Kinetics of Platelet 5-Hydroxytryptamine Uptake in Headache Patients

Platelet 5-hydroxytryptamine (5-HT) uptake was measured in asymptomatic headache patients attending a specialist migraine clinic, and in hospital staff who did not suffer from regular or severe headache. Current levels of anxiety and depression were assessed in all subjects using the Hospital Anxiety and Depression (HAD) scale and their possible influence on the uptake kinetics taken into account during the analysis of results. The Michaelis-Menten constant (K m) was significantly raised in common migraine and tension headache compared with controls ( p < 0.001 and p < 0.01, respectively), but not in classical migraine or cluster headache. The increase remained significant after adjusting for differences in age, sex, presence of anxiety or depression (HAD sub-scale score 3 8), drug intake during the week before testing, time elapsed since last attack and time of assay (am or pm). No differences were observed between patients and controls in the maximal rate of uptake ( Vmax) or platelet count, and previous reports of a reduction in Vmax in patients experiencing attack within 5 days prior to testing could not be confirmed. The cause and significance of an increased K m are not clear, but plasma factors acting as competitive inhibitors for the uptake site or an alteration in the configuration of the uptake site are possible explanations. If confirmed, the shared biochemical abnormality may suggest that common migraine and tension headache have a common pathogenesis.

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Concentration and Uptake of 5-Hydroxytryptamine in Platelets from Cluster Headache and Migraine Patients

Cephalalgia ◽

10.1046/j.1468-2982.1985.0501045.x ◽

1985 ◽

Vol 5 (1) ◽

pp. 45-54 ◽

Cited By ~ 33

Author(s):

Elisabet Waldenlind ◽

Svante B Ross ◽

Jan Sääf ◽

Karl Ekbom ◽

Lennart Wetterberg

Keyword(s):

Cluster Headache ◽

Whole Blood ◽

Significant Positive Correlation ◽

Healthy Controls ◽

Platelet Monoamine Oxidase ◽

5 Ht Uptake ◽

Low K ◽

Kinetics Of ◽

Obvious Relation ◽

Headache Patients

Concentrations of 5-hydroxytryptamine (5-HT) in platelets were determined in 33 cluster headache patients (17 males) and in 34 migraine patients (16 males) outside attacks. The 5-HT uptake into platelets was measured and the kinetic constants Vmax and Km determined in 26 cluster patients (14 males) and in 30 migraine patients (13 males). Significantly lower 5-HT concentrations in whole blood were found in cluster headache and migraine patients than in 50 healthy controls (19 males). The Vmax and Km values of the 5-HT uptake were significantly lower in cluster headache and migraine patients compared with 22 healthy controls (9 males). The 5-HT concentrations and the kinetics of the 5-HT uptake did not differ between cluster headache and migraine. In healthy controls a significant positive correlation was found between the 5-HT uptake rate at 0.25 μM and Km but not in cluster headache and migraine patients. The 5-HT concentrations in whole blood correlated positively with Vmax and Km, respectively, in cluster headache and with Km in healthy controls but not with Vmax nor with Km in migraine. There was no obvious relation between the kinetics of platelet monoamine oxidase (MAO) and the 5-HT uptake except for an increased incidence of low Vmax of MAO and low Km of the 5-HT uptake in cluster headache. The kinetics of the 5-HT uptake was apparently not related to the state of migraine. The results indicate a possible constitutional trait in cluster headache and migraine expressed as low 5-HT concentrations in whole blood and low Vmax and Km of the 5-HT uptake into platelets.

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Abnormal Platelet Serotonin Uptake and Binding Sites in Myeloproliferative Disorders

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661099 ◽

1984 ◽

Vol 51 (03) ◽

pp. 349-353 ◽

Cited By ~ 9

Author(s):

C Caranobe ◽

P Sié ◽

F Fernandez ◽

J Pris ◽

S Moatti ◽

...

Keyword(s):

Binding Sites ◽

High Capacity ◽

Specific Inhibitor ◽

Myeloproliferative Disorders ◽

Normal Subjects ◽

Binding Data ◽

Full Explanation ◽

Number Of Binding Sites ◽

5 Ht Uptake ◽

Kinetics Of

SummaryA simultaneous investigation of the kinetics of serotonin (5 HT) uptake and of binding sites was carried out in the platelets of normal subjects and of 10 patients affected with various types of myeloproliferative disorders (MD). The 5 HT uptake was analysed according to the Lineweaver-Burk and the Eadie-Hofstee methods. With the two methods, the patient’s platelets exhibited a dramatic reduction of the Vi max and of the Km; in some patients the Eadie-Hofstee analysis revealed that a passive diffusion phenomenon is superimposed on the active 5 HT uptake at least for the higher concentration used. The binding data were analysed with the Scatchard method. Two classes of binding sites (high affinity - low capacity, low affinity - high capacity) were found in normal subjects and patients. Pharmacological studies with imipramine, a specific inhibitor of 5 HT uptake, suggested that both the sites are involved in 5 HT uptake. The number of both binding sites was significantly decreased in patient’s platelets while the affinity constants of these binding sites were not significantly reduced in comparison with those of the control subjects. No correlations were found between Vi max, Km and the number of binding sites. These results suggest that a reduction in the number of platelet membrane acceptors for 5 HT commonly occurs in myeloproliferative disorders but does not provide a full explanation of the uptake defect.

