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Sample records for indium-111 platelet scintigraphy

  1. Detection of platelet deposition at the site of peripheral balloon angioplasty using indium-111 platelet scintigraphy

    SciTech Connect

    Pope, C.F.; Ezekowitz, M.D.; Smith, E.O.; Rapoport, S.; Glickman, M.; Sostman, H.D.; Zaret, B.L.

    1985-02-01

    Restenosis after balloon angioplasty may be mediated through platelet deposition at the site of arterial dilatation. The purpose of this study was to determine whether platelet deposition at the site of dilatation could be detected using indium-111 platelet scintigraphy. Fifteen patients, aged 60 +/- 9 years, with iliac or femoral (n . 12), renal artery (n . 2) or distal aortic (n . 1) stenoses were studied. All patients received intravenous heparin at the time of dilatation. Labeled platelets containing 471 +/- 65 muCi indium-111 were injected 0.25 to 4 hours after dilatation and 1 to 24 hours after imaging. In 11 of 12 patients with iliac and femoral dilatations, focal uptake was demonstrated at the angioplasty site. In 4 patients (2 patients with renal, 1 patient with iliofemoral, and 1 with distal aortic stenoses), uptake at the dilatation sites was not detected. This preliminary study indicates that despite intravenous heparin, platelets accumulate at sites of balloon dilatation. Platelet scintigraphy may be useful in predicting sites of future narrowing after angioplasty and may be used to test the efficacy of antiplatelet therapy in retarding restenosis.

  2. Early diagnosis of acute postoperative renal transplant rejection by indium-111-labeled platelet scintigraphy

    SciTech Connect

    Tisdale, P.L.; Collier, B.D.; Kauffman, H.M.; Adams, M.B.; Isitman, A.T.; Hellman, R.S.; Hoffmann, R.G.; Rao, S.A.; Joestgen, T.; Krohn, L.

    1986-08-01

    A prospective evaluation of /sup 111/In-labeled platelet scintigraphy (IPS) for the early diagnosis of acute postoperative renal transplant rejection (TR) was undertaken. The results of IPS were compared with in vitro biochemical tests, the clinical finding of graft tenderness, and combined (/sup 99m/Tc)DTPA and (/sup 131/I)orthoiodohippurate scintigraphy. With a sensitivity of 0.93 and a specificity of 0.95, IPS provided otherwise unavailable diagnostic information. Furthermore, postoperative IPS was a good predictor of long-term allograft survival.

  3. The use of indium-111 oxine platelet scintigraphy and survival studies in pediatric patients with thrombocytopenia

    SciTech Connect

    Castle, V.P.; Shulkin, B.L.; Coates, G.; Andrew, M. )

    1989-11-01

    We have utilized {sup 111}In-labeled heterologous platelets to investigate the mechanism of thrombocytopenia in ten children. From the scintigraphic findings, platelet survival times, and clinical information, thrombocytopenia was ascribed to decreased production or to increased destruction. Two patients were found to have bone marrow production defects. Two patients with hemangiomas were studied. In one, the hemangioma was shown not to be the cause of thrombocytopenia. In the second, the hemangioma was proven the source of platelet destruction, but was much more extensive than clinically evident. In both, surgical manipulation of the hemangioma was avoided. Six additional patients had thrombocytopenia due to accelerated destruction. In four, the spleen was shown responsible. In two, however, the spleen was shown not to be responsible for the low platelet counts, and splenectomy was avoided. Thus, {sup 111}In-platelet scintigraphy and survival studies are valuable in the classification and management of childhood thrombocytopenia. We believe that this study should be performed, when possible, in any child with thrombocytopenia where the mechanism is unclear or the therapeutic intervention involves splenectomy or resection of a hemangioma.

  4. Effect of aspirin and ticlopidine on platelet deposition in carotid atherosclerosis: assessment by indium-111 platelet scintigraphy

    SciTech Connect

    Isaka, Y.; Kimura, K.; Etani, H.; Uehara, A.; Uyama, O.; Yoneda, S.; Kamada, T.; Kusunoki, M.

    1986-11-01

    The antiplatelet effects of aspirin and ticlopidine were studied by a dual-tracer method, using indium-111 labeled platelets and technetium-99m human serum albumin, in a group of 12 patients with suspected ischemic cerebrovascular disease. The magnitude of platelet accumulation at the carotid bifurcation was expressed as the ratio of radioactivity of indium-111 platelets deposited on the vascular wall to those circulating in the blood-pool (PAI, platelet accumulation index), 48 hr after injection of labeled platelets. PAI values were measured before (baseline studies) and after the antithrombotic therapies (aspirin studies: 325 mg bid for 22.3 +/- 1.3 days, ticlopidine studies: 100 mg tid for 21.8 +/- 2.1 days). At the baseline, the mean PAI value at 24 carotid bifurcations in the patient group was 15.7 +/- 15.3% (mean +/- S.D.) compared to -4.3 +/- 9.1 at 24 carotid bifurcations in 12 normal subjects (p less than 0.01). We defined the upper limit for a normal PAI (%) value to be +13.9, namely the mean PAI plus 2 SD for the carotid bifurcation in normal subjects and used this value for semiquantitative analysis. At the baseline, significant elevation of PAI (more than 13.9%; positive scintigram) was observed at 12 of 24 vessels, while 12 other regions were negative (less than 13.9%). In the lesions with positive scintigraphic results at the baseline, the mean PAI (%) value from the baseline, aspirin and ticlopidine studies was 29.5 +/- 7.0, 11.2 +/- 8.5 (p less than 0.01 versus baseline) and 21.4 +/- 21.3 (not significant from baseline), respectively.

  5. Pitfalls in establishing the diagnosis of deep venous thrombophlebitis by indium-111 platelet scintigraphy

    SciTech Connect

    Seabold, J.E.; Conrad, G.R.; Kimball, D.A.; Ponto, J.A.; Bricker, J.A.

    1988-07-01

    Forty-seven /sup 111/In-platelet scintigraphs (In-PS) were analyzed retrospectively to identify sources of diagnostic error and to optimize the diagnostic criteria for active deep venous thrombophlebitis (DVT). The results of In-PS were compared with contrast venography, additional diagnostic studies, and clinical outcome. Three patterns of platelet localization emerged as the best predictors of active DVT: (a) focal or (b) linear 4-hr localization, or (c) an asymmetric blood-pool pattern on 4-hr imaging that evolved into a focal or linear pattern by 16 to 24 hr. All false-positive studies had abnormal patterns confined to the inguinal region at 24 hr. All patients with false-negative studies had received heparin between 4 and 24 hr. The potential pitfalls encountered in the evaluation of the iliac, femoral, and popliteal veins are reviewed and the importance of delayed imaging in selected cases is emphasized.

  6. Indium-111 leukocyte scintigraphy in Wegener's granulomatosis involving the spleen

    SciTech Connect

    Morayati, S.J.; Fink-Bennett, D.

    1986-12-01

    Indium-111-labeled leukocyte scintigraphy was performed on a 44-yr-old man to exclude an occult abscess. Four- and twenty-four-hour images of the abdomen revealed splenic photopenia except for a rim of activity medially. A subsequent computed tomography (CT) study demonstrated necrosis or hemorrhage of the spleen except for a medial rim. Exploratory laparotomy demonstrated necrotizing vasculitis with granuloma formation consistent with Wegener's granulomatosis and a rim of viable splenic tissue corresponding to the radionuclide and CT studies.

  7. Detection of accessory spleens with indium 111-labeled autologous platelets

    SciTech Connect

    Davis, H.H., II; Varki, A.; Heaton, W.A.; Siegel, B.A.

    1980-01-01

    In two patients with recurrent immune thrombocytopenia, accessory splenic tissue was demonstrated by radionuclide imaging following administration of indium 111-labeled autologous platelets. In one of these patients, no accessory splenic tissue was seen on images obtained with technetium 99m sulfur colloid. This new technique provides a simple means for demonstrating accessory spleens and simultaneously evaluating the life-span of autologous platelets.

  8. Thyrotropinoma with Graves’ disease detected by the fusion of indium-111 octreotide scintigraphy and pituitary magnetic resonance imaging

    PubMed Central

    Okuyucu, Kursat; Alagoz, Engin; Arslan, Nuri; Taslipinar, Abdullah; Deveci, Mehmet Salih; Bolu, Erol

    2016-01-01

    Thyroid-stimulating hormone-secreting pituitary adenoma (TSHoma) is a rare benign endocrinological tumor which produces TSH in the pituitary gland. Herein, we presented a female patient having TSHoma with Graves’ disease during and just after pregnancy that we found by indium-111 octreotide scintigraphy while investigating the patient for hyperthyroidism symptoms. PMID:27095865

  9. Appearance of acute gouty arthritis on indium-111-labeled leukocyte scintigraphy

    SciTech Connect

    Palestro, C.J.; Vega, A.; Kim, C.K.; Swyer, A.J.; Goldsmith, S.J. )

    1990-05-01

    Indium-111-labeled leukocyte scintigraphy was performed on a 66-yr-old male with polyarticular acute gouty arthritis. Images revealed intense labeled leukocyte accumulation in a pattern indistinguishable from septic arthritis, in both knees and ankles, and the metatarsophalangeal joint of both great toes, all of which were involved in the acute gouty attack. Joint aspirate as well as blood cultures were reported as no growth; the patient was treated with intravenous colchicine and ACTH for 10 days with dramatic improvement noted. Labeled leukocyte imaging, repeated 12 days after the initial study, revealed near total resolution of joint abnormalities, concordant with the patient's clinical improvement. This case demonstrates that while acute gouty arthritis is a potential pitfall in labeled leukocyte imaging, in the presence of known gout, it may provide a simple, objective, noninvasive method of evaluating patient response to therapy.

  10. Indium-111-oxine labeled platelet kinetics in patients with diabetes mellitus

    SciTech Connect

    Forstrom, L.A.; Luikens, B.; Johnson, T.

    1984-01-01

    The possible role of abnormal platelet function in the pathogenesis of vascular disease in patients with diabetes mellitus remains controversial. In vitro studies have shown variable alterations in platelet function in such patients. Studies of in vivo platelet kinetics in diabetic patients have been inconclusive, although decreased platelet survival has been observed in some cases. Earlier studies were carried out using chromium-51 or selenium-75 for platelet labeling. The authors have performed Indium-111-oxine labeled platelet kinetic and biodistribution studies in 4 patients with diabetes mellitus (ages 49-61 years), and in 4 control subjects (ages 46-60 years). All subjects were male. All diabetic patients were poorly controlled at the time of study, with blood glucose > 140 mg% and hemoglobin A-1c > 10%. Autologous platelets were labeled with Indium-111-oxine in ACD:plasma by previously reported methods, and reinjected in a dose of approximately 50 ..mu..Ci (range 42-67..mu..Ci). Average recovery of the injected platelets was 67% (range 41-85%). Computer analyzed images at 24 hours showed no significant difference in liver uptake between diabetic and control subjects. Mildly increased splenic uptake in diabetic patients was of borderline significance (p=.07). Platelet survival was slightly decreased in diabetic subjects by 3 of 4 models utilized (linear, exponential, multiple hit and weighted mean), although the difference achieved significance only for the weighted man model (p=.05). These data support observations by earlier methods which suggest that platelet survival may be decreased in patients with diabetes mellitus.

  11. Indium-111 labeled platelet survival time studies in patients with prosthetic heart valves

    SciTech Connect

    Martinovitch, U.; Carrick, P.; Lieberman, L.M.

    1985-05-01

    Platelet survival time (PST) studies are useful to demonstrate whether or not patients with prosthetic heart valves have normal or shortened PST. During treatment for recurrent TIAs the PST will signal whether the patient is returning towards a normal PST. Using Indium-111 labeled platelets (ILP) the authors studied 10 patients suffering recurrent TIAs after prosthetic valve surgery to determine whether low dose aspirin increased their PST toward normal and whether the treatment had a beneficial effect on their TIA episodes. The authors conclude that low dose aspirin therapy as studied by ILP has no beneficial effect on PST or in preventing recurrent TIA. ILP is an important technique that allows the physician to identify those patients with shortened PST and to determine response to therapy.

  12. Uptake of indium-111-labeled platelets and indium-111 oxine by murine kidneys after total-body irradiation

    SciTech Connect

    Ebbe, S.; Taylor, S.; Maurer, H.; Kullgren, B.

    1996-08-01

    Radiation nephropathy is a well-known late manifestation of renal irradiation in human beings and experimental animals. Its pathogenesis is unclear, but vascular injury may play a role. Endothelial cells have been demonstrated to manifest a variety of abnormalities within hours of exposure to radiation. In the present experiments mice were exposed to lethal doses of whole-body radiation, and the distribution of {sup 111}In-labeled platelets was evaluated during the first week after irradiation. The purpose was to determine if early abnormalities of endothelial cells would be manifested by altered sequestration of platelets in kidneys and other organs. It was found that the indium accumulated in the kidneys of irradiated mice to a greater extent than in nonirradiated mice, but the pattern of accumulation differed from that seen after injection of radiolabeled platelets. Renal hyperemia was not demonstrable with {sup 51}Cr-labeled red cells, renal vascular permeability was not detected with {sup 125}I-labeled albumin, and the pattern of renal uptake of plasma proteins labeled albumin, and the pattern of renal uptake of plasma proteins labeled with {sup 59}Fe {sup 111}In did not coincide with that seen from {sup 111}In administered as labeled platelets or oxine. Renal uptake of {sup 111}In-oxine was not associated with alterations in urinary or fecal excretion or an increase in total-body retention of the radioisotope. The findings are consistent with the notion that renal vascular injury at the time of irradiation results in accumulation of platelets or platelet constituents during the first week after total-body irradiation of mice. 29 refs., 5 figs., 3 tabs.

  13. Reduction of indium-111 platelet deposition on Dacron vascular grafts in humans by aspirin plus dipyridamole

    SciTech Connect

    Stratton, J.R.; Ritchie, J.L.

    1986-02-01

    Aspirin plus dipyridamole reduces platelet accumulation on short-term Dacron vascular grafts in man. To determine whether drug inhibition of platelet deposition is sustained on older grafts, we studied 18 men aged 41 to 87 years who had Dacron aortic bifurcation grafts in place a mean of 43.4 months (range 9.8 to 121.0) before and during short-term therapy with aspirin (325 mg tid) plus dipyridamole (75 mg tid). During both the baseline and drug studies, indium-111 (/sup 111/In) platelet deposition was quantitated by two techniques, standard planar imaging performed at 24, 48, and 72 hr after injection of platelets and single photon emission computed tomographic imaging performed at 24 and 72 hr after injection. All analyses were performed in a blinded fashion. On both the planar and tomographic images, platelet accumulation on the graft was quantitated by a graft/blood ratio that compared activity in the graft to simultaneously collected whole blood /sup 111/In platelet activity. Aspirin plus dipyridamole reduced the tomographic graft/blood ratio at 24 hr (20.6 +/- 3.5 vs 17.3 +/- 2.5) (+/-SEM) and at 72 hr (29.0 +/- 4.8 vs 25.0 +/- 4.1) after injection of platelets (p = .02). Dacron vascular grafts. Similarly, the planar graft/blood ratio was reduced at 24 hr (2.7 +/- 0.5 vs 2.4 +/- 0.5), 48 hr (3.7 +/- 0.9 vs 3.1 +/- 0.7), and 72 hr (4.0 +/- 0.9 vs 3.6 +/- 0.8) (p = .04). We conclude that aspirin (325 mg tid) plus dipyridamole (75 mg tid) reduces platelet accumulation on long-term Dacron vascular grafts.

  14. Early Indium-111 antimyosin scintigraphy for assessment of regional wall motion asynergy on discharge after myocardial infarction

    SciTech Connect

    van Vlies, B.; Baas, J.; Visser, C.A.; van Royen, E.; Delemarre, B.J.; Bot, H.; Dunning, A.J. )

    1990-01-01

    To assess the relation between early Indium-111 monoclonal antimyosin antibody scintigraphy and degree of regional asynergy on discharge, 38 patients with a first acute myocardial infarct were studied (18 anterior, 20 inferoposterior infarctions). In 21 patients thrombolytic therapy was administered. On the first day of myocardial infarction, 80 MBq Indium-111 Antimyosin was injected. Planar images, anterior, lateral and left anterior oblique, were made 24 hours later. Localized myocardial uptake was present in 37/38 patients, and was evaluated for Count Density Index (count density of infarct zone/left lung count density) in the left anterior oblique images, which displayed the infarct zone well. Regional asynergy on discharge was evaluated by cross-sectional echocardiography and defined mild (hypokinesia) or severe (akinesia or dyskinesia). Count density index was significantly lower in 15 patients with mild asynergy, compared with 22 patients with severe asynergy (1.61 +/- 0.25 vs. 2.42 +/- 0.40, p less than 0.001). This difference was present in both patient groups treated with or without thrombolysis. We conclude that early count density index, reflecting the amount of local necrosis, is highly correlated to the ultimate degree of wall motion impairment.

