Filter bleeding time: A new in vitro test of hemostasis II. Application to the study of von willebrand disease and platelet function inhibitors

1983 ◽  
Vol 31 (1) ◽  
pp. 117-125 ◽  
Author(s):  
S. Uchiyama ◽  
J.Q. Stropp ◽  
D.A. Claypool ◽  
P. Didisheim
Keyword(s):  
Platelet Function ◽  
Bleeding Time ◽  
Von Willebrand Disease ◽  
In Vitro Test ◽  
Vitro Test ◽  
Von Willebrand

Patients with isolated prolonged in vitro bleeding time

2011 ◽  
Vol 31 (S 01) ◽  
pp. S64-S68
Author(s):  
M. Stein ◽  
K. Scholz ◽  
B. Llugaliu ◽  
G. Asmelash ◽  
W. Miesbach ◽  
...  
Keyword(s):  
Platelet Function ◽  
Von Willebrand Factor ◽  
Bleeding Time ◽  
Von Willebrand Disease ◽  
Treatment Concept ◽  
Main Symptom ◽  
Platelet Function Disorders ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryIn patients with isolated prolonged in vitro bleeding time there is no standardised treatment concept. With this study we characterized the extent of bleeding symptoms. Patients, methods All diagnoses known to cause prolonged in vitro bleeding time (PFA-100) (epinephrine-cartridge >160 s, ADP-cartridge > 120 s) have been excluded, such as platelet function disorders, effects of medications, nutrition or von Willebrand disease. 75 patients (77%, n = 58 women; 23%, n = 17 men, median age 46 (16–81) years were included. All bleeding symptoms have been stored in a databank with help of a comprehensive questionnaire. Results 78% (n = 54) of all patients reported of having had an operation, 69.8% (n = 37) of them described postoperative bleedings (p = 0.0373). 13.5% (n = 5) of the 54 could remember having been randomly treated by the administration of a transfusion and only 2.7% (n = 1) were treated by substitution of von Willebrand factor. 71% (n = 51) patients indicated haematoma (p = 0.8116). About 33.8% (n = 24) patients had gum bleeding and 40.8% (n = 29, p = 0.7808) patients reported bleeding after the dentist. 41.4% (n = 29) patients suffered under frequent epistaxis (p = 0.0212). There was no correlation between prolonged epinephrine bleeding time to VWF : Ag (rho = 0.16) nor to VWF : RCo (rho = 0.12) nor between prolonged epinephrine and ADP bleeding time (rho = 0.01) nor to ROTEM® analysis. Conclusion Patients with isolated prolonged PFA are mainly women and can be affected by all kinds of bleedings while haematoma is the main symptom. VWD might not be causal

Filter bleeding time: A new in vitro test of hemostasis I. Evaluation in normal and thrombocytopetic subjects

1983 ◽  
Vol 31 (1) ◽  
pp. 99-115 ◽  
Author(s):  
S. Uchiyama ◽  
J.Q. Stropp ◽  
D.A. Claypool ◽  
P. Didisheim ◽  
M.K. Dewanjee
Keyword(s):  
Bleeding Time ◽  
In Vitro Test ◽  
Vitro Test

Evaluation of the PFA-100® System in the Diagnosis and Therapeutic Monitoring of Patients with von Willebrand Disease

1999 ◽  
Vol 82 (07) ◽  
pp. 35-39 ◽  
Author(s):  
Augusto Federici ◽  
Anna Lecchi ◽  
Barbara Agati ◽  
Rossana Lombardi ◽  
Federica Stabile ◽  
...  
Keyword(s):  
Platelet Function ◽  
Bleeding Time ◽  
Von Willebrand Disease ◽  
Therapeutic Monitoring ◽  
High Shear ◽  
Before And After ◽  
Type 3 ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryWe have evaluated platelet function at high shear with the PFA-100® system in different subtypes of von Willebrand disease (vWD), before and after the intravenous infusions of desmopressin or a factor-VIII/von Willebrand factor (vWF) concentrate. Closure times with the PFA-100® system were determined for both the collagen/ADP and the collagen/epinephrine cartridges in 52 patients with vWD (9 type 1 “platelet normal”, 5 type 1 “platelet-discordant”, 8 type 1 “platelet-low”, 6 type 2A, 9 type 2B, 6 type 2M Vicenza, 6 type 3 and 3 acquired vWD) and 40 controls. Measurements were repeated 1 and 4 h after the i.v. infusion of desmopressin (0.3 μg/Kg) in 26 patients with types 1, type 2M Vicenza or type 2A vWD, or of a factorVIII/vWF concentrate (Alphanate HT, 60 U/Kg) in 4 patients with type 3 vWD. At all time points, vWF plasma levels and the bleeding time (Symplate II) were also determined. Baseline closure times were longer in vWD patients than in controls with both the collagen/ADP and the collagen/ epinephrine cartridges. The sensitivity of the PFA-100® system (88% and 87% with the two cartridges) was higher than that of the bleeding time (65%). Treatment with desmopressin normalized the closure times in patients with type 1 “platelet-normal” or type 2M Vicenza vWD, had no significant effects in patients with type 1 “platelet-low”, type 1 “platelet-discordant” or type 2A vWD. Infusion of a factorVIII/vWF concentrate in patients with type 3 vWD slightly shortened their prolonged closure times. In general, changes in PFA-100® were paralleled by shortenings of the bleeding times and increases in plasma vWF levels. The PFA-100® test reflects vWF-dependent platelet function under high shear stress and could be useful in the diagnosis and therapeutic monitoring of patients with vWD.

