Platelet activity and genetics of MAO B: How do they relate to impulsivity and aggression?

SummarySmoking is a risk factor for the development of atherosclerotic cardiovascular disease, in men as well as in women. An increased urinary excretion of the thromboxane metabolite 2,3-dinor-thromboxane B2 (Tx-M) has been observed in smokers of both genders, suggesting that cigarette smoking may facilitate cardiovascular disease via an action on the platelets. The present study addressed the hypothesis that the increased Tx-M excretion in female smokers reflects a true facilitation of platelet reactivity in vivo, rather than an increased destruction of the platelets. In healthy female volunteers (aged 20–46 years, 18 smokers and 17 non-smokers) platelet life-span and indices of platelet activity were determined, together with plasma levels of plasminogen activator inhibitor-1 (PAI-1), fibrinogen, peripheral blood cell counts and hematocrit. The urinary excretion of Tx-M was higher in smokers than in non-smokers (361 vs. 204 pg/mg creatinine, respectively, p <0.05), while plasma and urinary β-thromboglobulin, plasma platelet factor 4, platelet mean life-span and platelet production rate did not differ between the groups. PAI-1 activity, white blood cell count and hematocrit were higher in smokers than in non-smokers (p <0.05). These data indicate that smoking facilitates platelet formation of thromboxane A2 without affecting platelet survival; i.e. it increases the activity of platelets without affecting their viability to a measurable extent. Such an increase in platelet activity, operating in parallel to a reduced fibrinolytic activity and a higher hematocrit and white blood cell count, may play an etiological role in smoking-induced cardiovascular disease in women.

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Measurement of the Platelet Response to Laser- induced Microvascular Injury

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648118 ◽

1974 ◽

Vol 32 (02/03) ◽

pp. 704-713 ◽

Cited By ~ 2

Author(s):

F. N McKenzie ◽

K.-E Arfors ◽

N. A Matheson

Keyword(s):

Inhibitory Effect ◽

Microvascular Blood Flow ◽

Platelet Response ◽

High Concentration ◽

Platelet Activity ◽

Microvascular Injury ◽

Arterial Blood ◽

Proximal Site ◽

Adenosine Phosphates

SummaryA study has been made of the biochemical factors underlying the platelet response to laser-induced microvascular injury. A platelet aggregating substance is produced at sites of laser-induced injury which markedly stimulates platelet activity at a site of injury inflicted a short distance downstream. Distal sites of injury are not similarly influenced if the distance between the injuries is increased or if the proximal site no longer shows platelet-stimulating activity. The stimulating effect of an adjacent proximal injury on platelet activity at a distal site is inhibited by local intra-arterial infusion of adenosine. Measurements of arterial blood pressure and microvascular blood flow velocity during adenosine infusion showed that its inhibitory effect on platelet activity is largely independent of its vasodilator properties. The effect of infusion of different adenosine phosphates (AMP, ADP, ATP) was also studied. Very small amounts of ADP markedly stimulated platelet activity and the emboli formed were similar to those normally produced at sites of laser injury. At high concentration AMP inhibited while ATP stimulated platelet activity in vivo. The results emphasise the fundamental role of ADP as a mediator of the platelet response at sites of laser- induced microvascular injury.

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The Spectrum of von Willebrand’s Disease

Thrombosis and Haemostasis ◽

10.1055/s-0038-1655015 ◽

1967 ◽

Vol 18 (01/02) ◽

pp. 040-056 ◽

Cited By ~ 13

Author(s):

E. J Walter Bowie ◽

P Didisheim ◽

J. H Thompson ◽

C. A Owen

Keyword(s):

