bluuebunny/crossref_metadata_2025_split huggingface dataset:
HISTOLOGY AND CYTOCHEMISTRY OF HUMAN SKIN
Authors: Montagna William 
Published: May 2004

1. Various amounts of ß-glucuronidase activity may be found in all of the cutaneous appendages.
2. In the epidermis, the basal layer and the Malpighian layer contain a moderate amount of it, but a band of cells, including the stratum granulosum and the cells immediately above it, is rich in ß-glucuronidase.
3. The cells of the duct of eccrine sweat glands have moderately strong enzyme activity, but those in the secretory coil are strongly reactive; small and large reactive granules are crowded in the reactive cytoplasm.
4. The cells of the secretory coil of the apocrine glands contain more ß-glucuronidase than any other cutaneous appendage.
5. In the sebaceous glands, a very strong concentration of enzyme activity is found in the undifferentiated peripheral cells, a smaller amount of it is found in the differentiating cells.
6. In active hair follicles, the largest amount of ß-glucuronidase is found in the outer root sheath and in the bulb. In the outer sheath, the strongest concentration is found around the level of the keratogenous zone of the cortex. The dermal papilla is strongly reactive. In quiescent hair follicles, the outer root sheath has a moderate amount of enzyme concentration, but the dermal papilla is unreactive.
7. In the dermis, the fibroblasts in the papillary layer, the smooth muscle cells of the arrectores pilorum and the tunica media of arteries, and the fat cells all exhibit enzyme activity. Mast cells show a great concentration of ß-glucuronidase.
MUCOPOLYSACCHARIDES PRODUCED IN TISSUE CULTURE
Authors: Grossfeld Henry , Meyer Karl , Godman Gabriel , Linker Alfred 
Published: May 2004

1. A method of mass tissue culture has been devised by which, in a relatively short period of time, samples large enough for chemical isolation of mucopolysaccharides can be obtained.
2. Chemical isolation of acid mucopolysaccharides from mass cultures of human fetal skin, human fetal bone, bovine fetal skin, and rat subcutaneous tissue has been carried out. It has been found that the fibroblasts of each of these tissues produce in tissue culture more than one mucopolysaccharide, namely, hyaluronic acid, and a chondroitin sulfate.
3. The chondroitin sulfate produced by fibroblasts of the above tissues in tissue culture was not fully sulfated. The possible significance of this finding is discussed.
INTRACELLULAR LOCALIZATION OF ENZYMES IN SPLEEN
Authors: Eichel Herbert J. ,   With the Technical Assistance of Jeanne Hagan
Published: May 2004

1. The intracellular distribution of nitrogen, DPNH cytochrome c reductase, succinic dehydrogenase, and cytochrome c oxidase has been studied in fractions derived by differential centrifugation from rat and guinea pig spleen homogenates.
2. In the spleens of each species, the nuclear fraction accounted for 40 to 50 per cent of the total nitrogen content of the homogenate, and the mitochondrial, microsome, and supernatant fractions contained about 8, 12, and 30 per cent of the total nitrogen, respectively.
3. Per mg. of nitrogen, DPNH cytochrome c reductase was concentrated in the mitochondria and microsomes of both rat and guinea pig spleens. Seventy per cent of the total DPNH cytochrome c reductase activity was recovered in these two fractions. The reductase activity associated with the nuclear fraction was lowered markedly by isolating nuclei from rat spleens with the sucrose-CaCl2 layering technique. The lowered activity was accompanied by the recovery of about 90 per cent of the homogenate DNA in the isolated nuclei, indicating that little, if any, of the reductase is present in spleen cell nuclei.
4. Per mg. of nitrogen, succinic dehydrogenase was concentrated about 10-fold in the mitochondria of rat spleen, and 65 per cent of the total activity was recovered in this fraction.
5. Cytochrome c oxidase was concentrated, per mg. of nitrogen, in the mitochondria of both rat and guinea pig spleens. The activity associated with the nuclear fraction was greatly diminished when this fraction was isolated from rat spleens by the sucrose-CaCl2 layering technique. Only 50 to 70 per cent of the total cytochrome c oxidase activity of the original homogenates was recovered among the four fractions from both rat and guinea pig spleens, while the specific activities of reconstructed homogenates were only 55 to 75 per cent of those of the original whole homogenates. This was in contrast to the results with DPNH cytochrome c reductase and succinic dehydrogenase where the recovery of total enzyme activity approached 100 per cent, and the specific activities of reconstructed homogenates equalled those of the original homogenates. The recovery of cytochrome c oxidase was greatly improved when only the nuclei were separated from rat spleen homogenates.
6. Data were presented comparing the concentrations (ratio of activity per mg. of nitrogen of the fraction to activity per mg. of nitrogen of the homogenate) of DPNH cytochrome c reductase in mitochondria and microsomes derived from different organs of different animals.
7. Data were presented comparing the activities per mg. of nitrogen of DPNH cytochrome c reductase in homogenates from several organs of various animals.
MORPHOLOGY OF THE OMMATIDIA OF THE COMPOUND EYE OF LIMULUS
Authors: Miller William H. 
Published: May 2004