  15. Imaging of acute myocardial infarction in pigs with Indium-111 monoclonal antimyosin scintigraphy and MRI

    SciTech Connect

    ten Kate, C.I.; van Kroonenburgh, M.J.; Schipperheyn, J.J.; Doornbos, J.; Hoedemaeker, P.J.; Maes, A.; v.d. Nat, K.H.; Camps, J.A.; Huysmans, H.A.; Pauwels, E.K. )

    1990-07-01

    Indium-111 antimyosin F(ab')2 was used in a series of scintigraphic studies on experimentally induced myocardial infarctions in pigs. Antimyosin distribution recorded by planar images of in vivo pigs and by single photon emission computed tomography (SPECT) of excised hearts delineated areas of myocardial necrosis if infarct volume exceeded 3.3 cm3. Scintigraphic images were compared with magnetic resonance images (MRI) obtained from excised hearts and with photographs of slices of the hearts. Infarct size and localization determined with antimyosin were compared. The MR images, with or without gadolinium-DTPA (Gd-DTPA), of the in vivo pigs were all false-negative; some myocardial wall thinning and high bloodpool signals were visible. Results show that both the antimyosin and the MR technique are specific methods for the visualization of induced myocardial necrosis in this animal model. However, the use of antimyosin is limited to a period ranging from 24 to 72 hours after infarction.

  16. Indium-111 antimyosin scintigraphy to assess myocardial damage in patients with suspected myocarditis and cardiac rejection

    SciTech Connect

    Carrio, I.; Berna, L.; Ballester, M.; Estorch, M.; Obrador, D.; Cladellas, M.; Abadal, L.; Ginjaume, M.

    1988-12-01

    Indium-111 antimyosin scans were used to assess myocardial damage in patients with suspected myocarditis and cardiac transplant rejection. The calculation of a myocardium to lung ratio (AM index) to quantify antimyosin uptake was performed. AM index in normal subjects (n = 8) at 48 hr postinjection was 1.46 +/- 0.04. In patients with suspected myocarditis (16 studies in 13 patients), AM index was 2.0 +/- 0.5 (p less than 0.001); suggesting a considerable incidence of ongoing cell damage in this group, despite the small proportion of positive right ventricular endomyocardial biopsy (RVbx) (4/13). In patients studied after cardiac transplantation (37 studies in 17 patients), AM indexes correlated with RVbx. In patients with RVbx proven rejection (n = 14), AM index was 1.87 +/- 0.19 (p less than 0.001). In patients with RVbx showing infiltrates but not myocyte damage (n = 13), AM index was 1.80 +/- 0.27 (p = 0.02). In patients with normal RVbx (n = 10), AM index was 1.56 +/- 0.17 (p = NS versus controls; p = 0.001 versus those with positive RVbx). Calculated AM indexes correlated with graded visual analysis of the scans (r = 0.823; p = 0.001). Antimyosin scans are an appropriate method to assess myocardial damage in patients with suspected myocarditis and cardiac rejection.

  17. Deep arterial injury during experimental angioplasty: relation to a positive indium-111-labeled platelet scintigram, quantitative platelet deposition and mural thrombosis

    SciTech Connect

    Lam, J.Y.; Chesebro, J.H.; Steele, P.M.; Dewanjee, M.K.; Badimon, L.; Fuster, V.

    1986-12-01

    Although it is not clear why coronary occlusion and restenosis occur after successful coronary angioplasty, factors related to the procedure may influence early and late results. The possible adverse effects of a medial tear documented histologically and produced during balloon angioplasty of the common carotid arteries were studied in 30 fully heparinized (100 U/kg body weight) normal pigs. Scanning electron microscopy showed endothelial denudation and extensive platelet deposition in all dilated arterial segments. Visible macroscopic mural thrombus was present within an hour of the procedure in 29 (91%) of the 32 arteries that had a medial tear documented by histologic study; the tear produced an indium-111-labeled platelet deposition of 116.4 +/- 26.5 X 10(6)/cm2 (mean +/- SE) and total thrombotic occlusion in 2 arteries (4%). None of the 24 arteries without a medial tear had a thrombus, and the mean platelet deposition in that group was 7.0 +/- 0.5 X 10(6)/cm2 (p less than 0.0008). In 12 pigs scanned with a gamma camera, visible thrombus was associated with platelet deposition in excess of 20 X 10(6)/cm2 in 12 arteries, 9 of which had a positive indium-111-labeled platelet scintigram. Thus, arterial angioplasty causes deep arterial injury, which appears to be a major cause of mural thrombosis, heavy platelet deposition, a positive indium-111-labeled platelet scintigram and acute arterial occlusion. A positive indium-111-labeled platelet scintigram was always associated with macroscopic thrombus of at least 20 > 10(6) platelets/cm2 and underlying deep arterial injury.

  18. Indium-111 platelet imaging for detection of platelet deposition in abdominal aneurysms and prosthetic arterial grafts

    SciTech Connect

    Ritchie, J.L.; Stratton, J.R.; Thiele, B.; Haminton, G.W.; Warrick, L.N.; Huang, T.W.; Harker, L.A.

    1981-04-01

    Thirty-four platelet imaging studies were performed in 23 patients to determine whether platelet deposition could be detected in patients with vascular aneurysms (18 patients) or in patients in whom Dacron prosthetic grafts had been placed (5 patients). In patients in whom abnormal platelet deposition was detected, the effect of administration of platelet-active drugs on platelet deposition was examined. Of the 18 patients with an aneurysm, 12 had equivocally positive studies on initial imaging and 2 had equivocally positive images. Of five patients with Dacron arterial grafts in place, four had diffuse platelet deposition in the grafts; the fifth patient had a platelet deposition only in a pseudoaneurysm. Eight patients with an abdominal aneurysm and positive or equivocally positive baseline images were restudied during platelet-active drug therapy either with aspirin plus dipyridamole (seven patients) or with sulfinpyrazone (four patients). No patient studied during treatment with aspirin plus dipyridamole had detectably decreased platelet deposition compared with baseline determinations. In contrast, two of four patients studied while receiving sulfinpyrazone showed decreased platelet deposition. Thus, platelet imaging may be of value for studying platelet physiology in vivo and for assessing platelet-active drugs and the thrombogenicity of prosthetic graft materials in human beings.

  19. Postoperative osteomyelitis following implant arthroplasty of the foot: diagnosis with indium-111 white blood cell scintigraphy

    SciTech Connect

    Bakst, R.H.; Kanat, I.O.

    1987-11-01

    Many complications can occur following insertion of silicone elastomer implants into the foot. Postoperative infection may be difficult to distinguish from other conditions such as dislodgment, fracture, ectopic and heterotopic new bone formation, synovitis, and bursitis. White blood cell scintigraphy, in conjunction with the clinical scenario, may prove to be an invaluable tool in the diagnosis of postoperative osteomyelitis, subsequent to implant arthroplasties. 32 references.

  20. Intratumoral consumption of indium-111 labeled platelets in a patient with hemangiomatosis and intravascular coagulation (Kasabach-Merritt syndrome)

    SciTech Connect

    Warrell, R.P. Jr.; Kempin, S.J.; Benua, R.S.; Reiman, R.E.; Young, C.W.

    1983-12-15

    Previous studies regarding sites of platelet destruction in patients with the Kasabach-Merritt syndrome are conflicting. The authors recently studied an adult patient with multiple large hemangiomata, thrombocytopenia, and intravascular coagulation by external imaging following the injection of autologous Indium-111 labeled platelets. Sequential images showed prompt accumulation of platelet-associated radioactivity in areas within the right hemithorax which corresponded to certain tumors noted on the chest roentgenogram. Despite the presence of multiple other lesions in bone and soft tissues, platelet radioactivity was otherwise normally confined to liver and spleen. Using data obtained from serial images, it was shown that radioactivity within the thoracic masses actually increased over time. These data indicate that platelet consumption occurred as an active process and that localization was not a result of tumor vascularity. It is concluded that platelets are locally consumed within certain hemangiomata. However, within the same individual, there may exist considerable heterogeneity among these tumors with respect to platelet-trapping ability. In similar patients with multiple tumors, indium-platelet scanning might be used to direct local therapy to particular lesions in an effort to correct the thrombocytopenia.

  1. Accurate diagnosis of renal transplant rejection by indium-111 platelet imaging despite postoperative cyclosporin therapy

    SciTech Connect

    Collier, B.D.; Adams, M.B.; Kauffman, H.M.; Trembath, L.; Hoffmann, R.G.; Tisdale, P.L.; Rao, S.A.; Hellman, R.S.; Isitman, A.T.

    1988-08-01

    Previous reports indicate that In-111 platelet scintigraphy (IPS) is a reliable test for the early diagnosis of acute post-operative renal transplant rejection (TR). However, the recent introduction of cyclosporin for post-transplantation immunosuppression requires that the diagnostic efficacy of IPS once again be established. Therefore, a prospective IPS study of 73 post-operative renal transplant recipients was conducted. Fourty-nine patients received cyclosporin and 24 patients did not receive this drug. Between these two patient groups, there were no significant differences in the diagnostic sensitivities (0.86 vs 0.80) and specificities (0.93 vs 0.84) with which TR was identified. We conclude that during the first two weeks following renal transplantation the cyclosporin treatment regimen used at our institution does not limit the reliability of IPS as a test for TR.

  2. Use of indium-111 oxine to study the effects of terbutaline on pulmonary and hepatic platelet sequestration in endotoxin shock

    SciTech Connect

    Christenson, J.T.; Sigurdsson, G.H.; Mousawi, M.; Owunwanne, A.

    1987-01-01

    This study describes the effects of the beta 2 receptor agonist terbutaline on platelet sequestration in sheep exposed to endotoxin shock. The in vivo behavior of Indium-111-labeled platelets was followed simultaneously in the lungs, liver, spleen, and kidneys. The effects on the respiratory function and the central hemodynamics were also followed. Twelve adult sheep were given endotoxin (10 micrograms/kg bw), and six of those received a continuous intravenous infusion of terbutaline (20 micrograms/kg/hr) during 4 hr, starting 30 min after injection of endotoxin. The other six acted as controls. It was found that a marked pulmonary and hepatic platelet sequestration occurred during and just after the endotoxin infusion and was followed by a marked platelet disaggregation within 30 min in both groups. Three hours after the endotoxin a second wave of platelet trapping occurred in the control animals in both the lungs and the liver, while no such increase was seen in the terbutaline-treated animals. In the spleen, however, there was a decrease in platelet sequestration after endotoxin in both groups, and in the kidneys only minor changes occurred. Furthermore, less marked hemodynamic and respiratory alterations occurred in the terbutaline group compared with the controls. It was concluded that terbutaline decreased sequestration of platelets in the lungs and in the liver of sheep in endotoxin shock, which may be of importance in the development of multiple organ failure.

  3. Detection of rejection of canine orthotopic cardiac allografts with indium-111 lymphocytes and gamma scintigraphy

    SciTech Connect

    Eisen, H.J.; Rosenbloom, M.; Laschinger, J.C.; Saffitz, J.E.; Cox, J.L.; Sobel, B.E.; Bolman, R.M. III; Bergmann, S.R.

    1988-07-01

    Previous studies have demonstrated the feasibility of detecting canine heterotopic cardiac allograft rejection scintigraphically after administration of 111In lymphocytes. To determine whether the approach is capable of detecting rejection in orthotopic cardiac transplants in which labeled lymphocytes circulating in the blood pool may reduce sensitivity, the present study was performed in which canine orthotopic cardiac transplants were evaluated in vivo. Immunosuppression was maintained with cyclosporine A (10-20 mg/kg/day) and prednisone (1 mg/kg/day) for 2 wk after transplantation. Subsequently, therapy was tapered. Five successful allografts were evaluated scintigraphically every 3 days after administration of 100-350 microCi 111In autologous lymphocytes. Correction for labeled lymphocytes circulating in the blood pool, but not actively sequestered in the allografts was accomplished by administering 3-6 mCi 99mTc autologous erythrocytes and employing a previously validated blood-pool activity correction technique. Cardiac infiltration of labeled lymphocytes was quantified as percent indium excess (%IE), scintigraphically detectable 111In in the transplant compared with that in blood, and results were compared with those of concomitantly performed endomyocardial biopsy. Scintigraphic %IE for hearts not undergoing rejection manifest histologically was 0.7 +/- 0.4. Percent IE for rejecting hearts was 6.8 +/- 4.0 (p less than 0.05). Scintigraphy detected each episode of rejection detected by biopsy. Scintigraphic criteria for rejection (%IE greater than 2 s.d. above normal) were not manifest in any study in which biopsies did not show rejection. Since scintigraphic results with 111In-labeled lymphocytes were concordant with biopsy results in orthotopic cardiac transplants, noninvasive detection of graft rejection in patients should be attainable with the approach developed.

  4. The effect of ibuprofen on accumulation of indium-111-labeled platelets and leukocytes in experimental myocardial infarction

    SciTech Connect

    Romson, J.L.; Hook, B.G.; Rigot, V.H.; Schark, M.A.; Swanson, D.P.; Lucchesi, B.R.

    1982-11-01

    To assess the ability of ibuprofen to influence the extent of platelet aggregation and leukocyte infiltration during acute myocardial infarction, autologous indium-111 (/sup 111/In)-labeled platelets or leukocytes were injected before 60 minutes of left circumflex coronary artery (LCx) occlusion, followed by 24 hours of reperfusion in the canine heart. Myocardial infarct size, as a percent of the area at risk, was reduced in the ibuprofen-treated group (12.5 mg/kg i.v. every 4 hours beginning 30 minutes before LCx occulsion) by 40%, from 48 +/- 4% in control animals to 29 +/- 4% in ibuprofen-treated dogs (p=0.005). Quantification of the platelet-associated /sup 111/In radioactivity in irreversibly injured myocardium indicated that ibuprofen did not alter the accumulation of platelets in infarcted myocardium. In contrast, leukocyte accumulation in infarcted tissue was reduced significantly. In tissue samples with 0.41-0.60 gram infarct, the infarcted/normal ratio of leukocyte radioactivity was 12 +/- 2 in control dogs and 4 +/- 1 in ibuprofen-treated dogs, which represents a 67% reduction in leukocyte accumulation in ibuprofen-treated compared with control dogs. Similar reductions were found in other gram-infarct-weight categories. Although both platelets and leukocytes acumulate in infarcted canine myocardium, ibuprofen may exert its beneficial effect on ischemic myocardium by suppressing the inflammatory response associated with myocardial ischemia and infarction.

  5. A Family with Von Hippel-Lindau Syndrome: The Findings of Indium-111 Somatostatin Receptor Scintigraphy, Iodine-123 Metaiodobenzylguanidine Scintigraphy and Single Photon Emission Computerized Tomography

    PubMed Central

    Arıcan, Pelin; Okudan Tekin, Berna; Naldöken, Seniha; Şefizade, Rıza; Berker, Dilek

    2017-01-01

    Von Hippel-Lindau syndrome (VHLS) is an autosomal dominant hereditary familial disorder characterized by development of malignant and benign neoplasms. Differential diagnosis of the adrenal and pancreatic masses are difficult in patients with VHLS. Iodine-123 metaiodobenzylguanidine (I-123 MIBG) and indium-111 somatostatin receptor scintigraphies (In-111 SRS) have important roles in the differential diagnosis of adrenal and pancreatic masses in those patients. In this case report, we present the findings of I-123 MIBG single-photon emission computerized tomography (SPECT/CT) and In-111 SRS SPECT/CT in three members of a family with VHLS. In case 1, a residual neuroendocrine tumor (NET) was detected in the head of pancreas on In-111 SRS SPECT/CT images. In case 2 and 3, I-123 MIBG SPECT/CT confirmed the adrenal masses as pheochromocytoma, and the extra-adrenal mass as NET, before surgery. We thought that In-111 SRS and I-123 MIBG scan might be helpful in the routine work up of VHLS patients for diagnostic and therapeutic purposes. Hybrid SPECT/CT system may improve diagnostic accuracy of planar images since it assesses morphologic and functional information together. PMID:28291009

  6. Indium-111-labeled platelets: effect of heparin on uptake by venous thrombi and relationship to the activated partial thromboplastin time

    SciTech Connect

    Fedullo, P.F.; Moser, K.M.; Moser, K.S.; Konopka, R.; Hartman, M.T.

    1982-09-01

    The goal of heparin thepapy in deep vein thrombosis is to prevent thrombus extension. The relationship between thrombus extension and the results of coagulation tests used to monitor heparin thepapy is unclear. To expose this relationship, we studied the effect of several heparin regimens on the accretion of indium-111-labeled platelets on fresh venous thrombi, as detected by gamma imaging, and monitored the activated partial thromboplastin time (APTT). Six dogs were treated with a 300-U/kg bolus of heparin followed by a 90-U/kg/hour heparin infusion, a dose of heparin sufficient to increase the APTT to levels greater than eight times baseline (APTT ratio); platelet accretion (thrombus imaging) occurred only after the heparin effect was reversed with protamine sulfate. Nineteen dogs were treated with a 150-U/kg bolus of heparin followed by a 4-hour, 45-U/kg/hour heparin infusion; a thrombus was demonstrated only after protamine injection in 12 (mean APTT ratio 1.3 +/- 0.19) and before protamine injection in seven. In thirteen of these 19 dogs, 30 minutes separated the platelet injection from heparin therapy, while in six this duration was less than 30 minutes. In four of these six dogs, thrombi were demonstrated before protamine therapy and at APTT ratios greater than 3.0. Finally, 10 dogs were treated with a 100-U/kg bolus followed by a 3-hour, 50-U/kg/hour heparin infusion, after which the APTT was allowed to return to baseline values spontaneously. In all 10 dogs, a thrombus was demonstrated only after cessation of the heparin infusion, and at a mean APTT ratio of 1.4 +/- 0.15 times baseline. These results suggest that, except with very early platelet injection, platelet accretion by thrombi is consistently inhibited by heparin at APTT ratios greater than 2.5.

