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LABORATORY CONTROL OF ANTICOAGULANT THERAPY

LAU KS, SINGH N

Med J Malaysia, 1963 Dec;18:107-15.
PMID: 14117278
Matched MeSH terms: Prothrombin Time*
Fulltext Effect of higher centrifugation speed and shortened centrifugation time on prothrombin and activated thromboplastin time

Azlin, I., Hafiza, A., Azma, R.Z., Aidifitrina, R.K., Hamidah, N.H.

Medicine & Health, 2011;6(1):68-72.
MyJurnal

Centrifugation of blood samples to produce platelet-poor plasma is one of the important steps for coagulation testing. Reduction of the time required for specimen processing without affecting quality of results should be ideal for tests which require immediate results. Centrifugation of platelet-poor plasma (3580 rpm) for 15 minutes performed for routine coagulation tests would prolong the turn-around time for an urgent test (30 minutes). This study was done to determine the effect of reducing centrifugation time for routine coagulation tests in order to meet the turn-around time (TAT) for urgent tests. Seventy-nine blood samples sent for routine coagulation tests, were assayed for prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen level and platelet counts, using two different centrifugation speed for plasma preparation: centrifugation at 3580 rpm for 15 minutes and rapid centrifugation at 4000 rpm for five minutes. Paired sample t-test showed that there was a significant
difference in the platelet count between the two groups (p=0.001). However, there was no significant difference in the normal APTT (p=0.16), abnormal APTT (p=0.80), abnormal PT (p=0.43) and the results of fibrinogen levels (p=0.36). In conclusion, rapid centrifugation at 4000 rpm for five minutes does not modify results of routine coagulation tests (PT, APTT and fibrinogen). It would be beneficial in providing rapid results for urgent coagulation tests.

Matched MeSH terms: Prothrombin Time
Optimization of the storage conditions for coagulation screening tests

Mohammed Saghir SA, Al-Hassan FM, Alsalahi OS, Abdul Manaf FS, Baqir HS

J Coll Physicians Surg Pak, 2012 May;22(5):294-7.
PMID: 22538033 DOI: 05.2012/JCPSP.294297

To determine the optimum storage temperature and time for prothrombin time and activated partial thromboplastin time at various intervals at both room temperature and refrigerator.

Matched MeSH terms: Prothrombin Time*
Fulltext Manufacturing and Characterization of Novel Electrospun Composite Comprising Polyurethane and Mustard Oil Scaffold with Enhanced Blood Compatibility

Jaganathan SK, Mani MP, Ismail AF, Ayyar M

Polymers (Basel), 2017 May 04;9(5).
PMID: 30970842 DOI: 10.3390/polym9050163

The objective of this work is to characterize and investigate the blood compatibility of polyurethane (PU)/mustard oil composites fabricated using electrospinning technique. The fabricated scaffold was characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), thermogravimetric analysis (TGA) and contact angle measurements. The activated partial thromboplastin time (APPT), prothrombin time (PT) and the hemolytic assay were done to investigate the blood compatibility of the developed composites. The SEM results revealed that the fiber diameter of the composites (761 ± 123 nm) was reduced compared to pristine PU control. The interaction between PU and mustard oil was confirmed by FTIR as evident through the shifting of peaks. The fabricated composites depicted hydrophobic behavior as insinuated by the increase in contact angle measurements. PU/mustard composites displayed improved crystallinity as confirmed by TGA. Atomic force micrographs suggested that developed PU/mustard oil composites showed an increase in the surface roughness (Ra) compared to pure PU. The Ra of pure PU was observed to be 723 nm but for the fabricated PU/mustard oil composite the Ra was found to be 1298 nm (Ra). The hemolytic index value for pure PU and fabricated composites was observed to be 2.73% and 1.15% indicating that developed composites showed a non-hemolytic behavior signifying the safety of the composites with red blood cells. Hence the newly developed composites with improved physicochemical and blood compatibility properties may be considered as a potential candidate for fabricating cardiac patches and grafts.

Matched MeSH terms: Prothrombin Time
Fulltext Apparent factor IX inhibitor

Jameela, S., Rozika, P., Rizalman, J., Phan, C.L., Visalachy, P., Chang, K.M.