The sensory portion of the ommatidium of the compound eye of Limulus has been studied with the electron microscope. In axial longitudinal section the rhabdom appears to be made up of small polygons, and in transverse section the rhabdom appears as a banded structure of dark lines. Thus in three dimensions the rhabdom resembles a honeycomb composed of tubular units, the long axes of which lie in transverse planes and are oriented perpendicular to the retinula cell's contours. The tubular units, which are about 140 mµ in diameter in Limulus (70 mµ in diameter in the spider and Scutigera), are microvilli of the borders of the retinula cells. The walls of these microvilli are continuous with fine linear structures (membranes) in the cytoplasm of the retinula cells.
In transverse sections of the ommatidium oval bodies interpreted as mitochondria are observed in an annular zone at the tips of the rhabdom's rays. These mitochondria, which are 2 to 10 µ in diameter, are crowded with irregular closed outlines about 100 mµ in diameter.
Possible functions of components of the ommatidium are discussed.
THE NISSL SUBSTANCE OF LIVING AND FIXED SPINAL GANGLION CELLS
Authors: Deitch Arline D. , Moses Montrose J. 
Published: May 2004

Living chick spinal ganglion neurons grown for 19 to 25 days in vitro were photographed with a color-translating ultraviolet microscope (UV-91) at 265, 287, and 310 mµ. This instrument was unique in permitting rapid accumulation of ultraviolet information with minimal damage to the cell.
In the photographs taken at 265 mµ of the living neurons, discrete ultraviolet-absorbing cytoplasmic masses were observed which were found to be virtually unchanged in appearance after formalin fixation. These were identical with the Nissl bodies of the same cells seen after staining with basic dyes. The correlation of ultraviolet absorption, ribonuclease extraction, and staining experiments with acid and basic dyes confirmed the ribonucleoprotein nature of these Nissl bodies in the living and fixed cells.
No change in distribution or concentration of ultraviolet-absorbing substance was observed in the first 12 ultraviolet photographs of a neuron, and it is concluded that the cells had not been subjected to significant ultraviolet damage during the period of photography.
On the basis of these observations, as well as previous findings with phase contrast microscopy, it is concluded that Nissl bodies preexist in the living neuron as discrete aggregates containing high concentrations of nucleoprotein.
THE FINE STRUCTURE OF CAPILLARIES AND SMALL ARTERIES
Authors: Moore Dan H. , Ruska Helmut 
Published: May 2004

Details of capillary endothelia of the mammalian heart are described and compared with capillaries of other organs and tissues. Continuous invagination and pinching off of the plasma membrane to form small vesicles which move across the cytoplasm are suggested as constituting a means of active and selective transmission through capillary walls (12). This might be designated as cytopempsis (transmission by cell).
The fine structure of the different layers in the walls of small heart arteries is demonstrated. Endothelial protrusions extend through windows of the elestica interna to make direct contact with smooth muscle plasma membranes. The elastica interna appears to vary greatly in both thickness and density, and probably restricts filtration, diffusion, and osmosis to such an extent that windows and the transport mechanisms described (cytopempsis) are necessary for the functional integrity of the smooth muscle layer. The contractile material consists of very fine, poorly oriented filaments.
THE SOLUBILITY AND PROPERTIES OF A PURIFIED ICHTHYOCOL IN SALT SOLUTIONS OF NEUTRAL pH
Authors: Gallop Paul M. , Seifter Sam , Meilman Edward 
Published: May 2004

