scholarly journals BRIEF REPORT: Appearance of Platelet-Clumping Substance in Plasma of Rabbits after Intravenous Injection of Agar-Solution, Bacterial Endotoxin or Adrenaline

Blood ◽  
1967 ◽  
Vol 30 (6) ◽  
pp. 792-795 ◽  
Author(s):  
HIROH YAMAZAKI ◽  
TATSUO SHIMAMOTO ◽  
HIROSHI MURASE ◽  
TAKIO SHIMAMOTO
Keyword(s):  
Escherichia Coli ◽  
Intravenous Injection ◽  
Saline Solution ◽  
Platelet Rich Plasma ◽  
The Other ◽  
Bacterial Endotoxin ◽  
Magnesium Ions ◽  
Normal Platelet ◽  
Rabbit Platelets ◽  
Edta Plasma

Abstract The platelet-clumping substance appeared statistically significant (p < 0.01 ∼ 0.05) in the heparinized plasma of 29 rabbits collected 5 minutes, 30 minutes, and 1 and 2 hours after the intravenous injection of either 5 ml./Kg. of 0.5 per cent agar-saline solution, 100 µg./Kg. of bacterial endotoxin derived from Escherichia coli, or 10 µg./Kg. of adrenaline, as compared with that in the platelet-saline suspension from the other 36 rabbits. At the same time, the circulating platelet count decreased significantly (p<0.01 ∼0.05). Twenty-four hours after the injection these changes disappeared. The platelet-clumping substance was detected only in heparinized plasma, and not in citrated, oxalated, and EDTA-plasma or serum. The addition or removal of calcium or magnesium ions did not affect the appearance of clumping of platelets. It is stable for storage at 4 C. and is not dialyzable. It induced clumping of platelets not only in the platelet-saline suspension, but also in the platelet-rich plasma, while ADP, serotonin, catecholamine or thrombin (0.001 ∼ 100µg./ml. or units/ml.) did not induce clumping of washed rabbit platelets even under the presence of the normal platelet-free heparinized plasma.

scholarly journals EFFECTS OF BACTERIAL ENDOTOXIN ON RABBIT PLATELETS

1964 ◽  
Vol 120 (2) ◽  
pp. 305-313 ◽  
Author(s):  
Roger M. Des Prez
Keyword(s):  
Platelet Rich Plasma ◽  
Bacterial Endotoxin ◽  
Clot Formation ◽  
Rabbit Platelet ◽  
Plasma Endotoxin ◽  
Rabbit Platelets ◽  
Lag Period ◽  
Injurious Effects ◽  
Thrombin Formation

The platelet injury produced by bacterial endotoxin and thrombin have been compared in studies utilizing citrated rabbit platelet-rich plasma. Endotoxin-induced platelet injury is characterized by a lag period, is progressive, and does not produce gross clot formation. Thrombin-induced platelet injury is immediate, non-progressive, and is associated with clot formation. The quantity of thrombin required to produce clot formation in this citrated system is less than that required to produce release of platelet 5-hydroxytryptamine. The endotoxin-induced platelet injury required extremely large quantities of heparin for inhibition. The platelet injury induced by thrombin can be inhibited by small quantities of heparin. It is concluded that the injurious effects of endotoxin on platelets is mediated through some mechanism other than thrombin formation.

scholarly journals EFFECTS OF BACTERIAL ENDOTOXIN ON RABBIT PLATELETS

1962 ◽  
Vol 116 (5) ◽  
pp. 619-633 ◽  
Author(s):  
Herbert I. Horowitz ◽  
Roger M. Des Prez ◽  
Edward W. Hook
Keyword(s):  
Platelet Rich Plasma ◽  
Blood Stream ◽  
Transient Increase ◽  
Bacterial Endotoxin ◽  
Rabbit Platelet ◽  
Temperature Dependent ◽  
Platelet Factor ◽  
Platelet Poor Plasma ◽  
Rabbit Platelets ◽  
Antigen Antibody

