Platelets contain a 210K microtubule-associated protein related to a similar protein in HeLa cells

1988 ◽  
Vol 90 (2) ◽  
pp. 317-324
Author(s):  
F. Tablin ◽  
M.J. Reeber ◽  
V.T. Nachmias
Keyword(s):  
Western Blotting ◽  
Indirect Immunofluorescence ◽  
Polyclonal Antibody ◽  
Hela Cells ◽  
Blood Platelets ◽  
The Other ◽  
Similar Protein ◽  
Other Hand ◽  
Protein Map ◽  
Tubulin Immunofluorescence

We have demonstrated the presence of a 210K (K = 10(3) Mr) microtubule-associated protein (MAP) in blood platelets and have studied its relationship to tubulin and to the cytoskeleton, using a well-characterized polyclonal antibody for the analysis. When platelet lysates were enriched for tubulin by an assembly cycle at 37 degrees C, the 210K MAP was also enriched, as detected by Western blotting, while the antigen was not detected in pellets from cold-treated samples that lacked stabilized tubulin. Immunofluorescence of resting platelets showed that the 210K antigen colocalized with the microtubule coil in ring-like structures. On the other hand, in preparations of platelet cytoskeletons, the 210K antigen was present in samples from platelets in which the coil was disassembled (cold-treated without taxol pretreatment) as well as from platelets in which the coil was preserved (at 37 degrees C without taxol, or 4 degrees C with taxol pretreatment). In chilled platelets with disassembled microtubule coils, indirect immunofluorescence using antibodies to 210K or tubulin gave a diffuse signal throughout the platelet cytoplasm. However, immunofluorescence of the 210K antigen in both resting and cold-treated platelets displayed discrete or patchy staining as compared to the continuous staining with antitubulin. We conclude that 210K MAP is present in platelets, that it copurifies with tubulin and that it is localized along the microtubule coil. Our results also suggest that the 210K MAP may interact with some other element(s) of the cytoskeleton, and hence that it might serve as a linking protein.

Photoreception of Paramecium cilia: localization of photosensitivity and binding with anti-frog-rhodopsin IgG

1991 ◽  
Vol 99 (1) ◽  
pp. 67-72
Author(s):  
Y. Nakaoka ◽  
R. Tokioka ◽  
T. Shinozawa ◽  
J. Fujita ◽  
J. Usukura
Keyword(s):  
Membrane Potential ◽  
Polyclonal Antibody ◽  
The Other ◽  
Paramecium Bursaria ◽  
Potential Response ◽  
Light Stimulation ◽  
Intact Cells ◽  
Other Hand ◽  
Immunocytochemical Studies ◽  
Antibody Labeling

Paramecium bursaria is photosensitive and accumulates in a lighted area. The cells can be deciliated by a brief suspension in dilute ethanol. Both intact and deciliated cells showed depolarization in response to light stimulation by a step-increase from dark to above 0.7 mW cm-2 (550 nm). On the other hand, after a step-increase to below 0.4 mW cm-1, intact cells showed hyperpolarization, while the deciliated cells showed no change in membrane potential. This difference in membrane potential response between ciliated and deciliated cells suggests that both somatic and ciliary structures are photosensitive. In our search for the photoreceptive molecules, a polyclonal antibody induced in rabbits against frog rhodopsin was found to cross-react with a 63x10(3) Mr protein of P. bursaria, by immunoelectrophoresis. Immunocytochemical studies showed that the antibody labeling was localized on both the ciliary and the somatic membranes. These results raise the possibility that P. bursaria may contain a rhodopsin-like protein as a photoreceptor molecule.

Alternative splicing of the mouse profilin II gene generates functionally different profilin isoforms

2000 ◽  
Vol 113 (21) ◽  
pp. 3795-3803 ◽  
Author(s):  
A. Di Nardo ◽  
R. Gareus ◽  
D. Kwiatkowski ◽  
W. Witke
Keyword(s):  
Alternative Splicing ◽  
Cell Motility ◽  
Hela Cells ◽  
The Other ◽  
Actin Dynamics ◽  
High Affinity ◽  
Other Hand ◽  
The Brain

Profilins are a conserved family of proteins participating in actin dynamics and cell motility. In the mouse, two profilin genes are known. Profilin I is expressed universally at high levels, while profilin II is expressed mainly in the brain. Here we describe the occurrence of two mouse profilin II isoforms, A and B, which are derived by alternative splicing. They are identical through residue 107 of the protein, but then have distinct C-terminal sequences. Profilin IIA binds to poly-L-proline and actin with high affinity similar to profilin I. Profilin IIB on the other hand does not bind to actin and the affinity for poly-L-proline is greatly diminished. However, tubulin was found to bind to GST-profilin IIB, and in vivo GFP-profilin IIB was recruited to spindles and asters during mitosis in HeLa cells. Our results indicate unexpected diversity in the functions of the profilin family of proteins, and suggest that in mouse profilin IIA is intimately involved in actin dynamics, while profilin IIB associates with other cytoskeletal components.

