scholarly journals Assembly properties of fluorescein-labeled tubulin in vitro before and after fluorescence bleaching.

1984 ◽  
Vol 99 (6) ◽  
pp. 2146-2156 ◽  
Author(s):  
R J Leslie ◽  
W M Saxton ◽  
T J Mitchison ◽  
B Neighbors ◽  
E D Salmon ◽  
...  
Keyword(s):  
Living Cells ◽  
Before And After ◽  
Ion Laser ◽  
Cross Links ◽  
Protein Incorporation ◽  
And Control ◽  
Argon Ion ◽  
Brain Tubulin ◽  
Control Protein

Brain tubulin has been conjugated with dichlorotriazinyl-aminofluorescein (DTAF) to form a visualizable complex for the study of tubulin dynamics in living cells. By using several assays we confirm the finding of Keith et al. (Keith, C. H., J. R. Feramisco, and M. Shelanski, 1981, J. Cell Biol., 88:234-240) that DTAF-tubulin polymerizes like control tubulin in vitro. The fluorescein moiety of the complex is readily bleached by the 488-nm line from an argon ion laser. When irradiations are performed over short times (less than 1 s) and in the presence of 2 mM glutathione, a mixture of DTAF-tubulin and control protein (as occurs after microinjection of the fluorescent conjugate into living cells) will retain full polymerization activity. Slow bleaching (approximately 5 min) or bleaching without glutathione promotes formation of covalent cross-links between neighboring polypeptides and kills the polymerization activity of DTAF-tubulin, including some molecules that are neither cross-linked nor bleached. Even under conditions that damage DTAF-tubulin, however, DTAF-microtubules are not destroyed by bleaching. They will continue to elongate by addition of DTAF-tubulin subunits to their free ends, and they neither bind nor exchange subunits along their lateral surfaces. These results suggest that DTAF-tubulin is a suitable analog for tubulin, both in studies of protein incorporation and for investigations of fluorescence redistribution after photobleaching.

Electron microscopic study of the membrane glycoproteins in the rat kidney after cisplatin treatment

1989 ◽  
Vol 47 ◽  
pp. 912-913
Author(s):  
S.K. Aggarwal
Keyword(s):  
Alkaline Phosphatase ◽  
Rat Kidney ◽  
Light And Electron Microscopy ◽  
Kidney Tissue ◽  
Membrane Glycoproteins ◽  
Electron Microscopic ◽  
Before And After ◽  
Interstrand Cross Links ◽  
Cross Links

The proposed primary mechanism of action of the anticancer drug cisplatin (Cis-DDP) is through its interaction with DNA, mostly through DNA intrastrand cross-links or DNA interstrand cross-links. DNA repair mechanisms can circumvent this arrest thus permitting replication and transcription to proceed. Various membrane transport enzymes have also been demonstrated to be effected by cisplatin. Glycoprotein alkaline phosphatase was looked at in the proximal tubule cells before and after cisplatin both in vivo and in vitro for its inactivation or its removal from the membrane using light and electron microscopy.Outbred male Swiss Webster (Crl: (WI) BR) rats weighing 150-250g were given ip injections of cisplatin (7mg/kg). Animals were killed on day 3 and day 5. Thick slices (20-50.um) of kidney tissue from treated and untreated animals were fixed in 1% buffered glutaraldehyde and 1% formaldehyde (0.05 M cacodylate buffer, pH 7.3) for 30 min at 4°C. Alkaline phosphatase activity and carbohydrates were demonstrated according to methods described earlier.

scholarly journals Effects of two different deep digital flexor tenotomy techniques on distal articular angles of equine cadaver forelimbs

2012 ◽  
Vol 42 (11) ◽  
pp. 2005-2010
Author(s):  
Antonio Cezar de Oliveira Dearo ◽  
Vitor Bruno Bianconi Rosa ◽  
Peter Reichmann ◽  
Milton Luis Ribeiro de Oliveira
Keyword(s):  
Quantitative Data ◽  
Statistical Significance ◽  
Surgical Approaches ◽  
Control Groups ◽  
Before And After ◽  
Distal Interphalangeal ◽  
The Difference ◽  
And Control ◽  
Flexor Tenotomy

