic. Similar cysts, containing “ Psorospermia,” have been found by Leydig in several species of fish, and in all parts nearly of their bodies, and even in the blood contained in the heart (p. 223), and in the peritoneal cavity.
Experiments on the Transmission of Intestinal Worms
Authors: Herbst M. 
Published: April 2021

ABSTRACT
The author’s experiments appear to have been directed only to the Trichina spiralis, or allied species. He recognizes three species of this genus. The first, corresponding in all respects with that discovered in the human body by Hilton, Owen, and Bischoff, was met with in the voluntary muscles of a large old cat. Shortly afterwards he met with a second species in the mesentery of Strix passerina. It occurred in the substance of the muscles, and also in the mesentery, in which situation the worm occupied yellowish tubercles about the size of a pin’s head. This Trichina is distinguished not only by a body double the size of that of the other, but principally by the abnormal form of its extremities. The enlarged head terminates in a short conical point, the surface of which is verrucose, and the attenuated tail seems to be furnished with two papillary protuberances at the extremity, as well as with an infundibuliform opening. The third species was met with by the author in 1848, in the muscles of a full-grown dog. The cysts were very small, scarcely visible to the naked eye. The vermiculi enclosed in them were much smaller, but in other respects resembled those of the first species, from which, consequently, it may be considered doubtful whether they are really specifically distinct.
On the Structure of the Cutaneous Follicles of the Toad, with some Experiments and Observations upon the Nature and alleged Venomous Properties of their Secretion
Authors: Rainey George 
Published: April 2021

ABSTRACT
From time immemorial a venomous quality has been attributed to one or other of the secretions of the toad. Scarcely any one who has spent much time in the provinces of this, and other countries, has failed to hear of instances of supposed poisoning by this reptile: these accounts, however, have always been so vague and imperfectly attested, as to obtain credit only among the uninformed and superstitious classes of the people, so that by enlightened persons the belief in the venomous powers of the Toad has been regarded only as a vulgar prejudice. Such were the doubts and opinions entertained upon this subject as late as 1851, when they were said to be set at rest, and the poisonous nature of the cutaneous secretion of the toad demonstrated by two French philosophers, MM. Gratiolet and S. Cloez, who, by inoculating various animals with the secretion in question, produced, according to the account given of these experiments, most decided results, and, in some instances, almost immediate death.
Observations on the Circulation of the Sap in the Leaf Cells of Anacharis Alsinastrum
Authors: Wenham F. H. 
Published: April 2021

ABSTRACT
There is no known plant in which the sap-rotation has been discovered that displays the phenomena of the circulation more distinctly, or in such variety of detail, as the newly imported water-weed, Anacharis Alsinastrum. Having observed some peculiar features in this, which I have not discovered in the circulating sap of any other plant, I venture to announce them. I must, however, premise that I have not made a special study of this department of vegetable physiology, and may therefore be excused from drawing any conclusions, or for showing a defective acquaintance with technicalities ;—I have simply to relate what I have seen.
On the Cellulose (in Animals) Question
Authors: Virchow R. 
Published: April 2021

ABSTRACT
Since my former communications respecting the substance met with in the human body resembling vegetable cellulose, I have taken much pains to ascertain more precisely its nature. In now recurring to the subject, it is not that I have been altogether successful in the inquiry, but rather because I perceive that it is becoming more and more involved in confusion. There are some even who, whether from superficiality or for other reasons, appear to regard what I have said,—as I believe with sufficient distinctness—as unsaid, and have busied themselves in associating with the amyloid bodies described by me, bodies of all kinds, only morphologically analogous with them. The reaction of iodine and sulphuric acid having once been established, nothing can be described as a corpus amylaceum which does not exhibit this reaction. At most can such bodies be termed corpora amylacea spuria.
On the Action of a Concentrated Solution of Urea upon the Blood-Cells
Authors: Kölliker A. 
Published: April 2021