  7. In vivo quantitation of platelet deposition on human peripheral arterial bypass grafts using indium-111-labeled platelets. Effect of dipyridamole and aspirin

    SciTech Connect

    Pumphrey, C.W.; Chesebro, J.H.; Dewanjee, M.K.; Wahner, H.W.; Hollier, L.H.; Pairolero, P.C.; Fuster, V.

    1983-03-01

    Indium-111-labeled autologous platelets, injected 48 hours after operation, were used to evaluate the thrombogenicity of prosthetic material and the effect of platelet inhibitor therapy in vivo. Dacron double-velour (Microvel) aortofemoral artery bifurcation grafts were placed in 16 patients and unilateral polytetrafluoroethylene femoropopliteal grafts were placed in 10 patients. Half the patients in each group received platelet inhibitors before operation (dipyridamole, 100 mg 4 times a day) and after operation (dipyridamole, 75 mg, and acetylsalicylic acid, 325 mg 3 times a day); the rest of the patients served as control subjects. Five-minute scintigrams of the graft region were taken with a gamma camera interfaced with a computer 48, 72, and 96 hours after injection of the labeled platelets. Platelet deposition was estimated from the radioactivities of the grafts and expressed as counts per 100 pixels per microcurie injected. Dipyridamole and aspirin therapy significantly reduced the number of platelets deposited on Dacron grafts and prevented platelet accumulation over 3 days. With the small amount of platelet deposition on polytetrafluoroethylene femoropopliteal artery grafts even in control patients, platelet inhibitor therapy had no demonstrable effect on platelet deposition on these grafts. It is concluded that (1) platelet deposition on vascular grafts in vivo can be quantitated by noninvasive methods, and (2) dipyridamole and aspirin therapy reduced platelet deposition on Dacron aortofemoral artery grafts.

  8. Effects of antithrombotic drugs in patients with left ventricular thrombi: assessment with indium-111 platelet imaging and two-dimensional echocardiography

    SciTech Connect

    Stratton, J.R.; Ritchie, J.L.

    1984-03-01

    Patients with left ventricular thrombi not caused by recent myocardial infarction were prospectively studied by indium-111 platelet imaging and two-dimensional echocardiography to determine the reproducibility of these techniques and the short-term effects of sulfinpyrazone (200 mg four times daily), aspirin (325 mg three times daily) plus dipyridamole (75 mg three times daily), and full-dose warfarin. At baseline, all patients underwent indium-111 platelet imaging and echocardiography, and the results were positive for thrombus. In six patients on no antithrombotic drug therapy, repeat platelet scans and echocardiographic studies at 6.0 +/- 3.3 weeks remained positive and were unchanged. In seven patients studied on sulfinpyrazone, three platelet scans became negative, two became equivocal, and two were unchanged; the presence and size of thrombus was constant by echocardiography in all seven patients. Of the six patients studied on aspirin plus dipyridamole, one platelet scan became negative, those of three became equivocal, and two were unchanged; all echocardiographic findings remained positive, but one patient had decreased thrombus size. Among four warfarin-treated patients, three had resolution of platelet deposition and one was unchanged; by echocardiography, thrombus resolved in one patient, was decreased in size in one, and was unchanged in two. We conclude that, in the absence of antithrombotic drug therapy, platelet imaging and echocardiographic findings are stable in patients with left ventricular thrombi not caused by recent myocardial infarction. Sulfinpyrazone, aspirin plus dipyridamole, and warfarin all interrupt platelet deposition in some patients with chronic left ventricular thrombi.

  9. Value of blood-pool subtraction in cardiac indium-111-labeled platelet imaging

    SciTech Connect

    Machac, J.; Vallabhajosula, S.; Goldman, M.E.; Goldsmith, S.J.; Palestro, C.; Strashun, A.; Vaquer, R.; Phillips, R.A.; Fuster, V. )

    1989-09-01

    Blood-pool subtraction has been proposed to enhance {sup 111}In-labeled platelet imaging of intracardiac thrombi. We tested the accuracy of labeled platelet imaging, with and without blood-pool subtraction, in ten subjects with cardiac thrombi of varying age, eight with endocarditis being treated with antimicrobial therapy and ten normal controls. Imaging was performed early after labeled platelet injection (24 hr or less) and late (48 hr or more). Blood-pool subtraction was carried out. All images were graded subjectively by four experienced, blinded readers. Detection accuracy was measured by the sensitivity at three fixed levels of specificity estimated from receiver operator characteristic curve analysis and tested by three-way analysis of variance. Detection accuracy was generally improved on delayed images. Blood-pool subtraction did not improve accuracy. Although blood-pool subtraction increased detection sensitivity, this was offset by decreased specificity. For this population studied, blood-pool subtraction did not improve subjective detection of abnormal platelet deposition by 111In platelet imaging.

  10. The use of indium-111 labeled platelet scanning for the detection of asymptomatic deep venous thrombosis in a high risk population

    SciTech Connect

    Siegel, R.S.; Rae, J.L.; Ryan, N.L.; Edwards, C.; Fortune, W.P.; Lewis, R.J.; Reba, R.C. )

    1989-11-01

    Five hundred indium-111 labeled platelet imaging studies (387 donor and 113 autologous) were performed postoperatively in 473 patients who had undergone total hip replacement, total knee replacement, or internal fixation of a hip fracture to detect occult deep venous thrombosis. All patients had been anticoagulated prophylactically with aspirin, warfarin sodium (Coumadin), or dextran. Thirty-four possible cases of proximal deep venous thrombosis were identified in 28 asymptomatic patients. To verify the scan results, 31 venograms were performed in 25 patients (three refused). In 21 of 31 cases, totally occlusive thrombi were detected; in 5 cases, partially occlusive thrombi were detected; in 5 cases, no thrombus was seen. No patient who had a negative scan nor any patient who had a verified positive scan (and received appropriate heparin therapy) subsequently developed symptoms or signs of pulmonary embolism. One hundred forty-one indium study patients also underwent Doppler ultrasonography/impedance plethysmography (Doppler/IPG) as a comparative non-invasive technique. In 137 cases, the results of the indium study and Doppler/IPG studies were congruent. The indium study had no false negative results that were detected by Doppler/IPG. No patient had any clinically evident toxicity. These results suggest that indium-111 labeled platelet scanning is a safe, noninvasive means for identifying DVT in high risk patients.

  11. Indium 111-labeled platelet kinetic studies and platelet-associated IgG in hairy cell leukemia

    SciTech Connect

    Panzer, S.; Lechner, K.; Neumann, E.; Meryn, S.; Haubenstock, A.

    1986-07-15

    In order to study the pathogenesis of thrombocytopenia in patients with hairy cell leukemia (HCL), levels of platelet-associated IgG (PAIgG), platelet life span (MLS), and the sequestration site of autologous /sup 111/In-labeled platelets were measured in nine patients with HCL. Splenectomized patients (n = 4) had a higher platelet count (x = 122.5 X 10(9)/l; range, 80-190 X 10(9)/l) as well as higher levels of PAIgG (x = 10.7%; range, 5.8-16.9%), than nonsplenectomized patients (platelets x = 76 X 10(9)/l, range 40-100 X 10(9)/l; PAIgG x = 3.2%, range 2.2-4.2%). A normal recovery of /sup 111/In-labeled platelets was found in splenectomized patients, whereas a very low recovery was observed in the nonsplenectomized group (x = 70.2%, range, 50-82.5%, versus x = 22.4%, range, 15-28.2%). The MLS was borderline normal in all patients. The site of sequestration was the spleen in nonsplenectomized patients. The low recovery of /sup 111/In-labeled platelets in nonsplenectomized patients suggests hypersplenism with pooling as a major cause of thrombocytopenia, in addition to impaired thrombocytopoiesis and possible immune-mediated platelet destruction.

  12. A quantitative method to measure human platelet chemotaxis using indium-111-oxine-labeled gel-filtered platelets

    SciTech Connect

    Lowenhaupt, R.W.; Silberstein, E.B.; Sperling, M.I.; Mayfield, G.

    1982-12-01

    Human blood platelets have been shown to migrate directionally and specifically toward collagen in plasma in vitro. We have developed a new system to monitor this behavior using a linear 7-compartment chamber with /sup 111/In-oxine-labeled gel-filtered platelets. The compartments are separated by various Nuclepore and Millipore filter membranes. Radiolabeled platelets suspended in plasma are placed in the central compartment and the other compartments are filled with platelet-free plasma. When collagen is added to an end compartment, platelets migrate toward that end. The degree of this directed movement or chemotaxis can be measured by counting the radioactivity of the contents of each compartment and then comparing the counts from radiolabeled platelets that have moved to the end that holds the chemotactic inducer with those that have randomly migrated to the opposite end, containing only plasma. This assay system allows quantitative comparisons between the chemotaxis-inducing abilities of different substances and permits the study of soluble materials. Experiments to determine the optimal conditons for the procedure are reported, and the advantages of this new method for the investigation of platelet chemotaxis and the identification of chemotaxins are discussed.

  13. Reduction in deposition of indium 111-labeled platelets after autologous endothelial cell seeding of Dacron aortic bifurcation grafts in humans: a preliminary report

    SciTech Connect

    Ortenwall, P.; Wadenvik, H.; Kutti, J.; Risberg, B.

    1987-07-01

    Autologous endothelial seeding (AES) of vascular prostheses in dogs increases thrombus-free surface and improves prosthetic prostacyclin production, patency, and the ability to withstand hematogenous challenge with bacteria. No such information is available in human subjects. In the present study one limb of an aortic Dacron bifurcation prosthesis was seeded with autologous endothelial cells (ECs) harvested from the distal portion of the saphenous vein by enzymatic treatment. The deposition of indium 111-labeled platelets on the vascular prostheses was studied 1 and 4 months after operation. In seven of nine patients seeding resulted in decreased accumulation of radiolabeled platelets compared with sham-seeded control limbs (p less than 0.04), when studied 1 month after surgery. A decrease in platelet accumulation occurred over the whole prosthesis between 1 and 4 months, and no significant difference was noted at 4 months between seeded and nonseeded graft limbs. Although the seeding density was very low (440 ECs/cm2), the observed difference in platelet accumulation for AES-treated graft limbs in the early postoperative course merits further investigation of this technique in human beings.

  14. Effect of different aspirin doses on arterial thrombosis after canine carotid endarterectomy: a scanning electron microscope and indium-111-labeled platelet study

    SciTech Connect

    Ercius, M.S.; Chandler, W.F.; Ford, J.W.; Swanson, D.P.; Burke, J.C.

    1984-02-01

    Although it is widely accepted that aspirin inhibits platelet aggregation in arterial thrombosis, the appropriate dosage of aspirin remains quite controversial. The purpose of this study was to determine the effect of different doses of aspirin (0.5 mg/kg vs. 10 mg/kg) on mural thrombus formation after carotid endarterectomy. Eighteen hours after oral aspirin administration, 20 endarterectomies were performed on mongrel dogs with the use of the operating microscope. Blood flow was then restored for 3 hours and the vessels were prepared for investigation with the scanning electron microscope. Ten endarterectomies were also performed on unmedicated dogs as controls. Five minutes before vessel unclamping, autologous indium-111-labeled platelets were administered intravenously, and the endarterectomized portions of the vessels were studied with a gamma counter system after harvesting. Group 1, the control group, revealed extensive mural thrombus consisting of platelet aggregates, fibrin, red blood cells, and white blood cells. Six of the 10 vessels in Group 2, premedicated with 0.5 mg of aspirin per kg, demonstrated varying amounts of mural thrombus. Group 3 (10 vessels), premedicated with 10 mg of aspirin per kg, revealed a platelet monolayer completely covering the exposed vessel wall media, with scattered white blood cells and infrequent fine fibrin strands overlying the platelet surface. The mean (+/- SD) radioactivity per group expressed as counts/minute/mm2 was: Group 1--2055.3 +/- 1905.5, log . 7.253 +/- 0.926; Group 2--1235.6 +/- 1234.3, log . 6.785 +/- 0.817; Group 3--526 +/- 433.06, log . 5.989 +/- 0.774.

  15. Detection of a prosthetic aortic valvular abscess with indium-111-labeled leukocytes

    SciTech Connect

    Oates, E.; Sarno, R.C.

    1988-10-01

    An unsuspected annular abscess at the base of a prosthetic aortic valve in a patient with endocarditis was identified by indium-111-labeled leukocyte scintigraphy alone. This highly sensitive and specific technique expediently demonstrated the surgically proven inflammatory focus.

  16. A new technique for quantification of platelet thrombosis on bovine pericardial valve prostheses (Ionescu-Shiley) in calves with indium-111 labeled platelets

    SciTech Connect

    Dewanjee, M.K.; Solis, E.E.; Mackey, S.; Chesebro, J.H.; Didisheim, P.; Edwards, W.D.; Zollman, P.E.; Kaye, M.P.

    1985-05-01

    Platelet thrombosis on components of tissue valve prosthesis explanted from Holstein calves was quantified with In-111-labeled autologous platelets. Twenty-eight calves were implanted with 25 mm bovine pericardial valve prostheses in mitral annulus and killed 1, 14, 30 and 90 days post-implantation. Twenty-four hours before killing 350-450 ..mu..Ci of autologous In-111 platelets were administered intravenously. Components of the explanted valve were imaged with a gamma camera. Mean (+- SD) value of platelet deposition (PlX10/sup 5//mm/sup 2/) on four sections of each leaflet (free edge: FE, central zone: CZ, flexion zone: FZ, attachment zone: AZ) was calculated from platelet count, radioactivity in blood, leaflet sections and area of leaflet sections. With fibrous ingrowth in sewing ring the tissue valve becomes less thrombogenic at 30 days post-implantation; with increase in calcification platelet thrombosis also increases in central zone of leaflet at 30 and 90 days.

  17. Frequency of myocardial indium-111 antimyosin uptake after uncomplicated coronary artery bypass grafting

    SciTech Connect

    van Vlies, B.; van Royen, E.A.; Visser, C.A.; Meyne, N.G.; van Buul, M.M.; Peters, R.J.; Dunning, A.J. )

    1990-11-15

    The reported incidence of myocardial damage after coronary artery bypass grafting (CABG) is highly related to the methods used. Since indium-111 monoclonal antimyosin antibody scintigraphy has been shown to be highly specific and sensitive for myocardial necrosis, even in small lesions, uptake of this radiotracer was evaluated after CABG. In 23 consecutive patients without previous myocardial infarction who underwent CABG for stable angina, 80 MBq indium-111 antimyosin was injected on the third postoperative day. Planar images were obtained 48 hours later and analyzed for myocardial uptake of indium-111 antimyosin. Scintigraphic results were related to creatine kinase MB levels, duration of both aortic cross-clamping and cardiopulmonary bypass, and electrocardiographic changes. In all patients surgical procedure and postoperative course was uncomplicated. Indium-111 antimyosin uptake was present in 19 of 23 patients (82%). It was diffused in 7 patients and localized in 12. No pathologic Q waves occurred postoperatively. Fourteen patients exhibited ST-segment changes. No good relation was found among indium-111 antimyosin uptake and creatine kinase MB levels, duration of cross-clamping or bypass, and ST-T changes. It is concluded that some degree of myocardial damage, though silent, is common after CABG.

  18. Deep venous thrombophlebitis: detection with 4-hour versus 24-hour platelet scintigraphy

    SciTech Connect

    Seabold, J.E.; Conrad, G.R.; Ponto, J.A.; Kimball, D.A.; Frey, E.E.; Ahmed, F.; Coughlan, J.D.; Jensen, K.C.

    1987-11-01

    Thirty-one nonheparinized patients with suspected deep venous thrombophlebitis (DVT) underwent contrast venography and indium-111 platelet scintigraphy (In-111 PS). Venography permitted identification of acute DVT in 12 of 31 cases (39%). One additional patient was considered to have acute DVT despite nonconclusive venography results. In-111 PS results were positive at 4 hours in nine of 13 cases (69%) and at 24 hours in 12 of 13 cases (92%). Two of four patients with false-negative 4-hour In-111 PS studies had received warfarin. Thus, the sensitivity of 4-hour In-111 PS in patients not receiving anticoagulants was 82%. Venography results were negative for acute DVT in 18 cases, and 4-hour In-111 PS studies were negative or equivocal in each. In-111 PS is an alternative to contrast venography for detecting acute DVT. If 4-hour In-111 PS results are positive, anticoagulation can be initiated. Delayed images are necessary if the 4-hour images are negative or equivocal.

  19. Indium-111 leukocyte scanning and fracture healing

    SciTech Connect

    Mead, L.P.; Scott, A.C.; Bondurant, F.J.; Browner, B.D. )

    1990-01-01

    This study was undertaken to determine the specificity of indium-111 leukocyte scans for osteomyelitis when fractures are present. Midshaft tibial osteotomies were performed in 14 New Zealand white rabbits, seven of which were infected postoperatively with Staphylococcus aureus per Norden's protocol. All 14 rabbits were scanned following injection with 75 microCi of indium 111 at 72 h after osteotomy and at weekly intervals for 4 weeks. Before the rabbits were killed, the fracture sites were cultured to document the presence or absence of infection. The results of all infected osteotomy sites were positive, whereas no positive scans were found in the noninfected osteotomies. We concluded from this study that uncomplicated fracture healing does not result in a positive indium-111 leukocyte scan.