Factor Viii ◽

Bleeding Time ◽

Severe Bleeding ◽

Platelet Adhesiveness ◽

Platelet Activity ◽

Von Willebrand's Disease ◽

Von Willebrand’S Disease ◽

The Third ◽

Generation Test

SummaryPatients (from 5 kindreds) with variants of von Willebrand’s disease are described. In one kindred the depression of factor VIII was moderate (20 to 40% of normal) and transfusion of 500 ml of normal plasma led to an increase higher than anticipated and to an almost normal level of factor VIII 17 to 24 hrs later. This represents the usual type of von Willebrand’s disease.In the second kindred the concentration of factor VIII was less than 2 % of normal in the son and daughter, who had severe bleeding and hemarthroses.The third kindred was characterized by reduction of factor VIII and a long bleeding time as well as by a serum defect in the thromboplastin-generation test comparable to that seen in patients with hemophilia B, yet with normal levels of factors IX, X, and VII. The severity of the serum defect, the positive result with the Rumpel-Leede test, and the reduced platelet activity in the thromboplastin-generation test are all compatible with the diagnosis of thrombopathy or ‘‘thrombopathic hemophilia.” In two other kindreds, one patient had a long bleeding time and normal levels of factor VIII and another had a normal bleeding time and decrease of factor VIII. The last patient had the type of response to transfusion usually seen in von Willebrand’s disease.In four kindreds, platelet adhesiveness in vivo was found to be strikingly abnormal (virtually absent).It would appear, therefore, that von Willebrand’s disease forms a spectrum, and whether the kindreds reported simply reflect variations of a single genetic disease state or represent separate entities will be answered only by clarification of the underlying etiology of that disease.

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Decrease of Platelet Activity After Intake of Small Amounts of Eicosapentaenoic Acid in Diabetics

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657299 ◽

1982 ◽

Vol 48 (03) ◽

pp. 344-344 ◽

Cited By ~ 19

Author(s):

B Velardo ◽

M Lagarde ◽

M Guichardant ◽

M Dechavanne ◽

M Beylot ◽

...

Keyword(s):

Eicosapentaenoic Acid ◽

Platelet Activity

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Off-Pump Coronary Artery Bypass Surgery May Produce a Hypercoagulable Patient

The Heart Surgery Forum ◽

10.1532/hsf.698 ◽

2005 ◽

Vol 6 (2) ◽

pp. 94 ◽

Cited By ~ 23

Author(s):

Robert L. Quigley ◽

David W. Fried ◽

John Pym ◽

Richard Y. Highbloom

Keyword(s):

Coronary Artery ◽

Coronary Artery Bypass ◽

Heart Surgery ◽

Artery Bypass ◽

Open Heart Surgery ◽

Anticoagulation Therapy ◽

Maximum Amplitude ◽

Platelet Activity ◽

Off Pump ◽

Pump Coronary Artery Bypass

Background: The incidence of thromboembolic events following traditional open heart surgery has not been clinically significant. However, with beating heart surgery, for which cardiopulmonary bypass (CPB) is not required, the incidence of spontaneous intravascular thrombosis may be similar to that encountered after general surgeries. Compounding this risk is that many cases of off-pump coronary artery bypass (OPCAB) surgery are reserved for the elderly patient with multiple comorbidities. The few studies to date that have assessed the coagulation profile in OPCAB patients have been limited to the first 24 hours after surgery. Methods: We prospectively studied 17 OPCAB and 6 on-pump patients over 4 days (hospital course) with daily thromboelastography. A coagulation index (CI) (reflecting R and K times, a angle, and maximum amplitude [MA]) was calculated for the patients, who served as their own controls. Results: The OPCAB patients demonstrated 3 days postoperatively a 17% increase in coagulation compared with the baseline. Specifically, the CI consistently revealed an elevation in the a angle and the MA, both of which reflect increased fibrinogen and platelet activity. On the other hand, 3 days following surgery the CI of the CPB group was tightly clustered around their respective baseline CI values, which had recovered from a significant decrease immediately after surgery. Conclusion: A state of hypercoagulability, as measured by thromboelastography, exists in the OPCAB patient beyond the first postoperative day, and this finding suggests that prophylactic postoperative anticoagulation therapy targeting fibrinogen and platelet activity may be indicated for these patients.

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A Study in Healthy Men to Test the Effects of Different Doses of BI 1467335 on MAO-B Activity in the Brain.

Case Medical Research ◽

10.31525/ct1-nct03927209 ◽

2019 ◽

Author(s):

Keyword(s):

Healthy Men ◽

Mao B ◽

The Brain ◽

Different Doses

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Targeting COVID-19 in Parkinson’s patients: Drugs repurposed.

Current Medicinal Chemistry ◽

10.2174/0929867327666200903115138 ◽

2020 ◽

Vol 27 ◽

Author(s):

Firoz Anwar ◽

Salma Naqvi ◽

Fahad A. Al-Abbasi ◽

Nauroz Neelofar ◽

Vikas Kumar ◽

...