Incubation of rabbit platelet-rich plasma with bacterial endotoxin results in activation of platelet factor 3, a precursor of blood thromboplastin. This platelet-endotoxin interaction is dose- and temperature-dependent, and is similar to the effects of antigen-antibody union in the presence of platelets. Injection of endotoxin intravenously is associated with a transient increase in platelet factor 3. Since platelet factor 3 can be demonstrated in platelet-poor plasma as well as platelet-rich plasma after endotoxin injection, it seems likely that an actual transfer of factor 3 from platelets to plasma occurs and that this activity is then rapidly inactivated or cleared from the blood stream.

Infection of Escherichia coli with bacteriophages

1969 ◽  
Vol 27 ◽  
pp. 370-371
Author(s):  
Manfred E. Bayer
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acid ◽  
Cell Surface ◽  
Virus Type ◽  
Infection Process ◽  
Adsorption Site ◽  
The Other ◽  
Specific Receptors ◽  
Bacterial Receptors

The first step in the infection of a bacterium by a virus consists of a collision between cell and bacteriophage. The presence of virus-specific receptors on the cell surface will trigger a number of events leading eventually to release of the phage nucleic acid. The execution of the various "steps" in the infection process varies from one virus-type to the other, depending on the anatomy of the virus. Small viruses like ØX 174 and MS2 adsorb directly with their capsid to the bacterial receptors, while other phages possess attachment organelles of varying complexity. In bacteriophages T3 (Fig. 1) and T7 the small conical processes of their heads point toward the adsorption site; a welldefined baseplate is attached to the head of P22; heads without baseplates are not infective.

The Nature of the Intramembrane Particle

1980 ◽  
Vol 38 ◽  
pp. 688-691
Author(s):  
A.J. Verkleij
Keyword(s):  
Escherichia Coli ◽  
Tight Junction ◽  
Gap Junction ◽  
The Other ◽  
Fracture Face ◽  
Band 3 Protein ◽  
Satisfactory Explanation ◽  
Freeze Fracturing ◽  
Intramembrane Particle ◽  
Luminal Membrane

Freeze-fracturing splits membranes into two helves, thus allowing an examination of the membrane interior. The 5-10 rm particles visible on both monolayers are widely assumed to be proteinaceous in nature. Most membranes do not reveal impressions complementary to particles on the opposite fracture face, if the membranes are fractured under conditions without etching. Even if it is considered that shadowing, contamination or fracturing itself might obscure complementary pits', there is no satisfactory explanation why under similar physical circimstances matching halves of other membranes can be visualized. A prominent example of uncomplementarity is found in the erythrocyte manbrane. It is wall established that band 3 protein and possibly glycophorin represents these nonccmplanentary particles. On the other hand a number of membrane types show pits opposite the particles. Scme well known examples are the ";gap junction',"; tight junction, the luminal membrane of the bladder epithelial cells and the outer membrane of Escherichia coli.

Enhancement of ADP-induced Platelet Aggregation by Adrenaline in Vivo and Its Prevention

1973 ◽  
Vol 29 (02) ◽  
pp. 490-498 ◽  
Author(s):  
Hiroh Yamazaki ◽  
Itsuro Kobayashi ◽  
Tadahiro Sano ◽  
Takio Shimamoto
Keyword(s):  
Platelet Count ◽  
Platelet Aggregation ◽  
Platelet Rich Plasma ◽  
The Other ◽  
Endothelial Surface ◽  
Important Interaction ◽  
Blood Coagulability ◽  
The Difference