  20. Differential diagnosis of CT-hypodense cranial lesions with indium-111-oxine-labeled leukocytes

    SciTech Connect

    Bellotti, C.; Aragno, M.G.; Medina, M.; Viglietti, A.L.; Oliveri, G.; Ettorre, F.; Barrale, S.; Camuzzini, G.

    1986-05-01

    Scintigraphy using indium-111-oxine-labeled white blood cells was used as a complementary diagnostic study in the differential diagnosis of 20 intracerebral cystic lesions for which computerized tomography scanning did not exclude abscess. To lower the rate of false-positive findings with scintiscanning, three criteria of positivity were tested in the 20 lesions. The most stringent criterion yielded 100% sensitivity, 94% specificity, and 96% diagnostic accuracy. The clinical and surgical implications of these results are discussed.

  1. Role of indium-111 chloride imaging in osteoid osteoma

    SciTech Connect

    Kumar, R.; Swischuk, L.E.; Schreiber, M.H.

    1986-10-01

    Indium-111 chloride imaging plays an important role in differentiating intracortical osteoid osteoma from chronic cortical abscess. The study also may be useful in the detection of intramedullary osteoid osteoma. Four patients who greatly benefited from indium-111 chloride imaging are presented.

  2. Aspirin inhibition of platelet deposition at angioplasty sites: demonstration by platelet scintigraphy

    SciTech Connect

    Cuningham, D.A.; Kumar, B.; Siegel, B.A.; Gilula, L.A.; Totty, W.G.; Welch, M.J.

    1984-05-01

    In-111 platelet scintigraphy was used to evaluate the effects of prior aspirin administration on the accumulation of In-111-labeled autologous platelets at sites of arterial injury resulting from iliac, femoral, or popliteal transluminal angioplasty in a nonrandomized study of 17 men. The degree of platelet localization at angioplasty sites was significantly less in nine men who had received aspirin in varying doses within the 4 days before angioplasty than in eight men who had not received aspirin for at least two weeks. The results suggest that aspirin treatment before angioplasty limits the early platelet deposition at the angioplasty site in men.

  3. Evaluation of indium-111-labeled antifibrin monoclonal antibody for the diagnosis of venous thrombotic disease

    SciTech Connect

    De Faucal, P.; Peltier, P.; Planchon, B.; Dupas, B.; Touze, M.D.; Baron, D.; Scaible, T.; Berger, H.J.; Chatal, J.F. )

    1991-05-01

    The potential advantage of using {sup 111}In-antifibrin ({sup 111}In-AF) monoclonal antibody for the diagnosis of deep venous thrombosis (DVT) was studied in 44 patients with suspected DVT (27 underwent heparin therapy before {sup 111}In-AF injection). All patients had contrast venography (considered as the gold standard) and {sup 111}In-AF scintigraphy within 24 hr. Two to 3 mCi of {sup 111}In-AF were injected intravenously, and planar scintigraphy of the limbs was recorded within 10 min (17 times), 3 hr (44 times), and 18 hr (39 times). Indium-111-AF images were then interpreted without knowledge of the results of the other examinations. The DVT diagnostic accuracy of {sup 111}In-AF was greater when interpretation was based on images recorded at different time periods after injection. Indium-111-AF sensitivity for diagnosis of DVT was 85% (29/34) and was not apparently decreased by heparin therapy. None of the 10 patients with negative contrast venography had a positive {sup 111}In-AF scan. The results demonstrate the importance of recording serial images and the excellent accuracy of {sup 111}In-AF for diagnosing DVT.

  4. Persistent uptake of indium-111-antimyosin monoclonal antibody in patients with myocardial infarction

    SciTech Connect

    Matsumori, A.; Yamada, T.; Tamaki, N.; Kawai, C.; Watanabe, Y.; Yonekura, Y.; Endo, K.; Konishi, J.; Yoshida, A.; Tamaki, S. )

    1990-11-01

    Indium-111(111In)-antimyosin scintigraphy was investigated in 27 patients with myocardial infarction. {sup 111}In-antimyosin Fab was administered intravenously, and planar and single photon emission computed tomographic images were obtained 48 hours later. Uptake of {sup 111}In-antimyosin was present in 9 of 10 patients (90%) studied within 6 days of infarction. During the second week positive scans were seen in 16 of 16 patients (100%) including 13 (81%) who had normal creatine kinase levels. The mechanism of persistent positive antimyosin images in the subacute stage of myocardial infarction remains to be clarified. {sup 111}In-antimyosin scintigraphy may be useful as a noninvasive method for the detection of myocardial injury late and early after a suspected acute myocardial infarction.

  5. The role of indium-111 antimyosin (Fab) imaging as a noninvasive surveillance method of human heart transplant rejection

    SciTech Connect

    De Nardo, D.; Scibilia, G.; Macchiarelli, A.G.; Cassisi, A.; Tonelli, E.; Papalia, U.; Gallo, P.; Antolini, M.; Pitucco, G.; Reale, A. )

    1989-09-01

    The identification of rejection after heart transplantation in patients receiving cyclosporine immunosuppressive therapy requires the endomyocardial biopsy, an invasive method associated with a finite morbidity. To evaluate the role of indium-111 antimyosin (Fab) scintigraphy as a noninvasive surveillance method of heart transplant rejection, the Fab fragment of murine monoclonal antimyosin antibodies labeled with indium-111 was administered intravenously in 30 scintigraphic studies to 10 consecutive heart transplant recipients. Endomyocardial biopsy specimens were obtained 72 hours after each scintigraphic study. Nineteen scintigraphic studies had negative findings; no false negative finding was obtained. Eleven antimyosin scintigraphic studies had positive findings, and in these studies endomyocardial biopsy revealed mild rejection in two cases, moderate acute rejection with myocyte necrosis in two cases, myocyte necrosis as a consequence of ischemic injury in six cases, and possibly cytotoxic damage in one case. Antimyosin scintigraphy may represent a reliable screening method for the surveillance of heart transplant patients. In the presence of a negative finding from antimyosin scintigraphy, it may be possible to avoid endomyocardial biopsy. Conversely, in patients who have a positive finding from antimyosin scintigraphy, the endomyocardial biopsy is mandatory to establish the definitive diagnosis by histologic examination of the myocardium.

  6. Indium-111-leukocyte imaging in acute cholecystitis

    SciTech Connect

    Fink-Bennett, D.; Clarke, K.; Tsai, D.; Nuechterlein, P.; Gora, G. )

    1991-05-01

    Eleven patients with suspected acute cholecystitis underwent sequential {sup 99}mTc-iminodiacetic derivative (IDA) and {sup 111}In-white blood cell (WBC) imaging to determine if {sup 111}In-WBCs accumulate within an acutely inflamed hemorrhagic gallbladder wall and, thus, could be employed as a reasonable alternative to {sup 99}mTc-IDA scintigraphy in detecting acute cholecystitis. Seven patients had surgically confirmed acute cholecystitis. Of these cases, five had a true-positive {sup 99}mTc-IDA and {sup 111}In-WBC, one an indeterminate {sup 111}In-WBC and true-positive {sup 99}mTc-IDA, and one a true-positive {sup 111}In-WBC and false-negative {sup 99}mTc-IDA scan. The remaining four patients did not have acute cholecystitis. All visualized their gallbladder within 1 hr after {sup 99}mTc-IDA administration and none had {sup 111}In-WBC gallbladder wall uptake. Both {sup 111}In-WBC and {sup 99}mTc-IDA scintigraphy accurately detected acute cholecystitis: hepatobiliary scintigraphy demonstrated a cystic duct obstruction and {sup 111}In-WBC imaging detected the inflammatory infiltrate within the gallbladder wall. The sensitivity and specificity of each was 86% and 100%, respectively.

  7. Indium-111 labeled anti-melanoma monoclonal antibodies

    DOEpatents

    Srivastava, S.C.; Fawwaz, R.A.; Ferrone, S.

    1984-04-30

    A monoclonal antibody to a high molecular weight melanoma-associated antigen was chelated and radiolabeled with indium-111. This material shows high affinity for melanoma and thus can be used in the detection, localization and imaging of melanoma. 1 figure.

  8. Sequential technetium-99m sulfur colloid/indium-111 white blood cell imaging in macroglobulinemia of Waldenstrom

    SciTech Connect

    Fink-Bennett, D.; Balon, H.R.; Irwin, R. )

    1990-06-01

    Technetium-99m sulfur colloid (SC) and indium-111 labeled leukocyte (In-111 WBC) scintigraphy was performed on a 77-year-old female patient to rule out a left periprosthetic infection. Anterior Tc-99m SC and In-111 WBC images of the pelvis and femurs revealed no abnormal deposition of radiotracer about the Austin-Moore prosthesis. Absent radiotracer uptake, however, was demonstrated within the left hemipelvis. A left iliac bone marrow aspirate and biopsy revealed a lymphoplasmacytic infiltrate consistent with Waldenstrom's macroglobulinemia.

  9. Use of indium-111-labeled cells in measurement of cellular dynamics of experimental cardiac allograft rejection

    SciTech Connect

    Oluwole, S.; Wang, T.; Fawwaz, R.; Satake, K.; Nowygrod, R.; Reemtsma, K.; Hardy, M.A.

    1981-01-01

    This study evaluates the kinetics and utility of infused indium-111-labeled cells in detecting rejection in ACI to Lewis rat heart allografts. Syngeneic leukocytes, lymph node lymphocytes, and platelets were isolated and labeled with indium-111 (/sup 111/In) oxine, respectively, and were infused i.v. into Lewis rats carrying beating ACI or syngeneic hearts from post-transplant days 0 to 6. Recipients were imaged serially at 24 hr after infusion of labeled cells followed by excision of both native and transplanted hearts for direct isotope count. Labeled leukocytes accumulative progressively in the allograft with the scan becoming positive by post-transplant day 4. The ratio of allograft to native heart isotope counts rose from 1.25 on day 1 to 10.07 (P less than 0.0001) on day 7. The Lewis recipients infused with labeled lymphocytes showed a positive scan on days 6 and 7 whereas the allograft to native heart isotope count ratio rose from 0.97 on day 1 to 5.33 (P less than 0.001) on day 7. Recipients infused with /sup 111/In-labeled platelets showed a positive scan on days 5 to 7 and the allograft to native heart isotope count ratio rose sharply from 2.56 on day 4 to 16.98 (P less than 0.005) on day 7. Syngeneic heart grafts failed to demonstrate significant accumulation of any of the labeled cell population. These studies confirm the importance of nonlymphocytic cells in cellular rejection, evaluate the kinetics of graft invasion by the various cell types, and suggest that the techniques used afford a method for a safe and an early detection of allograft rejection.

  10. Acute myocardial infarct imaging with indium-111-labeled monoclonal antimyosin Fab

    SciTech Connect

    Khaw, B.A.; Yasuda, T.; Gold, H.K.; Leinbach, R.C.; Johns, J.A.; Kanke, M.; Barlai-Kovach, M.; Strauss, H.W.; Haber, E.

    1987-11-01

    Indium-111 monoclonal antimyosin Fab scintigraphy was used to detect myocardial necrosis in 52 of 54 patients (96.3%) with acute myocardial infarction. Infarcts were visualized when coronary arteries were persistently occluded (n = 10), became patent after thrombolysis (n = 33), or became patent after spontaneous reperfusion (n = 7). Posteroinferolateral visualizations were obtained in two patients with clinical and enzymatic evidence of infarction but normal electrocardiograms. Of the two patients in whom no infarcts were visualized, one had an anterior myocardial infarct. This patient underwent successful thrombolytic therapy, with attendant minimization of creatine kinase release. The other patient had a small, nonreperfused inferior myocardial infarct. Five patients with a history of remote infarction and acute necrosis showed antimyosin uptake only in regions concordant with the acute episodes of infarction, and radiolabeled antimyosin Fab localized in neither old infarcts nor normal, noninfarcted myocardium. Antimyosin Fab scintigraphy, thus, appears to be a highly specific means of delineating necrotic myocardium, at least in this limited and selected group of patients.

  11. Scintigraphic detection of bone and joint infections with indium-111-labeled nonspecific polyclonal human immunoglobulin G

    SciTech Connect

    Oyen, W.J.; Claessens, R.A.; van Horn, J.R.; van der Meer, J.W.; Corstens, F.H. )

    1990-04-01

    The utility of indium-111-({sup 111}In) labeled immunoglobulin G (IgG) to detect infection of bone and adjacent tissues was investigated. Proof of infection was obtained by cultures taken at surgery. All 32 patients showed focally increased uptake on the technetium-99m- (99mTc) methylene diphosphonate (MDP) skeletal scintigraphies. Labeled immunoglobulin correctly identified presence, location, extent and soft-tissue involvement of the suspected inflammatory site. In these patients, focally increasing accumulation was noted over 48 hr. Discrimination between infection and sterile inflammatory lesions was not possible. Two fractures, 6-mo-old, and an aseptic loosening of a total-hip prosthesis were not visualized. Side effects after the immunoglobulin administration were not observed. Radiolabeled immunoglobulin is a new and safe radiopharmaceutical for the investigation of infectious bone and joint disease. The sensitivity of this agent appears at least as high as that of labeled leukocytes. However, labeled immunoglobulin can easily be prepared in every nuclear medicine department.

  12. Metabolic imaging with gallium-68- and indium-111-labeled low-density lipoprotein

    SciTech Connect

    Moerlein, S.M.; Daugherty, A.; Sobel, B.E.; Welch, M.J. )

    1991-02-01

    Low-density lipoprotein (LDL) labeled with either gallium-68 ({sup 68}Ga) or indium-111 ({sup 111}In) was evaluated as a potential PET or SPECT radiopharmaceutical for determination of hepatic lipoprotein metabolism in rabbits. Gallium-68 or {sup 111}In was linked to LDL via diethylenetriaminepentaacetic acid (DTPA) with a 25-70% radiochemical yield. Studies in vivo that compared {sup 68}Ga- or {sup 111}In-DTPA-LDL with dilactitol-({sup 125}I)-tyramine LDL and 131I-LDL showed that both {sup 68}Ga- and {sup 111}In-labeled LDL behaved as residualizing radiotracers. Localization of radioactivity within the liver of normal rabbits was visualized clearly with ({sup 68}Ga)DTPA-LDL by PET and with ({sup 111}In)DTPA-LDL by gamma scintigraphy. Significant differences were observed in hepatic uptake of normal compared with hypercholesterolemic rabbits in which low-capacity LDL receptor-mediated catabolism was saturated. Gallium-68 and {sup 111}In-DTPA-LDL are attractive radiopharmaceuticals for noninvasive delineation of tissue LDL metabolism under normal and pathophysiologic conditions.

  13. Noninvasive detection of rejection of transplanted hearts with indium-111-labeled lymphocytes

    SciTech Connect

    Eisen, H.J.; Eisenberg, S.B.; Saffitz, J.E.; Bolman, R.M. 3d.; Sobel, B.E.; Bergmann, S.R.

    1987-04-01

    To determine whether cardiac transplant rejection can be detected noninvasively with indium-111 (/sup 111/In)-labeled lymphocytes, we studied 11 dogs with thoracic heterotopic cardiac transplants without immunosuppression and five dogs with transplants treated with cyclosporine (10 mg/kg/day) and prednisone (1 mg/kg/day). All were evaluated sequentially with gamma scintigraphy after administration of 150 to 350 muCi of autologous /sup 111/In-lymphocytes. Technetium-99m-labeled red blood cells (1 to 3 mCi) were used for correction of radioactivity in the blood pool attributable to circulating labeled lymphocytes. Lymphocyte infiltration was quantified as the ratio of indium in the myocardium of the transplant or native heart compared with that in blood (indium excess, IE). Results were correlated with mechanical and electrical activity of allografts and with histologic findings in sequential biopsy specimens. In untreated dogs (n = 11), IE was 15.5 +/- 7.0 (SD) in transplanted hearts undergoing rejection and 0.4 +/- 1.1 in native hearts on the day before animals were killed. In dogs treated with cyclosporine and prednisone (n = 5), IE was minimal in allografts during the course of immunosuppression (0.8 +/- 0.4) and increased to 22.9 +/- 11.1 after immunosuppression was stopped. Scintigraphic criteria of rejection (IE greater than 2 SD above that in native hearts) correlated with results of biopsies indicative of rejection and appeared before electrophysiologic or mechanical manifestations of dysfunction. Thus infiltration of labeled lymphocytes in allografts, indicative of rejection, is detectable noninvasively by gamma scintigraphy and provides a sensitive approach potentially applicable to clinical monitoring for early detection of rejection and guidance for titration of immunosuppressive measures.

  14. Indium 111-labeled white blood cell scans after vascular prosthetic reconstruction

    SciTech Connect

    Sedwitz, M.M.; Davies, R.J.; Pretorius, H.T.; Vasquez, T.E.

    1987-11-01

    The clinical value of indium 111-labeled white blood cell (WBC) scanning done after vascular graft procedures was investigated to differentiate noninfectious postoperative inflammation associated with graft incorporation from early prosthetic graft infection. Indium 111-labeled WBC scans were initially obtained in 30 patients before discharge from the hospital and during the subsequent follow-up period (334 days). Fourteen of 30 patients (47%) had normal predischarge scans that included all 10 patients who had grafts confined to the abdomen and 4 of 20 patients (20%) who had grafts arising or terminating at the femoral arteries (p less than 0.05). Sixteen of 30 patients (53%) discharged with abnormal initial indium 111 WBC scans underwent serial scanning until the scan normalized or a graft complication developed. All of the 16 patients had grafts involving the groin region. Abnormal indium 111 uptake in the femoral region continued for a mean 114 days without the development of prosthetic graft infections. The sensitivity of indium 111-labeled WBC scans for detecting wound complications was 100%, whereas the specificity was 50%. Thus, the accuracy of the test was only 53%. We conclude that (1) abnormal indium 111 WBC scans are common after graft operations involving the groin region but are unusual after vascular procedures confined to the abdomen, and (2) in the absence of clinical suspicion, the indium 111-labeled WBC scan does not reliably predict prosthetic graft infection because of the low specificity of the test in the early postoperative period.

