Application of flow cytometry to platelet disorders.

Flow cytometry is a powerful and versatile tool that can be used to yield definitive information regarding the phenotypic status of platelets. The method provides a quantitative assessment of the physical and antigenic properties of platelets (e.g.

In vitro testing of fresh and lyophilized reconstituted human and baboon platelets.

Background: Studies have been performed on human fresh, liquid-preserved, and cryopreserved platelets (PLTs) to assess PLT-adhesive surface receptors, PLT membrane procoagulant activity, PLT aggregation, and thromboxane production. Lyophilization has been developed as a method to preserve PLTs. This study was performed to evaluate these measurements on human and baboon fresh and lyophilized reconstituted PLTs.

Release of soluble CD40L from platelets is regulated by glycoprotein IIb/IIIa and actin polymerization.

Objectives: The purpose of this study was to examine the effects of glycoprotein (GP) IIb/IIIa antagonists (abciximab, eptifibatide, and tirofiban) and other inhibitors on translocation of CD40L from intraplatelet stores to the platelet surface and on the release of soluble CD40L (sCD40L) from platelets.

Background: CD40L is a proinflammatory and prothrombotic ligand in the tumor necrosis factor family.

Methods: Platelet surface CD40L was measured by flow cytometry, and sCD40L was measured by enzyme-linked immunosorbent assay.

The impact of parental problem drug use on children: what is the problem and what can be done to help?

Aim: To review the literature on the impact of parental problem drug use on children, and indicate the efficacy of key evaluated interventions to reduce the impact of parental drug use on children.

Methods: Comprehensive narrative review of English language published research and intervention spanning the last three decades identified through searching library databases and citation.

Findings: Problem drug use can impede parenting and the provision of a nurturing environment.

Combined effects of mild hypothermia and glycoprotein IIb/IIIa antagonists on platelet-platelet and leukocyte-platelet aggregation.

Endovascular cooling was assessed as a potential treatment for percutaneous coronary intervention in patients with acute myocardial infarction. Here we show that mild hypothermia: (1) inhibits platelet aggregation; (2) augments eptifibatide- and tirofiban- but not abciximab-induced inhibition of platelet aggregation; (3) increases the formation of adenosine diphosphate-induced leukocyte-platelet aggregates; and (4) diminishes the glycoprotein IIb/IIIa antagonist-induced decrease in leukocyte-platelet aggregates.

A community-based intervention for siblings and parents of children with chronic illness or disability: the ISEE study.

Objective: Siblings of children with chronic illness or disability have been reported to have a 1.6 to 2.0 risk for behavioral and mental health problems.

Management of uncontrolled hypertension in a nurse-led clinic compared with conventional care for patients with type 2 diabetes.

Objective: To compare the effectiveness of a nurse-led hypertension clinic with conventional community care in general practice in the management of uncontrolled hypertension in patients with type 2 diabetes.

Research Design And Methods: We studied 120 men and women outpatient attendees (61% non-Caucasian) with type 2 diabetes and a seated blood pressure (BP) >or=140/80 mmHg. All patients were being treated for hypertension, and 71% had increased urinary albumin excretion (UAE).

Platelet FcgammaRIIA His131Arg polymorphism and platelet function: antibodies to platelet-bound fibrinogen induce platelet activation.

The His131Arg polymorphism of platelet FcgammaRIIA affects the binding affinity of certain IgG subclasses. The Arg131 allele has been associated with (auto)immune thrombocytopenia and heparin-induced thrombocytopenia in some studies. Because FcgammaRIIA can transmit platelet activation signals, we studied platelet responsiveness from 73 healthy donors to determine if this polymorphism modulated platelet function.

Treating childhood depression over videoconferencing.

Effective cognitive-behavioral treatments for childhood depression have developed over the last decade, but many families face barriers to such care. Telemedicine increases access to psychological interventions by linking the child and the clinician using videoconferencing (VC). The current study evaluated an 8-week, cognitive-behavioral therapy (CBT) intervention for childhood depression either face-to-face (F2F) or over VC.

Quantification of abciximab-induced platelet inhibition is assay dependent: a comparative study in patients undergoing percutaneous coronary intervention.

Background: The best method for measuring the degree of platelet inhibition with glycoprotein (GP) IIb-IIIa antagonists during percutaneous coronary intervention (PCI) and the optimal degree of periprocedural inhibition is uncertain. Low molecular weight heparins have been reported to cause less platelet activation than unfractionated heparin. Therefore, compared with unfractionated heparin (UHF), a low molecular weight heparin could enhance measured platelet inhibition.

The cleaved peptide of PAR1 is a more potent stimulant of platelet-endothelial cell adhesion than is thrombin.

Purpose: Platelet-endothelial cell adhesion is an important pathologic response to vessel injury or inflammation. On binding to its endothelial or platelet G protein-linked seven-transmembrane domain receptor, protease-activated receptor-1 (PAR1), thrombin releases a 41-amino acid peptide (TR(1-41)). We examined the effect of TR(1-41) on platelet activation and on platelet-endothelial cell adhesion.

Cardiac encasement by metastatic myxoid liposarcoma.

Isolated cardiac metastasis from a primary liposarcoma of noncardiac origin is a rare occurrence. A patient who presented with biventricular failure and constrictive hemodynamics years after successful resection of a primary liposarcoma of the thigh is described. Extensive cardiac encasement by tumor was suspected on diagnostic imaging.

Interrelationships among variables affecting well siblings and mothers in families of children with a chronic illness or disability.

