The Routine Measurement of Platelet Size Using Sodium Citrate Alone as the Anticoagulant

1993 ◽  
Vol 70 (04) ◽  
pp. 687-690 ◽  
Author(s):  
P M W Bath
Keyword(s):  
Incubation Time ◽  
Sodium Citrate ◽  
Dependent Manner ◽  
High Concentration ◽  
Distribution Width ◽  
Routine Measurement ◽  
Platelet Size ◽  
Coefficients Of Variation ◽  
Important Marker ◽  
Made In

SummaryMean platelet volume (MPV), a measure of platelet size, is becoming recognised as an important marker of platelet function. However, platelets swell in edetic acid (EDTA), the Standard haematology anticoagulant, in a time-dependent manner making such measurements potentially unreliable. The effect of incubation time on MPV, and platelet distribution width (PDW), as measured in EDTA, low (1:9 volume/volume with blood) or high (1:4 v/v with blood) concentration sodium citrate was studied. MPV measured in high concentration sodium citrate did not change with time in contrast to MPV measured in either low concentration sodium citrate or EDTA which both increased in an inverse exponential fashion. MPV and PDW, measured in high concentration sodium citrate, had similar within-assay and between-assay coefficients of Variation as other platelet, red cell and white cell haematology variables measured in EDTA: MPV 1.4%, 2.1%; PDW 1.4%, 1.5%; MCV 0.4%, 0.7%; PC 3.1%, 6.1%; WCC 1.5%, 7.3%; Hb 2.1%, 2.4% respectively. MPV measured in EDTA and corrected for incubation time approximated to, but was higher than, the MPV measured in high concentration sodium citrate. PDW correlated inversely with platelet count (r = <0.415, 2p <0.001). MPV may be measured in sodium citrate (at 1:4 v/v with blood) alone with a better accuracy and reproducibility than similar measurements made in EDTA. Furthermore, such measurements are not influenced by incubation time, unlike for EDTA.

The Immature Platelet Fraction Is Sensitive to the Platelet Size and a Useful Parameter for Screening for Macrothrombocytopenia

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1097-1097
Author(s):  
Koji Miyazaki ◽  
Yukako Koike ◽  
Mikio Danbara ◽  
Ryouichi Horie ◽  
Masaaki Higashihara
Keyword(s):  
Cold Storage ◽  
Conflicts Of Interest ◽  
Large Cell ◽  
Dependent Manner ◽  
Invasive Treatment ◽  
Distribution Width ◽  
Reticulated Platelets ◽  
Platelet Size ◽  
Immature Platelet Fraction ◽  
Platelet Aggregates

Abstract Abstract 1097 The immature platelet fraction (IPF) is a useful parameter indicating thrombopoietic activity to differentiate the causes of thrombocytopenia. We previously reported that the percentage of IPF (%IPF) is negatively correlated to the platelet count among ITP patients, and not among myelodysplastic syndrome (MDS) patients. We also noticed that some MDS patients exhibited extremely high %IPF values, which were dissociated from the percentages of reticulated platelets (%RP) measured by flow cytometry. Such discrepancies were also observed in hereditary macrothrombocytopenias, which are sometimes difficult to be distinguished from ITP, because ITP also exhibits increased number of reticulated platelets in a slightly larger size. Once misdiagnosed, a hereditary macrothrombocytopenia patient might be subjected to an invasive treatment such as splenectomy. In order to avoid such mistreatments, a clear marker to differentiate macrothrombocytopenia is desperately needed. In this study, we investigated the IPF values of 16 individuals from 12 families with various hereditary macrothrombocytopenia in order to clarify whether the IPF could be a useful marker to distinguish macrothrombocytopenia from ITP, and examined the IPF during EDTA aggregation and cold-storage to elucidate how platelet size may affect the IPF value. The IPF values were about 5 times higher in MYH9 disorders (%IPF 48.0 ± 1.8) and about 1.5 times higher in other macrothrombocytopenias (%IPF 17.0 ± 2.2) than immune thrombocytopenic patients with similar platelet counts (%IPF 9.3 ± 0.4). These results suggested that the platelet size can affect the IPF value. However it still remains the possibility that some factors specific to these macrothrombocytopenias other than the platelet size might make an influence on the IPF, because the characteristic of large platelets in hereditary macrothrombocytopenia has not been fully understood, and no one knows whether large platelets are functionally identical to normal platelets except for the size. In order to exclude the possibility, we next examined the changes of IPF values during EDTA aggregation and cold-storage. The IPF was significantly increased during storage in a time dependent manner along with forming platelet clumps. The IPF was strongly influenced by a few tiny platelet aggregates rather than other platelet indices, such as mean platelet volume (MPV), platelet-large cell ratio (P-LCR) and platelet distribution width (PDW). In conclusion, the IPF is susceptible to the platelet size, and could be a useful parameter for screening of macrothrombocytopenia from ITP. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Hematological Findings in Non-Treated and γ-Irradiated Mice Deficient for MIC-1/GDF15