  15. Early and delayed indium 111 leukocyte imaging in Crohn's disease

    SciTech Connect

    Navab, F.; Boyd, C.M.; Diner, W.C.; Subramani, R.; Chan, C.

    1987-10-01

    Twenty-seven patients with Crohn's disease were studied for the presence and location of activity by both early (4 h) and delayed (18-24 h) indium 111 leukocyte imaging. The results were compared with other parameters of disease activity including Crohn's disease activity index, barium studies, and endoscopy. There was a correlation between early images and Crohn's disease activity index (r = 0.78) and between delayed images and index (r = 0.82). Based upon the corresponding Crohn's disease activity index, the sensitivity of early and delayed imaging was 81.0% and 95.2%, respectively. Specificity of early and delayed imaging was 75.0% and 87.0%, respectively. Presence of activity on the early and delayed imaging agreed with activity on barium studies and colonoscopy in approximately 80% of cases. Correlation of location of disease by leukocyte imaging and x-ray was observed in 58.9% of early scans and 55.0% of delayed scans. Correlation of the location of disease by imaging and endoscopy was observed in 71.4% of early and 75.0% of delayed studies. Because of the possibility of occurrence of false-negative results in early images, delayed imaging should always be included in evaluation of disease activity in patients with Crohn's disease who are suspected of having mild activity. Delayed imaging is not required if the early imaging study clearly shows activity.

  16. Visualization of a prosthetic vascular graft due to platelet contamination during /sup 111/Indium-labeled leukocyte scintigraphy

    SciTech Connect

    Oates, E.; Ramberg, K.

    1988-09-01

    A prosthetic axillo-femoral bypass graft was visualized during /sup 111/In-labeled leukocyte scintigraphy in a patient referred for possible abdominal abscess. The presence of significant cardiac blood-pool activity raised the possibility that this uptake was due to deposition of contaminating labeled platelets rather than labeled leukocytes. An analysis of a small sample of the patient's blood confirmed that the circulating activity was due to labeled platelets. Increased activity along prosthetic vascular grafts in patients undergoing /sup 111/In-labeled leukocyte scintigraphy may be due to adherent platelet, and not indicative of infection.

  17. Quantitative evaluation of indium-111 (In-111) octreotide pituitary activity: Comparison in patient with and without pituitary tumors

    SciTech Connect

    Gupta, P.; Waxman, A.; Nguyen, K.

    1995-05-01

    Indium 111 Octreotide is known to detect pituitary tumors. Variable low level pituitary activity has been reported in pts. with no demonstrable pituitary tumors. To our knowledge, there have been no studies which quantitatively categorize pituitary activity with respect to distinguishing normal subject from pts. with pituitary tumors. 13 pts. with proven, treated acromegaly were included, as well as 15 pts. with no history of pituitary disorder. Both groups underwent SPECT In-111 scintigraphy 24 hours post-injection Average count per pixel ratios were obtained for the pituitary/calvarium (P/C) and pituitary/brain (P/B) regions. 10 pts. with acromegaly underwent growth hormone (GH) measurements 2 hours post-glucose load. Statistical correlation between growth hormone levels using P/C and P/B ratios were obtained. P/C ratios, as well as P/B ratios demonstrated high correlation with serum GH levels correlation coefficient(r)= .717 for P/C p<0.05, and correlation coefficient(r) = 0.828 for P/B ratios p<0.005. P/C ratios and P/B ratios for controls correlated closely with the upper level of normal predicted by P/C or P/B ratios as a function of serum growth hormone found in patients with acromegaly. Somatostatin receptor SPECT scintigraphy of the pituitary and appropriate quantitation can predict patients with growth hormone secreting tumors.

  18. Indium-111 labeled gold nanoparticles for in-vivo molecular targeting.

    PubMed

    Ng, Quinn K T; Olariu, Cristina I; Yaffee, Marcus; Taelman, Vincent F; Marincek, Nicolas; Krause, Thomas; Meier, Lorenz; Walter, Martin A

    2014-08-01

    The present report describes the synthesis and biological evaluation of a molecular imaging platform based on gold nanoparticles directly labeled with indium-111. The direct labeling approach facilitated radiolabeling with high activities while maintaining excellent stability within the biological environment. The resulting imaging platform exhibited low interference of the radiolabel with targeting molecules, which is highly desirable for in-vivo probe tracking and molecular targeted tumor imaging. The indium-111 labeled gold nanoparticles were synthesized using a simple procedure that allowed stable labeling of the nanoparticle core with various indium-111 activities. Subsequent surface modification of the particle cores with RGD-based ligands at various densities allowed for molecular targeting of the αvß3 integrin in-vitro and for molecular targeted imaging in human melanoma and glioblastoma models in-vivo. The results demonstrate the vast potential of direct labeling with radioisotopes for tracking gold nanoparticles within biological systems.

  19. Evaluation of musculoskeletal sepsis with indium-111 white blood cell imaging

    SciTech Connect

    Ouzounian, T.J.; Thompson, L.; Grogan, T.J.; Webber, M.M.; Amstutz, H.C.

    1987-08-01

    The detection of musculoskeletal sepsis, especially following joint replacement, continues to be a challenging problem. Often, even with invasive diagnostic evaluation, the diagnosis of infection remains uncertain. This is a report on the first 55 Indium-111 white blood cell (WBC) images performed in 39 patients for the evaluation of musculoskeletal sepsis. There were 40 negative and 15 positive Indium-111 WBC images. These were correlated with operative culture and tissue pathology, aspiration culture, and clinical findings. Thirty-eight images were performed for the evaluation of possible total joint sepsis (8 positive and 30 negative images); 17 for the evaluation of nonarthroplasty-related musculoskeletal sepsis (7 positive and 10 negative images). Overall, there were 13 true-positive, 39 true-negative, two false-positive, and one false-negative images. Indium-111 WBC imaging is a sensitive and specific means of evaluating musculoskeletal sepsis, especially following total joint replacement.

  20. Work in progress: radionuclide imaging of indium-111-labeled eosinophils in mice

    SciTech Connect

    Runge, V.M.; Rand, T.H.; Clanton, J.A.; Jones, J.P.; Colley, D.G.; Partain, C.L.; James, A.E. Jr.

    1983-05-01

    Eosinophils isolated from peritoneal exudates were labeled with indium-111-oxine and injected intravenously into sensitized mice. They became localized at sites of inflammation produced by intradermal injections of schistosomal antigen or Toxocara canis larvae, whereas labeled neutrophils did not. Intense uptake of eosinophils by normal spleen, liver, and bone marrow was noted, with tracer distribution effectively complete by 5 hours after injection. Indium-111-eosinophil studies appear to be quite sensitive to parasitic inflammatory reactions; in contrast, nonspecific inflammation such as that induced by turpentine causes localization of eosinophils, but to a lesser extent. This technique may be useful in the study of parasitic and allergic disease.

  1. Indium-111-labeled autologous leukocyte scanning in gastrointestinal graft versus host disease (GVHD)

    SciTech Connect

    Saverymuttu, S.H.; Peters, A.M.; O'Brien, C.; Chadwick, V.S.; Lavender, J.P.; Goldman, J.M.; Gordon-Smith, E.C.; Hodgson, H.J.

    1986-08-01

    The technique of scanning with indium-111 autologous leukocytes has been used to assess gastrointestinal graft-versus-host disease (GVHD) following allogenic marrow transplantation. In patients with active disease, abdominal scans showed extensive abnormal localization in the bowel, while in those whose disease was quiescent after responding to treatment, scans showed localized ileocecal involvement. Rectal histology showed excellent agreement with scanning in the diagnosis of GVHD, but in three of six cases with active disease underestimated disease severity. Indium-111 leukocyte scanning is a useful noninvasive technique for the diagnosis and assessment of gut GVHD.

  2. Evaluation for patients with chronic pulmonary thromboembolism using In-111 labeled platelet scintigraphy

    SciTech Connect

    Uchida, Y.; Minoshima, S.; Uno, K.

    1994-05-01

    This study was conducted to address possible differences in pathogenesis of chronic pulmonary thromboembolism in comparison with that in acute pulmonary embolism using In-111 labeled platelet scintigraphy. Six patients with acute pulmonary embolism and eight patients with chronic pulmonary embolism were involved in this study. Pulmonary emboli were confirmed by angiography. In each patient, autologous platelets were collected from a venous blood sample of 50 ml and labeled with 18.5 MBq of In-111 chloride using a method previously reported. Whole body and spot view images were obtained at twenty-four hours following intravenous administration of In-111 labeled platelets. Images were interpreted visually by two observers. In acute pulmonary embolism no definite abnormal accumulation was seen in the areas of pulmonary emboli, which was mostly consistent with previously published results. In chronic pulmonary embolism, three out of nine patients (33%) showed tracer accumulation corresponding to the areas of emboli in pulmonary vessels. These patients showed significantly lower arterial oxygen pressure in comparison with other patients without abnormal tracer accumulation. In addition, two of the three chronic patients with positive intrathoracic accumulation showed abnormal tracer uptake in the lower extremities. Surgical thrombectomy confirmed presence of progressive thrombi in the pulmonary arteries in scan positive patients. These results suggest possible mechanisms for thrombus formation and progression in the pulmonary vessels following initial thromboembolic events, which worsen the patient`s condition and cause a prolonged clinical course of pulmonary embolism. In-111 labeled scintigraphy can be used to depict possible thrombus formation in the pulmonary vessels in chronic pulmonary thromboembolic patients, who might require different therapeutic interventions from those for acute pulmonary embolism.

  3. Discordant gallium-67 and indium-111 leukocyte images in a suspected pelvic abscess

    SciTech Connect

    Intenzo, C.; Thakur, M.L.; Park, C.

    1984-11-01

    An Indium-111 labeled white blood cell scan suggested the presence of a pelvic abscess in a woman at four weeks postpartum. This was not identified on a subsequent gallium scan. This discrepancy can be attributed to the normal accumulation of white blood cells within the uterus at one month postpartum.

  4. Indium-111 leukocyte imaging in patients with rheumatoid arthritis

    SciTech Connect

    Uno, K.; Matsui, N.; Nohira, K.; Suguro, T.; Kitakata, Y.; Uchiyama, G.; Miyoshi, T.; Uematsu, S.; Inoue, S.; Arimizu, N.

    1986-03-01

    This study evaluates the usefulness of labeled leukocyte imaging in patients with rheumatoid arthritis. In 33 patients, the incidence of pain and swelling in 66 wrist joints and 66 knee joints was compared with the accumulation of (/sup 111/In)leukocytes. No accumulation of (/sup 111/In)leukocytes was seen in any of the patients' wrists (0/12) or knee joints (0/14) when both pain and swelling were absent. In contrast, 93% (25/27) of wrist joints and 80% (24/30) of knee joints with both pain and swelling were positive by (/sup 111/In)leukocyte scintigraphy. There was little correlation between the stage of the disease, as determined by radiography, and (/sup 111/In)leukocyte accumulation. This study suggests that (/sup 111/In)leukocyte imaging may be a reliable procedure for monitoring the activity of rheumatoid arthritis, especially for confirming the lack of an ongoing inflammatory response.

  5. Accumulation of indium-111-labeled granulocytes in malignant tumors

    SciTech Connect

    Schmidt, K.G.; Rasmussen, J.W.; Wedebye, I.M.; Frederiksen, P.B.; Pedersen, N.T.

    1988-04-01

    In a retrospective study of 220 (/sup 111/In)granulocyte scintigrams from 208 patients, 25 patients had malignant neoplasms. Among these, tumor uptake of /sup 111/In activity was observed in ten patients (intense activity in two patients with non-Hodgkin's lymphoma and colonic carcinoma, respectively; moderate uptake in a patient with non-Hodgkin's lymphoma, and in a patient with an ovarian carcinoma; weak activity in three patients with cerebral neoplasms; and activity within otherwise cold metastatic lesions of the liver in three patients). Microscopic investigation following specific granulocyte staining revealed the greatest extent of granulocyte infiltration in the tumors which took up /sup 111/In activity, emphasizing the importance of tumor granulocyte infiltration as the single most important factor underlying tumor accumulation of /sup 111/In activity during (/sup 111/In)granulocyte scintigraphy.

  6. Indium 111-granulocyte scanning in the assessment of disease extent and disease activity in inflammatory bowel disease. A comparison with colonoscopy, histology, and fecal indium 111-granulocyte excretion

    SciTech Connect

    Saverymuttu, S.H.; Camilleri, M.; Rees, H.; Lavender, J.P.; Hodgson, H.J.; Chadwick, V.S.

    1986-05-01

    Indium 111-leukocyte scanning has recently been introduced as a new method for imaging inflammatory bowel disease. The technique has recently been made more specific for acute inflammation by labeling a pure granulocyte fraction rather than the conventional mixed leukocyte preparation. We now report a prospective study comparing 111In-granulocyte scanning with endoscopy, histology, and fecal 111In-granulocyte excretion for the assessment of disease extent and severity in colonic inflammatory bowel disease. In 52 patients with Crohn's disease or ulcerative colitis, disease extent and severity were assessed macroscopically, histologically, or by scanning using a numerical grading system. Excellent correlations were found between both endoscopy and histology and 111In scans (r = 0.90 (endoscopy) and r = 0.90 (histology) for extent; r = 0.86 and r = 0.91 for disease activity). Severity graded by scanning also showed a close correlation with fecal 111In-granulocyte excretion (r = 0.90). Indium 111-granulocyte scans are a rapid, accurate, noninvasive means of assessing both disease extent and severity of colonic involvement in inflammatory bowel disease.

  7. Advantage of indium-111 leukocytes over ultrasound in imaging an infected renal cyst

    SciTech Connect

    Fortner, A.; Taylor, A. Jr.; Alazraki, N.; Datz, F.L.

    1986-07-01

    Indium-111-labeled leukocyte scanning is a highly sensitive and specific method of detecting abscesses. This report describes a patient with polycystic kidneys and a single infected cyst. Ultrasound could not determine which cyst was infected, but the infected cyst could be localized by (/sup 111/In)leukocyte imaging in conjunction with a (/sup 99m/Tc)DMSA renal scan. The two radionuclide studies were used to identify an infected renal cyst and direct ultrasound guided aspiration.

  8. Ultrasonography and indium 111 white blood cell scanning for the detection of intraabdominal abscesses

    SciTech Connect

    Carroll, B.; Silverman, P.M.; Goodwin, D.A.; McDougall, I.R.

    1981-07-01

    Ultrasound and indium 111 white blood cell scanning were performed on 163 patients with suspected intraabdominal abscesses. In all but one case, intraabdominal abscesses were correctly identified by one or both tests; conversely, no patient was falsely diagnosed by both tests to have an abscess. Sonography was useful in those patients with focal symptoms, and frequently identified nonabscess causes for fever. White cell scanning was valuable when focal signs were absent, and frequently identified extraabdominal sources of sepsis. The two imaging modalities are complementary and provide a highly accurate and sensitive means of intraabdominal abscess detection.

  9. Synthesis, characterization and theranostic evaluation of Indium-111 labeled multifunctional superparamagnetic iron oxide nanoparticles.

    PubMed

    Zolata, Hamidreza; Abbasi Davani, Fereydoun; Afarideh, Hossein

    2015-02-01

    Indium-111 labeled, Trastuzumab-Doxorubicin Conjugated, and APTES-PEG coated magnetic nanoparticles were designed for tumor targeting, drug delivery, controlled drug release, and dual-modal tumor imaging. Superparamagnetic iron oxide nanoparticles (SPIONs) were synthesized by thermal decomposition method to obtain narrow size particles. To increase SPIONs circulation time in blood and decrease its cytotoxicity in healthy tissues, SPIONs surface was modified with 3-Aminopropyltriethoxy Silane (APTES) and then were functionalized with N-Hydroxysuccinimide (NHS) ester of Polyethylene Glycol Maleimide (NHS-PEG-Mal) to conjugate with thiolated 3,6,9,15-tetraazabicyclo[9.3.1]pentadeca-1(15),11,13-triene-3,6,9,-triacetic acid (PCTA) bifunctional chelator (BFC) and Trastuzumab antibody. In order to tumor SPECT/MR imaging, SPIONs were labeled with Indium-111 (T1/2=2.80d). NHS ester of monoethyl malonate (MEM-NHS) was used for conjugation of Doxorubicin (DOX) chemotherapeutic agent onto SPIONs surface. Mono-Ethyl Malonate allows DOX molecules to be attached to SPIONs via pH-sensitive hydrazone bonds which lead to controlled drug release in tumor region. Active and passive tumor targeting were achieved through incorporated anti-HER2 (Trastuzumab) antibody and EPR effect of solid tumors for nanoparticles respectively. In addition to in vitro assessments of modified SPIONs in SKBR3 cell lines, their theranostic effects were evaluated in HER2 + breast tumor bearing BALB/c mice via biodistribution study, dual-modal molecular imaging and tumor diameter measurements.