Medicine & Health, 2011;6(2):126-130.
MyJurnal

The causes of an isolated prolonged activated partial thromboplastin time (APTT) with a normal prothrombin time (PT) are either a deficiency of clotting factors VIII, IX, XI or XII or the presence of an inhibitor. The inhibitor may be specific to an individual clotting factor or it may be a non-specific inhibitor like the lupus anticoagulant which has opposite therapeutic implications. We report a patient referred to our hospital for treatment that was previously diagnosed at another medical institution as an acquired factor IX inhibitor following an investigation for a prolonged APTT. On further testing this turned out to be a potent lupus anticoagulant which interfered with the phospholipid-dependent factor assays. The use of dilution studies, chromogenic assays and phospholipid neutralization can help differentiate these inhibitors. Great care must be taken in the interpretation of factor assays in the presence of lupus anticoagulant to avoid misdiagnosis and inappropriate treatment.

Matched MeSH terms: Prothrombin Time
Fulltext Coagulation Factor Activities Changes Over 5 Days in Thawed Fresh Frozen Plasma Stored at Different Initial Storage Temperatures

Noordin SS, Karim FA, Mohammad WMZBW, Hussein AR

Indian J Hematol Blood Transfus, 2018 Jul;34(3):510-516.
PMID: 30127563 DOI: 10.1007/s12288-017-0879-8

Thawed plasma is fresh frozen plasma (FFP) that has been stored for 5 days at 1-6 °C. Duration of storage and different storage temperatures might affect the coagulation factor activity in thawed FFP. This study measured the changes of coagulation factor activities over 5 days in thawed FFP and stored at two different initial storage temperatures. Thirty-six units of FFP, which consisted of nine units each from blood groups A, B, AB, and O, were thawed at 37 °C. Each unit was divided into two separate groups (Group A and Group B) based on initial storage temperature. The first group was stored at 2-6 °C for 5 days (Group A). The second group was stored at 20-24 °C for initial 6 h followed by 2-6 °C for 5 days (Group B). Prothrombin time (PT), activated partial thromboplastin time (APTT), coagulation factor activities of fibrinogen, factor (F) II, FV, FVII, FVIII, FIX, FX, and von Willebrand factor antigen (vWF Ag) were assessed at baseline after thawing, at 6 h, and on days 1, 3, and 5 of storage for both groups. All coagulation factors mean activities in both storage groups decreased significantly over 5 days of storage. The mean FVIII activity at day 5 of storage was 36.9% in Group A and 39.8% in Group B. The other coagulation factors mean activities were > 50% on day 5 of storage in both groups. The coagulation factor activities of thawed FFP stored for 5 consecutive days were reduced in the two storage groups but most of the activities were still above 30%. This study suggests that thawed FFP stored for 5 days has the potential to ameliorate coagulation factor deficiencies in affected patients.

Matched MeSH terms: Prothrombin Time
Fulltext Intracranial haemorrhage due to late haemorrhagic disease of infancy

Yeo TC

Med J Malaysia, 1987 Dec;42(4):276-83.
PMID: 3454400

Thirteen cases of late haemorrhagic disease of infancy due to vitamin K deficiency presenting with intracranial haemorrhage were seen over a three - year period from 1984 to 1986. The clinical picture was fairly typical; a short history of being unwell (poor feeding, vomiting, irritability, high pitched cry, fits) and physical findings of pallor, a normal body temperature, impairment of consciousness, abnormal respiration and a very tense anterior fontanelle. Vitamin K deficiency was implicated by the prolonged prothrombin time which rapidly returned to normal with vitamin K injection. The outcome was poor. Possible factors giving rise to vitamin K deficiency are discussed. The author suggests the introduction of the giving of vitamin K to all new-borns.