1. Purified citrate-extracted ichthyocol obtained from carp swim bladders has been further characterized with respect to its content of certain amino acids and carbohydrate substances.
2. The degree of solubilization or dispersion of ichthyocol by solutions of certain salts maintained in the range of neutral pH and at a temperature of 0–2°C. has been determined.
3. While a number of salts of monovalent cations had no significant solubilizing effects on ichthyocol, ammonium chloride in a concentration of 1 M did cause solution of the protein.
4. Sodium thiosulfate in a range of concentrations caused the solubilization of ichthyocol but was most effective in an intermediate concentration of 0.25 M.
5. Several salts of divalent cations, in particular the chlorides of calcium, magnesium, and barium, and magnesium thiosulfate in concentrations ranging from 0.3 to 1 M caused the immediate and complete solubilization of the ichthyocol.
6. Solutions of ichthyocol in calcium chloride, magnesium chloride, and sodium thiosulfate buffered or adjusted to pH 7.0, were studied with respect to intrinsic viscosity of the protein, optical rotation, ultracentrifugal sedimentation, and reconstitution into fibers. It was found in each case that the original characteristics of the collagen, as determined previously in acid solution, were maintained when the protein was dissolved in salt solutions of neutral pH. No evidence of denaturation or gelatinization could be found when ichthyocol was solubilized under the stated conditions.
7. Collagen in neutral solution with sodium thiosulfate, calcium chloride, or magnesium chloride was not attacked by trypsin as determined viscometrically at 20.0°C., but was rapidly degraded by a purified bacterial collagenase.
THE EFFECTS OF FLUORIDE FEEDING ON THE ORGANIC MATRIX OF BONES AND TEETH OF PIGS AS OBSERVED BY AUTORADIOGRAPHY AFTER IN VITRO UPTAKE OF CA45 AND S35
Authors: Bélanger L. F. , Visek W. J. , Lotz W. E. , Comar C. L. 
Published: May 2004

Demineralized sections of fluorinated bones and teeth have been studied by autoradiography following in vitro uptake of Ca45 or S35O4.
The portions of tissue which do not become mineralized (cartilage, prebone, predentine, and precementum) show an increased Ca45 uptake apparently related to an increase in chondroitin sulfate content in fluorosis.
The tissues from the fluoride-fed animals show an increase of in vitro uptake of sulfur in the tissues which become mineralized (bone, dentine, cementum).
HISTOCHEMICAL DEMONSTRATION OF THE SITES OF ACTIVITY OF DEHYDROGENASE SYSTEMS WITH THE ELECTRON MICROSCOPE
Authors: Barrnett Russell J. , Palade George E. 
Published: May 2004

In the present study a histochemical method demonstrating the activity of dehydrogenase systems was developed for electron microscopy, utilizing potassium tellurite as the hydrogen or electron acceptor. This reagent was used intravitally (intravenously, intraperitoneally, or intraluminally in hollow organs) or supravitally on small blocks of tissue for the demonstration of endogenous dehydrogenase activity. Blocks of tissue which had been frozen and thawed or which had been washed in 0.44 M sucrose to prevent endogenous activity, were used to demonstrate the activity of the succinic dehydrogenase system. In the latter case, the incubating medium contained tellurite, succinate, phosphate buffer, sucrose, and activators. The incubation was as performed either aerobically (with or without the addition of potassium cyanide) or anaerobically. The specificity and the enzymatic nature of the reactions were ascertained by appropriate control experiments.
Reduced tellurite, the end product of this histochemical reaction, could be visualized in thin sections of osmium tetroxide-fixed, methacrylate-embedded tissues as crystals or fine particulate deposits of high density, localized on, or in close relationship to mitochondrial membranes. The results of these experiments are demonstrated, utilizing heart muscle (rat) as the source of the enzyme systems.
ELECTRON MICROSCOPE STUDIES OF THE FORMATION OF NODES OF RANVIER IN MOUSE SCIATIC NERVES
Authors: Uzman Betty Geren , Nogueira-Graf Genevieve 
Published: May 2004