  10. Indium 111-labeled granulocyte scan in the diagnosis and management of acute inflammatory bowel disease

    SciTech Connect

    Nelson, R.L.; Subramanian, K.; Gasparaitis, A.; Abcarian, H.; Pavel, D.G. )

    1990-06-01

    The indium 111 granulocyte scan was used to evaluate 39 individuals known to have or suspected of having inflammatory bowel disease. Twenty-three of these individuals had positive scans and 16 had negative scans. Eighty-seven confirmatory studies, which consisted of barium radiography, endoscopy, operative findings, and histopathology, were performed in 37 of these individuals. The remaining two negative scans corroborated only by clinical course, CBC, and erythrocyte sedimentation rate. In addition, 10 follow-up scans were performed in six of the 39 patients to monitor therapy or investigate a change in symptoms. As an anatomic indicator of acute granulocytic infiltration of the intestinal lamina propria and crypts, the authors found that this scan had a 97 percent rate of sensitivity and 100 percent specificity. Specific indications for the use of the indium 111-labeled granulocyte scan are described. For the authors, in general, this test has become a vital adjunct to endoscopy and radiography in the diagnosis and management of patients with symptoms of inflammatory bowel disease.

  11. Endothelial cell labeling with indium-111-oxine as a marker of cell attachment to bioprosthetic surfaces

    SciTech Connect

    Sharefkin, J.B.; Lather, C.; Smith, M.; Rich, N.M.

    1983-03-01

    Canine vascular endothelium labeled with indium-111-oxine was used as a marker of cell attachment to vascular prosthetic surfaces with complex textures. Primarily cultured and freshly harvested endothelial cells both took up the label rapidly. An average of 72% of a 32 micro Ci labeling dose was taken up by 1.5 X 10(6) cells in 10 min in serum-free medium. Over 95% of freshly labeled cells were viable by trypan blue tests and only 5% of the label was released after 1 h incubations at 37 degrees C. Labeled and unlabeled cells had similar rates of attachment to plastic dishes. Scanning electron microscopic studies showed that labeled cells retained their ability to spread on tissue culture dishes even at low (1%) serum levels. Labeled endothelial cells seeded onto Dacron or expanded polytetrafluoroethylene vascular prostheses by methods used in current surgical models could be identified by autoradiography of microscopic sections of the prostheses, and the efficiency of cell attachment to the prosthesis could be measured by gamma counting. Indium-111 labeling affords a simple and rapid way to measure initial cell attachment to, and distribution on, vascular prosthetic materials. The method could also allow measurement of early cell loss from a flow surface in vivo by using external gamma imaging.

  12. Bone-marrow imaging with indium-111 chloride in aplastic anemia and myelofibrosis: concise communication

    SciTech Connect

    Sayle, B.A.; Helmer, R.E.; Birdsong, B.A.; Balachandran, S.; Gardner, F.H.

    1982-02-01

    Twenty-nine patients with aplastic anemia and 11 patients with myelofibrosis were evaluated with indium-111 chloride bone-marrow imaging, ferrokinetics, and bone-marrow core biopsies. There was good correlation between the erythrocyte cellularity of the marrow and the In-111 bone-marrow scan grades in most patients. In some, the overall scan grade tended to underestimate the erythroid elements because the core biopsy had been taken from the area of the greatest radionuclide concentration on the scan. In patients with aplastic anemia, there was good correlation between the plasma iron clearance t1/2 and the scan grade. Less agreement was found in the comparison between the Fe-59 sacral and organ counts and the red-cell iron utilization. In patients with myelofibrosis, there was poor correlation between the surface counts over the sacrum and the red-cell iron utilization. Plasma iron clearances were abnormally short and were unrelated to the transferrin saturation levels. Eighteen patients were studied several times to evaluate their responses to steroid therapy. In all, there was good correlation between the bone-marrow imaging, the erythrocyte cellularity, ferrokinetics, and the patient's response to therapy. Indium-111 bone-marrow imaging is useful both in evaluating marrow erythroid activity and in following the response to therapy in patients with these diseases.

  13. In-111 labeled leukocyte scintigraphy in a case of multifocal candidiasis

    SciTech Connect

    Palestro, C.J.; Vega, A.; Kim, C.K.; Goldsmith, S.J. )

    1990-06-01

    The value of indium-111 labeled leukocyte scintigraphy for the diagnosis of infection in the general population is well documented; there is less information available on its role in the evaluation of the immunocompromised patient. In this study, leukocyte scintigraphy was performed on a 31-year-old immunocompromised woman who had a possible intra-abdominal abscess. No abscess was detected, but intense oral, esophageal, gastric, and vaginal uptake was observed. Candida infection was histologically confirmed at all four sites.

  14. Clinical application of radiolabelled platelets

    SciTech Connect

    Kessler, C. )

    1990-01-01

    This book presents papers on the clinical applications of radiolabelled platelets. The papers are grouped into six sections on platelet labelling techniques, radiolabelled platelets in cardiology, monitoring of antiplatelet therapy, platelet scintigraphy in stroke patients, platelet scintigraphy in angiology, and platelet scintigraphy in hematology and other clinical applications, including renal transplant rejection.

  15. Noninvasive detection of human cardiac transplant rejection with indium-111 antimyosin (Fab) imaging

    SciTech Connect

    Frist, W.; Yasuda, T.; Segall, G.; Khaw, B.A.; Strauss, H.W.; Gold, H.; Stinson, E.; Oyer, P.; Baldwin, J.; Billingham, M.

    1987-11-01

    Diagnosis of rejection after cardiac transplantation is currently made by right ventricular endomyocardial biopsy. To evaluate antimyosin imaging as a noninvasive means of detecting human cardiac rejection, the Fab fragment of murine monoclonal antimyosin antibodies was labeled with indium-111 and given intravenously to 18 patients (age 45 +/- 12 years) in 20 studies 7 days to 9 years after transplantation. Endomyocardial biopsy specimens were obtained at the time of each imaging study. Eight patients had positive scans confirmed by biopsy as rejection, and eight patients had negative scans and no evidence of rejection on biopsy. Discordance was observed in four studies, two with positive scans and no rejection on biopsy and two with negative scans and positive biopsy. The sensitivity, specificity, and overall accuracy of the technique were each 80%. Imaging with radiolabeled antimyosin antibody Fab fragments may be of value in the noninvasive identification of rejection in the cardiac transplant recipient.

  16. Indium-111 chloride imaging in patients with suspected abscesses: concise communication

    SciTech Connect

    Sayle, B.A.; Balachandran, S.; Rogers, C.A.

    1983-12-01

    Two hundred and fifty-eight patients with clinically suspected inflammatory processes were studied. Seventy-two images were categorized as true positive; 211 as true negative. There were nine false-positive studies, four of which were due to activity in beds of excised organs. There were six false-negative studies, four of which were due to walled-off abscesses found either at surgery or biopsy. The sensitivity was 92%, the specificity 95%, and the accuracy 94%. This study shows that indium-111 chloride imaging provides a reliable way to locate inflammatory processes and overcomes the disadvantages of other imaging agents, for example gastrointestinal activity or the demonstration of healing surgical wounds with gallium-67, and the false-positive images due to cystic fibrosis and other respiratory diseases, or accessory spleens as seen with In-111-labeled white cells.

  17. Quantitative assessment of overall inflammatory bowel disease activity using labelled leucocytes: a direct comparison between indium-111 and technetium-99m HMPAO methods.

    PubMed Central

    Mansfield, J C; Giaffer, M H; Tindale, W B; Holdsworth, C D

    1995-01-01

    The ideal imaging method in inflammatory bowel disease would reliably detect inflammation, identify the correct intestinal location, and assess the severity of the disease. The aim of this study was to compare scintigraphic methods of quantifying overall disease activity using both indium-111 (111In) and technetium-99M (99mTc) HMPAO labelled leucocyte scans. The four day faecal excretion of 111In was measured after 111In scintigraphy in 24 patients known to have inflammatory bowel disease. The same patients also underwent 99mTc HMPAO scanning. The scans were performed 10 days or less apart with no changes in treatment between scans. Bowel activity on the 99mTc HMPAO scans was assessed using a computer based method (scan score) and a visual grading method in a further 54 99mTc HMPAO. The results showed a close correlation between inflammatory activity defined by faecal 111In excretion and the scan score generated from the computer analysis of the 99mTc HMPAO image (Spearman rank correlation: rs = 0.78; p < 0.001). Accurate information to localise inflammatory activity could be obtained by simple visual assessment of both types of scan images, although image quality was superior with 99mTc HMPAO. Qualification of disease activity from 99mTc HMPAO images by visual grading was associated with a large variability, only 69% of scans had similar scores when graded by three observers. Computer generated image analysis was more reproducible. In conclusion, in inflammatory bowel disease 99mTc HMPAO scintigraphy and faecal 111In excretion correlated well. Either method can quantify and localise the inflammation. As 99mTc HMPAO scanning provides a quicker result, with a lower radiation dose, and avoids faecal collection, it may be the preferred method. Images Figure 2 PMID:8549945

  18. Clinical uses of radiolabeled platelets

    SciTech Connect

    Datz, F.L.; Christian, P.E.; Baker, W.J.

    1985-12-01

    Platelets were first successfully radiolabeled in 1953. At that time, investigators were primarily interested in developing a technique to accurately measure platelet life span in both normal and thrombocytopenic patients. Studies using platelets labeled with /sup 51/Cr have shown shortened platelet survival times in a number of diseases including idiopathic thrombocytopenic purpura, coronary artery disease, and diabetes mellitus. More recently, labels such as /sup 111/In have been developed that allow in vivo imaging of platelets. Indium-111 platelets are being used to better understand the pathophysiology of atherosclerosis, thrombophlebitis, pulmonary embolism and clotting disorders, and to improve the clinical diagnosis of these diseases.

  19. Predictive value of indium-111 antimyosin uptake for improvement of left ventricular wall motion after thrombolysis in acute myocardial infarction

    SciTech Connect

    van Vlies, B.; Baas, J.; Visser, C.A.; van Royen, E.; Delemarre, B.J.; Bot, H.; Dunning, A.J.

    1989-07-15

    In 21 patients treated with thrombolysis for acute myocardial infarction (AMI), the degree of myocardial uptake of indium-111 monoclonal antimyosin antibodies injected within 24 hours after onset of AMI was compared with the degree and extent of regional asynergy on admission and discharge, as assessed by 2-dimensional echocardiography. On the first day of AMI, 80 MBq of indium-111 antimyosin was injected and planar images were made 24 hours later. Indium-111 antimyosin uptake was evaluated for count density index (count density of infarct zone/left lung count density) in the left anterior oblique projection, in which the infarction zone was well displayed in all patients. Using 2-dimensional echocardiography, the left ventricle was divided into 13 segments and evaluated for regional asynergy, which was considered severe (akinesia or dyskinesia) or mild (hypokinesia). The extent of regional asynergy was measured by the number of asynergic segments. All 21 patients had severe regional asynergy on admission. Nine of 21 showed only mild regional asynergy on discharge and 12 of 21 had persistent severe regional asynergy in at least 1 segment. The count density index was significantly lower in patients with mild regional asynergy on discharge compared with patients with severe regional asynergy (1.63 +/- 0.27 vs 2.50 +/- 0.42, p less than 0.01).

  20. Effect of leukocyte antibodies on the fate in vivo of indium-111-labeled granulocytes

    SciTech Connect

    McCullough, J.; Weiblen, B.J.; Clay, M.E.; Forstrom, L.

    1981-07-01

    The effect of different leukocyte antibodies on the fate in vivo of granulocytes is not known. Thus, the optimum in vitro serologic tests to determine a safe and effective granulocyte transfusion or to diagnose immune destruction of granulocytes in other clinical situations have not been identified. We have studied the effect of granulocyte agglutinating (GA), granulocytotoxic (GC), and lymphocytotoxic (LC) antibodies on the intravascular recovery and half-life (t 1/2) and the extravascular localization of Indium-111-granulocytes in 50 patients. GA antibodies caused reduced granulocyte recovery and t 1/2 in three of three non-neutropenic patients (one with anti-NB1), increased sequestration of cells in the liver, and failure of granulocytes to localize at sites of infection in two of two patients (one with anti-NA1). In contrast, GC antibodies in five patients and LC antibodies in one patient did not cause reduced intravascular recovery or t 1/2 of granulocytes. In nine patients with GC and six patients with LC antibodies, incompatible granulocytes localized at known sites of infection. It appears that GA, but not GC nor LC, antibodies alter the fate in vivo of granulocytes.

  1. Indium-111-labeled LDL: A potential agent for imaging atherosclerotic disease and lipoprotein biodistribution

    SciTech Connect

    Rosen, J.M.; Butler, S.P.; Meinken, G.E.; Wang, T.S.; Ramakrishnan, R.; Srivastava, S.C.; Alderson, P.O.; Ginsberg, H.N. )

    1990-03-01

    Radiolabeling of low-density lipoprotein (LDL) and external imaging with a gamma camera would offer a means of taking advantage of the metabolic activity of developing atherosclerotic lesions in order to noninvasively detect and determine the extent of atherosclerotic cardiovascular disease. Indium-111-({sup 111}In) labeled LDL was prepared and its purity demonstrated by agarose electrophoresis and ultracentrifugation. In vitro studies with cultured human fibroblasts demonstrated significant inhibition of iodine-125-({sup 125}I) LDL binding to LDL receptors by {sup 111}In-LDL, although this was less than the inhibition produced by unlabeled LDL. Adrenal gland uptake of {sup 111}In-LDL by hypercholesterolemic rabbits was reduced by 86% compared to the level of uptake observed in normal rabbits. These results were compatible with downregulation of adrenal LDL receptors in the hypercholesterolemic rabbits. Uptake of {sup 111}In-LDL in the atherosclerotic proximal aorta of hypercholesterolemic rabbits was 2.5 times higher than in normal rabbits. These results suggest that {sup 111}In-LDL has the potential to be a useful agent for external imaging of atherosclerotic lesions and lipoprotein biodistribution.

  2. Role of indium-111 white blood cells in inflammatory bowel disease

    SciTech Connect

    Froelich, J.W.; Field, S.A.

    1988-10-01

    Inflammatory bowel disease in patients may be difficult to diagnose because of the complex problems associated with this disease. Radionuclides are able to provide a rapid and effective method of imaging the bowel in patients with active inflammatory bowel disease. In the past, clinical work-ups have included barium x-ray studies and endoscopy. Scarring and fistula formation have made it difficult to determine between the active disease and abscesses that may occur. Gallium-67 (67Ga) has been very useful in imaging patients with inflammatory bowel disease, but the multiple-day imaging procedure has been a limitation for the clinicians when achieving a diagnosis. Recent results with Indium-111 (111In)--labeled WBCs have provided excellent correlation between clinical symptoms and colonoscopy findings in patients with inflammatory bowel disease. This technique has also allowed the differentiation between reoccurring inflammatory bowel disease and abscesses that accompany the disease within a 24-hour time period. The use of intravenous (IV) glucagon has increased the clarity of the images in the small bowel. Technetium 99m (99mTc) diethylenetriaminepentaacetic acid (DTPA) has been used in patients with inflammatory bowel disease demonstrating promising results. Investigators feel labelling 99mTc with WBCs will be improved, therefore yielding a greater efficiency, which will have a major impact on imaging patients with inflammatory bowel disease. Imaging patients with inflammatory bowel disease using radionuclides has yielded promising results. This is a significant advancement over barium radiography and endoscopy exams.24 references.

  3. In vivo traffic of indium-111-oxine labeled human lymphocytes collected by automated apheresis

    SciTech Connect

    Read, E.J.; Keenan, A.M.; Carter, C.S.; Yolles, P.S.; Davey, R.J. )

    1990-06-01

    The in vivo traffic patterns of autologous lymphocytes were studied in five normal human volunteers using lymphocytes obtained by automated apheresis, separated on Ficoll-Hypaque gradients, and labeled ex vivo with {sup 111}In-oxine. Final lymphocyte infusions contained 1.8-3.1 X 10(9) cells and 270-390 microCi (9.99-14.43 MBq) {sup 111}In, or 11-17 microCi (0.41-0.63 MBq) per 10(8) lymphocytes. Gamma imaging showed transient lung uptake and significant retention of radioactivity in the liver and spleen. Progressive uptake of activity in normal, nonpalpable axillary and inguinal lymph nodes was seen from 24 to 96 hr. Accumulation of radioactivity also was demonstrated at the forearm skin test site, as well as in its associated epitrochlear and axillary lymph nodes, in a subject who had been tested for delayed hypersensitivity with tetanus toxoid. Indium-111-oxine labeled human lymphocytes may provide a useful tool for future studies of normal and abnormal lymphocyte traffic.

  4. Indium-111 leukocyte scintigraphic detection of myocardial abscess formation in patients with endocarditis

    SciTech Connect

    Cerqueira, M.D.; Jacobson, A.F.

    1989-05-01

    Myocardial abscess formation in patients with bacterial endocarditis in most clinical settings, especially in patients with prosthetic valves, is a primary indicator for surgical valve replacement. We report the detection of myocardial abscesses using /sup 111/In leukocyte scintigraphy in three patients with prosthetic or native valve endocarditis and nondiagnostic echocardiograms. Leukocyte scintigraphy may allow identification of myocardial abscess formation earlier than other imaging modalities.

