Determinants of platelet kinetics: effects of pulmonary microembolism

We examined the mechanisms of platelet uptake in the lungs after alpha-thrombin-induced pulmonary microembolism. Platelets labeled with 111In-oxine were reinfused into chronically prepared sheep. Pulmonary microembolism resulted in an increase in lung platelet radioactivity (95.5 +/- 15.3%; n = 4), which was followed by an exponential washout (half-life = 115 +/- 4 min). Platelet uptake in the lungs was more sustained after prior fibrinolytic inhibition with tranexamic acid (half-life = 178 +/- 11 min), although the initial increase was similar (90.7 +/- 9.6%; n = 7). Prior depletion of fibrinogen with ancrod (Arvin), blunted the initial increase in lung platelet uptake after alpha-thrombin challenge (31.7 +/- 11.3%, n = 5), indicating that the effect of thrombin was markedly dependent on fibrinogen. We examined the role of circulating granulocytes, since platelets may bind to subendothelial matrix exposed after granulocyte-mediated lung vascular injury. Maximal pulmonary platelet uptake after thrombin in granulocytopenic sheep was not different from control (71.7 +/- 14.4%; n = 4). The results indicate that pulmonary microembolism results in lung platelet sequestration. Platelet uptake is not dependent on granulocyte-mediated vascular injury but requires fibrin deposition and is sustained if fibrinolysis is inhibited.

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Binding of 131I-Labeled Tissue-Type Plasminogen Activator on De-Endothelialized Lesions in Rabbits

Nuklearmedizin ◽

10.1055/s-0038-1628893 ◽

1987 ◽

Vol 26 (05) ◽

pp. 224-228 ◽

Cited By ~ 2

Author(s):

Y. Isaka ◽

H. Etani ◽

K. Kimura ◽

S. Yoneda ◽

T. Kamada ◽

...

Keyword(s):

Plasminogen Activator ◽

Abdominal Aorta ◽

Half Life ◽

Balloon Catheter ◽

Biochemical Properties ◽

Tissue Type ◽

Fibrin Deposition ◽

Tissue Type Plasminogen Activator ◽

High Affinity ◽

Type Plasminogen Activator

Tissue-type plasminogen activator (t-PA) which has a high affinity for fibrin in the clot, was labeled with 131I by the iodogen method, and its binding to de-endothelialized lesions in the rabbit was measured to assess the detectability of thrombi. The de-endothelialized lesion was induced in the abdominal aorta with a Fogarty 4F balloon catheter. Two hours after the de-endothelialization, 131I-labeled t-PA (125 ± 46 μCi) was injected intravenously. The initial half-life of the agent in blood (n = 12) was 2.9 ± 0.4 min. The degree of binding of 131I-labeled t-PA to the de-endothelialized lesion was evaluated at 15 min (n = 6) or at 30 min (n = 6) after injection of the agent. In spite of the retention of the biochemical properties of 131I-labeled t-PA and the presence of fibrin deposition at the de-endothelialized lesion, the binding of t-PA to the lesion was not sufficiently strong. Lesion-to-control ratios (cpm/g/cpm/g) were 1.65 ± 0.40 (at 15 min) and 1.39 ± 1.31 (at 30 min), and lesion-to-blood ratios were 1.39 ± 0.32 (at 15 min) and 1.36 ± 0.23 (at 30 min). These results suggest that radiolabeled t-PA may be inappropriate as a radiopharmaceutical for the scintigraphic detection of a pre-existing thrombotic lesion.

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The Role of Tranexamic Acid in Controlling Bloodloss During PCNL for Staghorn Calculi

Revista de Chimie ◽

10.37358/rc.18.12.6833 ◽

2019 ◽

Vol 69 (12) ◽

pp. 3745-3748

Author(s):

Raluca Costina Barbilian ◽

Victor Cauni ◽

Bogdan Mihai ◽

Ioana Buraga ◽

Mihai Dragutescu ◽

...