Keyword(s):

Day Treatment ◽

Treatment Options ◽

Developed Countries ◽

Methyl Transferase ◽

Comt Inhibitors ◽

Mao B ◽

Pharmacokinetic Properties ◽

Us Fda ◽

Approved Drugs ◽

Fda Approved Drugs

: The last couple of months have witnessed the world in a state of virtual standstill. The SARS-CoV-2 virus has overtaken globe to economic and social lockdown. Many patients with COVID-19 have compromised immunity, especially in an aged population suffering from Parkinson disease (PD). Alteration in dopaminergic neurons or deficiency of dopamine in PD patients is the most common symptoms affecting 1% population above the age of 60 years. The compromised immune system and inflammatory manifestation in PD patients make them an easy target. The most common under trial drugs for COVID-19 are Remdesivir, Favipiravir, Chloroquine and Hydroxychloroquine, Azithromycin along with adjunct drugs like Amantadine with some monoclonal antibodies. : Presently, clinically US FDA approved drugs in PD includes Levodopa, catechol-O-methyl transferase (COMT) inhibitors, (Entacapone and Tolcapone), Dopamine agonists (Bromocriptine, Ropinirole, Pramipexole, and Rotigotine), Monoamine oxidase B (MAO-B) inhibitors (Selegiline and Rasagiline), Amantadine and Antimuscarinic drugs. The drugs have established mechanism of action on PD patients with known pharmacodynamics and pharmacokinetic properties along with dose and adverse effects. : Conclusion and relevance of this review focus on the drugs that can be tried for the PD patients with SAR CoV-2 infection, in particular, Amantadine approved by all developed countries a common drug possessing both antiviral properties by downregulation of CTSL, lysosomal pathway disturbance and change in pH necessary to uncoat the viral proteins and antiParkinson properties. The significant prognostic adverse effect of SARS-CoV-2 on PD and the present-day treatment options, clinical presentation and various mechanism is warrant need of the hour.

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Dendrobium officinalis Flower Improves Learning and Reduces Memory Impairment by Mediating Antioxidant Effect and Balancing the Release of Neurotransmitters in Senescent Rats

Combinatorial Chemistry & High Throughput Screening ◽

10.2174/1386207323666200407080352 ◽

2020 ◽

Vol 23 (5) ◽

pp. 402-410 ◽

Cited By ~ 1

Author(s):

Lin-Zi Li ◽

Shan-Shan Lei ◽

Bo Li ◽

Fu-Chen Zhou ◽

Ye-Hui Chen ◽

...

Keyword(s):

Learning And Memory ◽

Brain Aging ◽

Morris Water Maze Test ◽

Control Group ◽

Histopathological Analysis ◽

Hippocampal Damage ◽

Common Belief ◽

Mao B ◽

Positive Effects ◽

The Brain

Aim and Objective: The Dendrobium officinalis flower (DOF) is popular in China due to common belief in its anti-aging properties and positive effects on “nourish yin”. However, there have been relatively few confirmatory pharmacological experiments conducted to date. The aim of this work was to evaluate whether DOF has beneficial effects on learning and memory in senescent rats, and, if so, to determine its potential mechanism of effect. Materials and Methods: SD rats were administrated orally DOF at a dose of 1.38, or 0.46 g/kg once a day for 8 weeks. Two other groups included a healthy untreated control group and a senescent control group. During the 7th week, a Morris water maze test was performed to assess learning and memory. At the end of the experiment, serum and brain samples were collected to measure concentrations of antioxidant enzymes, including malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GSH-Px) in serum, and the neurotransmitters, including γ-aminobutyric acid (γ-GABA), Glutamic (Glu), and monoamine oxidase B (MAO-B) in the brain. Histopathology of the hippocampus was assessed using hematoxylin-eosin (H&E) staining. Results: The results suggested that treatment with DOF improved learning as measured by escape latency, total distance, and target quadrant time, and also increased levels of γ-GABA in the brain. In addition, DOF decreased the levels of MDA, Glu, and MAO-B, and improved SOD and GSHPx. Histopathological analysis showed that DOF also significantly reduced structural lesions and neurodegeneration in the hippocampus relative to untreated senescent rats. Conclusion: DOF alleviated brain aging and improved the spatial learning abilities in senescent rats, potentially by attenuating oxidative stress and thus reducing hippocampal damage and balancing the release of neurotransmitters.

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