Deep digital flexor (DDF) tenotomy is a technique employed for years to treat selected disorders of the musculoskeletal system in horses. Although two different surgical approaches (i.e. mid-metacarpal and pastern) have been described for performing the procedure, in vitro quantitative data regarding the modifications induced by either technique on the distal articular angles is lacking. Therefore, the purpose of the study reported here was to investigate the viability of a proposed biomechanical system of induced-traction used to compare the two DDF tenotomy techniques by measuring the distal articular angles of equine cadaver forelimbs. Ten pairs of forelimbs were collected and mounted to a biomechanical system developed to apply traction at the toe level. Dorsal articular angles of the metacarpophalangeal (MP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints were determined by geometric lines on radiographs taken before and after performing each technique. Comparisons between each tenotomy group and its own control, for each joint, and between the two tenotomy groups using as variable the difference between the tenotomy and control groups were tested. Despite the lack of statistical significance, the DDF tenotomy technique at the pastern level produced extension, to a lesser and greater extent, of the PIP and DIP joints, respectively when compared to the mid-metacarpal level. No remarkable differences could be observed for the MP joint. The developed traction-induced biomechanical construct seemed to be effective in producing valuable quantitative estimations of the distal articular angles of equine cadaver forelimbs subjected to different DDF tenotomy techniques.

scholarly journals The role of the centriolar region in animal cell mitosis. A laser microbeam study.

1977 ◽  
Vol 72 (2) ◽  
pp. 351-367 ◽  
Author(s):  
M W Berns ◽  
J B Rattner ◽  
S Brenner ◽  
S Meredith
Keyword(s):  
Animal Cell ◽  
Metaphase Plate ◽  
B Chromosome ◽  
Ultrastructural Analysis ◽  
Laser Microbeam ◽  
Membrane Breakdown ◽  
Pericentriolar Material ◽  
Ion Laser ◽  
Argon Ion

An argon ion laser microbeam (488 and 514 nm) was used to selectively irradiate one of the two centriolar regions of rat kangaroo Potorous tridactylis (PtK2) prophase cells in vitro. The cells were sensitized to the laser radiation by treatment with acridine orange (0.1-0.2 mug/ml). Ultrastructural examination of the irradiated centriolar regions demonstrated that the primary site of damage was the pericentriolar material. This result suggests that nucleic acid is present in the pericentriolar material. Behavioral and ultrastructural analysis demonstrated that cells with one damaged pericentriolar zone could undergo (a) nuclear membrane breakdown, (b) chromosome condensation, (c) metaphase plate formation, and (d) cytokinesis. However, the chromosomes neither separated nor exhibited any anaphase movements. Detailed ultrastructural analysis revealed the presence of kinetochore microtubules on both sides of chromosome mass and a lack of microtubules in the cytokinesis constriction. These results indicate that the pericentriolar material is important in spindle orgainization and essential for the formation of the interpolar microtubules.

Dynamic aspects of rhodamine dye photosensitization in vitro with an argon-ion Laser

1989 ◽  
Vol 9 (2) ◽  
pp. 83-89 ◽  
Author(s):  
Christopher R. Shea ◽  
Norah Chen ◽  
Tayyaba Hasan
Keyword(s):  
Argon Ion Laser ◽  
Ion Laser ◽  
Rhodamine Dye ◽  
Argon Ion

scholarly journals Preliminary screening of the possible protective effect of Moroccan propolis against chromium-induced nephrotoxicity in animal model

2020 ◽  
Vol 13 (7) ◽  
pp. 1327-1333
Author(s):  
Soukaina El-Guendouz ◽  
Soumia Zizi ◽  
Youssef Elamine ◽  
Badiaa Lyoussi
Keyword(s):  
Animal Model ◽  
Protective Effect ◽  
Creatinine Clearance ◽  
Potassium Dichromate ◽  
Treated Group ◽  
Control Groups ◽  
Before And After ◽  
And Control

Background and Aim: Hexavalent chromium (Cr (VI)) compounds have been shown to induce nephrotoxicity associated with oxidative stress in humans and animals. The aim of the present study was to investigate the nephroprotective effect of bee propolis, as highly antioxidant natural product, in vivo using an animal model. Materials and Methods: First of all, total phenol and flavonoid contents of propolis sample were estimated in vitro. Afterward, to study the protective effect of propolis on renal damages caused by an injection of a single dose of potassium dichromate (15 mg/kg b.wt), 24 male Wister rats were divided into test and control groups. Propolis treatment was performed by oral gavage of 100 mg/kg b.wt/day, while the control groups received water instead. The 24 h urine was collected and blood samples were withdrawn before and after each treatment for further analysis. Results: Propolis revealed to be rich in polyphenols and flavonoids. Chromate provoked a nephrotoxic effect expressed by a drastic decrease in glomerular filtration assessed by creatinine clearance. However, the administration of propolis attenuated the renal damages induced by the chromate. This attenuation can be seen by the increase of creatinine clearance when comparing propolis treated group to the non-treated group. Conclusion: Propolis showed a protective potential against chromate-induced nephrotoxicity through the amelioration of chromate's toxic effects. It might be concluded that propolis could be effective as chemoprotectant in the management of potassium dichromate-induced nephrotoxicity.

scholarly journals Diffusion coefficient of fluorescein-labeled tubulin in the cytoplasm of embryonic cells of a sea urchin: video image analysis of fluorescence redistribution after photobleaching.

