Chromatin Substance Research Articles

Cutting the nerve and its consequences
 1. Biedl. Ueber das histologische Verhalten der peri pheren Nerven und ihrer Centren nach der Durchschneidung. Wien. Klin. Wochenschrift, 1897 № 17.
 2. Marinesco. On the phenomena of reporation in the nerve centers after the section of peripheral nerves. Press medic .; 1898 № 82.
 3. A. Van-Gehuchten. The repair phenomena in the nerve

The question, about which will be discussed below, with all the mania, which he repeatedly turned out to be observers, is still far from complete solution. New and new research arouses new interpretations. Biedl (1), dealing with this issue using the Nissl method, obtained such data. Along the nerve cut in the ganglion cells, which represent the beginning of its fibers, after 3 days, one can detect degenerative changes in the cellular structure in the form of dilution and fine-grained decay of the chromatin substance in the spinal nodes.

Switch of fractal properties of DNA in chicken erythrocytes nuclei by mechanical stress.

The small-angle neutron scattering (SANS) on the chicken erythrocyte nuclei demonstrates the bifractal nature of the chromatin structural organization. Use of the contrast variation (D_{2}O-H_{2}O) in SANS measurements reveals the differences in the DNA and protein arrangements inside the chromatin substance. It is the DNA that serves as a framework that constitutes the bifractal behavior showing the mass fractal properties with D=2.22 at a smaller scale and the logarithmic fractal behavior with D≈3 at a larger scale. The protein spatial organization shows the mass fractal properties with D≈2.34 throughout the whole nucleus. The borderline between two fractal levels can be significantly shifted toward smaller scales by centrifugation of the nuclei disposed on the dry substrate, since nuclei suffer from mechanical stress transforming them to a disklike shape. The height of this disk measured by atomic force microscopy (AFM) coincides closely with the fractal borderline, thus characterizing two types of the chromatin with the soft (at larger scale) and rigid (at smaller scale) properties. The combined SANS and AFM measurements demonstrate the stress induced switch of the DNA fractal properties from the rigid, but loosely packed, mass fractal to the soft, but densely packed, logarithmic fractal.

The effects of rapamycin on the proliferation and apoptosis of human retinal pigment epithelium cells in vitro

Background Rapamycin(RAPA)is a specific inhibitor of the mammalian target of rapamycin (mTOR).Researches showed that RAPA inhibits the proliferation of lens epithelium cells(LECs)and tumor cells and induces apoptosis of tumor cells.To investigate whether rapamycin has the inhibitory effect on retinal pigment epithelium(RPE)cells is very important for the prevention and management of proliferative vitreoretinopathy (PVR).Objective This study was to investigate the effects of RAPA on the proliferation and apoptosis of human RPE cells in vitro.Methods Human RPE cells(D407 strain)were cultured and passaged and then divided into regular culture group(blank control group),DMSO control group(0.1‰ DMSO +regular culture),and different concentrations RAPA-treatment groups(5,10,20,40,80,160,320 nmol/L).The proliferation(A490)of human RPE cells was detected using MTT,and the inhibitory rates of RAPA on the proliferation of RPE cells were calculated and compared among different groups at 12,24 and 48 hours.The apoptosis rates of the cells were analyzed among various groups by Hoechst staining after 12,24,48 hours.Results The inhibitory rates of RAPA on RPE cells were significantly different among various groups(F=484.451,P＜0.01)and evidently elevated in 20-320 nmol/L RAPA groups compared with DMSO control group(P ＜ 0.01).The inhibition of RAPA on the cells was considerably enhanced as the lapse of time(F=232.262,P＜0.01)with more dominant effects in 24 and 48 hours compared to 12 hours after addition of RAPA(P＜0.05-0.01).Compared with blank control group and DMSO control group,the apoptotic rates of the cells were evidently increased in 12,24,48 hours in 10 nmol/L RAPA group(all P＜0.05),and higher cellular apoptotic rates were found in 20-320 nmol/L RAPA groups(all P＜0.01).The alteration of cellular apoptotic rate showed a gradually incremental trend as the acting time of RAPA(F =625.584,P＜0.01).Karyorrhexis and mass-like density staining and chromatin substance were seen in RPE cells under the fluorescence microscope in ≥ 10 nmoL/L RAPA groups.Conclusions RAPA suppresses the proliferation and induces the apoptosis of human RPE cells in concentration-and time-dependent manner in vitro. Key words: Rapamycin ; Retinal pigment epithelial cells; Proliferative vitreoretinopathy ; Apoptosis