A structural equation model (SEM) examined interrelationships among psychosocial variables known to affect the health and development of well siblings and parents when a child with a chronic illness or disability is a member of the family. Using dyads of 252 well children and parents, socioeconomic status (SES) and family cohesion were associated with the parent-reported behavior of the well sibling. SES also influenced the mood of the mother that in turn influenced family cohesion.

Platelet-monocyte aggregates in patients with chronic venous insufficiency remain elevated following correction of reflux.

Introduction: An increased number of circulating platelet-monocyte aggregates (PMAs) is present in patients with all clinical classes of chronic venous insufficiency (CVI). The purpose of this study was to determine whether patients with CVI maintain elevated levels of PMAs following complete surgical correction of chronic venous insufficiency.

Methods: Patients with superficial venous insufficiency and a normal deep venous system documented by duplex scan were included in the study.

Changes in brain size with treatment in patients with hyper- or hypothyroidism.

Background And Purpose: Although neuropsychological symptoms and signs are common in thyroid disease, their organic substrate is unknown. We performed brain MR imaging in patients with hyperthyroidism or hypothyroidism before and after treatment and correlated the results with hormonal markers.

Methods: Eight patients with hyperthyroid disease and three with hypothyroid disease underwent imaging within 1-2 days of a thyroid hormone testing.

Evaluation and correction for a 'training effect' in the cognitive assessment of older adults.

Background: Repeated administration of psychometric instruments frequently results in a higher score on retesting, the so-called training effect. Yet, a training effect has been poorly considered in longitudinal studies of cognitive changes in older persons.

Methods: We investigated the presence, magnitude and potential adjustments for training effect in the older participants of the Systolic Hypertension in the Elderly Program (SHEP).

Leukocyte-platelet aggregation, platelet surface P-selectin, and platelet surface glycoprotein IIIa after percutaneous coronary intervention: Effects of dalteparin or unfractionated heparin in combination with abciximab.

Background: Plaque disruption with resultant platelet activation and leukocyte-platelet aggregation is a pathophysiologic process common to both acute coronary syndromes and percutaneous coronary interventions. Unfractionated heparin is a standard antithrombotic therapy in patients with both acute coronary syndromes and in those undergoing percutaneous coronary interventions. Low-molecular-weight heparins have been reported to cause less platelet activation than unfractionated heparin.

Circulating monocyte-platelet aggregates are an early marker of acute myocardial infarction.

Objectives: We investigated whether elevated levels of circulating monocyte-platelet aggregates (MPA) can be used to identify patients with acute myocardial infarction (AMI).

Background: Commonly used blood markers of AMI reflect myocardial cell death, but do not reflect the earlier pathophysiologic processes of plaque rupture, platelet activation and resultant thrombus formation. Circulating MPA form after platelet activation.

Circulating monocyte-platelet aggregates are a more sensitive marker of in vivo platelet activation than platelet surface P-selectin: studies in baboons, human coronary intervention, and human acute myocardial infarction.

Background: Platelet surface P-selectin is considered the "gold standard" marker of platelet activation. Degranulated, P-selectin-positive platelets, however, aggregate with leukocytes in vitro and rapidly lose surface P-selectin in vivo.

Methods And Results: Flow cytometric tracking of autologous, biotinylated platelets in baboons enabled us to directly demonstrate for the first time in vivo that (1) infused degranulated platelets very rapidly form circulating aggregates with monocytes and neutrophils, and (2) 30 minutes after infusion of the degranulated platelets, the percentage of circulating monocytes aggregated with infused platelets persist at high levels, whereas the percentage of circulating neutrophils aggregated with infused platelets and the platelet surface P-selectin of nonaggregated infused platelets return to baseline.

Dissociation of glycoprotein IIb/IIIa antagonists from platelets does not result in fibrinogen binding or platelet aggregation.

Background: The primary mechanism of action of glycoprotein (GP) IIb/IIIa antagonists is inhibition of the final common pathway of platelet aggregation: fibrinogen binding to the GP IIb/IIIa complex. However, it has been reported that induction of fibrinogen binding and platelet aggregation is an intrinsic prothrombotic property of low-dose GP IIb/IIIa antagonists. These apparently paradoxical results have been extensively referenced in the cardiology literature.

Evaluating outpatient pediatric psychology services in a primary care setting.

Objective: To provide descriptive and outcome information of an outpatient pediatric psychology clinic based in a medical center in a major metropolitan area.

Methods: We coded the characteristics and outcomes of 100 patients prospectively on a number of dimensions. Surveys and interviews were used to gather follow-up information.

Serial determinations of platelet counts in mice by flow cytometry.

Elucidation of the pathophysiological basis of platelet disorders in murine models requires a reliable method for the frequent determinations of platelet counts in individual mice. Here, we present a rapid, reproducible and accurate flow cytometric method for enumeration of platelets that involves fluorescent staining of platelets in whole blood with specific antibody and the addition of known numbers of fluorescent beads for standardization of the sample volume. Analysis of platelets obtained by tail bleeding indicated that this sampling procedure did not activate platelets, and that only five microliters of blood were required for platelet counting.

Smoking cessation in pregnant women.

Cigarette smoking is considered the most significant modifiable cause of adverse pregnancy outcomes in US women. Smoking cessation in pregnant patients is one of the most effective ways to reduce negative pregnancy outcomes of fetal growth retardation, preterm delivery, and perinatal mortality. Research evidence documenting the effectiveness of health care provider interventions in smoking cessation has led to the PHS recommendation to screen and counsel every patient.