scholarly journals THE INDUCTION OF MELANIZATION IN GOLDFISH SCALES WITH ACTH, IN VITRO

1963 ◽  
Vol 18 (1) ◽  
pp. 181-194 ◽  
Author(s):  
Alden V. Loud ◽  
Yutaka Mishima
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Silver Nitrate ◽  
Light And Electron Microscopy ◽  
Subcellular Structure ◽  
Acth Stimulation ◽  
Cytoplasmic Bodies ◽  
Silver Nitrate Staining ◽  
Stimulation Of

The induction of melanization in xanthic goldfish scales with ACTH in vitro has been studied by light and electron microscopy utilizing ammoniated silver nitrate staining of premelanin and melanin. The melanized cells (melanophores and melanocytes) and the yellow pigmented cells (lipophores and the newly described lipocytes) were found to possess many similarities at the levels of cellular and subcellular structure. The latter cells contain characteristic cytoplasmic bodies which react positively to the premelanin stain. Changes accompanying ACTH stimulation of goldfish scales in tissue culture suggest that these bodies in the lipocytes and lipophores can become melanized. Electron micrographs illustrate the intermediate staining of newly formed melanin granules in an induced melanocyte and the appearance of a transitional melanolipophore. It is postulated that ACTH can promote the association of the enzyme tyrosinase with the preformed structure of unmelanized granules.

Symptomatic Rathke's cleft cyst

1977 ◽  
Vol 47 (3) ◽  
pp. 451-458 ◽  
Author(s):  
Jun Yoshida ◽  
Tatsuya Kobayashi ◽  
Naoki Kageyama ◽  
Masaki Kanzaki
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Rare Case ◽  
Light And Electron Microscopy ◽  
Rathke’S Cleft Cyst ◽  
Rathke's Cleft Cyst ◽  
Content Type ◽  
Rathke's Cleft ◽  
Fine Print

✓ A rare case is reported in which a symptomatic Rathke's cleft cyst was studied by light and electron microscopy and tissue culture. The findings are compared with those of a craniopharyngioma studied in the same way. The patient was a 26-year-old woman presenting with headache, chiasmatic syndrome, and hypopituitarism. A cyst containing a mural nodule was partially removed and an Ommaya reservoir placed in the operative site for further treatment. The cyst wall was composed of connective tissue and three kinds of epithelial cells: non-ciliated squamous, ciliated columnar, and mucous-secreting cells. The morphology of these cells in vitro was similar to prickle cells seen in craniopharyngioma and the epidermis. It is concluded that both Rathke's left cyst and craniopharyngioma originate in remnants of Rathke's pouch, but at times may show some histological differences.

Ultrastructure of two neoplasms in culture compared with original biopsies

1984 ◽  
Vol 42 ◽  
pp. 50-51
Author(s):  
Joseph M. Harb ◽  
James T. Casper ◽  
Vlcki Piaskowski
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Biopsy Specimen ◽  
Cultured Cells ◽  
Light And Electron Microscopy ◽  
Human Tumor ◽  
Soft Agar ◽  
Human Tumor Cells ◽  
Morphological Distinction ◽  
Tumor Types

The application of tissue culture and the newer methodologies of direct cloning and colony formation of human tumor cells in soft agar hold promise as valuable modalities for a variety of diagnostic studies, which include morphological distinction between tumor types by electron microscopy (EM). We present here two cases in which cells in culture expressed distinct morphological features not apparent in the original biopsy specimen. Evaluation of the original biopsies by light and electron microscopy indicated both neoplasms to be undifferentiated sarcomas. Colonies of cells propagated in soft agar displayed features of rhabdomyoblasts in one case, and cultured cells of the second biopsy expressed features of Ewing's sarcoma.

Development of an in vitro Model for the Study of the Response of Equine Tendon Fibroblasts to Injury and Medication

1997 ◽  
Vol 10 (01) ◽  
pp. 6-11 ◽  
Author(s):  
R. F. Rosenbusch ◽  
L. C. Booth ◽  
L. A. Dahlgren
Keyword(s):  
Electron Microscopy ◽  
Extracellular Matrix ◽  
Light Microscopy ◽  
Light And Electron Microscopy ◽  
Tendon Healing ◽  
Matrix Proteins ◽  
Isolated Cells ◽  
Superficial Digital Flexor Tendon ◽  
Vitro Model

SummaryEquine tendon fibroblasts were isolated from explants of superficial digital flexor tendon, subcultured and maintained in monolayers. The cells were characterized by light microscopy, electron microscopy and radiolabel studies for proteoglycan production. Two predominant cell morphologies were identified. The cells dedifferentiated toward a more spindle shape with repeated subcultures. Equine tendon fibroblasts were successfully cryopreserved and subsequently subcultured. The ability to produce proteoglycan was preserved.The isolated cells were identified as fibroblasts, based on their characteristic shape by light microscopy and ultrastructure and the active production of extracellular matrix proteins. Abundant rough endoplasmic reticulum and the production of extracellular matrix products demonstrated active protein production and export. Proteoglycans were measurable via liquid scintillation counting in both the cell-associated fraction and free in the supernatant. This model is currently being utilized to study the effects of polysulfated glycosaminoglycan on tendon healing. Future uses include studying the effects of other pharmaceuticals, such as hyaluronic acid, on tendon healing.A model was developed for in vitro investigations into tendon healing. Fibroblasts were isolated from equine superficial digital flexor tendons and maintained in monolayer culture. The tenocytes were characterized via light and electron microscopy. Proteoglycan production was measured, using radio-label techniques. The fibroblasts were cryopreserved and subsequently subcultured. The cells maintained their capacity for proteoglycan production, following repeated subculturing and cryopreservation.