2018 ◽  
pp. 623-636
Author(s):  
M. HOFER ◽  
Z. HOFEROVÁ ◽  
J. REMŠÍK ◽  
M. NOVÁKOVÁ ◽  
J. PROCHÁZKOVÁ ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Hematological Parameters ◽  
Blood Platelet ◽  
Dependent Manner ◽  
Distribution Width ◽  
Knock Out ◽  
Pathological Conditions ◽  
Platelet Size ◽  
Radiation Induced

Several members of the TGF-ß family are known to effectively regulate the fate of hematopoietic progenitor cells in a complex and context-dependent manner. Growth differentiation factor-15 (GDF15) is a divergent member of the TGF-ß family. This stress-induced cytokine has been proposed to possess immunomodulatory functions and its high expression is often associated with progression of a variety of pathological conditions. GDF15 is also induced by chemotherapy and irradiation. Very few fundamental studies have been published regarding the effect of GDF15 in hematopoiesis. In this study, we analyzed the hematological status of untreated and γ-irradiated mice deficient for GDF15 as a result of genetic knock-out (KO), in order to clarify the regulatory role of GDF15 in hematopoiesis. Significant differences between GDF15 KO mice and their pertinent WT controls were found in the parameters of blood monocyte numbers, blood platelet size, and distribution width, as well as in the values of bone marrow granulocyte/macrophage progenitor cells. Different tendencies of some hematological parameters in the GDF15 KO mice in normal conditions and those under exposure of the mice to ionizing radiation were registered. These findings are discussed in the context of the GDF15 gene function and its lack under conditions of radiation-induced damage.

Does coffee, tea and caffeine consumption reduce the risk of incident breast cancer? A systematic review and network meta-analysis

2021 ◽  
pp. 1-13
Author(s):  
Shu Wang ◽  
Xiang Li ◽  
Yue Yang ◽  
Jingping Xie ◽  
Mingyue Liu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Systematic Review ◽  
Postmenopausal Women ◽  
Meta Analysis ◽  
High Dose ◽  
Dependent Manner ◽  
Tea Consumption ◽  
Case Control Studies ◽  
High Concentration ◽  
Coffee Intake

Abstract Objective: We aimed to evaluate the association between coffee and/or tea consumption and breast cancer (BC) risk among premenopausal and postmenopausal women and to conduct a network meta-analysis. Design: Systematic review and network meta-analysis. Setting: We conducted a systematic review of electronic publications in the last 30 years to identify case–control studies or prospective cohort studies that evaluated the effects of coffee and tea intake. Results: Forty-five studies that included more than 3 323 288 participants were eligible for analysis. Network meta-analysis was performed to determine the effects of coffee and/or tea consumption on reducing BC risk in a dose-dependent manner and differences in coffee/tea type, menopause status, hormone receptor and the BMI in subgroup and meta-regression analyses. According to the first pairwise meta-analysis, low-dose coffee intake and high-dose tea intake may exhibit efficacy in preventing ER(estrogen receptor)− BC, particularly in postmenopausal women. Then, we performed another pairwise and network meta-analysis and determined that the recommended daily doses were 2–3 cups/d of coffee or ≥5 cups/d of tea, which contained a high concentration of caffeine, particularly in postmenopausal women. Conclusions: Coffee and tea consumption is not associated with a reduction in the overall BC risk in postmenopausal women and is associated with a potentially lower risk of ER− BC. And the highest recommended dose is 2–3 cups of coffee/d or ≥5 cups of tea/d. They are potentially useful dietary protectants for preventing BC.