Curcumin Prevents Cytokine-Mediated Tissue Factor Pathway Inhibitor Down-Regulation in Human Endothelial Cells

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1202-1202
Author(s):  
Keiko Maruyama ◽  
Eriko Morishita ◽  
Yukie Goto ◽  
Akiko Sekiya ◽  
Hidesaku Asakura ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tissue Factor ◽  
Western Blotting ◽  
Tissue Factor Pathway Inhibitor ◽  
The Other ◽  
Tnf Alpha ◽  
Down Regulation ◽  
Protein Levels ◽  
Other Hand ◽  
Tissue Factor Pathway

Abstract Abstract 1202 Objective: Curcumin (diferuloyl methane), an active component of the spice turmeric, has been shown to exhibit anti-inflammatory and antioxidant activities in addition to an anticartinogenic activity in vitro and in vivo. Furthermore, we reported that curcumin inhibited the induction of tissue factor (TF) expression in human umbilical vein endothelial cells (HUVECs) at 52nd ASH 2010. Therefore, curcumin may ameliorate hyper-coagulable state associated with inflammation or oxidative stress. On the other hand, tissue factor pathway inhibitor (TFPI) which is expressed by endothelial cells plays a crucial role in hemostasis by regulating TF-induced initiation of coagulation. This study examined whether curcumin modulates the expression of TFPI in HUVECs. Methods: HUVECs were pretreated with curcumin at the concentration of 20 μM for 3h, washed and stimulated with tumor necrosis factor-alpha (TNF-alpha, 10 ng/ml) for additional 12 or 24h. The mRNA and protein levels of TFPI in the cultured HUVECs were determined by reverse transcriptase polymerase chain reaction (RT-PCR) and western blotting, respectively. To determine whether curcumin affects the MAPK signaling pathways, the phosphorylation of p38 mitogen-activated protein kinase (p38MAPK), extracellular signal-regulated kinase1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK) in the HUVECs were analyzed with western blotting. Additionally, to determine whether curcumin affects nuclear factor-kappa B (NF-kB) pathway, nuclear and cytoplasmic fractions were extracted and protein levels were determined by western blotting for NF-kB (p65), p-IkB and IkB. Results: After TNF-alpha stimulation, TFPI mRNA levels were approximately decreased by 40% compared to the control (p<0.05; Figure 1B). Similarly to the mRNA expression, TFPI protein levels were decreased (Figure 1A). On the other hand, pretreatment of HUVECs with curcumin significantly suppresses TNF-alpha-induced TFPI mRNA and protein down-regulation (p<0.05; Figure 1A, B). Curcumin inhibited TNF-alpha-induced activation of p38MAPK, ERK1/2, and JNK. Moreover, curcumin inhibits TNF-alpha-induced IkB activation in HUVECs. And, translocation of NF-kB from the cytosol into the nucleus by TNF-alpha was inhibited by curcumin. Conclusions: These results indicate that curcumin may suppress the TNF-alpha-induced TFPI down-regulation via NF-kB pathways. Thus, curcumin may offer a novel antithrombotic option for treatment of the hypercoagulable state associated with inflammation. Disclosures: No relevant conflicts of interest to declare.

Morphology of Haemostatic Plugs Before and After Aspirin

1975 ◽  
Author(s):  
J. Wester ◽  
J. van der Veen ◽  
J. J. Sixma
Keyword(s):  
Blood Vessel ◽  
Blood Vessels ◽  
Bleeding Time ◽  
Blood Platelets ◽  
The Other ◽  
Normal Volunteers ◽  
Other Hand ◽  
Before And After

Punch biopsies of bleeding time wounds according to Mielke were taken at 3 minutes in normal volunteers before and 2.5 hours after 2 gr. of aspirin. Haemostatic plugs were found at the end of blood vessels. No plug was encountered that had no relation to a blood vessel. Fibrin on the other hand was found in the wound but not in the blood vessel. Some vessels were occluded by capsule-like haemostatic plugs. In many others an extension into the blood vessel was observed. The extension into the blood vessel showed little or no degranulation. Blood platelets were more degranulated and showed peripheral ballooning before aspirin intake. After aspirin intake much less degranulation was observed and less peripheral ballooning was found.