A Method of Maintaining Parenchymal Cells from Adult Rat Liver In Vitro

1972 ◽  
Vol 11 (1) ◽  
pp. 249-260
Author(s):  
J. ALWEN ◽  
JENNIFER J. GALLHAI-ATCHARD
Keyword(s):  
Electron Microscopy ◽  
Endothelial Cells ◽  
Protein Synthesis ◽  
Light And Electron Microscopy ◽  
Rat Hepatocytes ◽  
Adult Rat ◽  
Adult Rat Hepatocytes ◽  
Rna And Protein Synthesis ◽  
Parenchymal Cells

A method for preparing suspensions of adult rat hepatocytes suitable for maintenance in vitro is described. Cultures were established from the cell suspensions by the squash technique. Cells were examined by light and electron microscopy; histochemically for glycogen, bile, lipid and glucose-6-phosphatase; and by autoradiography for DNA, RNA and protein synthesis. Hepatocytes could be maintained in vitro for at least 3 days and began to aggregate after 1 day. Uridine and leucine were incorporated, but not thymidine. Cultures consisted mainly of hepatocytes, though reticulo-endothelial cells were sometimes present.

Cytasters induced within unfertilized sea-urchin eggs

1983 ◽  
Vol 61 (1) ◽  
pp. 175-189
Author(s):  
R. Kuriyama ◽  
G.G. Borisy
Keyword(s):  
Electron Microscopy ◽  
Sea Urchin ◽  
Sea Water ◽  
Light And Electron Microscopy ◽  
Sea Urchin Eggs ◽  
Microtubule Organizing Centres ◽  
Treatment Step

Conditions that induce the formation of asters in unfertilized sea-urchin eggs have been investigated. Monasters were formed by treatment of eggs with acidic or basic sea-water, or procaine- or thymol-containing sea-water. A second treatment step, incubation with D2O-containing, ethanol-containing or hypertonic sea-water induced multiple cytasters. The number and size of cytasters varied according to the concentration of agents and duration of the first and second treatments, and also upon the species of eggs and the season in which the eggs were obtained. Generally, a longer second treatment or a higher concentration of the second medium resulted in a higher number of cytasters per egg. Asters were isolated and then examined by light and electron microscopy. Isolated monasters apparently lacked centrioles, whereas cytasters obtained from eggs undergoing the two-step treatment contained one or more centrioles. Up to eight centrioles were seen in a single aster; the centrioles appeared to have been produced during the second incubation. Centrospheres prepared from isolated asters retained the capacity to nucleate the formation of microtubules in vitro as assayed by light and electron microscopy. Many microtubules radiated from the centre of isolated asters, whether they contained centrioles or not. This observation is consistent with many other reports that microtubule-organizing centres need not contain centrioles.

scholarly journals ELECTRON MICROSCOPY OF PLASMA-CELL TUMORS OF THE MOUSE

1961 ◽  
Vol 9 (2) ◽  
pp. 369-381 ◽  
Author(s):  
D. F. Parsons ◽  
M. A. Bender ◽  
E. B. Darden ◽  
Guthrie T. Pratt ◽  
D. L. Lindsley
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Complex Structure ◽  
Granular Body ◽  
Virus Particles ◽  
Culture Cells ◽  
Large Numbers ◽  
Tumor Agent

The X5563 tumor has been grown in tissue culture. Cells similar to those of the original tumor migrated from the explant and attached to the glass walls of the culture vessels. Electron microscopy showed that large numbers of particles, similar in morphology to virus particles, were associated with these cells after 7 days of culture. The two principal types of particles found in the tumor in vivo appear to be present in vitro. Many more of these particles, however, were larger and showed a more complex structure. Whereas the particles were mainly localized inside endoplasmic reticulum or the Golgi zone in the tumors in vivo, in the tissue culture the majority of the particles were associated with the plasma membrane and were found outside of the cells. The relation of the particles to the granular body is discussed as well as a possible relation to the mammary tumor agent.