SummaryThe authors previously reported a transient decrease in adhesive platelet count and an enhancement of blood coagulability after administration of a small amount of adrenaline (0.1-1 µg per Kg, i. v.) in man and rabbit. In such circumstances, the sensitivity of platelets to aggregation induced by ADP was studied by an optical density method. Five minutes after i. v. injection of 1 µg per Kg of adrenaline in 10 rabbits, intensity of platelet aggregation increased to 115.1 ± 4.9% (mean ± S. E.) by 10∼5 molar, 121.8 ± 7.8% by 3 × 10-6 molar and 129.4 ± 12.8% of the value before the injection by 10”6 molar ADP. The difference was statistically significant (P<0.01-0.05). The above change was not observed in each group of rabbits injected with saline, 1 µg per Kg of 1-noradrenaline or 0.1 and 10 µg per Kg of adrenaline. Also, it was prevented by oral administration of 10 mg per Kg of phenoxybenzamine or propranolol or aspirin or pyridinolcarbamate 3 hours before the challenge. On the other hand, the enhancement of ADP-induced platelet aggregation was not observed in vitro, when 10-5 or 3 × 10-6 molar and 129.4 ± 12.8% of the value before 10∼6 molar ADP was added to citrated platelet rich plasma (CPRP) of rabbit after incubation at 37°C for 30 second with 0.01, 0.1, 1, 10 or 100 µg per ml of adrenaline or noradrenaline. These results suggest an important interaction between endothelial surface and platelets in connection with the enhancement of ADP-induced platelet aggregation by adrenaline in vivo.

Human Platelet Acetylcholinesterase: The Effects of Anticholinesterases on Platelet Function

1979 ◽  
Vol 42 (05) ◽  
pp. 1615-1619 ◽  
Author(s):  
Martin J Smith ◽  
Boyd Braem ◽  
Kent D Davis
Keyword(s):  
Platelet Function ◽  
Ache Activity ◽  
Room Temperature ◽  
Platelet Rich Plasma ◽  
Complete Inhibition ◽  
Clot Retraction ◽  
Plasma Clot ◽  
Normal Platelet ◽  
Aggregation Factor

SummaryPlatelet acetylcholinesterase (AChE) activity was measured in gel-filtered platelet preparations. Three different anticholinesteratic agents (eserine, neostigmine, and diiso- propylphosphorofluoridate) at final concentrations of 10 μM caused complete inhibition of AChE activity after 30 min incubation at room temperature with either platelet-rich plasma or gel-filtered platelets. Complete inhibition of platelet AChE had no effect on platelet aggregation, factor-3 availability, and plasma clot retraction. We conclude that platelet membrane AChE activity is not required for normal platelet function as measured by these in vitro parameters.

Thrombotic Thrombocytopenic Purpura: Mechanism for Effectiveness of Plasmapheresis

1979 ◽  
Author(s):  
J. G. Kelton ◽  
P. B. Neame ◽  
I. Walker ◽  
A. G. Turpie ◽  
J. McBride ◽  
...  
Keyword(s):  
Platelet Count ◽  
Thrombotic Thrombocytopenic Purpura ◽  
The Other ◽  
Unknown Etiology ◽  
Normal Range ◽  
Antiplatelet Antibody ◽  
Thrombocytopenic Purpura ◽  
Serious Illness ◽  
Normal Platelet ◽  
Very High

Thrombotic thrombocytopenic purpura (TTP) is a rare but serious illness of unknown etiology. Treatment by plasmapheresis has been reported to be effective but the mechanism for benefit is unknown. We have investigated the effect of plasmapheresis in 2 patients with TTP by quantitating platelet associated IgG (PAIgG) levels prior to and following plasmapheresis. Both patients had very high levels of PAIgG at presentation (90 and A8 fg IgG/platelet respectively, normal 0-5). in both, the PAIgG levels progressively fell to within the normal range and the platelet count rose following plasmapheresis. One patient remained in remission with normal platelet counts and PAIgG levels. The other relapsed after plasmapheresis and the PAIgG level rose prior to the fall in platelet count. Plasmapheresis was repeated and resulted in normalization of both the platelet count and PAIgG level. It is suggested that plasmapheresis removes antiplatelet antibody or immune complexes which may be of etiological importance in this illness.

scholarly journals Lac Operon Boolean Models: Dynamical Robustness and Alternative Improvements