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Experimental and Kinetic Production of Ethanol Using Mucilage Juice Residues from Cocoa Processing

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2017-0262 ◽

2018 ◽

Vol 16 (11) ◽

Cited By ~ 2

Author(s):

Teresa Romero Cortes ◽

Jaime A. Cuervo-Parra ◽

Víctor José Robles-Olvera ◽

Eduardo Rangel Cortes ◽

Pablo A. López Pérez

Keyword(s):

Ethanol Yield ◽

Scale Up ◽

Pilot Scale ◽

Product Formation ◽

Model Parameters ◽

Pichia Kudriavzevii ◽

Proposed Model ◽

Analysis Of Results ◽

Residual Plots ◽

Kinetics Of

AbstractEthanol was produced using mucilage juice residues from processed cocoa with Pichia kudriavzevii in batch fermentation. Experimental results showed that maximum ethanol concentration was 13.8 g/L, ethanol yield was 0.50 g-ethanol/g glucose with a productivity of 0.25 g/L h. Likewise, a novel phenomenological model based on the mechanism of multiple parallel coupled reactions was used to describe the kinetics of substrate, enzyme, biomass and product formation. Model parameters were optimized by applying the Levenberg-Marquardt approach. Analysis of results was based on statistical metrics (such as confidence interval), sensitivity and by comparing calculated curves with the experimental data (residual plots). The efficacy of the proposed mathematical model was statistically evaluated using the dimensionless coefficient for efficiency. Results indicated that the proposed model can be applied as a way of augmenting bioethanol production from laboratory scale up to semi-pilot scale.

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Interleukin-6 Levels in Tension Headache Patients

Clinical Journal of Pain ◽

10.1097/ajp.0b013e3181e8d9b6 ◽

2010 ◽

pp. 1 ◽

Cited By ~ 2

Author(s):

Abdulkadir Koçer ◽

Emel Koçer ◽

Ramazan Memişoğullar ◽

Füsun M. Domaç ◽

Hatice Yüksel

Keyword(s):

Interleukin 6 ◽

Tension Headache ◽

Headache Patients

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The prevalence of stress, anxiety and depression within front-line healthcare workers caring for COVID-19 patients: a systematic review and meta-regression

Human Resources for Health ◽

10.1186/s12960-020-00544-1 ◽

2020 ◽

Vol 18 (1) ◽

Author(s):

Nader Salari ◽

Habibolah Khazaie ◽

Amin Hosseinian-Far ◽

Behnam Khaledi-Paveh ◽

Mohsen Kazeminia ◽

...

Keyword(s):

Systematic Review ◽

Sample Size ◽

Healthcare Workers ◽

Meta Analysis ◽

Research Work ◽

Hospital Staff ◽

Anxiety And Depression ◽

Front Line ◽

Prevalence Of Depression ◽

Meta Regression

Abstract Background Stress, anxiety, and depression are some of the most important research and practice challenges for psychologists, psychiatrists, and behavioral scientists. Due to the importance of issue and the lack of general statistics on these disorders among the Hospital staff treating the COVID-19 patients, this study aims to systematically review and determine the prevalence of stress, anxiety and depression within front-line healthcare workers caring for COVID-19 patients. Methods In this research work, the systematic review, meta-analysis and meta-regression approaches are used to approximate the prevalence of stress, anxiety and depression within front-line healthcare workers caring for COVID-19 patients. The keywords of prevalence, anxiety, stress, depression, psychopathy, mental illness, mental disorder, doctor, physician, nurse, hospital staff, 2019-nCoV, COVID-19, SARS-CoV-2 and Coronaviruses were used for searching the SID, MagIran, IranMedex, IranDoc, ScienceDirect, Embase, Scopus, PubMed, Web of Science (ISI) and Google Scholar databases. The search process was conducted in December 2019 to June 2020. In order to amalgamate and analyze the reported results within the collected studies, the random effects model is used. The heterogeneity of the studies is assessed using the I2 index. Lastly, the data analysis is performed within the Comprehensive Meta-Analysis software. Results Of the 29 studies with a total sample size of 22,380, 21 papers have reported the prevalence of depression, 23 have reported the prevalence of anxiety, and 9 studies have reported the prevalence of stress. The prevalence of depression is 24.3% (18% CI 18.2–31.6%), the prevalence of anxiety is 25.8% (95% CI 20.5–31.9%), and the prevalence of stress is 45% (95% CI 24.3–67.5%) among the hospitals’ Hospital staff caring for the COVID-19 patients. According to the results of meta-regression analysis, with increasing the sample size, the prevalence of depression and anxiety decreased, and this was statistically significant (P < 0.05), however, the prevalence of stress increased with increasing the sample size, yet this was not statistically significant (P = 0.829). Conclusion The results of this study clearly demonstrate that the prevalence of stress, anxiety and depression within front-line healthcare workers caring for COVID-19 patients is high. Therefore, the health policy-makers should take measures to control and prevent mental disorders in the Hospital staff.