Observations with the electron microscope of longitudinal sections of the sciatic nerves of infant mice during the period of early myelin formation are described.
These observations are interpreted in relation to previous studies of transverse sections, and a general picture of the formation of an internodal length of the myelin sheath in three dimensions is formulated.
In general, an internodal length of myelin sheath is attained by the spiral wrapping of the infolded Schwann cell surface; the increase in length of the internode during maturation is at least partially explained by the increased length of axon covered by the overlapping of successive layers during the wrapping of the infolded Schwann cell surface; and the nodes of Ranvier refer to the structure complex at the junctions of adjacent non-syncytial Schwann cells. The fact that the mode of formation of myelin brings each of its layers into intimate contact with the axon surface at the nodes is emphasized because of the possible functional significance of this arrangement. The manner of origin of Schmidt-Lantermann clefts remains obscure.
Certain isolated observations provide evidence for the possibility that occasional internodes of myelin may form from several small segments of myelin within a single Schwann cell.
ELECTRON MICROSCOPY OF HELA CELLS AFTER THE INGESTION OF COLLOIDAL GOLD
Authors: Harford Carl G. , Hamlin Alice , Parker Esther 
Published: May 2004

Tissue cultures of HeLa cells were grown in media containing colloidal gold, and after various intervals, the cells were fixed, embedded, and sectioned for electron microscopy. Uncoated grids with small holes were used in many of the experiments.
Intracellular particles of gold were identified in areas surrounded by single membranes, in moderately dense granules, in globoid bodies, and in the cytoplasmic matrix. Gold particles were not found in typical mitochondria, Golgi complex, ergastoplasm (granular forms of endoplasmic reticulum), or nuclei.
The phenomenon of pinocytosis was considered to be the most likely means by which the gold particles were ingested, and the locations of gold particles appeared to have significance concerning theories that membranous organelles of the cytoplasm may be derived from the cell membrane.
AUTORADIOGRAPHIC DETERMINATION OF S35 IN TISSUES AFTER INJECTION OF METHIONINE-S35 AND SODIUM SULFATE-S35
Authors: Edwards Leon C. , Udupa K. N. 
Published: May 2004

The loss of "bound" S35 that occurs during various mounting procedures used in autoradiography was studied in healing surface wounds of rats treated with either methionine-S35 or Na2S35O4. Valid autoradiography of bound S35 in this tissue is not possible until 48 hours after radiosulfate and 24 hours after radiomethionine injection, when the S35 is almost entirely bound in large protein and polysaccharide molecules.
Autoradiograms of S35 given in both the organic and inorganic form reveal substantial over-all loss of the bound isotope from sections subjected to contact with solvents prior to autoradiography. A comparison of autoradiograms prepared by dry-mounting sections of frozen-dried tissue with autoradiograms of wet-mounted sections of the same tissue suggest that the loss is proportional to the extent of the contact with solvents. Evidence suggests that loss of the isotope occurs during contact of the ribbon or section itself with solutions after fixation and cutting and prior to radiation exposure. No appreciable loss of the bound isotope seems to occur during contact of the intact tissue specimen with a variety of fluid fixatives except for a marginal zone at the excision edges of the tissue. The potential hazard of displacement of the isotope during fixation, however, remains.
Technics which prevent loss of the isotope and fogging of the nuclear emulsion permit the use of thinner sections and emulsion films and the fine resolution of image rendered possible by the physical properties of S35.
ELECTRON MICROSCOPIC OBSERVATIONS OF AMOEBA PROTEUS IN GROWTH AND INANITION
Authors: Cohen Adolph I. 
Published: May 2004

Electron microscopic observations have been made on growing and dividing specimens of Amoeba proteus and also on starving animals. Structures presumably corresponding to the mitochondria, alpha particles, vacuoles, and Golgi material are described. A new entity, designated as a foamy particle, is noted.
Descriptions are given of the cytoplasmic and nuclear membranes. During division the inner, thick nuclear membrane component is seen to vanish and the outer membrane persist. Measurements suggest a gradual reappearance of the inner component with growth.
Starving animals show a loss of cytoplasmic granularity and an increase in the electron density of mitochondria, presumably due to lipide accumulation.
CHANGES IN "DROPLET" FRACTIONS FROM RAT KIDNEY CELLS AFTER INTRAPERITONEAL INJECTION OF EGG WHITE
Authors: Straus Werner 
Published: May 2004