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 600 ◽  
Author(s):  
Marco Montalva-Medel ◽  
Thomas Ledger ◽  
Gonzalo A. Ruz ◽  
Eric Goles
Keyword(s):  
Escherichia Coli ◽  
Limit Cycles ◽  
The Other ◽  
Lac Operon ◽  
Boolean Models ◽  
Bistable Behavior

In Veliz-Cuba and Stigler 2011, Boolean models were proposed for the lac operon in Escherichia coli capable of reproducing the operon being OFF, ON and bistable for three (low, medium and high) and two (low and high) parameters, representing the concentration ranges of lactose and glucose, respectively. Of these 6 possible combinations of parameters, 5 produce results that match with the biological experiments of Ozbudak et al., 2004. In the remaining one, the models predict the operon being OFF while biological experiments show a bistable behavior. In this paper, we first explore the robustness of two such models in the sense of how much its attractors change against any deterministic update schedule. We prove mathematically that, in cases where there is no bistability, all the dynamics in both models lack limit cycles while, when bistability appears, one model presents 30% of its dynamics with limit cycles while the other only 23%. Secondly, we propose two alternative improvements consisting of biologically supported modifications; one in which both models match with Ozbudak et al., 2004 in all 6 combinations of parameters and, the other one, where we increase the number of parameters to 9, matching in all these cases with the biological experiments of Ozbudak et al., 2004.

scholarly journals Intravenous injection of elemental mercury: A report of two cases

2008 ◽  
Vol 41 (02) ◽  
pp. 214-218
Author(s):  
A. Gopalakrishna ◽  
T. V. Pavan Kumar
Keyword(s):  
Intravenous Injection ◽  
Elemental Mercury ◽  
The Other ◽  
Surgical Removal

ABSTRACTTwo cases of intravenous injection of elemental mercury are described in this report. One patient succumbed and the other remains asymptomatic two years after the surgical removal of all the injected mercury. Management of intravenous injection of elemental mercury (intended to be an aphrodisiac in these two cases) is discussed here and the need for surgical removal of all accessible mercury has been emphasized

scholarly journals Escherichia coli O157:H7 SURVIVAL IN TRADITIONAL AND LOW LACTOSE YOGURT DURING FERMENTATION AND COOLING PERIODS

2017 ◽  
Vol 18 (0) ◽  
Author(s):  
Camila Sampaio Cutrim ◽  
Raphael Ferreira de Barros ◽  
Robson Maia Franco ◽  
Marco Antonio Sloboda Cortez
Keyword(s):  
Escherichia Coli ◽  
The Other ◽  
Lactose Hydrolysis ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Gas Formation ◽  
Whole Milk ◽  
Milk Contamination ◽  
Different Types ◽  
Fermentation Period

Abstract The purpose of this study was to evaluate the behavior of E. coli O157:H7 during lactose hydrolysis and fermentation of traditional and low lactose yogurt. It also aimed to verify E. coli O157:H7 survival after 12 h of storage at 4 ºC ±1 ºC. Two different types of yogurts were prepared, two with whole milk and two with pre-hydrolyzed whole milk; in both groups one yogurt was inoculated with E. coli O157:H7 and the other one was not inoculated. The survival of E. coli and pH of yogurt were determined during fermentation and after 12-h refrigeration. The results showed that E. coli O157:H7 was able to grow during the fermentation period (from 4.34 log CFU.mL-1 to 6.13 log CFU.mL-1 in traditional yogurt and 4.34 log CFU.mL-1 to 6.16 log CFU.mL-1 in low lactose yogurt). The samples with E. coli O157:H7 showed gas formation and syneresis. Thus, E. coli O157:H7 was able to survive and grow during fermentation of traditional and low lactose yogurts affecting the manufacture technology. Moreover, milk contamination by E. coli before LAB addition reduces the growth of L. bulgaricus and S. thermophilus especially when associated with reduction of lactose content.

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