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Kinetics of serotonin uptake in isolated rabbit lungs

Journal of Applied Physiology ◽

10.1152/jappl.1989.66.5.2328 ◽

1989 ◽

Vol 66 (5) ◽

pp. 2328-2337 ◽

Cited By ~ 5

Author(s):

F. A. Peeters ◽

T. A. Bronikowski ◽

C. A. Dawson ◽

J. H. Linehan ◽

H. Bult ◽

...

Keyword(s):

Endothelial Function ◽

Bolus Injection ◽

Rabbit Lung ◽

Future Studies ◽

High Affinity ◽

Lung Physiology ◽

Extraction Pattern ◽

Uptake Data ◽

5 Ht Uptake ◽

Kinetics Of

The single-pass, bolus-injection method was used to study the effect of serotonin (5-HT) concentration on the extraction of 5-HT by isolated perfused rabbit lungs. The extraction pattern suggested that an uptake model, which includes multiple parallel uptake processes, provided a better representation of the data than the simple Michaelis-Menten equation, which has commonly been used to fit the saturable uptake data in previous studies. In particular, the rabbit lung data could be fit with two such parallel pathways. Since the 5-HT uptake could virtually be completely blocked by imipramine, both pathways can be considered to be carrier-mediated processes. The high-affinity pathway was saturable within the range of concentrations studied, with a Km and Vmax of approximately 0.84 microM and 0.21 nmol.s-1.g wet lung wt-1. The Km for the low-affinity pathway was larger than concentrations for which accurate uptake measurements are practical in the perfused organ. Thus, for the low-affinity pathway, only Vmax/Km was identifiable. Vmax/Km values for the high- and low-affinity pathways were approximately 2.87 and 0.35 ml/s, respectively. The results suggest that it will be worthwhile to investigate the behavior of these uptake parameters in response to changes in lung physiology and endothelial function in future studies.

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Simulation of experimental data, the design of experiments, and the analysis of results. Kinetics of catalyzed ester hydrolysis

Journal of Chemical Education ◽

10.1021/ed054p323 ◽

1977 ◽

Vol 54 (5) ◽

pp. 323 ◽

Cited By ~ 3

Author(s):

Donald Rosenthal ◽

David Arnold

Keyword(s):

Experimental Data ◽

Design Of Experiments ◽

Ester Hydrolysis ◽

Analysis Of Results ◽

Kinetics Of

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So-Called “Tension Headache” — The Response to a 5-HT Uptake Inhibitor: Femoxetine

Cephalalgia ◽

10.1046/j.1468-2982.1983.0301053.x ◽

1983 ◽

Vol 3 (1) ◽

pp. 53-60 ◽

Cited By ~ 20

Author(s):

Ottar Sjaastad

Keyword(s):

Weight Gain ◽

Tension Headache ◽

Headache Frequency ◽

Double Blind ◽

Uptake Inhibition ◽

Uptake Inhibitor ◽

Gastrointestinal Discomfort ◽

5 Ht Uptake ◽

Blind Fashion

Sixteen patients with a headache resembling the so-called “tension headache” and a clear response to doxepin (demonstrated in a previous work) were given femoxetine, 400 mg p.d., and placebo in a cross-over, double-blind fashion. Only single blindness was kept in the last third of the study. Placebo and femoxetine tablets were each given for four weeks. Whereas there was a daily or practically daily occurring headache untreated, placebo was associated with a headache frequency of 92%. The corresponding figures for doxepin and femoxetine were 27% and 41%, respectively. Femoxetine led to transitory nausea and gastrointestinal discomfort, but in contrast to doxepin, no weight gain and only slight, if any, sedation. Most patients preferred femoxetine to doxepin. Femoxetine, an antidepressant phenylpiperidine derivative with predominant serotonin re-uptake inhibition (little effect on noradrenaline), thus seems to counteract so-called “tension headache”.

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