Matched MeSH terms: Prothrombin Time
Fulltext Evaluation of the merit of the methanolic extract of Andrographis paniculata to supplement anti-snake venom in reversing secondary hemostatic abnormalities induced by Naja naja venom

Nayak AG, Kumar N, Shenoy S, Roche M

3 Biotech, 2021 May;11(5):228.
PMID: 33959471 DOI: 10.1007/s13205-021-02766-z

Increasing evidence suggests a sizable involvement of hemotoxins in the morbidity associated with envenomation by the Indian spectacled cobra, Naja naja (N.N). This study investigates the ability of Indian polyvalent anti-snake venom (ASV), methanolic extract of Andrographis paniculata (MAP) and their combination in reversing the hemostatic abnormalities, viz. activated partial thromboplastin time(aPTT), prothrombin time(PT) and thrombin time(TT) in citrated plasma. These parameters were assessed in 2 groups of experiments. Group 1: Without the prior incubation of plasma with venom and Group 2: With prior incubation of plasma with venom for 90 min at 37°C. Venom caused significant (p

Matched MeSH terms: Prothrombin Time
Uncontrollable bleeding due to hypofibrinogenemia in a case of acute myelo-monocytic leukaemia

Banerjee AK

Med J Malaya, 1971 Mar;25(3):187-92.
PMID: 4253245
Matched MeSH terms: Prothrombin Time
Congenital coagulation disorders in Malaysia

Duraisamy, G.

Malaysian Journal of Child Health, 1998;10(1):62-71.
MyJurnal

Congenital Coagulation Disorders (CCD) are inherited and present from birth. Their diagnosis depends on clinical awareness and correct laboratory investigations. The central registry for CCD or Congenital Bleeding Disorders (CBD) is at the Blood Services Centre, Kuala Lumpur Hospital and was established in 1975. There are 871 CCD registered. The commonest CCD are 631 (72%) Haemophilia A, 102 (12%) Haemophilia B and 93 (10.7%) von Willebrand's Disease. The other deficiencies registered are rare, only 45 in total:— Factor 1 (4), FV (4), FVII (21), FX (4), FXII (6), and FXIII (6). Diagnosis is based on clinical suspicion, screening tests namely the Prothrombin Time (PT) and activated Partial Thromboplastin Time (aPTT) and confirmation of the diagnosis was by doing specific factor assays. Molecular studies were done on FVIII and FXIII. Treatment is by transfusing the deficient factor when there is bleeding and comprehensive care involving the specialities like the neurologist/ neurosurgeon /orthopaedic / physiotherapy/ dental besides the haematologist and paediatrician to manage the complicatioons seen. There are fewer problems now as patients are diagnosed earlier and managed better. There is now a good prognosis and a better quality of life.

Matched MeSH terms: Prothrombin Time
Comparison of rivaroxaban concentrations between Asians and Caucasians and their correlation with PT/INR

Ng Tsai HO, Goh JJN, Aw JWX, Lin Y, Fong AYY, Tiong LL, et al.

J Thromb Thrombolysis, 2018 Nov;46(4):541-548.
PMID: 30155672 DOI: 10.1007/s11239-018-1726-y

The objectives of this study are to compare steady-state trough (Cmin,ss) and peak (Cmax,ss) concentrations of rivaroxaban between Asians and Caucasians and to evaluate the relationship between rivaroxaban concentrations and prothrombin time/international normalized ratio (PT/INR). Recruited patients were advised on the time to take rivaroxaban. Cmin,ss and PT/INR were taken when patients arrived. Cmax,ss and PT/INR were drawn between 2 and 4 h later after the patient took rivaroxaban with food. Thirty patients were included in the analyses: 57% (n = 17) males and 43% (n = 13) females, 77% (n = 23) on 20 mg and 23% (n = 7) on 15 mg. Median PTtrough and PTpeak are moderately correlated with Cmin,ss (r2 = 0.43) and Cmax,ss (r2 = 0.49), respectively. Patients on 15 mg have lower Cmin,ss and Cmax,ss versus Caucasians [12 ng/ml vs. 57 ng/ml (Cmin,ss); 87 ng/ml vs. 229 ng/ml (Cmax,ss), p

Matched MeSH terms: Prothrombin Time
A Case Study on Chronic Hepatitis-C Viral infection Associated with Hepatocellular Carcinoma in a Tertiary Hospital of Bangladesh

Islam MJ, Saha SK, Das AK, Jahan MS, Pervin S, Karim CF, et al.

