Study of the in vivo and in vitro photosensitizing capabilities of uroporphyrin I compared to photofrin II

1986 ◽  
Vol 6 (2) ◽  
pp. 131-136 ◽  
Author(s):  
J. Stuart Nelson ◽  
Chung-Ho C. Sun ◽  
Michael W. Berns
Keyword(s):  
Photofrin Ii

The influence of oxygen on the radiosensitizing activity of Photofrin II and hypericin

2007 ◽  
Vol 11 (10) ◽  
pp. 736-741 ◽  
Author(s):  
Pamela Schaffer ◽  
Ulrike Kulka ◽  
Birgit Ertl-Wagner ◽  
Roswita Hell ◽  
Alina Balandin ◽  
...  
Keyword(s):  
Carcinoma Cell ◽  
Cell Damage ◽  
Human Bladder ◽  
Photofrin Ii ◽  
Carcinoma Cell Lines ◽  
Radiation Induced ◽  
Low Levels ◽  
Sufficient Oxygen

Several clinical studies, as well as investigations performed on tissue cultures and murine tumor models, have demonstrated the in vitro and in vivo efficacy of Photofrin II and hypericin as radiosensitizing agents. The mechanisms involved in the radiosensitizing action of Photofrin II and hypericin are partially understood; the recognition of the major role performed by oxygen regarding the modulation of cellular radiosensitivity has prompted the present investigations on the relevance of oxygenation for the success of Photofrin II or hypericin-based radiation therapy of tumors. RT4 human bladder carcinoma cell lines were seeded and incubated with various concentrations of Photofrin II or hypericin under ambient and 5% oxygen levels. The cells were irradiated with ionizing radiation between 1 and 6 Gy. The same experiments were repeated with Photofrin II and hypericin alone, without radiation. The cell survival was evaluated. The results demonstrated an increase of radiation-induced cell damage in the presence of Photofrin II and hypericin, respectively, when sufficient oxygen was available. Low levels of oxygen reduced the activity of Photofrin II as well as of hypericin as a radiosensitizer, with minimal tumor damage ( p < 0.05 in a Student t-test). The mechanism of action of Photofrin II and hypericin as radiosensitizers requires the presence of sufficiently high oxygen concentrations.

Photosensitization by the Near-IR-absorbing Photosensitizer Lutetium Texaphyrin: Spectroscopic, In Vitro and In Vivo Studies

1998 ◽  
Vol 02 (05) ◽  
pp. 383-390 ◽  
Author(s):  
GENADY KOSTENICH ◽  
TANYA BABUSHKINA ◽  
ADINA LAVI ◽  
YAKOV LANGZAM ◽  
ZVI MALIK ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Structural Damage ◽  
Biological Properties ◽  
In Vivo Studies ◽  
Outer Cell ◽  
Lipid Bilayer Membranes ◽  
Photofrin Ii ◽  
Ionic Imbalance

The spectroscopic and biological properties of the new photosensitizer lutetium texaphyrin (Lu-Tex) were assessed in vitro and in vivo on a C26 colon carcinoma model, in comparison with hematoporphyrin (Hp), photofrin II (PII) and chlorin e 6( Chl ). Strong binding of Lu-Tex to lipid bilayer membranes was observed. The results of confocal fluorescence microscopy on C26 cells showed that Lu-Tex was localized in small vesicles in the cytoplasm, possibly in the lysosomes, while Chl and Hp were distributed in larger cytoplasmic vesicles attributed to mitochondria. Scanning electron microscopy and X-ray microanalysis revealed that photodynamic therapy with Lu-Tex induced only slight damage to the cell membrane, leading to a delayed cell response. Chl and Hp caused significant structural damage to the outer cell membrane, resulting in ionic imbalance and fast cell death. The in vitro quantitative assessment of the relative efficiency per absorbed photon of the sensitizers revealed that Lu-Tex was less effective than Chl and Hp . However, the results of our in vivo study showed that at the same light and drug doses the anti-tumor efficiency of the agents was in the following order: Lu-Tex > Chl > PII . The strong in vivo anti-tumor effect of Lu-Tex can be explained by its higher integrated absorption in the long-wavelength range.

scholarly journals In vitro photosensitization of tumour cell enzymes by Photofrin II administered in vivo