  5. Assessment of myocardial damage in dilated-phase hypertrophic cardiomyopathy by using indium-111-antimyosin Fab myocardial scintigraphy

    SciTech Connect

    Nishimura, T.; Nagata, S.; Uehara, T.; Hayashida, K.; Mitani, I.; Kumita, S. )

    1991-07-01

    For the detection of myocardial cell damage, an 111In-antimyosin Fab study was carried out on seven patients (Group A) in the dilated phase of hypertrophic cardiomyopathy, seven patients (Group B) with dilated cardiomyopathy, and eight control patients (Group C). Imaging was done 48 hr after intravenous injection of 74 MBq of 111In-antimyosin Fab. Myocardial antimyosin uptake was visually graded as 0, +1, +2 or +3. A score of +2 or +3 was considered positive. The heart/lung ratio of antimyosin uptake (antimyosin index) also was determined. Antimyosin uptake was positive in seven (100%), nine (90%) and no (0%) patients in Groups A, B, and C, respectively. The antimyosin index in Groups A and B was 2.46 {plus minus} 0.49 and 2.04 {plus minus} 0.24, respectively, findings were significantly higher than that in Group C (1.51 {plus minus} 0.13) (p less than 0.01). Positive biopsy findings were noted in only two patients in Group A. Thus, antimyosin uptake was increased in dilated phase hypertrophic cardiomyopathy and dilated cardiomyopathy, which suggests ongoing necrotic changes in these patients.

  6. The value of indium 111 leukocyte scanning in the evaluation of painful or infected total knee arthroplasties

    SciTech Connect

    Rand, J.A.; Brown, M.L. )

    1990-10-01

    Evaluation of painful total knee arthroplasties (TKAs) for infection can be difficult. Indium 111 ({sup 111}In) leukocyte bone scanning provides a minimally invasive technique for evaluation of possible infection. Thirty-eight patients with a painful TKA who had surgical exploration after {sup 111}In leukocyte scanning were reviewed. The scan had an accuracy of 84%, a sensitivity of 83%, and a specificity of 85%. The {sup 111}In leukocyte scans must be interpreted in conjunction with the clinical evaluation of the patient because they are less accurate for study of TKAs than of total hip arthroplasties.

  7. Myocardial uptake of indium-111-labeled antimyosin in acute subendocardial infarction: Clinical, histochemical, and autoradiographic correlation of myocardial necrosis

    SciTech Connect

    Hendel, R.C.; McSherry, B.A.; Leppo, J.A. )

    1990-11-01

    Indium-111-labeled antimyosin has been utilized in the diagnosis and localization of acute transmural myocardial infarction. The present report describes a patient who presented with a massive subendocardial infarction. Two days after the injection of antimyosin, the patient's clinical status markedly deteriorated and he expired. Postmortem examination demonstrated severe three-vessel coronary artery disease with extensive myocyte death in the endocardium. Autoradiography and histochemical staining of the prosected heart demonstrated high correlation for myocardial necrosis and corresponded to clinical evidence for diffuse subendocardial infarction.

  8. Sensitivity of scintigraphy with /sup 111/In-lymphocytes for detection of cardiac allograft rejection

    SciTech Connect

    Eisenberg, S.B.; Eisen, H.J.; Sobel, B.E.; Bergmann, S.R.; Bolman, R.M. 3d.

    1988-12-01

    We recently demonstrated the feasibility of noninvasive detection of cardiac allograft rejection after administration of indium-111-labeled lymphocytes. To determine the sensitivity and specificity of the technique, as well as its value for delineating the severity of rejection, we studied 16 dogs with heterotopic thoracic cardiac allografts. Five animals were evaluated while exposed to immunosuppressive agents. Animals were scanned sequentially after administration of 100-400 microCi of indium-111-labeled autologous lymphocytes. Myocardial lymphocyte infiltration was expressed as the indium excess (IE), defined as the ratio of indium activity of the transplant or native heart compared with that in blood. Scintigraphic results were compared with characteristics of simultaneously obtained endomyocardial biopsies. Among 17 biopsy documented episodes of rejection, 16 were detected scintigraphically. Among 18 biopsies with no evidence of rejection, scintigraphy was uniformly negative. Thus, the sensitivity and specificity of scintigraphy were 94 and 100%, respectively. Biopsies graded as showing no rejection were associated with an IE of 0.3 +/- 0.5 (+/- SD); those graded as mild, 2.8 +/- 1.7; those as moderate, 10.7 +/- 7.2; and those graded as indicative of severe rejection, 14.2 +/- 4.5. Thus, scintigraphy with indium-111-labeled lymphocytes sensitively and specifically detects cardiac allograft rejection and delineates the intensity of the rejection process. It should be useful clinically for assessing potential allograft rejection noninvasively.

  9. Radioimmunoimaging of metastatic medullary carcinoma of the thyroid gland using an indium-111-labeled monoclonal antibody to CEA

    SciTech Connect

    Edington, H.D.; Watson, C.G.; Levine, G.; Tauxe, W.N.; Yousem, S.A.; Unger, M.; Kowal, C.D.

    1988-12-01

    Elevated levels of carcinoembryonic antigen (CEA) or calcitonin after surgical therapy for medullary carcinoma of the thyroid gland (MCT) indicate the presence of residual or metastatic disease. CEA elevations appear to be prognostically more reliable in patients with metastatic disease and suggest a more virulent tumor. Attempts to stage the disease with use of conventional imaging techniques are usually inadequate, as is the therapy for disseminated or recurrent MCT. An indium-111-labeled anti-CEA monoclonal antibody (ZCE-025) was used to image metastases in a patient with MCT. Potential applications of monoclonal antibody technology in the management of MCT would include (1) preoperative differentiation of unicentric from multicentric thyroid gland involvement, (2) detection of regional or distant metastases or both, (3) measurement of response to systemic therapy, and (4) the facilitation of radionuclide immunoconjugate therapy.

  10. Novel indium-111 labeled gastrin peptide analogues (MG-CL1-4): synthesis and quality control.

    PubMed

    Naqvi, Syed Ali-Raza; Khan, Zulfiqar Ali; Nagra, Saeed Ahmad; Yar, Muhammad; Sherazi, Tauqir A; Shahzad, Sohail Shahzad; Shah, Syed Qaiser; Mahmood, Nasir; Ishfaq, Malik Muhammad; Mather, Stephen John

    2013-03-01

    Radiolabeled neuropeptides are widely investigated to diagnose and therapy of tumors. These peptides get internalization after binding with particular receptors at the surface of cells and finally move to lysosome. Internalization into tumor cells helps in mapping the infected site. Minigastrin peptide analogues (MG-CL1-4) were synthesised and labeled with 111-In radioisotope under different sets of conditions for imaging CCk-2 receptor bearing tumors. Different parameters such as temperature (80-100°C), pH (4-12), incubation time (5-30 minutes) and dilution effect were investigated to get the maximum labeling yield and stability. The results indicated that MG-CL1-4 is successfully labeled with indium-111 at pH 4.5 with heating at 98°C for 15 minute. At these conditions i.e. heating, pH and incubation minimum oxidized and maximum labeling yield, more than 94 %, was obtained. The labeling stability was studied by incubating the radiolabeled complex for predefined time points in PBSA and blood serum. Results show that more than 90% radiolabeled MG-CL1-4 remained intact.

  11. Alloimmunization prevents the migration of transfused indium-111-labeled granulocytes to sites of infection

    SciTech Connect

    Dutcher, J.P.; Schiffer, C.A.; Johnston, G.S.; Papenburg, D.; Daly, P.A.; Aisner, J.; Wiernik, P.H.

    1983-08-01

    111In-labeled granulocytes were used to study the effects of histocompatibility factors on the migration of transfused granulocytes to infected sites. Fourteen alloimmunized and 20 nonalloimmunized patients received approximately 10(8) 111In-labeled granulocytes from ABO-compatible, non-HLA-matched donors, and scans were performed over known infected sites. All 14 alloimmunized patients had lymphocytotoxic antibody (LCTAb) and required HLA-matched platelet transfusions. Of the nonalloimmunized patients, 20/20 had positive scans at sites of infection. None of the 20 had LCTAb, 0/17 had a positive lymphocytotoxic crossmatch (LCTXM) with the donor, and 3/18 had a positive leukoagglutinin crossmatch (LAXM). Thus, histocompatibility testing was not found to be important in nonalloimmunized patients. In contrast, only 3/14 alloimmunized patients had positive scans at sites of infection (p . 0.00001 compared to nonalloimmunized patients). One of 3 had a positive LCTXM and 2/3 had a positive LAXM. Of the alloimmunized patients, 10/11 with negative scans had a positive LCTXM and 8/11 had a positive LAXM. Labeled granulocytes failed to reach sites of infection in 11/14 (78%) alloimmunized patients, demonstrating that histocompatibility factors can be of major importance in affecting the outcome of granulocyte transfusions. Granulocytes from random donors are unlikely to be effective in alloimmunized patients. The lack of an adequate crossmatching technique is a major problem limiting the ability to provide granulocyte transfusions for alloimmunized patients.

  12. A comparative study of indium-111 DTPA radionuclide and iothalamate meglumine roentgenographic arthrography in the evaluation of painful total hip arthroplasty

    SciTech Connect

    Maxon, H.R.; Schneider, H.J.; Hopson, C.N.; Miller, E.H.; Von Stein, D.E.; Kereiakes, J.G.; Cummings, D.D.; McDevitt, R.M. )

    1989-08-01

    Fifteen patients with painful total hip prostheses were referred for nuclear medicine and roentgenographic arthrography studies to exclude loosening of the acetabular and/or the femoral component. A new radioisotopic technique suitable for the evaluation of both components was developed using dual-isotope single-photon tomography with {sup 99m}technetium methylene diphosphonate bone imaging and indium-111 diethylenetriaminepentacetic acid arthrography. Thirteen of the 15 subjects were subsequently treated with additional surgery. The surgical findings were compared with the nuclear medicine and roentgenographic results. The overall diagnostic accuracy of both arthrographic procedures was approximately 80%, but the roentgenographic arthrogram was more sensitive and the radionuclide arthrogram was more specific.

  13. Indium-111-labeled leukocyte and technetium-99m-sulfur colloid uptake by a malignant fibrous histiocytoma: Phagocytosis by tumor cells

    SciTech Connect

    Palestro, C.J.; Klein, M.; Kim, C.K.; Swyer, A.J.; Goldsmith, S.J. )

    1990-09-01

    Indium-111-labeled leukocyte imaging, performed on a patient with a calcified mass in the right thigh, demonstrated labeled leukocyte accumulation in this mass. Technetium-99m-sulfur colloid imaging was performed to differentiate labeled leukocyte uptake in heterotopic bone marrow from uptake in a focus of infection. Leukocyte and sulfur colloid images were virtually identical, and the study was interpreted as without evidence of infection. Excision of the mass revealed an angiomatoid malignant fibrous histiocytoma with metaplastic bone formation. While no marrow elements were present in either the tumor or the metaplastic bone, phagocytosis of leukocytes by tumor cells was identified. Phagocytosis of leukocytes by tumor cells may be another cause of white cell accumulation in uninfected neoplasms.

  14. Renal Scintigraphy

    MedlinePlus

    ... size with caption Related Articles and Media General Nuclear Medicine Radiation Dose in X-Ray and CT Exams X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Renal Scintigraphy Sponsored by ...

  15. Indium-111 labeled monoclonal antibodies (Ab): The effect of DTPA conjugation on the Ab activity and tissue distribution

    SciTech Connect

    Sakahara, H.; Endo, K.; Nakashima, T.; Ohta, H.; Okada, K.; Yoshida, O.; Ohmomo, Y.; Horiuchi, K.; Yokoyama, A.; Torizuka, K.

    1984-01-01

    Monoclonal antibodies (Ab) to human ..cap alpha..-fetoprotein (AFP) were conjugated with diethylenetriaminepentaacetic acid (DTPA) using cyclic DTPA anhydride and the obtained conjugates, DTPA-Ab, were labeled with In-111. The effect of DTPA conjugation on the affinity constant and the maximum binding capacity of Ab was evaluated by radioimmunoassay and Scatchard plot analysis and In-111 labeled DTPA-Ab were used for the radioimmunodetection of tumor. Ab containing 1.0 DTPA molecule per Ab showed almost full retention of both the affinity constant and the maximum binding capacity. Then, 40 ..mu..Ci of In-111 labeled DTPA-Ab were injected intravenously to nude mice bearing AFP-producing human testicular tumor and the resulted were compared with I-131 labeled Ab. Scintigraphy clearly revealed transplanted tumor. Localization of In-111 labeled DTPA-Ab was significantly higher than I-131 labeled Ab. Tumor to blood ratio obtained at 4 days after injection was 2.59 with In-111 labeled DTPA-Ab compared to 0.99 with I-131 labeled Ab. When more than 1.9 DTPA molecules were incorporated per Ab, the maximum binding capacity decreased, although the affinity constant was less affected. These In-111 labeled DTPA-Ab caused significantly higher liver accumulation. These results indicate that In-111 labeled DTPA-Ab at a cojugated DTPA to Ab molar ratio of 1.0 may be superior to I-131 labeled Ab for tumor imaging, but the maximum binding capacity and tissue distribution of In-111 labeled DTPA-AB are greatly dependent upon the number of DTPA molecules incorporated per Ab molecule.

  16. Myocardial distribution of indium-111-antimyosin Fab in acute inferior and right ventricular infarction: comparison with technetium-99m-pyrophosphate imaging and histologic examination

    SciTech Connect

    Nakata, T.; Sakakibara, T.; Noto, T.; Shoji, T.; Tsuda, T.; Kubota, M.; Hattori, A.; Iimura, O. )

    1991-05-01

    In a postmortem study of a 69-yr-old female patient who had suffered 2 yr previously a non-Q-wave anterior infarction and who had sustained just seven days earlier a left inferior and right ventricular infarction, the distribution of {sup 111}In-antimyosin Fab was compared to the results of {sup 99}mTc-pyrophosphate imaging and histologic examination. Indium-111-antimyosin Fab imaging could not be performed because of cardiogenic shock. However, postmortem gamma scintillation counting revealed increased activities of antimyosin Fab in the inferoapical and right ventricular infarcted regions in which {sup 99}mTc-pyrophosphate positive imagings were observed; in contrast, a histologically confirmed old subendocardial anterior infarction had no definite activity. Thus, the myocardial distribution of {sup 111}In-antimyosin Fab corresponded well to the results of {sup 99}mTc scintigrams and histologic examinations in a human heart, suggesting that this technique could be useful in vivo for detecting several-day-old myocardial infarction of the right ventricle as well as the left ventricle. Tissue from the 2-yr-old infarction was not identified by this technique.

  17. Diagnosis of infection by preoperative scintigraphy with indium-labeled white blood cells

    SciTech Connect

    Wukich, D.K.; Abreu, S.H.; Callaghan, J.J.; Van Nostrand, D.; Savory, C.G.; Eggli, D.F.; Garcia, J.E.; Berrey, B.H.

    1987-12-01

    Scintigraphy with indium-labeled white blood cells has been reported to be sensitive and specific in the diagnosis of low-grade sepsis of the musculoskeletal system. We reviewed the records of fifty patients who had suspected osteomyelitis or suspected infection about a total joint prosthesis and who underwent scintigraphy with technetium-99m methylene diphosphonate and scintigraphy with indium-111 oxine-labeled white blood cells before an open surgical procedure. Any patient who received preoperative antibiotics was not included in the study. For all of the patients, gram-stain examination of smears, evaluation of a culture of material from the operative site, and histological examination were done. The patients were divided into two groups. Group I was composed of twenty-four patients, each of whom had a prosthesis in place and complained of pain. Group II was composed of twenty-six patients for whom a diagnosis of chronic osteomyelitis had to be considered. With the indium scans alone, there was only one false-negative result (in Group II), but there were eighteen false-positive results (eight patients in Group II and ten patients in Group I). Although scintigraphy with indium-labeled white blood cells is quite sensitive, it is not specific in detecting chronic osteomyelitis; a negative scan should be considered highly suggestive that osteomyelitis is not present. Specificity can be increased by interpreting the indium scan in conjunction with the technetium scan.

  18. Use of indium-111 oxine to study pulmonary and hepatic leukocyte sequestration in endotoxin shock and effects of the beta-2 receptor agonist terbutaline

    SciTech Connect

    Sigurdsson, G.H.; Christenson, J.T.; al-Mousawi, M.; Owunwanne, A. )

    1989-01-01

    The dynamic behavior of indium-111 oxine-labeled leukocytes was simultaneously recorded in multiple organs during endotoxin shock in sheep. Also, the effects of the beta-2 receptor agonist terbutaline were studied. An experimental protocol was designed to mimic a clinical condition in an intensive care setting as far as possible. The animals were ventilated with 50% oxygen to avoid hypoxemia and were given large amounts of intravenous fluids to reduce adverse effects of hypovolemia. A moderate dose of E. coli endotoxin (10 micrograms/kg bwt) was given by intravenous infusion to 14 adult sheep, seven of them receiving continuous intravenous infusion of terbutaline (20 micrograms/kg/hr) during 4 hr, starting 30 min after endotoxin, when signs of lung injury had developed. The other seven acted as controls. A marked pulmonary and hepatic leukocyte sequestration together with a sharp drop in leukocyte counts in peripheral blood occurred within minutes after start of the endotoxin infusion in both groups. However, no changes were observed in the kidneys or the gut. After 60 min and until the end of the experiment, there was a significantly lower activity in the lungs and in the liver of the animals treated with terbutaline than in the controls (P less than .01). Furthermore, less marked hemodynamic and respiratory alterations occurred in the terbutaline group compared with the controls. This study confirms the results of other investigators showing that significant leukocyte sequestration occurs in the lungs during endotoxemia, but it also demonstrates that leukocytes sequestrate in the liver, although slightly less than in the lungs.