Detoxification of Citrinin and Ochratoxin A by Hydrogen Peroxide

1994 ◽  
Vol 77 (3) ◽  
pp. 631-637 ◽  
Author(s):  
Sophie G Fouler ◽  
Alka B Trivedi ◽  
Naofumi Kitabatake
Keyword(s):  
Hydrogen Peroxide ◽  
Ochratoxin A ◽  
Hela Cells ◽  
Room Temperature ◽  
The Other ◽  
Toxic Compound ◽  
Other Hand ◽  
Alkaline Conditions

Abstract The effects of hydrogen peroxide on citrinin and ochratoxin A toxicity were examined using HeLa cells. The citrinin was completely detoxified by prior incubation with 0.05% hydrogen peroxide for 30 min at room temperature, and the toxic compound(s) that resulted from heating citrinin at 100°C were also detoxified upon reheating it with hydrogen peroxide. On the other hand, ochratoxin A was not detoxified by hydrogen peroxide at room temperature, but its toxicity was reduced by heating ochratoxin A with hydrogen peroxide under alkaline conditions.

Evidence for Glycoprotein Abnormality in Platelets from Patients with May-Hegglin Anomaly

1985 ◽  
Vol 54 (04) ◽  
pp. 862-865 ◽  
Author(s):  
Giorgio Ricci ◽  
Roberto Manservigi ◽  
Loredana Albonici ◽  
Giorgio Zavagli ◽  
Enzo Cassai
Keyword(s):  
Gel Electrophoresis ◽  
Blood Platelets ◽  
Protein Analysis ◽  
The Other ◽  
Specific Antiserum ◽  
Membrane Glycoproteins ◽  
Other Hand ◽  
Pattern Resolution

SummaryIn the present research protein analysis on SDS-polyacry-lamide gel electrophoresis (PAGE) has been used to study the glycoprotein pattern of the blood platelets of four members from a family affected by May-Hegglin anomaly. In order to characterize the glycoprotein fractions, lactoperoxidase-iodination and immunoprecipitation procedures were used.N,N’diallyltartardiamide (DATD) cross-linked gel electrophoresis was shown to improve the glycoprotein pattern resolution, although with the lactoperoxidase-iodination the glycoprotein characterization of May-Hegglin platelets overlapped the normal. On the other hand with the immunoprecipitation the specific antiserum precipitated all the five major fractions of normal membrane glycoproteins, but it was shown to react quite poorly with the component V of the May-Hegglin glycoprotein pattern.

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

Life Beyond 1MeV

1980 ◽  
Vol 38 ◽  
pp. 30-33
Author(s):  
K.H. Westmacott
Keyword(s):  
Electron Microscopy ◽  
Past Experience ◽  
The Other ◽  
Good Case ◽  
Other Hand ◽  
The U.S

Life beyond 1MeV – like life after 40 – is not too different unless one takes advantage of past experience and is receptive to new opportunities. At first glance, the returns on performing electron microscopy at voltages greater than 1MeV diminish rather rapidly as the curves which describe the well-known advantages of HVEM often tend towards saturation. However, in a country with a significant HVEM capability, a good case can be made for investing in instruments with a range of maximum accelerating voltages. In this regard, the 1.5MeV KRATOS HVEM being installed in Berkeley will complement the other 650KeV, 1MeV, and 1.2MeV instruments currently operating in the U.S. One other consideration suggests that 1.5MeV is an optimum voltage machine – Its additional advantages may be purchased for not much more than a 1MeV instrument. On the other hand, the 3MeV HVEM's which seem to be operated at 2MeV maximum, are much more expensive.

Can the Academic Self-Concept be Positive and Realistic?

2005 ◽  
Vol 19 (3) ◽  
pp. 129-132 ◽  
Author(s):  
Reimer Kornmann
Keyword(s):  
Academic Performance ◽  
Opposite Effect ◽  
Self Esteem ◽  
Point Of View ◽  
The Other ◽  
Self Concept ◽  
High Ability ◽  
Self Image ◽  
Other Hand

Summary: My comment is basically restricted to the situation in which less-able students find themselves and refers only to literature in German. From this point of view I am basically able to confirm Marsh's results. It must, however, be said that with less-able pupils the opposite effect can be found: Levels of self-esteem in these pupils are raised, at least temporarily, by separate instruction, academic performance however drops; combined instruction, on the other hand, leads to improved academic performance, while levels of self-esteem drop. Apparently, the positive self-image of less-able pupils who receive separate instruction does not bring about the potential enhancement of academic performance one might expect from high-ability pupils receiving separate instruction. To resolve the dilemma, it is proposed that individual progress in learning be accentuated, and that comparisons with others be dispensed with. This fosters a self-image that can in equal measure be realistic and optimistic.

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