Flow Devices to Assess Platelet Function: Historical Evolution and Current Choices

2019 ◽  
Vol 45 (03) ◽  
pp. 297-301 ◽  
Author(s):  
Raisa Silva ◽  
Eric Grabowski
Keyword(s):  
Blood Flow ◽  
Platelet Function ◽  
Von Willebrand Disease ◽  
Cell Monolayers ◽  
Shear Rates ◽  
Platelet Disorders ◽  
Adhesive Proteins ◽  
Von Willebrand ◽  
Flow Devices

AbstractPlatelet function testing, which began more than a hundred years ago, is a time-consuming and uncertain process. Simulating hemostasis and the blood vessel microenvironment in vitro is challenging, which poses a difficulty for diagnosing platelet dysfunction and mild von Willebrand disease (VWD). In an effort to simulate the rheological microenvironment within blood vessels, several blood flow devices have been introduced since the 1980s. These devices are capable of reproducing the shear rates found in arterioles and venules, and of incorporating endothelial cell monolayers and surfaces with adsorbed platelet-adhesive proteins. The authors will describe and review here the presently most well-known blood flow devices. The technologies inherent in these devices offer a combination of physiologic accuracy and small blood volume requirements in the evaluation of platelet disorders and mild VWD (or “symptomatic low von Willebrand factor”) in flowing whole blood, with the potential to individualize therapeutic options for and to achieve greater diagnostic accuracy in mild platelet disorders and VWD.

Platelet Function and the Bleeding Time in Progressive Renal Failure

1988 ◽  
Vol 60 (01) ◽  
pp. 083-087 ◽  
Author(s):  
M P Gordge ◽  
R W Faint ◽  
P B Rylance ◽  
G H Neild
Keyword(s):  
Renal Failure ◽  
Platelet Aggregation ◽  
Platelet Function ◽  
Bleeding Time ◽  
C Reactive Protein ◽  
Severe Renal Failure ◽  
Reactive Protein ◽  
Thromboxane Production ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryBleeding time and platelet function tests were performed on 31 patients with progressive chronic renal failure (CRF) due to non-immunological (urological) causes, and compared with 22 healthy controls. Patients were classified as mild (plasma creatinine <300 μmol/l), moderate (300-600 μmol/l) or severe renal failure (>600 μmol/l). Bleeding time was rarely prolonged in mild and moderate CRF and mean bleeding time significantly elevated only in severe CRF (p <0.005). Haematocrit was the only index which correlated with bleeding time (r = -0.40). Platelet counts, collagen stimulated thromboxane generation, and platelet aggregation responses to ADP, collagen and ristocetin were all either normal or increased in all three CRF groups, but thromboxane production in clotting blood was reduced. Plasma fibrinogen, C reactive protein and von Willebrand factor (vWF) were elevated in proportion to CRF. We found no evidence that defects in platelet aggregation or platelet interaction with vWF prolong the bleeding time in patients with progressive CRF.

Haemostatic Platelet Plug Formation in the Isolated Rabbit Mesenteric Preparation - An Analysis of Red Blood Cell Participation

1980 ◽  
Vol 44 (01) ◽  
pp. 006-008 ◽  
Author(s):  
D Bergqvist ◽  
K-E Arfors
Keyword(s):  
Whole Blood ◽  
Platelet Rich Plasma ◽  
Adenosine Diphosphate ◽  
In Vitro Test ◽  
Pharmacological Agents ◽  
Vitro Test ◽  
Releasing Effect ◽  
Plug Formation