Spastic pseudosclerosis (cortico-pallido-spinal degeneration), by Charles Davison (New York), Brain 1932: 55; 247-264 and Severe dementia associated with bilateral symmetrical degeneration of the thalamus, by K. Stern (From the National Hospital, Queen Square, London), Brain 1939: 62; 157-171.

Dr Davison has recently seen two cases in adults—running a rapid course characterized by mental symptoms, pyramidal and extrapyramidal signs, and muscle atrophy—that ‘do not conform to any disorder recognized hitherto’. J.R. has a 3-year history of weakness in the left leg that does not change until 1 year before presentation, when his speech deteriorates and the upper limbs become involved. On admission he is bedridden, drooling, with spasmodic laughter and crying and severe dysarthria. Examination shows rigidity, dystonia in a ‘striatal attitude’, increased tendon reflexes and bilateral Babinski signs, as well as muscle atrophy with generalized ‘fibrillary twitchings’. He is dishevelled, with impaired memory and responds only to simple commands. Bulbar function deteriorates thereafter and within a few months he is dead from aspiration pneumonia. At autopsy, the brain and spinal cord are obviously atrophic. Microscopic examination shows proliferated and occluded small vessels, some with calcification, in the cortex and basal ganglia. However, the most conspicuous histological findings are destruction of ganglion cells in the third, fifth and sixth layers of the cortex, with vacuolation; loss of the giant pyramidal Betz cells; ‘enormous’ proliferation of microglia and protoplasmic astrocytes in white and grey matter; marked neuronal loss and demyelination of surviving axons, in the rostral and middle portions of the globus pallidus, corpus Luysii and paraventricular nuclei; and degeneration both of the pyramidal tracts and anterior horn cells (Fig. 1). Taken together, these pathologies are not those of a primary inflammatory or vascular disorder; nor are the plaques and other pathological hallmarks of Alzheimer's disease present; and in the spinal cord, the appearances are typical of amyotrophic lateral sclerosis. Figure 1 Case 1 (J.R.): two ganglion cells from the globus pallidus; one showing satellitosis and the other poor chromatin substance. Cresyl violet stain, ×700 (reproduced from Davison, 1932). E.G. dies the …

Biological responses in low-dose range

Out of the wealth of biological responses a few have been selected for discussion, namely, those which point to sensitive cellular reactions with possible consequences, or, those which might be promising in occupational medicine as indicators of a possible burden to persons, radiological or nuclear workers, and which might be used in the future as a routine laboratory technique in assessment of individual sensitivities. Accordingly, alterations of the two critical targets, the cell membrane and the chromatin substance with the end-point of lymphocyte micronucleus formation are presented. Effect and risk-modifying factors like adaptive response, intercellular communication, the antioxidant status, tumour necrosis factor alpha cytokine influences are mentioned and discussed. In the biological responses at low doses, the decisive roles of biological and health conditions are emphasised.

The Relationship Between Cytomixis, Chromosome Mutation and Karyotype Evolution in Lily

SUMMARYSpontaneous intercellular chromatin migration (cytomixis) occurred in PMCs of Lilium davidii at synizesis stage of meiosis, and less frequent in later stages. This process has led to the formation of up to 9.44% to 13.6% of PMCs, microspores, and generative cells with chromosome numbers deviating from the normal haploid chromosome complement, n= 12. The abnormal cells contained chromosome numbers ranging from 8 to 15. The patterns of intercellular chromatin migration may be divided into two types: (a) The chromatin substance may migrate from one nucleus into one adjacent cell, and (b) from one nucleus into two or more cells or from two or more nuclei into one cell. According to the chi-square test, it has been shown that the differences between the patterns of intercellular chromatin migration and the variation of chromosome number in the PMCs, microspores or generative cells are not significant. Because of cytomixis, about 10% cells proved to be aneuploids, with hypoploids predominating. It shows that the descending basic number is greater than that of the ascending. This is in accordance with the principle of the trend in karyotype evolution—the progressive reduction of the basic chromosome number. If these newly established karyotypes are survived by rigorous selection, they may be expected to accomplish fertilization and thus give rise to aneuploid progeny in a population. It is these selected chromosome mutations which may be of considerable evolutionary significance.