Keyword(s):

Blood Loss ◽

Tranexamic Acid ◽

Percutaneous Nephrolithotomy ◽

Kidney Stones ◽

Postoperative Bleeding ◽

Invasive Technique ◽

Transfusion Rate ◽

Staghorn Calculi ◽

Type Of Surgery

The aim of this paper is to assess the efficiency and safety of the tranexamic acid in reducing blood loss and the need for transfusion in patients diagnosed with staghorn calculi treated by percutaneous nephrolithotomy. Percutaneous nephrolithotomy (PCNL) is a minimally invasive technique used for large kidney stones. Hemorrhagic complications and urinary sepsis are serious complications associated with this type of surgery. Tranexamic acid is an antifibrinolytic drug that has the property of reducing intra or postoperative bleeding. The experience with tranexamic acid in preventing blood loss during percutaneous nephrolithotomy for is limited. The use tranexamic acid in percutaneous nephrolithotomy for staghorn type stones is safe and is associated with reduced blood loss and a lower transfusion rate.

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Tcf4 Is Involved in Subset Specification of Mesodiencephalic Dopaminergic Neurons

Biomedicines ◽

10.3390/biomedicines9030317 ◽

2021 ◽

Vol 9 (3) ◽

pp. 317

Author(s):

Simone Mesman ◽

Iris Wever ◽

Marten P. Smidt

Keyword(s):

Neuronal Differentiation ◽

Dopaminergic Neurons ◽

Neuronal Development ◽

Neuronal Population ◽

Minor Role ◽

Initial Increase ◽

E Box ◽

A Minor ◽

Bhlh Factor

During development, mesodiencephalic dopaminergic (mdDA) neurons form into different molecular subsets. Knowledge of which factors contribute to the specification of these subsets is currently insufficient. In this study, we examined the role of Tcf4, a member of the E-box protein family, in mdDA neuronal development and subset specification. We show that Tcf4 is expressed throughout development, but is no longer detected in adult midbrain. Deletion of Tcf4 results in an initial increase in TH-expressing neurons at E11.5, but this normalizes at later embryonic stages. However, the caudal subset marker Nxph3 and rostral subset marker Ahd2 are affected at E14.5, indicating that Tcf4 is involved in correct differentiation of mdDA neuronal subsets. At P0, expression of these markers partially recovers, whereas expression of Th transcript and TH protein appears to be affected in lateral parts of the mdDA neuronal population. The initial increase in TH-expressing cells and delay in subset specification could be due to the increase in expression of the bHLH factor Ascl1, known for its role in mdDA neuronal differentiation, upon loss of Tcf4. Taken together, our data identified a minor role for Tcf4 in mdDA neuronal development and subset specification.

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Role of glaciers in watershed hydrology: a preliminary study of a "Himalayan catchment"

The Cryosphere ◽

10.5194/tc-4-115-2010 ◽

2010 ◽

Vol 4 (1) ◽

pp. 115-128 ◽

Cited By ~ 123

Author(s):

R. J. Thayyen ◽

J. T. Gergan

Keyword(s):

Mass Balance ◽

River Flow ◽

Initial Increase ◽

Glacier Mass Balance ◽

Mountain Range ◽

Humid Climate ◽

Flow Response ◽

Sustainable Water Resources Management ◽

South West Monsoon

Abstract. A large number of Himalayan glacier catchments are under the influence of humid climate with snowfall in winter (November–April) and south-west monsoon in summer (June–September) dominating the regional hydrology. Such catchments are defined as "Himalayan catchment", where the glacier meltwater contributes to the river flow during the period of annual high flows produced by the monsoon. The winter snow dominated Alpine catchments of the Kashmir and Karakoram region and cold-arid regions of the Ladakh mountain range are the other major glacio-hydrological regimes identified in the region. Factors influencing the river flow variations in a "Himalayan catchment" were studied in a micro-scale glacier catchment in the Garhwal Himalaya, covering an area of 77.8 km2. Three hydrometric stations were established at different altitudes along the Din Gad stream and discharge was monitored during the summer ablation period from 1998 to 2004, with an exception in 2002. These data have been analysed along with winter/summer precipitation, temperature and mass balance data of the Dokriani glacier to study the role of glacier and precipitation in determining runoff variations along the stream continuum from the glacier snout to 2360 m a.s.l. The study shows that the inter-annual runoff variation in a "Himalayan catchment" is linked with precipitation rather than mass balance changes of the glacier. This study also indicates that the warming induced an initial increase of glacier runoff and subsequent decline as suggested by the IPCC (2007) is restricted to the glacier degradation-derived component in a precipitation dominant Himalayan catchment and cannot be translated as river flow response. The preliminary assessment suggests that the "Himalayan catchment" could experience higher river flows and positive glacier mass balance regime together in association with strong monsoon. The important role of glaciers in this precipitation dominant system is to augment stream runoff during the years of low summer discharge. This paper intends to highlight the importance of creating credible knowledge on the Himalayan cryospheric processes to develop a more representative global view on river flow response to cryospheric changes and locally sustainable water resources management strategies.