Mymensingh Med J, 2019 Oct;28(4):935-939.
PMID: 31599264

Hepatocellular carcinoma (HCC) is an important reason of liver-related death globally. HCC is the fifth most common cancer, the third most common cause for cancer related death in the world and responsible for approximately one million deaths each year. The incidence of HCC is expected to increase in the next two decades, largely due to hepatitis C infection and secondary cirrhosis. We have reported a case of hepatocellular carcinoma in a 56-year-old man with peritoneal metastasis. Diagnostic imaging (Ultra sonogram & CT-Scan) shown: a large hypo density, irregular outline lesion noted in right lower liver, post contrast image shown patchy enhancement of the lesion. His serum Alpha-Feto Protein (AFP) level was very high with elevated serum alanine amino transaminase (ALT) enzyme and prothrombin time. Histopathological (microscopic) features are compatible with Hepatocellular carcinoma. His Hepatitis C viral DNA load e.g., core protein variants and genotype 1, have been reported. The patient was treated by surgical resection followed by conservative treatment includes sorafenib & interferon alpha. This case report aims to outlines the epidemiology of HCC in chronic HCV, risk factors and pathophysiology that contribute to this disease process, related pathophysiology of patient's clinical features, screening recommendations, and the available statistics on the impact of new direct-acting antiviral treatment on the development on HCC.

Matched MeSH terms: Prothrombin Time
Fulltext Delayed traumatic intracranial haemorrhage and progressive traumatic brain injury in a major referral centre based in a developing country

Jeng TC, Haspani MS, Adnan JS, Naing NN

Malays J Med Sci, 2008 Oct;15(4):56-67.
PMID: 22589639

A repeat Computer Tomographic (CT) brain after 24-48 hours from the 1(st) scanning is usually practiced in most hospitals in South East Asia where intracranial pressure monitoring (ICP) is routinely not done. This interval for repeat CT would be shortened if there was a deterioration in Glasgow Coma Scale (GCS). Most of the time the prognosis of any intervention may be too late especially in hospitals with high patient-to-doctor ratio causing high mortality and morbidity. The purpose of this study was to determine the important predictors for early detection of Delayed Traumatic Intracranial Haemorrhage (DTICH) and Progressive Traumatic Brain Injury (PTBI) before deterioration of GCS occurred, as well as the most ideal timing of repeated CT brain for patients admitted in Malaysian hospitals. A total of 81 patients were included in this study over a period of six months. The CT scan brain was studied by comparing the first and second CT brain to diagnose the presence of DTICH/PTBI. The predictors tested were categorised into patient factors, CT brain findings and laboratory investigations. The mean age was 33.1 ± 15.7 years with a male preponderance of 6.36:1. Among them, 81.5% were patients from road traffic accidents with Glasgow Coma Scale ranging from 4 - 15 (median of 12) upon admission. The mean time interval delay between trauma and first CT brain was 179.8 ± 121.3 minutes for the PTBI group. The DTICH group, 9.9% of the patients were found to have new intracranial clots. Significant predictors detected were different referral hospitals (p=0.02), total GCS status (p=0.026), motor component of GCS (p=0.043), haemoglobin level (p<0.001), platelet count (p=0.011) and time interval between trauma and first CT brain (p=0.022). In the PTBI group, 42.0% of the patients were found to have new changes (new clot occurrence, old clot expansion and oedema) in the repeat CT brain. Univariate statistical analysis revealed that age (p=0.03), race (p=0.035), types of admission (p=0.024), GCS status (p=0.02), pupillary changes (p=0.014), number of intracranial lesion (p=0.004), haemoglobin level (p=0.038), prothrombin time (p=0.016) as the best predictors of early detection of changes. Multiple logistics regression analysis indicated that age, severity, GCS status (motor component) and GCS during admission were significantly associated with second CT scan with changes. This study showed that 9.9% of the total patients seen in the period of study had DTICH and 42% had PTBI. In the early period after traumatic head injury, the initial CT brain did not reveal the full extent of haemorrhagic injury and associated cerebral oedema. Different referral hospitals of different trauma level, GCS status, motor component of the GCS, haemoglobin level, platelet count and time interval between trauma and the first CT brain were the significant predictors for DTICH. Whereas the key determinants of PTBI were age, race, types of admission, GCS status, pupillary changes, number of intracranial bleed, haemoglobin level, prothrombin time and of course time interval between trauma and first CT brain. Any patients who had traumatic head injury in hospitals with no protocol of repeat CT scan or intracranial pressure monitoring especially in developing countries are advised to have to repeat CT brain at the appropriate quickest time .