Effect of cannabis (hashish) on mitosis of Allium cepa L. root tips. II. Dissolution of the chromatic material in the interphase nuclei of Allium cepa cells after long exposure times with cannabis (hashish).

Cannabis causes the dissolution of the chromatin substances of Allium cepa cells. We were able, in this present investigation, to pursue the process of chromatin dissolution by applying cannabis for long exposure periods. Exposure to cannabis for a long treatment time dissolved the chromatin material within the nuclei, leaving only the nuclear membrane bounding an empty area. It seems that the process of dissolution of the chromatin substance is irreversible.Micronuclei can be induced in long exposure time with cannabis. Micronuclei can be considered as a test of chromosomal damage. But in short exposure treatment cannabis has not the ability to affect the chromosome structure.As far as the nuclear membrane is concerned, there does not seem to be any difference between normal and treated cells. The only unusual feature which is frequently found is deep invaginations of the membrane into the nucleoplasm. These infoldings are responsible for the irregular outline of many nuclei observed in root tips treated with cannabis.

Cytological Changes in the Cerebrospinal Fluid following Intrathecal Methotrexate Treatment

In two patients of meningeal leukemia, the changes of CSF cell pattern following intrathecal methotrexate (MTX) therapy were serially examined by light microscopy. The first case reacted well to cytostatic treatment. 72 h after the first intrathecal MTX injection, an alteration of the chromatin structure could be observed in the nucleus of CSF blast cells; there was a condensation of the heterochromatin, a fragmentation of the nucleus and a dispersal of the chromatin into the cytoplasm. With the therapy-resistant patient No. 2, 72 h after intrathecally administered MTX, the rate of blast cells did not change, and nuclear damage has manifested itself by a rarefaction and disappearance of the chromatin substance. There is strong evidence that these nuclear changes are due to intrathecal MTX treatment. Such changes, however, may not be considered to be specific.

Fine structure of neuroblastoma--a case report.

Ultrastructural observation was carried out on neuroblastoma cells in a 4‐year‐old girl. The nuclei of these neoplastic cells were irregular with occasional cytoplasmic invaginations, and proportionally large with diffusely dispersed chromatin substance. Rare mitotic figures were also present. The cell‐to‐cell interfaces were relatively simple with only finely wavy membranes but without interdigitations. A few desmosomes were, however, apparent. The cytoplasmic pseudopodes were frequently observed in a limited area of the cell surface and nearly free of organelles. The main findings of the intracytoplasmic organelles consisted of some mitochondrial changes, poor development of Golgi bodies, occasional formation of focal cytoplasmic degradation, and intracytoplasmic Abrillar aggregates. Numerous large round to oval dense bodies encircled by a double membrane were highly suggestive of lipid bodies. The central area of rosette‐like cell aggregates was noted to be composed of cytoplasmic processes of neoplastic cells.

The Fine Structure of Hyphae of Helminthosporium oryzae Ito et Kurib. and Pyricularia oryzae Cavara

Comparisons were made on the fine structure of hyphae of Helminthosporium oryzae Ito et Kurib. and Pyricularia oryzae Cavara by electron microscopy.The fine structure of the cell wall, number of nuclei, mitochondrial volume and the arrangement of cristae were found to be highly differentiated in both hyphae of H. oryzae and P. oryzae.The results obtained are as follows:(1) Hyphae of Helminthosporium oryzaeThe cell wall of hyphae was consisted of three layers (outer, middle and inner layers), as seen in conidia, and the hyphae of this fungus were recognized to be multinucleate. The cytoplasm contained well-defined mitochondria (0.76×0.51μ), endoplasmic reticula (ER), vacuoles and unidentified spherical bodies.(2) Hyphae of Pyricularia oryzaeTwo layers (outer and inner layers) were detectable in the cell wall structures of hyphae. Each cell seemed to possess a single nucleus surrounded by a double membrane with nuclear pores. The nucleus contained a comparatively dense body identified as chromatin substance. The cytoplasm also contained coiled membrane fragments, twisted-ER, variable surfaced ER, large mitochondria (1.28×0.62μ) and lipid granules (1.50μ in diameter).