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THE ROLE OF VASCULAR INJURY IN PULMONARY ALLOGRAFT REJECTION

Transplantation Journal ◽

10.1097/00007890-196601000-00008 ◽

1966 ◽

Vol 4 (1) ◽

pp. 66-78 ◽

Cited By ~ 21

Author(s):

MARTIN H. FLAX ◽

BENJAMIN A. BARNES

Keyword(s):

Vascular Injury ◽

Allograft Rejection

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Expression of Concern: Dysregulation of Claudin-5 in HIV-induced Interstitial Pneumonitis and Lung Vascular Injury: Protective Role of PPAR-γ

American Journal of Respiratory and Critical Care Medicine ◽

10.1164/ajrccm.186.3.e5 ◽

2012 ◽

Vol 186 (3) ◽

pp. e5-e5

Keyword(s):

Vascular Injury ◽

Interstitial Pneumonitis ◽

Protective Role ◽

Ppar Γ

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Role of Tranexamic Acid in Oral Surgery

Indian Journal of Public Health Research & Development ◽

10.37506/ijphrd.v11i6.9882 ◽

2020 ◽

Keyword(s):

Tranexamic Acid ◽

Oral Surgery

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Half-Life Systematics across theN=126Shell Closure: Role of First-Forbidden Transitions in theβDecay of Heavy Neutron-Rich Nuclei

Physical Review Letters ◽

10.1103/physrevlett.113.022702 ◽

2014 ◽

Vol 113 (2) ◽

Cited By ~ 32

Author(s):

A. I. Morales ◽

J. Benlliure ◽

T. Kurtukián-Nieto ◽

K.-H Schmidt ◽

S. Verma ◽

...

Keyword(s):

Half Life ◽

Forbidden Transitions

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Prophylaxis for Hemophilia in the Era of Extended Half-Life Factor VIII/Factor IX Products

Seminars in Thrombosis and Hemostasis ◽

10.1055/s-0036-1571315 ◽

2016 ◽

Vol 42 (05) ◽

pp. 518-525 ◽

Cited By ~ 34

Author(s):

Erik Berntorp ◽

Nadine Andersson

Keyword(s):

Half Life ◽

Safety Margin ◽

Clinical Development ◽

Factor Ix ◽

Life Extension ◽

Bleeding Events ◽

Treatment And Prevention ◽

Trough Levels ◽

Life Factor

There are two main bioengineering approaches to extending the half-life of factor (F)VIII or FIX products used for hemophilia replacement therapy. These are fusion to Fc-immunoglobulin G (FVIII and FIX) or to albumin (FIX) or pegylation/glycopegylation (FVIII and FIX). Four FVIII and three FIX products are in clinical development or have recently been licensed in regions of the world. The reported half-life extension is approximately 1.5-fold for FVIII and 2.5-fold, or even longer, for FIX. Clinical trials have shown promising results with respect to extension of dose intervals and efficacy in the treatment and prevention of bleeding events. The role of these products in clinical practice has been discussed in terms of either improving convenience and adherence through prolongation of the interval between infusions or maintaining current intervals thereby increasing trough levels and the safety margin against bleeds. This review of extended half-life products addresses the possibilities and problems of their introduction in hemophilia treatment.

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