Matched MeSH terms: Prothrombin Time
Shortened activated partial thromboplastin time, a hemostatic marker for hypercoagulable state during acute coronary event

Abdullah WZ, Moufak SK, Yusof Z, Mohamad MS, Kamarul IM

Transl Res, 2010 Jun;155(6):315-9.
PMID: 20478546 DOI: 10.1016/j.trsl.2010.02.001

Various factors may contribute to a hypercoagulable state and acute vascular thrombosis. A prospective study was conducted involving 165 coronary heart disease (CHD) patients from the Cardiology Unit, Hospital Universiti Sains Malaysia. The purpose of this study was to investigate the relationship among factor VIII (FVIII), prothrombin time (PT), activated partial thromboplastin time (APTT), and activated protein C resistance (APC-R) state among CHD patients and to look for potential clinical applications from these laboratory findings. There were 110 cases diagnosed as acute coronary syndrome (ACS), whereas another 55 were stable coronary artery disease (SCAD) patients. PT, APTT, FVIII, and APC-R assays were performed on all subjects. There was a significant difference between the FVIII level and the APTT results (P value < 0.0001). A negative relationship was found between the FVIII level and the APTT from linear regression analysis (R(2) = 10%, P value < 0.0001). For each 1% increase in the FVIII level, the APTT was reduced by 0.013 s (95% confidence interval (CI) between -0.019 and -0.007). Interestingly, none of the SCAD patients had abnormally short APTT. Approximately 68.4% of cases with a positive APC-R assay were found to have a high FVIII level. In conclusion, the APTT test is a potential hemostatic marker for hypercoagulable state including in arterial thrombosis.
Study site: Cardiology unit (outpatient and inpatient), Hospital Universisti Sains Malaysia (HUSM), Kelantan, Malaysia

Matched MeSH terms: Prothrombin Time
Microvascular thrombosis in pediatric multiple organ failure: Is it a therapeutic target?

Nguyen T, Hall M, Han Y, Fiedor M, Hasset A, Lopez-Plaza I, et al.

Pediatr Crit Care Med, 2001 Jul;2(3):187-196.
PMID: 12793940

PURPOSE: To discuss the current rationale for the use of specific and nonspecific therapies for thrombotic microangiopathy in thrombocytopenia-associated pediatric multiple organ failure syndromes. Methods: Pertinent PubMed and MEDLINE citations and proceedings of recent critical care meeting presentations were reviewed. RESULTS: Critical care clinicians have reported using antithrombin III concentrate, protein C concentrate, activated protein C, prostacyclin and its analogues, heparin, tissue factor pathway inhibitor concentrate, plasma infusion, plasma exchange, whole blood exchange, pentoxifylline, tissue plasminogen activator, urokinase, and streptokinase with perceived therapeutic benefits in patients with thrombocytopenia-associated multiple organ failure, including those with thrombotic thrombocytopenic purpura/hemolytic uremic syndrome, disseminated intravascular coagulation syndrome, and secondary thrombotic microangiopathy syndrome without prolonged prothrombin time/activated partial thromboplastin time. CONCLUSION: Assuming that underlying disease is remediable, a consensus has developed that thrombotic microangiopathy is a therapeutic target in children with thrombocytopenia-associated multiple organ failure syndromes. Studies are warranted to delineate efficacious use of specific and nonspecific therapies to prevent and reverse thrombotic microangiopathy in these patients.