The observation on the electron-microscopic pictures of cancer cells under the actions of chemotherapeutic agents.

1) In the present paper were studied changes in fine structure of Yoshida's ascites sarcoma cells as well as Ehrlich's ascites hepatoma cells by several anticancer remedies: Citral, Nitromin, Sarcomycin, Carcinophyllin, Chromomycin, Azan, PCMB, and Colchicine. 2) The localities of the points of attack upon tumor cells by these remedies are quite different. Nitromin causes changes unanimously of the fine structures of tumor cells. Azan and Sarcomycin come next to Nitromin in the order of effectiveness. Carcinophyllin and Chromomycin act moderately and they affect structures of cytoplasm rather than nucleus. Citral when acted mildly causes changes in nuclear membrane, nucleolus, chromatin substance in the nucleus. Change of endoplasmic reticulum is much more remarkable than that of mitochondria. PCMB damages mitochondria almost exclusively. 3) A potential co-operation of these two kinds of remedies, aldehydes and PCMB, is discussed.

X-ray Therapy of Carcinoma of the Lip and Skin

THE Brooklyn Cancer Institute, a unit in the Department of Hospitals of New York City, cares for patients received from other hospitals or referred by its own staff of physicians. The hospital beds at our Institute are limited to the care of those cancer patients requiring urgent surgical or radium therapy. Chronic cases are sent to the Welfare Island Custodial Cancer Hospital. Due to the present necessity for economy and because our bed service is limited, we have found x-ray therapy the most efficient method of treating these ambulatory cases. In many instances such treatment is given with radium emanation. Generally speaking, the radiosensitivity of any cell, including the tumor cell, ies in direct relationship to its nuclear or chromatin substance. The usual basal-cell growth is rich in chromatin substance, and, being on the surface, an exact dose can be given without fear of injury to overlying structures, while if a non-penetrating or long wave length x-ray beam is used, damage to deep structures may be avoided. The relative penetration of the x-ray into tissues has been carefully worked out by physicists and roentgenologists; for instance, the estimation of the half value layer in aluminium by William H. Meyer (1) and the penetration of x-ray beams of different voltages as measured in a water phantom by J. L. Weatherwax (2). Measurement of the biologic reaction in absolute roentgens (3) showed a variation with unaltered rays of longer wave length from 400 r, increasing with harder filtered rays to 700 r, as marking a threshold erythema, without backscattering. This has led to a most accurate estimation of dosage to the surface plus a good estimation of the depth in tissues. In spite of these accurate physical and biologic comparisons, it has been demonstrated definitely that much more than one surface erythema dose is necessary to produce a normal erythema to a lesion 2 cm. or less in diameter. This increased tolerance is carried up the scale in larger doses which would normally give vesiculation and total destruction, a knowledge of which has been taken advantage of by F. Liberson (4), who treated deeper lesions with increased doses of x-radiation without injury to the overlying skin. J. M. Martin (5) compared the results following surgery and his own results in radiation in lip and mouth cases, reporting a large percentage of five-year cures. B. P. Widmann (6) demonstrated how the underlying structures will tolerate very large doses to the surface, as high as 35 skin erythemas in a single case. This irradiation was delivered in divided doses, being given over relatively large areas. The present report covers a group of cases composed of all types of epitheliomas of the skin and lip.

Microincineration of Degenerating Anterior Horn Cells in Experimental Poliomyelitis.