SummaryIn a model using an isolated rabbit mesenteric preparation microvessels were transected and the time until haemostatic plugs formed was registered. Perfusion of platelet rich plasma gave no haemostasis whereas whole blood did. Addition of chlorpromazine or adenosine to the whole blood significantly prolonged the time for haemostasis, and addition of ADP to the platelet rich plasma significantly shortened it. It is concluded that red cells are necessary for a normal haemostasis in this model, probably by a combination of a haemodynamic and ADP releasing effect.The fundamental role of platelets in haemostatic plug formation is unquestionable but there are still problems concerning the stimulus for this process to start. Three platelet aggregating substances have been discussed – thrombin, adenosine diphosphate (ADP) and collagen. Evidence speaking in favour of thrombin is, however, very minimal, and the discussion has to be focused on collagen and ADP. In an in vitro system using polyethylene tubings we have shown that "haemostasis" can be obtained without the presence of collagen but against these results can be argued that it is only another in vitro test for platelet aggregation (1).To be able to induce haemostasis in this model, however, the presence of red blood cells is necessary. To further study this problem we have developed a model where haemostatic plug formation can be studied in the isolated rabbit mesentery and we have briefly reported on this (2).Thus, it is possible to perfuse the vessels with whole blood as well as with platelet rich plasma (PRP) and different pharmacological agents of importance.

Evaluation of the Abnormal Platelet Function in von Willebrand Disease by the Blood Filtration Test

1996 ◽  
Vol 76 (03) ◽  
pp. 460-468 ◽  
Author(s):  
Francesco I Pareti ◽  
Marco Cattaneo ◽  
Luca Carpinelli ◽  
Maddalena L Zighetti ◽  
Caterina Bressi ◽  
...  
Keyword(s):  
Platelet Function ◽  
Relevant Information ◽  
Von Willebrand Disease ◽  
Type I ◽  
Cumulative Number ◽  
Primary Hemostasis ◽  
Normal Platelet ◽  
Filter Test ◽  
Type 3 ◽  
Von Willebrand

SummaryWe have evaluated platelet function in different subtypes of von Willebrand disease (vWD) by pushing blood through the capillarysized channels of a glass filter. Patients, including those with type IIB vWD, showed lower than normal platelet retention and increased cumulative number of blood drops passing through the filter as a function of time. In contrast, shear-induced platelet aggregation, measured in the cone-and-plate viscometer, was paradoxically increased in type IIB patients. Treatment with l-desamino-8-D-arginine vasopressin (DDAVP) tended to normalize the filter test in patients with type I-platelet normal and type I-platelet low vWD, but infusion of a factor VUI/von Willebrand factor (vWF) concentrate lacking the largest vWF multimers was without effect in type 3 patients. Experiments with specific monoclonal antibodies demonstrated that the A1 and A3 domains of vWF, as well as the glycoproteins Ibα and Ilb-IIIa on platelets, are required for platelet retention in the filter. Thus, the test may reflect vWF function with regard to both platelet adhesion and aggregation under high shear stress, and provide relevant information on mechanisms involved in primary hemostasis.

scholarly journals In Vitro Newly Isolated Environmental Phage Activity against Biofilms Preformed by Pseudomonas aeruginosa from Patients with Cystic Fibrosis

2021 ◽  
Vol 9 (3) ◽  
pp. 478
Author(s):  
Ersilia Vita Fiscarelli ◽  
Martina Rossitto ◽  
Paola Rosati ◽  
Nour Essa ◽  
Valentina Crocetta ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Multidrug Resistant ◽  
In Vitro Test ◽  
Chronic Infections ◽  
Hospital Environments ◽  
Vitro Test ◽  
General Reliability ◽  
Phage Activity

As disease worsens in patients with cystic fibrosis (CF), Pseudomonas aeruginosa (PA) colonizes the lungs, causing pulmonary failure and mortality. Progressively, PA forms typical biofilms, and antibiotic treatments determine multidrug-resistant (MDR) PA strains. To advance new therapies against MDR PA, research has reappraised bacteriophages (phages), viruses naturally infecting bacteria. Because few in vitro studies have tested phages on CF PA biofilms, general reliability remains unclear. This study aimed to test in vitro newly isolated environmental phage activity against PA isolates from patients with CF at Bambino Gesù Children’s Hospital (OBG), Rome, Italy. After testing in vitro phage activities, we combined phages with amikacin, meropenem, and tobramycin against CF PA pre-formed biofilms. We also investigated new emerging morphotypes and bacterial regrowth. We obtained 22 newly isolated phages from various environments, including OBG. In about 94% of 32 CF PA isolates tested, these phages showed in vitro PA lysis. Despite poor efficacy against chronic CF PA, five selected-lytic-phages (Φ4_ZP1, Φ9_ZP2, Φ14_OBG, Φ17_OBG, and Φ19_OBG) showed wide host activity. The Φ4_ZP1-meropenem and Φ14_OBG-tobramycin combinations significantly reduced CF PA biofilms (p < 0.001). To advance potential combined phage-antibiotic therapy, we envisage further in vitro test combinations with newly isolated phages, including those from hospital environments, against CF PA biofilms from early and chronic infections.

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