Matched MeSH terms: Prothrombin Time
Coagulopathy in acute head injury--a study of its role as a prognostic indicator

Selladurai BM, Vickneswaran M, Duraisamy S, Atan M

Br J Neurosurg, 1997 Oct;11(5):398-404.
PMID: 9474270

The aim of this investigation was to determine the prognostic value of coagulation abnormalities in a defined subset of patients with acute head injury. Prothrombin time, accelerated partial thromboplastin time (APTT), thrombin clotting time, fibrinogen assay, platelet count, fibrin degradation products (FDP) were assayed in 204 patients with acute closed head injury. Their values were graded on a score 0-3 and the sum score for each patient regarded as the disseminated intravascular coagulation (DIC) score. Moderate to severe DIC scores were evident in 38% of the cohort. At least one parameter was abnormal in 71% of patients. The DIC score correlated inversely with the Glasgow coma score (GCS) (p < 0.0001). In the GCS 13-15 subset, FDP scores were significant predictors of poor outcome (p < 0.001). In the GCS 6-12 subset, the APTT score (p < 0.001), and DIC score (p < 0.0001) predicted an adverse outcome. The DIC scores were significantly abnormal in most patients who had a poor outcome, without evidence of adverse predictors on CT. Logistic regression analysis confirmed the independent predictive capacity of APTT, FDP and DIC scores when values for GCS were fixed. Abnormal haemostatic parameters may enhance the predictive ability in subsets of patients with acute head injury defined by clinical or CT predictors.

Matched MeSH terms: Prothrombin Time
Fulltext Effect of Ocimum sanctum (Tulsi) aqueous leaf extract on prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT) of human plasma

Gunendren, M., Noordin S.S., Muggundha, R., Nozlena A.S.

Journal of Biomedical and Clinical Sciences, 2017;2(1):62-68.
MyJurnal

Conventional anticoagulant therapy is the mainstay of medical treatment for deep vein thrombosis disorders. However,there are many complications associated with these agents such as bleeding. Hence, the search for novel anticoagulant derived from natural substances such as plants origin is in high demand nowadays. Ocimum sanctum(O.sanctum) also known as Ocimum tenuiform (OT), tulsi or holy basil from the family of Lamiaceae has been widely used for thousands of years in Ayurveda and Unani systems to cure or prevent a number of illnessessuch as headache, malaria, ulcers, bronchitis, cough, flu, sore throat and asthma. The objective is to investigate theeffect ofO. sanctum(Tulsi) aqueous leaf extract on prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT) in human plasma. Coagulation activity of O. sanctum was measured via PT, APTT and TT assay in citrated plasma collected from thirty-six healthy regular blood donors. The plasma was tested against different concentrations of O. sanctum aqueous extract as follows: 0.1mg/ml, 0.5 mg/ml and 1.0 mg/ml. Result shows the aqueous extract of O. sanctum prolonged the PT and APTT assays (p0.05). The gas chromatography-mass spectrometry (GC-MS) analysis had identified the linolenic acid at 1-10% of ethanol and aqueousconcentration at different retention time which was responsible for the coagulation activities of O. sanctumin human plasma. This study suggests that O. sanctum does affect coagulation activity in human plasma and can be potentially used as naturally derived anticoagulant products in the future.

Matched MeSH terms: Prothrombin Time
Macular haemorrhage in adult acute leukaemia patients at presentation and the risk of subsequent intracranial haemorrhage

Jackson N, Reddy SC, Harun MH, Quah SH, Low HC

Br J Haematol, 1997 Jul;98(1):204-9.
PMID: 9233585

Retinal changes are common in adult acute leukaemia patients at presentation, but whether they correlate with the risk of subsequent intracranial haemorrhage is unknown. A 4-year study has been carried out in 82 newly-diagnosed acute leukaemia patients, aged 12-77 years, who were studied prospectively for the presence of intra-retinal haemorrhages (IRH), white-centred haemorrhages (WCH), cotton-wool spots (CWS) and macular haemorrhages (MH). Groups with and without these features were compared for their risk of intra-cranial haemorrhage (ICH) within the first 30 d following diagnosis. There was no association between the incidence of ICH and the presence of IRH, WCH or CWS. However, 6/13 of those with MH developed ICH, compared to 6/69 of those without MH (relative risk 5.0, CI 95% [2.03-12.33], P=0.003). The only other identifiable risk factor for ICH was the M3 subtype of AML, but if the four cases of M3-AML were discounted from analysis, MH remained a highly significant risk factor for ICH. Patients with MH should be monitored intensively for the development of ICH, and receive priority in the allocation of platelets where these are in short supply.