The literature concerned with poliomyelitis seems to be largely composed of results of studies on the more general and gross pathological aspects of the disease. Another line of investigation has been opened up by Marinesco, Policard and Cowdry which begins with the cell rather than the symptom. As yet, no such approach has been made toward the understanding- of poliomyelitis. The present paper deals with but a single phase of the cytopathology of the disease—the changes in inorganic constitution as determined by the microincineration method. The material was obtained from autopsies of 43 monkeys (Maeacus rhesus) experimentally infected with poliomyelitis by the intracerebral and intranasal routes. The tissues were fixed in absolute alcohol formalin and prepared for incineration according to the method described by Scott. Alternate serial sections were incinerated or were stained with hematoxylin and eosin in such a manner that colored and ashed preparations of the same cell were available for comparison. For controls, similarly prepared material from 10 normal monkeys or monkeys dying of diseases other than poliomyelitis was used. The normal anterior horn cell incinerated under optimum conditions leaves a characteristic and uniform ash. The cytoplasm is represented by a very finely divided, mist-like, bluish or whitish ash. Against this filmy background spots of somewhat denser whitish, powdery material may usually be seen, evidently representing the Nissl bodies. The nucleus appears as a hole in the cell, set here and there with refractile granules, sometimes yellowish, but more often white, which may be identified as the chromatin substance. The mineral residue of the nucleolus is seen as a flat white, finely granular material of varying intensity. In the spinal cord of a monkey inoculated with poliomyelitis virus, several forms of degenerating cells may be seen. Three typical pictures will be described here: 1. During the early stages of degeneration the cell becomes somewhat swollen, the Nissl bodies are lost and the cytoplasm tends to take a lighter stain. The nucleus is often enlarged and may occupy an excentric position in the cell body.

DIE BILDUNG DER ERYTHROCYTEN IM KERNE DER PLASMOCYTEN; DER HÄMOGLOBINSCHWUND IM BLUTKREISLAUFE MIT DER PIGMENTMETAMORPHOSE UND OHNE DERSELBEN UND DIE BESONDERE ELIMINIERUNGSART DER CHROMATINSUBSTANZ AUS DER ZELLE IM BLUTE DES BATRACHOSEPS ATTENUATUS ESCH.

AbstractIn the blood of Batrachoseps one part of the erythrocytes is formed inside the nucleus of plasmocytes as a result of the metamorphosis of chromatin substance. When erythrocytes are completely formed, they separate themselves from the plasmocytes.Disappearance of the hemoglobin of erythrocytes with pigment metamorphosis is visible in the drawings.When the disappearance of hemoglobin with pigment metamorphosis takes place, the color of the hemoglobin cytoplasm frequently becomes very pale. The hemoglobin cytoplasm may vanish also without pigment metamorphosis in such a way that the whole cell (nucleus and cytoplasm) swells, and the cytoplasm becomes paler, and finally only a pale shadow remains which is rather difficult to distinguish. The author has noticed in the blood of Batrachoseps, besides extrusion of small nuclei from the erythrocytes, also a particular way in which chromatin substance is eliminated from the cell. While the cell and the nucleus become pear‐shaped, the nucleus moves toward the periphery, touching the surface of the cell with its funnel‐shaped narrow side. From this narrow side the chromatin substance flows out in the form of a band stained red, according to Romanowsky.

An hydrodynamic explanation of mitotic figures

The distinctly polar arrangement of the chromatin substance about the astral centers in dividing cells, combined with the pronounced curvature of the astral rays and of the spindle fibers, have demanded the assumption of some polar force as universally operative. On such an assumption it is of course necessary to assume further that astral centers represent either opposite or like poles. On the alternative of opposite poles, we should expect, with any force so far proposed, a configuration of astral rays simulating that of iron filings between opposite magnetic poles, coupled with a mutual attraction of the astral centers. On the other alternative, we should similarly expect a configuration of astral rays and spindle fibers simulating that of iron filings between like magnetic poles, coupled with a mutual repulsion of the astral centers. Actually, we have neither of these conditions, but instead, a configuratian like that of iron filings between opposite magnetic poles and at the same time an apparent repulsion between the astral centers or the centrosomes. This is not the case with the forces of attraction or repulsion existing between bodies oscillating or pulsating in a fluid medium. More specifically, if two spheres are pulsating synchronously and in opposite phase, or oscillating synchronously and in the same phase, they will repel one another, but at the same time the field between them will simulate the configuration of iron filings between opposite magnetic poles. If then we assume that the centrosomes are pulsating in opposite phase, or better, oscillating in the same phase, we will obtain the desired repulsion and at the same time have a configuration like that actually observed.