scholarly journals Functional Coupling between the P2X7 Receptor and Pannexin-1 Channel in Rat Trigeminal Ganglion Neurons

2021 ◽  
Vol 22 (11) ◽  
pp. 5978
Author(s):  
Hiroyuki Inoue ◽  
Hidetaka Kuroda ◽  
Wataru Ofusa ◽  
Sadao Oyama ◽  
Maki Kimura ◽  
...  
Keyword(s):  
Trigeminal Ganglion ◽  
P2x7 Receptor ◽  
P2x Receptor ◽  
Functional Coupling ◽  
Dependent Manner ◽  
High Concentration ◽  
Receptor Antagonists ◽  
P2x7 Receptors ◽  
Pannexin 1 ◽  
Ganglion Neurons

The ionotropic P2X receptor, P2X7, is believed to regulate and/or generate nociceptive pain, and pain in several neuropathological diseases. Although there is a known relationship between P2X7 receptor activity and pain sensing, its detailed functional properties in trigeminal ganglion (TG) neurons remains unclear. We examined the electrophysiological and pharmacological characteristics of the P2X7 receptor and its functional coupling with other P2X receptors and pannexin-1 (PANX1) channels in primary cultured rat TG neurons, using whole-cell patch-clamp recordings. Application of ATP and Bz-ATP induced long-lasting biphasic inward currents that were more sensitive to extracellular Bz-ATP than ATP, indicating that the current was carried by P2X7 receptors. While the biphasic current densities of the first and second components were increased by Bz-ATP in a concentration dependent manner; current duration was only affected in the second component. These currents were significantly inhibited by P2X7 receptor antagonists, while only the second component was inhibited by P2X1, 3, and 4 receptor antagonists, PANX1 channel inhibitors, and extracellular ATPase. Taken together, our data suggests that autocrine or paracrine signaling via the P2X7-PANX1-P2X receptor/channel complex may play important roles in several pain sensing pathways via long-lasting neuronal activity driven by extracellular high-concentration ATP following tissue damage in the orofacial area.

Endothelium and mechanical responses of isolated monkey pulmonary veins to histamine

1990 ◽  
Vol 259 (4) ◽  
pp. H1032-H1037 ◽  
Author(s):  
T. Matsuki ◽  
T. Ohhashi
Keyword(s):  
Pulmonary Veins ◽  
Dependent Manner ◽  
High Concentration ◽  
Concentration Dependent Manner ◽  
Mechanical Responses ◽  
Relaxing Factor ◽  
Prostaglandin F2 Alpha ◽  
H2 Receptors ◽  
Endothelium Derived Relaxing Factor ◽  
Stimulation Of

Ring strips of monkey pulmonary veins precontracted with a high concentration of prostaglandin F2 alpha (PGF2 alpha) relaxed in a concentration-dependent manner in response to histamine. Treatment with mepyramine and/or famotidine attenuated the relaxation. 2-Pyridylethylamine (2PEA) and dimaprit caused relaxations in the precontracted preparations, which were inhibited by pretreatment with mepyramine and famotidine, respectively. Removal of endothelium reversed the histamine- and 2PEA-induced relaxations to dose-related contractions. On the other hand, the removal had no effect on the dimaprit-induced relaxations, which were significantly reduced by pretreatment with famotidine. Histamine-induced relaxations in the precontracted strips with endothelium in the presence and absence of famotidine were suppressed or abolished by treatment with methylene blue or hemoglobin but were unaffected by aspirin. It may be concluded that histamine-induced relaxation in monkey pulmonary veins precontracted with PGF2 alpha is mediated by H2-receptors in smooth muscle and H1-receptors in endothelium. Also, stimulation of the endothelial H1-receptors liberates an endothelium-derived relaxing factor.