In vitro study of chorionic and ectoplacental trophoblast differentiation in the mouse

Development ◽  
1975 ◽  
Vol 34 (3) ◽  
pp. 633-644
Author(s):  
Danièle Hernandez-Verdun ◽  
Chantal Legrand
Keyword(s):  
Electron Microscopy ◽  
Morphological Study ◽  
Light And Electron Microscopy ◽  
In Vitro Study ◽  
Capillary Network ◽  
Vitro Study ◽  
Trophoblast Cells ◽  
Trophoblast Differentiation ◽  
Somite Stage

Mouse chorioallantoic pre-placental structures alone or in association with the embryo were explanted during the 9th day of gestation (7-somite stage) and cultured in a static medium for 24 to 48 h. From the subsequent morphological study of trophoblast differentiation, using both light and electron microscopy, we draw the following conclusions. 1. The allantoic mesoderm cells migrate inside the trophoblastic population but they do not differentiate a capillary network and trophoblast cells phagocytose the existing foetal erythrocytes. 2. In the absence of allantoic mesoderm, chorionic trophoblast cells remain undifferentiated. 3. The development of the chorionic trophoblast is modified in that chorionic trophoblast cells fail to establish close junctions with ectoplacental trophoblast, and some chorionic cells initiate the formation of multinucleated syncytia. The genesis of these syncytia is discussed.

scholarly journals Virus-Like Particles and Cytopathic Activity in Urine of Patients with Leukemia

Blood ◽  
1966 ◽  
Vol 28 (3) ◽  
pp. 465-478 ◽  
Author(s):  
RICHARD P. AMES ◽  
JOSEPH T. SOBOTA ◽  
REGINALD L. REAGAN ◽  
MYRON KARON
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Acute Leukemia ◽  
Vitro Assay ◽  
Chronic Granulocytic Leukemia ◽  
Virus Like Particles ◽  
Cytopathic Effects ◽  
Culture Activity ◽  
Granulocytic Leukemia

Abstract Urine pellet material of patients with leukemia was examined by electron microscopy in an effort to find more convenient sources of virus material for tissue culture and animal infectivity studies. Thirty urine specimens from 16 patients with acute leukemia, 2 patients with chronic granulocytic leukemia and 1 patient with Burkitt’s lymphoma, and 17 urine samples from 15 control patients were examined. Virus-like particles were observed in 7 of the 16 patients with acute leukemia, 1 of the 2 patients with chronic granulocytic leukemia, and 1 of the 15 controls. Although these particles showed slight morphologic differences, many were similar in ultrastructure and in density gradient characteristics to the virus particles observed in murine leukemia and to the particles seen by other workers in plasma and tissues of patients with leukemia and lymphoma. Cytopathic effects on WI-38 fibroblasts were observed in urine from 3 patients with leukemia. These effects resembled cytomegalovirus infection, but confirmatory tests were not carried out. Whether the virus-like particles demonstrated by electron microscopy in this study are responsible for the cytopathic effects is at present uncertain. The correlation of a morphologic structure with tissue culture activity cannot be answered until suitable in vitro assay and transformation systems are developed to purify and test these particles. This study suggests that urine may serve as a convenient source for the study and development of such test systems using the electron microscope to correlate structure with biologic activity.

Effect of basolateral acidification on the frog oxynticopeptic cell

1990 ◽  
Vol 259 (4) ◽  
pp. G564-G570 ◽  
Author(s):  
S. Arvidsson ◽  
K. Carter ◽  
A. Yanaka ◽  
S. Ito ◽  
W. Silen
Keyword(s):  
Electron Microscopy ◽  
Gastric Mucosa ◽  
Light And Electron Microscopy ◽  
Structure And Function ◽  
Intracellular Acidification ◽  
Intracellular Acidosis ◽  
Normal Morphology ◽  
And Function ◽  
Oxynticopeptic Cells

The effects of intracellular acidosis induced by acidification of the basolateral (nutrient) perfusate on the structure and function of the oxynticopeptic cell were studied in in vitro frog gastric mucosa. Changing the pH of the unbuffered nutrient perfusate (UNB) from 7.2 to 3.5 acidified the oxynticopeptic cell with no change in potential difference (PD) or resistance (R). Intracellular pH (pHi), PD, and R were 7.05 +/- 0.01, 16 +/- 1 mV, 165 +/- 7 omega.cm2 before and 6.44 +/- 0.01, 16 +/- 2 mV, 170 +/- 9 omega.cm2 after nutrient acidification. Acid secretion (H+) increased from 0.86 +/- 0.07 to 1.88 +/- 0.18 mu eq.cm-2.h-1. Addition of forskolin to tissues perfused with nutrient pH (pHn) 3.5 decreased PD to 2 +/- 2 mV and further increased H+ to 3.07 +/- 0.19 mu eq.cm-2.h-1. By light and electron microscopy oxynticopeptic cells perfused with UNB, pHn 3.5, appeared normal. Oxynticopeptic cells in tissues pretreated with omeprazole and then exposed to UNB, pHn 3.5, had extensive morphological damage. On increasing the pH of the nutrient perfusate from 3.5 to 7.2 there was prompt recovery of pHi in untreated and forskolin-stimulated mucosae (pHi 6.87 +/- 0.06 and 6.85 +/- 0.04) but no recovery of pHi in tissues pretreated with omeprazole or cimetidine (pHi 6.26 +/- 0.04 and 6.44 +/- 0.06, n = 6, 30 min after reexposure to UNB, pHn 7.2). We conclude that in a secreting mucosa intracellular acidification of the oxynticopeptic cell to pHi 6.4 is associated with normal morphology, PD, R, and increased H+, and that intracellular acidosis is not de facto deleterious.

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