1. Kidney homogenates from rats injected with egg white and from control rats were fractionated simultaneously into six fractions and the content of acid phosphatase, ribonuclease, desoxyribonuclease, cathepsin, and ß-glucuronidase in corresponding fractions from treated and untreated animals was compared. These observations were correlated with the amount of dark brown bottom sediments in fractions NDrI, DrII, and DrIII, and with the number of droplets in fraction NDrI.
2. It was found that after injection of egg white the amount of small droplets decreased as indicated by the decrease of the dark brown bottom layer in the sediment of fraction DrIII and by the concomitant decrease of hydrolytic enzymes in the same fraction, and that the number of large droplets increased as indicated by the increase of brown sediment in fraction NDrI and the increase in the number of droplets counted in a bacterial counting chamber in the same fraction. It was concluded that the treatment with egg white induced the transformation of small droplets into large droplets.
3. The decrease of hydrolytic enzymes in the fractions containing the small droplets was accompanied by a marked increase of these enzymes in the supernatant fluid. The enzyme content of fraction NDrI was not increased after treatment, although it contained greatly increased numbers of large droplets. Counting of the droplets in this fraction showed decreased enzymatic activity of the average large droplet after treatment with egg white. It was suggested that during the transformation of small into large droplets, a portion of the hydrolytic enzymes was released into the surrounding cytoplasm, and that this was partly responsible for the increased enzyme content of the supernatant fluid after fractionation of the kidney homogenate. In contrast to the four other hydrolytic enzymes, ß-glucuronidase was not increased in the supernatant fluid.
4. Eighteen hours after intraperitoneal injection of egg white, the specific enzymatic activities of kidney homogenates showed a 25 to 35 per cent increase for cathepsin, ribonuclease, and desoxyribonuclease, no change for acid phosphatase and ß-glucuronidase, and approximately a 7 per cent decrease for cytochrome oxidase. The increase of cathepsin, ribonuclease, and desoxyribonuclease in the total homogenate was interpreted as an indication of the formation of new enzymes, and it was suggested that this partly accounted for the increase of these enzymes in the supernatant fluid.
5. The activation of the enzymes by osmotic effects was investigated in vitro by incubation of droplet fractions in the presence of different concentrations of sucrose.
MICROSPECTROPHOTOMETRY OF CELL NUCLEI STAINED WITH THE FEULGEN REACTION
Authors: Naora Hiroto 
Published: May 2004

1. DNA contents of the individual parenchymal nuclei of rat livers during postnatal growth were estimated by microspectrophotometric apparatus, and different ploidy classes of nuclei were classified by their DNA contents. With the same material the total number of parenchymal nuclei in the liver was counted microscopically.
2. If the DNA content of nuclei encountered most frequently in several tissues represents the diploid class, the ploidy classes of the rat liver cell nuclei correspond to di-, tri-, tetra-, and octoploid, with the di- and tetraploid ones predominating considerably.
3. In suckling rats (below 25 gm. of body weight) the liver parenchyma is composed almost exclusively of cells with diploid nuclei, whereas in young rats (above 80 gm.), of tetraploid nuclei. In the growth stage between 25 and 80 gm., there is a remarkable replacement of the diploid nuclei by the tetraploid ones. However, in the liver of adult rats weighing more than 150 gm., any increase or decrease in the frequency of diploid and tetraploid nuclei is hardly observable. In such rats, the nuclear population of the liver parenchyma seems to reach a cell-ecological equilibrium which is considered to be a stable one.
4. It is shown that such nuclear populations and the total number of nuclei in a liver are controlled by the growth state, and not by the age.
5. The decrease in the total number of diploid nuclei and the increase in tetraploid nuclei in the growing livers of rats weighing from 40 up to 130 gm. can both be explained by the hypothesis that the tetraploid nuclei originate from the interphase diploid nuclei without involving mitosis. This hypothesis implies that mitosis is confined to the reproduction of diploid cells alone.
6. It is suggested that, in general, the synthesis of DNA does not necessarily result in the formation of visible mitotic chromosomes.
7. Mitotic time and generation time of diploid nuclei and the percentage of the tetraploidization from diploid nuclei are calculated and discussed.