• The Journal of Korean Physical Therapy
• /
• v.13 no.1
• /
• pp.139-149
• /
• 2001

We found out that there exists threshold dose for the decreased platelet count when we apply change of the platelet count to the defense of the ultrasound experiment. Those diminution is definite effects from the defense of the ultrasound. The number of the platelet count is decreased when we are exposed to ultrasound simultaneously. This should not be occurred. It is easy to use the number of the platelet count in the measurement of the biological dosage and intensity in high dosage relatively due to definite quantative relationship. The biological index to understand synergic effects. which are present when two harmful environmental factors are operating at the same time is functionally assending and antagonistic. There are scattered many factors as physical, Chemical, or physiochemically elements which are harmful to human body in the environment in consideration of ultrasound and the other factors. This experiment is demonstrating that we can use the change of the platelet as an index representing synergic effects of ultrasound.

• Journal of Food Hygiene and Safety
• /
• v.11 no.4
• /
• pp.273-276
• /
• 1996

Platelets serve many biological functions, including a major role in the haemostatic process. But platelets also play a crucial role in the formation of arterial thrombosis, arteriosclerosis and other pathologic processes. Thus, there have been many studies to develop new antiplatelet agents from foods and plants for decades. Inthis study, inhibitory effects of the oriental onion (Allium fistulosum) on platelet aggregation were investigated using platelet rich plasma (PRP). Water extracts of oriental onion was separated into two fractions (Fraction I and Fraction II) by Sephadex G-150 column. Platelet aggregations were inhibited by total water extracts as well as Fraction I and II. IC50 value of Fraction I was much lower than that of Fraction II. Inhibitory effects of total water extracts of oriental onion on ATP release by PRP were also observed.

• Korean Journal of Pharmacognosy
• /
• v.51 no.4
• /
• pp.231-237
• /
• 2020

Euchrestaflavanone B (EFB) is a flavonoid that can be found in root bark, particularly in Cudrania tricuspidata (C. tricuspidata). The extract of C. tricuspidata is widespread throughout Asia and used in traditional medicine. In a previous study, we found anti-platelet effects of substances isolated from C. tricuspidata on collagen-induced human platelets. However, the C. tricuspidata still contains numerous substances, thus, we have searched new candidate, EFB isolated from C. tricuspidata for anti-platelet effect. Our results showed that EFA inhibited collagen-induced platelet aggregation and glycoprotein IIb/IIIa (αIIb/β3)-mediated signaling events, including platelet adhesion, granule secretion, thromboxane A2 production and clot retraction. These results suggest that EFA has inhibitory effects on human platelet activities and thrombus formation and has potential value as a natural substance for preventing platelet-induced thrombosis.

• BMB Reports
• /
• v.40 no.5
• /
• pp.678-683
• /
• 2007

Extracts from the leaves of the Ginkgo biloba are becoming increasingly popular as a treatment that is claimed to reduce atherosclerosis, coronary artery disease, and thrombosis. In this study, the effect of ginkgolide B (GB) from Ginkgo biloba leaves in collagen (10 ${\mu}g/ml$)-stimulated platelet aggregation was investigated. It has been known that human platelets release matrix metallo-proteinase-9 (MMP-9), and that it significantly inhibited platelet aggregation stimulated by collagen. Zymographic analysis confirmed that pro-MMP-9 (92-kDa) was activated by GB to form an MMP-9 (86-kDa) on gelatinolytic activities. And then, activated MMP-9 by GB dose-dependently inhibited platelet aggregation, intracellular $Ca^{2+}$ mobilization, and thromboxane $A_2$ ($TXA_2$) formation in collagen-stimulated platelets. Activated MMP-9 by GB directly affects down-regulations of cyclooxygenase-1 (COX-1) or $TXA_2$ synthase in a cell free system. In addition, activated MMP-9 significantly increased the formation of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), which have the anti-platelet function in resting and collagen-stimulated platelets. Therefore, we suggest that activated MMP-9 by GB may increase the intracellular cAMP and cGMP production, inhibit the intracellular $Ca^{2+}$ mobilization and $TXA_2$ production, thereby leading to inhibition of platelet aggregation. These results strongly indicate that activated MMP-9 is a potent inhibitor of collagen-stimulated platelet aggregation. It may act a crucial role as a negative regulator during platelet activation.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.20 no.1
• /
• pp.31-41
• /
• 2004