ABSTRACT
In the prosecution of a series of researches, respecting the influence of various reagents upon the spermatic filaments, I have almost always employed the blood-cells as a test of the degree of concentration of the fluids experimented with. I was thus led to observe, in the Frog, a remarkable change produced in the blood-cells by a concentrated solution of urea (30 per cent.). The blood-cells gradually acquired an irregular, jagged outline, and were rapidly transformed into the most beautiful stellate cells, usually having 3—6 tolerably long and somewhat clavate processes, so as to be brought to resemble very closely the irregularly-stellate pigment-cells of the lamina fusca of the sclerotic. This elegant form, however, was not long retained ; for the processes now began speedily to become melted down, sometimes disappearing by a gradual process of fusion commencing at the border of the cell, and occasionally in detaching larger or smaller droplets, which immediately became pale and disappeared. Thus, at last, the nuclear part of the cell only remained as a minute, round, dark-red, brilliant globule, which, ultimately, also lost its colour and disappeared up to the nucleus without leaving a trace.
Notice respecting the Occurrence of Lymph-Corpuscles in the commencements of the Lymphatic Vessels
Authors: Kölliker A. 
Published: April 2021

ABSTRACT
The recent researches of Virchow on the one hand, and of Brücke, Donders, and myself on the other., have shown that the lymphatic glands are the principal seat of origin of the cellæform elements of the chyle. The further question arises, as to whether lymph-cells are formed in other situations besides those organs, and particularly, whether the independent formation of such cells, in the commencement of the-lacteals, which has recently been almost universally assumed, be really deducible from well-ascertained facts. This question is of the greater interest, that the formation of lymph-cells in the commencement of lymphatics has hitherto been regarded as one of the most certain instances of the formation of cells around isolated nuclei contained in a fluid, whilst the more recent results of histological inquiries have tended more and more to limit the occurrence of a free cell-formation independent of pre-existing cells. Consideration of the foregoing facts, would certainly, at first sight, appear to render the question now in discussion superfluous, inasmuch as it has long been proved that the lacteal s of the small intestine, even at their commencement between the intestine and the mesenteric glands, contain lymph-corpuscles ; but here the possibility arises, that the cells may be derived from the Peyerian and solitary follicles, whose connexion with the lacteals is asserted by Brücke, and which on this account have been regarded as a kind of lymphatic glands. In this state of things, it is above all necessary to investigate the conditions under which, and the situations in which, the lymphatics contain cellæform elements previously to their reaching the lymphatic glands, and where not; an investigation which, when carried out sufficiently, is more difficult than it appears at first sight. Although I have had neither opportunity nor leisure of instituting detailed researches on this subject, still I am in a condition to communicate some facts, which may serve as an introduction to further inquiries.
On the Influence of Caustic Alkalies upon the Motions of the Spermatic Filaments
Authors: Kölliker A. 
Published: April 2021

ABSTRACT
Setting out with the well-known observation of Virchow (Virch. Archiv., vol. vi., p. 133, 1853; Quart. Journ. Mic. Sci., vol. ii., p. 108), with respect to the action of caustic potass and soda on the cilia, I have in the last winter investigated their action upon the spermatic filaments. To my agreeable surprise a perfect correspondence was exhibited between these two motile bodies, except that I noticed an influence from ammonia upon the spermatic filaments, which had not been observed by Virchow in the cilia. In order to observe the action of caustic alkalies upon the spermatic filaments, the best mode of proceeding is to allow them to become perfectly quiescent in a dilute solution of sugar or of albumen, and afterwards to introduce the caustic in small quantity beneath the covering glass. It will then be seen wherever the potass or soda reaches that the mass is again put into the most lively motion, fully as active as that of the perfectly-fresh spermatozoids; but after a short time ( —1—2 minutes) a total quiescence takes place, from which the spermatic filaments cannot in any way be again roused. This phenomenon is best witnessed on the application of a solution containing from 1 to 5 parts in 100 of caustic soda or potass. In stronger solutions it undoubtedly takes place, but in this case the movement is soon over, nor does it occur in all the filaments, many of which, and especially those which first come into contact with the stream, exhibit, instead of active vibratile and locomotive movements, only a few rotations on the axis, and then become quiescent in the extended posture. Concentrated solutions of caustic alkalies, containing from 10 to 50 in 100, also produce the phenomena of revivification in a mass of quiescent spermatic filaments, and in a well-marked manner, but in this case care is still more requisite than with more dilute solutions.
On the Restoration of the Motions of the Spermatozoids of the Mammalia
Authors: Moleschott MM. , Ricchetti J. C. 
Published: April 2021