Matched MeSH terms: Prothrombin Time
Fulltext Development and blood compatibility assessment of electrospun polyvinyl alcohol blended with metallocene polyethylene and plectranthus amboinicus (PVA/mPE/PA) for bone tissue engineering

Qi J, Zhang H, Wang Y, Mani MP, Jaganathan SK

Int J Nanomedicine, 2018;13:2777-2788.
PMID: 29785105 DOI: 10.2147/IJN.S151242

Introduction: Currently, the design of extracellular matrix (ECM) with nanoscale properties in bone tissue engineering is challenging. For bone tissue engineering, the ECM must have certain properties such as being nontoxic, highly porous, and should not cause foreign body reactions.
Materials and methods: In this study, the hybrid scaffold based on polyvinyl alcohol (PVA) blended with metallocene polyethylene (mPE) and plectranthus amboinicus (PA) was fabricated for bone tissue engineering via electrospinning. The fabricated hybrid nanocomposites were characterized by scanning electron microscopy (SEM), Fourier transform and infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), contact angle measurement, and atomic force microscopy (AFM). Furthermore, activated partial thromboplastin time (APTT), prothrombin time (PT), and hemolytic assays were used to investigate the blood compatibility of the prepared hybrid nanocomposites.
Results: The prepared hybrid nanocomposites showed reduced fiber diameter (238±45 nm) and also increased porosity (87%) with decreased pore diameter (340±86 nm) compared with pure PVA. The interactions between PVA, mPE, and PA were identified by the formation of the additional peaks as revealed in FTIR. Furthermore, the prepared hybrid nanocomposites showed a decreased contact angle of 51°±1.32° indicating a hydrophilic nature and exhibited lower thermal stability compared to pristine PVA. Moreover, the mechanical results revealed that the electrospun scaffold showed an improved tensile strength of 3.55±0.29 MPa compared with the pristine PVA (1.8±0.52 MPa). The prepared hybrid nanocomposites showed delayed blood clotting as noted in APTT and PT assays indicating better blood compatibility. Moreover, the hemolysis assay revealed that the hybrid nanocomposites exhibited a low hemolytic index of 0.6% compared with pure PVA, which was 1.6% suggesting the safety of the developed nanocomposite to red blood cells (RBCs).
Conclusion: The prepared nanocomposites exhibited better physico-chemical properties, sufficient porosity, mechanical strength, and blood compatibility, which favors it as a valuable candidate in bone tissue engineering for repairing the bone defects.

Matched MeSH terms: Prothrombin Time
Expression and characterization of anticoagulant activity of salivary protein alALP from Asian tiger mosquito Aedes albopictus

Li XP, Lin D, Zhang Y, Chen SQ, Bai HQ, Zhang SN, et al.

Trop Biomed, 2020 Mar 01;37(1):116-126.
PMID: 33612723

Several bioactive molecules isolated from the saliva of blood-sucking arthropods, such as mosquitoes, have been shown to exhibit potential anticoagulant function. We have previously identified a 30kDa allergen named Aegyptin-like protein (alALP), which is highly homologous to Aegyptin, from the salivary glands of female Aedes albopictus (Asian tiger mosquito). In this study, we identified the conserved functional domain of alALP by using bioinformatic tools, and expressed the His-tagged alALP recombinant protein in sf9 insect cells by generation and transfection of a baculoviral expression plasmid carrying the fulllength cDNA of alALP. We purified this recombinant protein and examined its function on the inhibition of blood coagulation. The results showed that the purified His-alALP prolonged the Activated Partial Thromboplastin Time (APTT), Prothrombin Time (PT) and Thrombin Time (TT) in vitro as well as the Bleeding Time (BT) in vivo, which suggest that alALP could be a novel anticoagulant.

Matched MeSH terms: Prothrombin Time

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