Immunoradiometric assay with use of magnetizable particles: measurement of thyrotropin in blood spots, to screen for neonatal hypothyroidism.

1986 ◽  
Vol 32 (10) ◽  
pp. 1966-1968 ◽  
Author(s):  
K V Waite ◽  
G F Maberly ◽  
G Ma ◽  
C J Eastman
Keyword(s):  
Incubation Time ◽  
Separation Procedure ◽  
Immunoradiometric Assay ◽  
Assay Sensitivity ◽  
Neonatal Hypothyroidism ◽  
Blood Spots ◽  
Standard Curve ◽  
Coefficients Of Variation ◽  
Specialized Equipment ◽  
Short Incubation Time

Abstract We adapted a commercial immunoradiometric assay (IRMA) to measure thyrotropin in filter-paper blood spots. Two 3-mm blood spots are used for each standard and sample. These are incubated for 2 h with radiolabeled antibody and for 30 min with magnetic antibody, followed by a 10-min separation procedure. Assay sensitivity is 6 milli-int. units/L. Coefficients of variation (precision profile of the standard curve) ranged from 4.3 to 9.6%. The coefficient of correlation (r) between thyrotropin concentrations in the blood spots and in serum was 0.93. Pre-elution of the blood spots is necessary for short incubation time. Short incubation time, little need for specialized equipment, the high precision and sensitivity characteristic of IRMA, and ease of collection, transport, and storage of the blood-spot samples make this assay suitable for neonatal hypothyroid screening.

Brain sites involved in the regulation of growth hormone secretion in the young male domestic fowl

1984 ◽  
Vol 103 (3) ◽  
pp. 327-332 ◽  
Author(s):  
J. Rabii ◽  
L. Knapp ◽  
A. De La Guardia ◽  
P. Zafian ◽  
T. J. Lauterio ◽  
...  
Keyword(s):  
Domestic Fowl ◽  
Arcuate Nucleus ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Young Male ◽  
High Concentration ◽  
Gh Secretion ◽  
Regulation Of Growth ◽  
Fair Degree ◽  
Made In

ABSTRACT To study brain sites involved in the regulation of GH secretion in the domestic fowl, lesions were placed in and around the hypothalamus of 1-week-old cockerels. Circulating concentrations of GH were then measured at weekly intervals for 4 weeks after the placement of lesions. At the termination of the experiment, histological procedures were used to determine the exact site of the lesion in each bird. Although a fair degree of overlap existed between the lesion sites leading to stimulation and those causing an inhibition of GH secretion, a clear distinction could be made in the overall distribution of stimulatory and inhibitory sites of GH control. A high concentration of lesion sites resulting in GH decline (presumed GH-releasing factor-rich areas) appeared to reside in the general area of the ventromedial and the arcuate nucleus of the hypothalamus. Lesion sites causing a GH rise (presumed somatostatin-rich areas), on the other hand, seemed to have a more caudal distribution. In addition, some evidence of an anterior hypothalamic distribution of these presumed 'somatostatin' neurones was observed. These agree with the existing immunohistochemical data on the distribution of somatostatin and constitute experimental evidence for localization of presumed GH-releasing factor sites within the avian brain. J. Endocr. (1984) 103, 327–332

Self-Inhibition in Ca2+-Evoked Taste Responses: A Novel Tool for Functional Dissection of Salt Taste Transduction Mechanisms