1984 ◽  
Vol 99 (6) ◽  
pp. 2157-2164 ◽  
Author(s):  
E D Salmon ◽  
W M Saxton ◽  
R J Leslie ◽  
M L Karow ◽  
J R McIntosh
Keyword(s):  
Diffusion Coefficient ◽  
Sea Urchin ◽  
Video Camera ◽  
Laser Fluorescence ◽  
Lytechinus Variegatus ◽  
Embryonic Cells ◽  
Ion Laser ◽  
Argon Ion ◽  
Brain Tubulin ◽  
Small Oligomer

The diffusion coefficient of tubulin has been measured in the cytoplasm of eggs and embryos of the sea urchin Lytechinus variegatus. We have used brain tubulin, conjugated to dichlorotriazinyl-aminofluorescein, to inject eggs and embryos. The resulting distributions of fluorescence were perturbed by bleaching with a microbeam of light from the 488-nm line of an argon ion laser. Fluorescence redistribution after photobleaching was monitored with a sensitive video camera and photography of the television-generated image. With standard photometric methods, we have calibrated this recording system and measured the rates of fluorescence redistribution for tubulin, conjugated to dichlorotriazinyl-aminofluorescein, not incorporated into the mitotic spindle. The diffusion coefficient (D) was calculated from these data using Fick's second law of diffusion and a digital method for analysis of the photometric curves. We have tested our method by determining D for bovine serum albumin (BSA) under conditions where the value is already known and by measuring D for fluorescein-labeled BSA in sea urchin eggs with a standard apparatus for monitoring fluorescence redistribution after photobleaching. The values agree to within experimental error. Dcytoplasmtubulin = 5.9 +/- 2.2 X 10(-8) cm2/s; DcytoplasmBSA = 8.6 +/- 2.0 X 10(-8) cm2/s. Because DH2OBSA = 68 X 10(-8) cm2/s, these data suggest that the viscosity of sea urchin cytoplasm for protein is about eight times that of water and that most of the tubulin of the sea urchin cytoplasm exists as a dimer or small oligomer, which is unbound to structures that would impede its diffusion. Values and limitations of our method are discussed, and we draw attention to both the variations in D for single proteins in different cells and the importance of D for the upper limit to the rates of polymerization reactions.

Apelin-13 deteriorates hypertension in rats after damage of the vascular endothelium by ADMA

2013 ◽  
Vol 91 (9) ◽  
pp. 708-714 ◽  
Author(s):  
Xue Han ◽  
Dong-Liang Zhang ◽  
Dao-Xin Yin ◽  
Qi-Dong Zhang ◽  
Wen-Hu Liu
Keyword(s):  
Endothelial Dysfunction ◽  
Treated Group ◽  
Control Group ◽  
Transmission Electron ◽  
Before And After ◽  
Pass Through ◽  
Mlc Phosphorylation ◽  
And Control

Asymmetric dimethylarginine (ADMA) is a risk factor for endothelial dysfunction. The polypeptide apelin has biphasic effects on blood vessels in vivo and in vitro. We investigated the effect of apelin-13 on ADMA-damaged vessels. Rats were divided among ADMA-treated and control groups, which were treated with ADMA (10 mg·(kg body mass)−1·day−1) or saline, respectively, for 4 weeks. Systolic blood pressure (SBP) was measured before and after the injection of apelin-13. The ultrastructure of endothelial cells in caudal arteries was examined using transmission electron microscopy. The reactivities of isolated caudal artery rings were observed after exposure to apelin-13, and myosin light chain (MLC) phosphorylation was assessed by immunohistochemistry in rings treated with or without apelin-13. ADMA induced hypertension and endothelial dysfunction. After injection of apelin-13, SBP declined in the control group but was elevated in the ADMA-treated group. In vitro, apelin-13 caused relaxation in rings in the control group, but it contracted rings in the ADMA-treated group. Apelin-13 promoted MLC phosphorylation in vascular smooth muscle cells (VSMCs) in the ADMA group. These results indicate that apelin-13 might pass through ADMA-damaged endothelium and act on VSMCs to increase MLC phosphorylation, thus contributing to vasoconstriction and exacerbating hypertension.

Sign in / Sign up

Export Citation Format

Share Document