The osseointegration in implant therapy is achieved following general wound healing mechanism. Platelet play a major role in wound healing process. In addition to blood clot formation, they secrete many growth factors which regulate the attachment, proliferation and differentiation of nearly all cell types. The use of these growth factors is now known to be very effective methods to improve the cellular activity. Platelet-rich plasma which is made with the newly developed technique concentrating platelets 3-folds or more is also proven to be very effective method to stimulate and accelerate the healing of bone and soft tissue. Previous study proved that platelet-rich plasma enhanced the cellular attachment by inducing fibronectin, vitronectin from osteoblast. So, this study was aimed to investigate the effect of platelet-rich plasma on the cellular proliferation and differentiation in vitro. The effect on the proliferation was evaluated by MTT assay. To evaluate autocrine and paracrine effect, conditioned medium was made and compared. By measuring alkaline phosphatase activity, the effect on the cellular differentiation was evaluated. The results were as following: The cellular proliferation of osteoblast cell line increased depending on the concentration of platelet-rich plasma and conditioned medium. The alkaline phosphatase activity increased depending on the concentration of platelet-rich plasma and conditioned medium. These findings imply that platelet-rich plasma enhance the cellular proliferation and differentiation and maximize the cellular activity by using the autocrine and paracrine effect.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.15
• /
• pp.6239-6241
• /
• 2014

Purpose: To compare the diagnostic accuracy of the neutrophil/lymphocyte ratio (NLR) with the platelet/lymphocyte ratio (PLR) in predicting malignancy of pelvic masses which are pre-operatively malignant suspicious. Materials and Methods: In this retrospective study we evaluated the clinical features of patients with ovarian masses which had pre-operatively been considered suspicious for malignancy. The patients whose intraoperative frozen sections were malign were classified as the study group, while those who had benign masses were the control group. Data recorded were age of the patient, diameter of the mass, pre-operative serum Ca 125 levels, platelet count, neutrophil/lymphocyte ratio and platelet/lymphocyte ratio. Results: There was statistically significantly difference between the groups in terms of age, diameter of the mass, serum Ca 125 levels, platelet number and platelet/lymphocyte ratio. Mean neutrophil/lymphocyte ratios showed no difference between the groups. ROC curve analysis showed that age, serum Ca 125 levels, platelet number and PLR were discriminative markers in predicting malignancy in adnexal masses. Conclusions: According to the current study, serum Ca 125 levels, pre-operative platelet number and PLR may be good prognostic factors, while NLR is an ineffective marker in predicting the malignant characteristics of a pelvic mass.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.47 no.3
• /
• pp.190-196
• /
• 2021

Objectives: The risk of bleeding after tooth extraction in thrombocytopenia patients remains unclear. Therefore, the present study aimed to assess the risk of bleeding after tooth extraction in patients with thrombocytopenia. Materials and Methods: The study included 220 patients who had a medical history of thrombocytopenia and underwent tooth extraction (330 teeth). The patients were divided into those who had thrombocytopenia (platelet count <150k) immediately before the tooth extraction, and those who had platelet counts that were between 150k and 250k before the extraction. Bleeding complications were recorded and compared between the patient groups. Results: Of the 220 patients, 130 underwent tooth extractions while having thrombocytopenia (platelet count <150k), and 90 had platelet counts that were between 150k and 250k before tooth extractions. Bleeding complications occurred in 11 patients (5.0%) of the 220 patients. Among those 11 patients with bleeding complications, 10 patients (7.7%) had thrombocytopenia (platelet count <150k) of the 130 patients, and 1 patient (1.1%) had a normal platelet count of the 90 patients. There was a significant difference between the patient groups regarding bleeding after extractions (P<0.001). No significant difference in the incidence of post-extraction bleeding was found between the subgroups by platelet count within the thrombocytopenia group. Conclusion: Thrombocytopenia (platelet count <150k) increases the risk of post-tooth extraction bleeding. Therefore, bleeding control under the proper evaluation of hemostasis and performing delicate tooth extraction procedures using hemostatic plugs is necessary during the tooth extraction of patients with thrombocytopenia.