ABSTRACT
The author’s researches were made on the spermatozoids of the Bull, taken in each experiment from the epididymis. These spermatozoids have a lynx-shaped head, the depression in which is small and situated towards the inferior third, and a very long tail, furnished with a minute appendicular nodosity, which is soluble in the alkalies, and is usually placed in the middle of the filament, though in some individuals it is situated nearer to the head.
Observations on aphanizomenon flos-aquæ, and a species of peridinea
Authors: Allman G. J. 
Published: April 2021

ABSTRACT
The substance of the following communication has already appeared in the Proceedings of the Royal Irish Academy ; but having made some additional observations, I have thought them of sufficient interest for publication in the Microscopical Journal. The first part of the paper consists of the results of some observations made on Aphanizomenon Flos-aquœ. This minute alga has appeared in great abundance in the large pond of the Zoological Gardens, Dublin. The best account we possess of the plant is in an excellent paper on the Nostochineæ, by Mr. Ralfs ; * but as the specimens from which Mr. Ralfs’s description was drawn up were not in a recent state, some important points of structure have necessarily escaped him.
On a Post-Tertiary Lacustrine Sand, containing Diatomaceous Exuviæ, from Glenshira, near Inverary
Authors: Gregory William 
Published: April 2021

ABSTRACT
This remarkable deposit was sent to me in February last by the Duke of Argyll, who had found it in the valley of Glen shira, the waters of which flow into Loch Fine, well known as a sea-loch, at its upper part. The sand occurs above a mile from the mouth of the valley, lying under a considerable depth of good alluvial soil. It is nearly black, with shining particles of mica, and very dense. It consists chiefly of the detritus of the surrounding mountains, formed of micaceous schist, and contains therefore much quartz and mica. There is also a considerable proportion of an iron ore, and of a dark matter of vegetable origin, and apparently somewhat of a peaty character. To the last-named ingredients the dark colour of the sand is due.
On the Structure of Noctiluca Miliaris
Authors: Huxley Thomas H. 
Published: April 2021

ABSTRACT
Among the many striking and beautiful appearances presented by the Ocean, there is none, perhaps, which has more attracted the attention both of the naturalist and of the casual observer, than the silvery, sparkling, phosphorescent light, which may often be seen on dark nights, illuminating the track of every boat and defining the contours of the waves as they break upon the shore.
Memoir on the Coloration of the China Sea
Authors: Dareste M. Camille 
Published: April 2021

ABSTRACT
We learn from the observations of M. Ehrenberg, and more recently from those of MM. E. Dupont and Montagne, that the waters of the Red Sea are, at certain epochs, coloured red by the development, in prodigious quantities, of microscopical Algæ belonging to a species described by the former of these observers under the name of Trichodesmium erythrœum.
On the Development of the Spermatozoids in Torrea Vitrea
Authors: Quatrefages M. A. de 
Published: April 2021

ABSTRACT
In a memoir on the organs of sense in the Annelids (Ann. d. Sc. Nat., Зe Serie, t. xiii), I designated, under the name of Torrea vitrea, a worm remarkable for the complex nature and the development of the eyes, and the extreme transparency of the tissues. Owing to this favourable circumstance, as well as to the unusual size of the spermatogenous masses, I was enabled at once to observe in it phenomena, of which I have spoken in a note annexed to the report of Milne Edwards on the results of his travels in Sicily (Ann. d. Sc. Nat., Зe Serie, t. iii.), and concerning which I shall now enter more into detail.
On the cystolites or Calcareous Concretions in the Urticaceæ and other Plants
Authors: Weddel H. A. 
Published: April 2021

ABSTRACT
About the year 1827, J. Meyen discovered in the leaves of Ficus elastica, and of several other species belonging to the same genus, certain pedunculate corpuscles, constituted, as he supposed, of gum or of some analogous substance; he ascertained that these corpuscles increased by the superposition of new layers, and that ultimately they became covered with notches and elevations composed of a calcareous, crystalline material, soluble with effervescence in acids (carbonate of lime).