1998 ◽  
Vol 79 (2) ◽  
pp. 911-921 ◽  
Author(s):  
Mamoun A. Kloub ◽  
Gerard L. Heck ◽  
John A. Desimone
Keyword(s):  
Tight Junctions ◽  
Ion Selectivity ◽  
Critical Concentration ◽  
Dependent Manner ◽  
High Concentration ◽  
Salt Taste ◽  
Cation Conductance ◽  
Taste Transduction ◽  
Transduction Mechanisms ◽  
Paracellular Pathways

Kloub, Mamoun A., Gerard L. Heck, and John A. DeSimone. Self-inhibition in Ca2+-evoked taste receptors: a novel tool for functional dissection of salt taste transduction mechanisms. J. Neurophysiol. 79: 911–921, 1998. Rat chorda tympani (CT) responses to CaCl2 were obtained during simultaneous current and voltage clamping of the lingual receptive field. Unlike most other salts, CaCl2 induced negatively directed transepithelial potentials and gave CT responses that were auto-inhibitory beyond a critical concentration. CT responses increased in a dose-dependent manner to ∼0.3 M, whereafter they decreased with increasing concentration. At concentrations where Ca2+ was self-inhibitory, it also inhibited responses to NaCl, KCl, and NH4Cl present in mixtures with CaCl2. Ca2+ completely blocked the amiloride-insensitive component of the NaCl CT response, the entire KCl-evoked CT response, and the high-concentration-domain CT responses of NH4Cl (≥0.3 M). The overlapping Ca2+-sensitivity between the responses of the three Cl− salts (Na+, K+, and NH+ 4) suggests a common, Ca2+-sensitive, transduction pathway. Extracellular Ca2+ has been shown to modulate the paracellular pathways in different epithelial cell lines by decreasing the water permeability and cation conductance of tight junctions. Ca2+-induced modulation of tight junctions is associated with Ca2+ binding to fixed negative sites. This results in a conversion of ion selectivity from cationic to anionic, which we also observed in our system through simultaneous monitoring of the transepithelial potential during CT recording. The data indicate the paracellular pathway as the stimulatory and modulatory site of CaCl2 taste responses. In addition, they indicate that important transduction sites for NaCl, KCl, and NH4Cl taste reception are accessible only through the paracellular pathways. More generally, they show that modulation of paracellular transport by Ca2+ in an intact epithelium has functional consequences at a systemic level.

scholarly journals Effects of cGMP and sodium nitroprusside on odor responses in turtle olfactory sensory neurons

1998 ◽  
Vol 275 (5) ◽  
pp. C1201-C1206 ◽  
Author(s):  
Kouhei Inamura ◽  
Makoto Kashiwayanagi ◽  
Kenzo Kurihara
Keyword(s):  
Sodium Nitroprusside ◽  
Dependent Manner ◽  
High Concentration ◽  
No Donor ◽  
Inward Current ◽  
Inward Currents ◽  
Induced Currents ◽  
Dose Dependent ◽  
Camp And Cgmp ◽  
Dependent Pathway

The effects of cGMP and sodium nitroprusside (SNP) on odor responses in isolated turtle olfactory neurons were examined. The inward current induced by dialysis of a mixture of 1 mM cAMP and 1 mM cGMP was similar to that induced by dialysis of 1 mM cAMP or 1 mM cGMP alone. After the neurons were desensitized by the application of 1 mM cGMP, 3 mM 8-(4-chlorophenylthio)-cAMP, a membrane-permeable cAMP analog, did not elicit any current, indicating that both cAMP and cGMP activated the same channel. Extracellular application of SNP, a nitric oxide (NO) donor, evoked inward currents in a dose-dependent manner. However, application of SNP did not induce any currents after desensitization of the cGMP-induced currents, suggesting that SNP-induced currents are mediated via the cGMP-dependent pathway. Application of the cAMP-producing odorants to the neurons induced a large inward current even after neurons were desensitized to a high concentration of cGMP or SNP. These results suggest that the transduction pathway independent of cAMP, cGMP, and NO also contributes to the generation of odor responses in addition to the cAMP-dependent pathway.

Sign in / Sign up

Export Citation Format

Share Document