• Journal of Ginseng Research
• /
• v.45 no.4
• /
• pp.490-497
• /
• 2021

Background and objective: Synthetic ginsenoside compounds G-Rp (1,3, and 4) and natural ginsenosides in Panax ginseng 20(S)-Rg3, Rg6, F4 and Ro have inhibitory actions on human platelets. However, the inhibitory mechanism of ginsenoside Rk1 (G-Rk1) is still unclear thus, we initiated investigation of the anti-platelet mechanism by G-Rk1 from Panax ginseng. Methodology: Our study focused to investigate the action of G-Rk1 on agonist-stimulated human platelet aggregation, inhibition of platelet signaling molecules such as fibrinogen binding with integrin α_IIbβ₃ using flow cytometry, intracellular calcium mobilization, fibronectin adhesion, dense granule secretion, and thromboxane B2 secretion. Thrombin-induced clot retraction was also observed in human platelets. Key Results: Collagen, thrombin, and U46619-stimulated human platelet aggregation were dose-dependently inhibited by G-Rk1, while it demonstrated a more effective suppression on collagen-stimulated platelet aggregation using human platelets. Moreover, G-Rk1 suppressed collagen-induced elevation of Ca²⁺ release from endoplasmic reticulum, granule release, and α_IIbβ₃ activity without any cytotoxicity. Conclusions and implications: These results indicate that G-Rk1 possess strong anti-platelet effect, proposing a new drug candidate for treatment and prevention of platelet-mediated thrombosis in cardiovascular disease.

• Journal of Animal Science and Technology
• /
• v.60 no.8
• /
• pp.20.1-20.4
• /
• 2018

Platelet rich plasma (PRP) is popularly used in the horse industry to enhance regeneration of tissue injury that has limitation of blood supply. This study aimed to compare the methods for platelet rich plasma preparation since they has not been established yet. Blood was collected from six horses and platelets were concentrated by three different methods (2-step centrifugation, separated centrifugation and separated centrifugation using histopaque). Concentrated blood was analyzed using Advia hematology systems. In the result, separated centrifugation with histopaque showed the significantly lower number of red blood cells than other groups. The 2-step centrifugation showed the significantly higher number of white blood cells than other groups, while it contained the highest concentration of red blood cells among three groups. In the 2-step centrifugation, separated centrifugation and separated centrifugation with histopaque, platelets were concentrated 4.5, 5.3 and 5.6 times, respectively. And no significant difference of the platelet concentration between the three groups was found. This study demonstrated that separated centrifugation using histopaque was the best method for platelet rich plasma preparation because of the proper amount of platelets and the separation of red blood cells from platelet rich plasma.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1994.04a
• /
• pp.280-280
• /
• 1994

혈행 장애 예방 및 치료 약물의 개발을 목적으로 혈소판 기능에 대한 약물의 영향을 연구하는데 있어, 효율적인 실험 조건의 선택은 중요하다. 본 연구에서는 마늘 메탄을 추출물의 혈소판 응집 억제능율 platelet rich plasma(PRP), washed platelet(Ca$^2$비첨가), washed platelet(Ca$^{2+}$ 첨가) 등 세가지 분리 조건을 사용하여 실험하였다. 그 결과 마늘 추출물의 $IC_{50}$/이 각각 2348 $\mu\textrm{g}$/ml, 221 $\mu\textrm{g}$/ml, 851 $\mu\textrm{g}$/ml로서, washed platelet(Ca$^{2+}$ 비첨가)가 마늘 추출물의 혈소판 응집 억제 작용에 가장 민감한 것으로 나타났다. 또한 마늘 추출물과는 다른 기전으로 혈소판 응집 억제 효과를 나타내는 menadione과 propranolol도 이와 동일한 결과를 보였다. 실험 조건에 따른 이러한 차이가 PRP 중에 존재하는 알부민 등과의 단백 결합에의한 약물의 유효농도 감소에 기인한다고 추정되어, washed platelet에 여러 농도의 알부민을 첨가하여 혈소판 응집 억제 실험을 실시한 결과 약물의 $IC_{50}$/은 알부민 농도 의존적으로 증가하였다. 혈소판 응집과 함께 혈소판 기능 변화를 측정하는 지표인 혈소판 분비능을 분비된 ATP를 Luciferin-Luciferase로 측정하여 알아보았다. 그 결과 thrombin에 의한 혈소판의 ATP 유리에 미치는 마늘 추출물의 영향을 위의 세 실험조건에서 실험하여 $IC_{50}$/을 비교한 결과 그 값이 washed platelet에서 가장 낮고 PRP에서 가장 높아, 혈소판 응집 억제 실험과 동일한 결과를 나타내었다. 이상의 결과는 세가지 혈소판 분리 조건 중 washed platelet(Ca$^{2+}$비첨가)가 약물에 의한 혈소판 기능 억제 실험에 가장 효율적임을 제시하고 있으며, 그 주요한 원인은 알부민 등 단백 결합에 의한 유효 약물 농도 감소때문 이라고 추정된다.