Acanthamoeba culbertsoni : Electron-Dense Granules in a Highly Virulent Clinical Isolate

2016 ◽  
Vol 63 (6) ◽  
pp. 744-750 ◽  
Author(s):  
Bibiana Chávez-Munguía ◽  
Lizbeth Salazar-Villatoro ◽  
Maritza Omaña-Molina ◽  
Martha Espinosa-Cantellano ◽  
Elizabeth Ramírez-Flores ◽  
...  
Keyword(s):  
Clinical Isolate ◽  
Dense Granules ◽  
Acanthamoeba Culbertsoni ◽  
Highly Virulent

scholarly journals Draft Genome Sequence of a Rare Israeli Clinical Isolate of Burkholderia pseudomallei

2019 ◽  
Vol 8 (19) ◽  
Author(s):  
Ofir Israeli ◽  
Inbar Cohen-Gihon ◽  
Tal Brosh-Nissimov ◽  
Shay Weiss ◽  
Anat Zvi ◽  
...  
Keyword(s):  
Clinical Isolate ◽  
Genome Sequence ◽  
Burkholderia Pseudomallei ◽  
Virulent Strain ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Content Type ◽  
Highly Virulent

We report here the draft genome sequence of Burkholderia pseudomallei MAA2018. This highly virulent strain was isolated in 2018 from the first melioidosis case in Israel associated with recreational travel to Goa, India.

Evaluation of platelet dense granules for determining storage pool deficiencies by HVEM image and quantitative analysis

1996 ◽  
Vol 54 ◽  
pp. 770-771
Author(s):  
W.T. Gunning ◽  
J.N. Turner ◽  
K. Buttle ◽  
E.P. Calomeni ◽  
N.A. Lachant ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Platelet Function ◽  
Electron Microscopic ◽  
Von Willebrand's Disease ◽  
Dense Granules ◽  
Storage Pool ◽  
Prolonged Bleeding ◽  
Microscopic Evaluation ◽  
Storage Pools ◽  
Electron Lucent

There are a variety of conditions which have been associated with prolonged bleeding times. If other etiologies including von Willebrand's disease have been ruled out, a platelet function disorder must be considered. The best, if not only, technique to make this diagnosis is the electron microscopic evaluation of whole air dried platelets. Bull first described the presence of dense granules in whole platelets in 1968 and the technique has been utilized extensively The electron dense or delta granules are easily distinguished from the larger more numerous alpha granules which are electron lucent. The significance of the dense granules is that they are known to be “storage pools” of serotonin, calcium, adenosine di- and triphosphate, and pyrophosphate. Prolonged bleeding times may be directly related to an insufficiency of these substances. The diagnosis of a storage pool deficiency is made when either the storage content of the dense granules is abnormal or their number is diminished. We observe normal platelets to have 4-6 dense granules, which agrees with the literature.

Protective effect of Trypanosoma rangeli against infections with a highly virulent strain of Trypanosoma cruzi

1997 ◽  
Vol 2 (5) ◽  
pp. 482-487 ◽  
Author(s):  
Claudio Zuniga ◽  
Teresa Palau ◽  
Pilar Penin ◽  
Carlos Gamallo ◽  
Jose Antonio de Diego
Keyword(s):  
Trypanosoma Cruzi ◽  
Protective Effect ◽  
Virulent Strain ◽  
Trypanosoma Rangeli ◽  
Highly Virulent

Small GTP-binding Protein RalA Associates with Weibel-Palade Bodies in Endothelial Cells

1999 ◽  
Vol 82 (09) ◽  
pp. 1177-1181 ◽  
Author(s):  
Hubert de Leeuw ◽  
Pauline Wijers-Koster ◽  
Jan van Mourik ◽  
Jan Voorberg
Keyword(s):  
Endothelial Cells ◽  
Binding Proteins ◽  
Binding Protein ◽  
Control Release ◽  
Small Gtpase ◽  
Gtp Binding Protein ◽  
Two Dimensional Gel Electrophoresis ◽  
Gtp Binding Proteins ◽  
Dense Granules ◽  
Gtp Binding

SummaryIn endothelial cells von Willebrand factor (vWF) and P-selectin are stored in dense granules, so-called Weibel-Palade bodies. Upon stimulation of endothelial cells with a variety of agents including thrombin, these organelles fuse with the plasma membrane and release their content. Small GTP-binding proteins have been shown to control release from intracellular storage pools in a number of cells. In this study we have investigated whether small GTP-binding proteins are associated with Weibel-Palade bodies. We isolated Weibel-Palade bodies by centrifugation on two consecutive density gradients of Percoll. The dense fraction in which these subcellular organelles were highly enriched, was analysed by SDS-PAGE followed by GTP overlay. A distinct band with an apparent molecular weight of 28,000 was observed. Two-dimensional gel electrophoresis followed by GTP overlay revealed the presence of a single small GTP-binding protein with an isoelectric point of 7.1. A monoclonal antibody directed against RalA showed reactivity with the small GTP-binding protein present in subcellular fractions that contain Weibel-Palade bodies. The small GTPase RalA was previously identified on dense granules of platelets and on synaptic vesicles in nerve terminals. Our observations suggest that RalA serves a role in regulated exocytosis of Weibel-Palade bodies in endothelial cells.