1989 ◽  
Vol 59 (1) ◽  
pp. 47-53 ◽  
Author(s):  
SL Gibson ◽  
RS Murant ◽  
MD Chazen ◽  
ME Kelly ◽  
R Hilf
Keyword(s):  
Tumour Cell ◽  
Photofrin Ii

Direct comparison of in-vitro and in-vivo photofrin-II mediated photosensitization using a pulsed KTP pumped dye laser and a continuous wave argon ion pumped dye laser

1991 ◽  
Vol 11 (5) ◽  
pp. 404-410 ◽  
Author(s):  
Angela Ferrario ◽  
Natalie Rucker ◽  
Stefan W. Ryter ◽  
Daniel R. Doiron ◽  
Charles J. Gomer
Keyword(s):  
Continuous Wave ◽  
Dye Laser ◽  
Photofrin Ii ◽  
Argon Ion

The role of radical derivatives of high reactivity in the radiosensitizing action of Photofrin II

2006 ◽  
Vol 10 (12) ◽  
pp. 1398-1402 ◽  
Author(s):  
Moshe Schaffer ◽  
Ulrike Kulka ◽  
Pamela Schaffer ◽  
Birgit Ertl-Wagner ◽  
Luigi Corti ◽  
...  
Keyword(s):  
Cell Survival ◽  
Mechanism Of Action ◽  
Colorimetric Assay ◽  
High Reactivity ◽  
Oh Radicals ◽  
Lower Survival Rate ◽  
Photofrin Ii ◽  
Derivatives Of

The in vitro and in vivo efficacy of Photofrin II as a selective radiosensitizing agent has recently been demonstrated, the mechanism of action still being unknown. We aimed to investigate the mechanism of action of Photofrin II and the role played by radiolytically generated cytotoxic species. RT4 human bladder carcinoma cell lines were seeded and incubated with Photofrin II and mannitol, with Photofrin II alone, and with no added agent. The cells were treated with ionizing radiation (6 Gy). The numbers of colonies in the respective groups were compared. In addition, the influence of mannitol and histidine on cell survival after Photofrin-incubation and irradiation (0-1-2-4-6 Gy) was evaluated by a tetrazolium-based colorimetric assay in an ELISA reader. RT4 cells, which were exposed to 6 Gy radiation after incubation with Photofrin II, showed a significantly lower survival rate compared to cells exposed to the same radiation dose in the absence of Photofrin II ( p < 0.05 in a Student t-test). The addition of mannitol as a scavenger for OH radicals exerted a protective effect especially against the radiosensitizing action of Photofrin. Increased cell survival was observed when mannitol and histidine were present in addition to Photofrin II. The mechanism of radio sensitization by Photofrin II appears to involve the formation of radical derivatives of high reactivity, such as OH radicals.

Induction and Differentiation of Dental Epithelium in Vivo and in Vitro

1982 ◽  
Vol 40 ◽  
pp. 142-145
Author(s):  
E. J. Kollar
Keyword(s):  
Connective Tissue ◽  
Oral Mucosa ◽  
Basal Lamina ◽  
Functional Derivatives ◽  
Specific Source ◽  
Dental Epithelium ◽  
Connective Tissue Stroma

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.

Ultrastructural Correlations between Clonal Human Tumor Colonies and in Vivo Neoplasms

1982 ◽  
Vol 40 ◽  
pp. 210-211
Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman
Keyword(s):  
Cultured Cells ◽  
Human Tumor ◽  
Cell Type ◽  
Tumor Mass ◽  
Initial Cell ◽  
Cloning Assay ◽  
Human Tumor Cloning ◽  
The Relationship

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.

Ultrastructure of melanocyte-keratinocyte interactions and pigment transfer in vitro

1978 ◽  
Vol 36 (2) ◽  
pp. 650-651
Author(s):  
Raul I. Garcia ◽  
Evelyn A. Flynn ◽  
George Szabo
Keyword(s):  
Direct Injection ◽  
Skin Pigmentation ◽  
Freeze Fracture ◽  
Pigment Granule ◽  
Time Lapse ◽  
Ultrastructural Level ◽  
Lanthanum Tracer ◽  
A Cell

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

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