ADP Plays a Key Role in Thrombogenesis in Rats

1988 ◽  
Vol 59 (02) ◽  
pp. 225-230 ◽  
Author(s):  
J P Maffrand ◽  
A Bernat ◽  
D Delebassée ◽  
G Defreyn ◽  
J P Cazenave ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Bleeding Time ◽  
Thrombus Formation ◽  
Vascular Wall ◽  
Cyclooxygenase Inhibitors ◽  
High Dose ◽  
Silk Thread ◽  
Dense Granules ◽  
Prolonged Bleeding Time ◽  
Venous Shunt

SummaryThe relative importance of ADP, arachidonic acid metabolites and serotonin as thrombogenic factors was evaluated in rats by comparing, after oral administration, the effects of two inhibitors of ADP-induced platelet aggregation (ticlopidine and PCR 4099), three cyclo-oxygenase inhibitors (aspirin, triflusal and indobufen) and a selective serotonin 5HT2 receptor antagonist (ketanserin) on platelet aggregation, in four platelet-dependent thrombosis models and on bleeding time. Platelet aggregation induced by ADP and collagen was completely inhibited by ticlopidine and PCR 4099 whereas only the collagen aggregation was reduced by the cyclo-oxygenase inhibitors. Ketanserin or a depletion of platelet serotonin by reserpine did not affect platelet aggregation. Ticlopidine and PCR 4099 greatly prolonged rat tail transection bleeding time. This is probably related to their known ability to inhibit ADP-mediated platelet aggregation. In contrast, the cyclooxygenase inhibitors did not affect bleeding time at all. Reserpine and ketanserin prolonged bleeding time by interfering with the action of serotonin on the vascular wall. Ticlopidine and PCR4099 were very potent antithrombotics in all the models. Aspirin, only at a high dose, inhibited poorly thrombus formation on a silk thread in an arterio-venous shunt, suggesting that the inhibition of cyclo-oxygenase was not responsible. Triflusal was inactive in all models while indobufen slightly reduced thrombus formation in the silk thread and metallic coil models. Ketanserin and reserpine reduced thrombus only in the metallic coil model. Thrombus formation was greatly reduced in fawn-hooded rats, which lack ADP in their platelet dense granules because of a genetic storage pool deficiency. Taken together, the results obtained with the drugs and with the fawn-hooded rats support the concept that ADP plays a key role in thrombogenesis in rats.

Smooth Muscle Proliferation in Chronically Injured Canine Pulmonary Arteries Is Reduced by a Potent Platelet Aggregation Inhibitor U-53,059

1985 ◽  
Vol 53 (03) ◽  
pp. 351-355 ◽  
Author(s):  
Robert G Schaub ◽  
James C Keith ◽  
Carol A Simmons ◽  
Clarence A Rawlings
Keyword(s):  
Smooth Muscle ◽  
Platelet Aggregation ◽  
Dirofilaria Immitis ◽  
Leukocyte Adhesion ◽  
Pulmonary Arteries ◽  
Cell Loss ◽  
Endothelial Cell Loss ◽  
Dense Granules ◽  
Smooth Muscle Proliferation ◽  
Aggregation Inhibitor

Summary Dirofilaria immitis (DI) infection chronically injures canine pulmonary arteries. This injury produces endothelial cell loss, platelet/leukocyte adhesion, and smooth muscle proliferation. In the present study we assessed the effect of the cyclooxygenase inhibitor, U-53,059, on platelet function, platelet kinetics, coagulation, and smooth muscle proliferation in DI infected dogs.Platelet aggregation to the combination of arachidonic acid/ ADP was significantly inhibited by U-53,059. Coagulation and hematologic parameters were not effected by either DI infection or U-53,059 treatment. Platelet survival and the number of platelet dense granules were reduced in DI infection. Quantification of the lesions demonstrated that U-53,059 reduced both severity and density compared to non-treated dogs. U-53,059 is a potent and effective inhibitor of platelet aggregation which modifies smooth muscle proliferation produced by chronic vascular injury.

Acanthamoeba Species in Tap Water, Egypt

2017 ◽  
Vol 9 (1) ◽  
Author(s):  
Ahmad Z Al-Herrawy ◽  
Mohamed A Marouf ◽  
Mahmoud A. Gad
Keyword(s):  
Water Samples ◽  
Tap Water ◽  
Pcr Analysis ◽  
Pulmonary Infections ◽  
Clinical Syndromes ◽  
Acanthamoeba Species ◽  
Amebic Encephalitis ◽  
Acanthamoeba Culbertsoni ◽  
Autumn And Winter

Genus Acanthamoeba causes 3 clinical syndromes amebic keratitis, granulomatous amebic encephalitis and disseminated granulomatous amebic disease (eg, sinus, skin and pulmonary infections). A total of 144 tap water samples were collected from Giza governorate, Egypt. Samples were processed for detection of Acanthamoeba species using non-nutrient agar (NNA) and were incubated at 30oC. The isolates of Acanthamoeba were identified to species level based on the morphologic criteria. Molecular characterization of the Acanthamoeba isolates to genus level was performed by using PCR. The obtained results showed that the highest occurrence percentage of Acanthamoeba species in water samples was observed in summer season (38.9%), then it decreased to be 30.6% in spring and 25% in each of autumn and winter. PCR analysis showed that 100% of 43 Acanthamoeba morphologically positive samples were positive by genus specific primer. In the present study eight species of Acanthamoeba can be morphologically recognized namely Acanthamoeba triangularis, Acanthamoeba echinulata, Acanthamoeba astronyxis, Acanthamoeba comandoni, Acanthamoeba griffini, Acanthamoeba culbertsoni, Acanthamoeba quina and Acanthamoeba lenticulata. In conclusion, the most common Acanthamoeba species in tap water was Acanthamoeba comandoni

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