  19. Platelet thrombosis in cardiac-valve prostheses

    SciTech Connect

    Dewanjee, M.K.

    1989-01-01

    The contribution of platelets and clotting factors in thrombosis on cardiovascular prostheses had been quantified with several tracers. Thrombus formation in vivo could be measured semiquantitatively in animal models and patients with indium-111, Technetium-99m labeled platelets, iodine-123, iodine-131 labeled fibrinogen, and In-111 and Tc-99m labeled antibody to the fibrinogen-receptor on the platelet- membrane, or fibrin. The early studies demonstrated that certain platelet-inhibitors, e.g. sulfinpyrazone, aspirin or aspirin- persantine increased platelet survival time with mechanical valves implanted in the baboon model and patients. Thrombus localization by imaging is possible for large thrombus on thrombogenic surface of prosthesis in the acute phase. The majority of thrombus was found in the sewing ring (Dacron) in the acute phase in both the mechanical and tissue valves. The amount of retained thrombus in both mechanical and tissue valves in our one-day study in the dog model was similar (< 1% if injected In-111 platelets = 5 billion platelets). As the fibrous ingrowth covered the sewing ring, the thrombus formation decreased significantly. Only a small amount of thrombus was found on the leaflets at one month in both the dog and calf models. 38 refs., 9 figs., 5 tabs.

  20. Noninvasive radioisotopic technique for detection of platelet deposition in mitral valve prostheses and quantitation of visceral microembolism in dogs

    SciTech Connect

    Dewanjee, M.K.; Fuster, V.; Rao, S.A.; Forshaw, P.L.; Kaye, M.P.

    1983-05-01

    A noninvasive technique has been developed in the dog model for imaging, with a gamma camera, the platelet deposition on Bjoerk-Shiley mitral valve prostheses early postoperatively. At 25 hours after implantation of the prosthesis and 24 hours after intravenous administration of 400 to 500 microCi of platelets labeled with indium-111, the platelet deposition in the sewing ring and perivalvular cardiac tissue can be clearly delineated in a scintiphotograph. An in vitro technique was also developed for quantitation of visceral microemboli in brain, lungs, kidneys, and other tissues. Biodistribution of the labeled platelets was quantitated, and the tissue/blood radioactivity ratio was determined in 22 dogs in four groups: unoperated normal dogs, sham-operated dogs, prosthesis-implanted dogs, and prosthesis-implanted dogs treated with dipyridamole before and aspirin and dipyridamole immediately after operation. Fifteen to 20% of total platelets were consumed as a consequence of the surgical procedure. On quantitation, we found that platelet deposition on the components of the prostheses was significantly reduced in prosthesis-implanted animals treated with dipyridamole and aspirin when compared with prosthesis-implanted, untreated dogs. All prosthesis-implanted animals considered together had a twofold to fourfold increase in tissue/blood radioactivity ratio in comparison with unoperated and sham-operated animals, an indication that the viscera work as filters and trap platelet microemboli that are presumably produced in the region of the mitral valve prostheses. In the dog model, indium-111-labeled platelets thus provide a sensitive marker for noninvasive imaging of platelet deposition on mechanical mitral valve prostheses, in vitro evaluation of platelet microembolism in viscera, in vitro quantitation of surgical consumption of platelets, and evaluation of platelet-inhibitor drugs.

  1. In vitro model of platelet aggregation in stenotic arteries

    SciTech Connect

    Morley, D.; Santamore, W.P.

    1988-07-01

    Clinical and experimental evidence suggest a strong relationship between arterial stenosis, platelet aggregation, and subsequent thrombus formation. To facilitate the study of platelet accumulation in stenotic arteries, we developed an in vitro preparation. Arterial segments were perfused with whole citrated blood. A stenosis was created by applying an external plastic constrictor to the artery. Platelet accumulation within the stenosis was assessed by scanning electron microscopy and by radioactive counts from Indium-111 labeled platelets. Utilizing this preparation, 30 carotid arterial segments from 10 mongrel dogs were perfused at 100 mmHg for 15 min. In 10 arteries without a stenosis, scanning electron microscopy and radioactive counts demonstrated little platelet accumulation. In contrast, extensive platelet aggregation was observed in 10 arteries with stenoses. Moreover, in 10 stenotic arteries exposed to the thromboxane mimetic, U46619 (Upjohn Diagnostic Group), scanning electron microscopy and radioactive counts demonstrated a significant increase in platelet deposition. Conversely, we demonstrated a dimunition of platelet accumulation in stenosed arterial segments exposed to the prostacyclin analogue platelet inhibitor, Iloprost. The in vitro preparation allows precise control of hemodynamic variables and makes it possible to perform multiple tests on segments of the same vessel from the same animal.

  2. Skeletal Scintigraphy

    PubMed Central

    McDougall, I. Ross

    1979-01-01

    Skeletal scintigraphy, using phosphates or diphosphonates labeled with technetium 99m, is a sensitive method of detecting bone abnormalities. The most important and most frequent role of bone scanning is evaluating the skeletal areas in patients who have a primary cancer, especially a malignant condition that has a tendency to spread to bone areas. The bone scan is superior to bone radiographs in diagnosing these abnormalities; 15 percent to 25 percent of patients with breast, prostate or lung cancer, who have normal roentgenograms, also have abnormal scintigrams due to metastases. The majority of bone metastases appear as hot spots on the scan and are easily recognized. The incidence of abnormal bone scans in patients with early stages (I and II) of breast cancer varies from 6 percent to 26 percent, but almost invariably those patients with scan abnormalities have a poor prognosis and should be considered for additional therapies. Progression or regression of bony lesions can be defined through scanning, and abnormal areas can be identified for biopsy. The incidence of metastases in solitary scan lesions in patients with known primary tumors varies from 20 percent to 64 percent. Bone scintigraphy shows positive uptake in 95 percent of cases with acute osteomyelitis. Stress fractures and trauma suspected in battered babies can be diagnosed by scanning before there is radiological evidence. The procedure is free from acute or long-term side effects and, except in cases of very young patients, sedation is seldom necessary. Although the test is sensitive, it is not specific and therefore it is difficult to overemphasize the importance of clinical, radiographic, biochemical and scanning correlation in each patient. ImagesFigure 2.Figure 3.Figure 4.Figure 5.Figure 6.Figure 7.Figure 8.Figure 9.Figure 10. PMID:390886

  3. Platelet deposition in rat heart allografts and the effect of a thromboxane receptor antagonist

    SciTech Connect

    Foegh, M.L.; Khirabadi, B.S.; Ramwell, P.W.

    1986-07-01

    The effect of a thromboxane antagonist, L640,035 on platelet deposition in heart allografts was studied. Twenty Lewis rats received heterotopic allografts from Lewis x Brown-Norway F1 hybrid. All recipients received azathioprine (5 mg/kg/day). The rats were divided into three groups. Groups II and III were also treated daily with either the vehicle for L640,035 or L640,035 respectively. Syngeneic indium-111-labeled platelet deposition was determined in the allograft and the native heart at 6, 9, and 13 days after transplantation; group III was studied on the sixth and ninth day only. A rapidly increasing platelet deposition was seen in allografts from rats given azathioprine; whereas the thromboxane antagonist prevented the increase in platelet deposition on the ninth day.

  4. Detection of abnormalities in febrile AIDS patients with In-111-labeled leukocyte and Ga-67 scintigraphy

    SciTech Connect

    Fineman, D.S.; Palestro, C.J.; Kim, C.K.; Needle, L.B.; Vallabhajosula, S.; Solomon, R.W.; Goldsmith, S.J.

    1989-03-01

    Thirty-six patients with acquired immunodeficiency syndrome (AIDS), who were febrile but without localizing signs, underwent indium-111 leukocyte scintigraphy 24 hours after injection of labeled white blood cells (WBCs) and were restudied 48 hours after injection of gallium-67 citrate. Fifty-six abnormalities were identified as possible sources of the fever; 27 were confirmed with biopsy. Of these 27, 15 were identified only on In-111 WBC scans (including colitis, sinusitis, and focal bacterial pneumonia); six, only on Ga-67 scans (predominantly Pneumocystis carinii pneumonia and lymphadenopathy); and six, on both studies (predominantly pulmonary lesions). In-111 WBC scanning revealed 21 of 27 abnormalities (78%) and gallium scanning, 12 of 27 (44%). If only one scintigraphic study has been performed, particularly with Ga-67, a significant number of lesions would not have been detected. The authors believe radionuclide evaluation of the febrile AIDS patient without localizing signs should begin with In-111 WBC scintigraphy. Gallium scanning may be used depending on results of In-111 WBC scans or if there is a high index of suspicion for P carinii pneumonia.

  5. Preformed confluent endothelial cell monolayers prevent early platelet deposition on vascular prostheses in baboons

    SciTech Connect

    Schneider, P.A.; Hanson, S.R.; Price, T.M.; Harker, L.A.

    1988-09-01

    We assessed the capacity of preformed confluent endothelial cell (EC) monolayers on small-caliber prosthetic grafts to prevent early platelet deposition in a baboon model. Cultured human umbilical vein ECs were attached to expanded polytetrafluoroethylene (Gore-Tex, 4 mm inner diameter, 3 cm length) precoated with type I collagen and perfused in vitro for 2 hours at 15 ml/min with serum-containing culture medium to achieve cell spreading into confluent monolayers. Cell numbers were quantified by deoxyribonucleic acid assay or isotopic counting of indium 111-labeled ECs. Saturation density for cell attachment was 3.55 +/- 0.29 x 10(5) cells per square centimeter of graft. After 1 hour of in vitro perfusion at 100 ml/min, 92.8% +/- 1.8% of cells remained attached and the flow surface was morphologically confluent. When grafts were inserted as extension segments into arteriovenous silicone rubber (Silastic) shunts in baboons, thereby exposing the endothelialized grafts to native flowing blood (100 ml/min) for 1 hour, the EC monolayers remained confluent with 81.05% +/- 5.88% of the cells attached. Indium 111-labeled platelet deposition onto grafts was quantified by dynamic scintillation camera imaging. Platelet deposition on 10 endothelialized grafts was markedly reduced (0.16 +/- 0.04 x 10(9) platelets per graft) compared with 10 untreated control grafts (1.84 +/- 0.59 x 10(9) platelets, p less than 0.02), eight grafts with early attached unspread ECs (2.38 +/- 0.66 x 10(9) platelets, p less than 0.005), and 11 grafts treated with collagen alone (5.93 +/- 0.72 x 10(9) platelets, p less than 0.002).

  6. Noninvasive radioisotopic technique for detection of platelet deposition in mitral valve prosthesis and renal microembolism in dogs

    SciTech Connect

    Dewanjee, M.K.; Kaye, M.P.; Fuster, V.; Rao, S.A.

    1980-01-01

    At 24 hrs after implantation of Bjoerk-Shiley mitral prosthesis in 5 dogs, in vivo images were obtained with a gamma camera after intravenous administration (0.5-0.6 mCi) one hour postoperatively of autologous Indium-111-labeled platelets. The site of platelet deposition in the teflon ring and perivascular damaged cardiac tissue is clearly delineated in the scintiphoto. In vitro biodistribution (mean % +/- SD of injected dose) at 24 hrs after injection of the 5 implanted and 7 normal dogs performed with a gamma counter demonstrated that (45.1 +/- 10.6)% and (0.7 +/- 0.4)% were in blood and kidneys in normal dogs and (28.5 +/- 6.8)%, (1.6 +/- 0.6)%, (0.3 +/- 0.1)%, and (0.2 +/- 0.1)% were in blood, kidneys, teflon rings, and perivascular damaged cardiac tissue, respectively. The strut and pyrolytic carbon-coated disc retained only (0.0033 +/- 0.0004)% and (0.0031 +/- 0.0003)%, respectively. There was a 2.3-fold increase of labeled platelets in kidneys of implanted dogs due to renal trapping of microembolism. Also, three- to fivefold increase in ratios of lung, brain, cardiac, and skeletal muscle to blood indicates that internal organs and whole body work as filter for microembolism generated by cardiovascular surgery and mitral prosthesis. Twenty percent of the administered platelets are consumed in surgical repair of damaged tissue. Indium-111-labeled platelets thus provide a sensitive marker for noninvasive imaging of Bjoerk-Shiley mitral prosthesis, thromboembolism after implantation of prosthetic device, and in vitro quantitation of surgical consumption.

  7. Renal scintigraphy in veterinary medicine.

    PubMed

    Tyson, Reid; Daniel, Gregory B

    2014-01-01

    Renal scintigraphy is performed commonly in dogs and cats and has been used in a variety of other species. In a 2012 survey of the members of the Society of Veterinary Nuclear Medicine, 95% of the respondents indicated they perform renal scintigraphy in their practice. Renal scintigraphy is primarily used to assess renal function and to evaluate postrenal obstruction. This article reviews how renal scintigraphy is used in veterinary medicine and describes the methods of analysis. Species variation is also discussed.

  8. 111In platelet imaging of left ventricular thrombi. Predictive value for systemic emboli

    SciTech Connect

    Stratton, J.R.; Ritchie, J.L. )

    1990-04-01

    To determine whether a positive indium 111 platelet image for a left ventricular thrombus, which indicates ongoing thrombogenic activity, predicts an increased risk of systemic embolization, we compared the embolic rate in 34 patients with positive {sup 111}In platelet images with that in 69 patients with negative images during a mean follow-up of 38 +/- 31 (+/- SD) months after platelet imaging. The positive and negative image groups were similar with respect to age (59 +/- 11 vs. 62 +/- 10 years), prevalence of previous infarction (94% vs. 78%, p less than 0.05), time from last infarction (28 +/- 51 vs. 33 +/- 47 months), ejection fraction (29 +/- 14 vs. 33 +/- 14), long-term or paroxysmal atrial fibrillation (15% vs. 26%), warfarin therapy during follow-up (26% vs. 20%), platelet-inhibitory therapy during follow-up (50% vs. 33%), injected {sup 111}In dose (330 +/- 92 vs. 344 +/- 118 microCi), and latest imaging time (greater than or equal to 48 hours in all patients). During follow-up, embolic events occurred in 21% (seven of 34) of patients with positive platelet images for left ventricular thrombi as compared with 3% (two of 69) of patients with negative images (p = 0.002). By actuarial methods, at 42 months after platelet imaging, only 86% of patients with positive images were embolus free as compared with 98% of patients with negative images (p less than 0.01).

  9. The acetabulum: A prospective study of three-phase bone and indium white blood cell scintigraphy following porous-coated hip arthroplasty

    SciTech Connect

    Oswald, S.G.; Van Nostrand, D.; Savory, C.G.; Anderson, J.H.; Callaghan, J.J. )

    1990-03-01

    Although few studies address the use of three-phase bone scanning (TPBS) and indium-111-labeled white blood cell scintigraphy ({sup 111}In-WBC) in hip arthroplasty utilizing a porous-coated prosthesis, the literature suggests that scintigraphic patterns in the uncomplicated patient may differ from that seen with the cemented prosthesis. In an attempt to determine the scintigraphic natural history, 25 uncomplicated porous-coated hip arthroplasties in 21 patients were prospectively studied with serial TPBS and {sup 111I}n-WBC at approximately 7 days, and 3, 6, 12, 18, and 24 mo postoperatively. This report deals with findings related to the acetabulum. All 25 prostheses (144 of 144 scans) demonstrated increased uptake on the bone-phase images. Although this activity decreased with time, 76% had persistent uptake at 24 mo. Twenty-three of 25 prostheses (126 of 140 scans) showed increased uptake on {sup 111}In-WBC scintigraphy, invariably decreasing with time, but with 37% having significant uptake at 24 mo. Scintigraphic patterns in the uncomplicated porous-coated hip arthroplasty patient appear to differ from patterns described in cemented prostheses.

  10. Synthesis and evaluation of bombesin derivatives on the basis of pan-bombesin peptides labeled with indium-111, lutetium-177, and yttrium-90 for targeting bombesin receptor-expressing tumors.

    PubMed

    Zhang, Hanwen; Chen, Jianhua; Waldherr, Christian; Hinni, Karin; Waser, Beatrice; Reubi, Jean Claude; Maecke, Helmut R

    2004-09-15

    Bombesin receptors are overexpressed on a variety of human tumors like prostate, breast, and lung cancer. The aim of this study was to develop radiolabeled (Indium-111, Lutetium-177, and Yttrium-90) bombesin analogues with affinity to the three bombesin receptor subtypes for targeted radiotherapy. The following structures were synthesized: diethylenetriaminepentaacetic acid-gamma-aminobutyric acid-[D-Tyr6, beta-Ala11, Thi13, Nle14] bombesin (6-14) (BZH1) and 1,4,7,10-tetraazacyclododecane-N,N',N",N"' -tetraacetic acid-gamma-aminobutyric acid-[D-Tyr6, beta-Ala11, Thi13, Nle14] bombesin (6-14) (BZH2). [111In]-BZH1 and in particular [90Y]-BZH2 were shown to have high affinity to all three human bombesin receptor subtypes with binding affinities in the nanomolar range. In human serum metabolic cleavage was found between beta-Ala11 and His12 with an approximate half-life of 2 hours. The metabolic breakdown was inhibited by EDTA and beta-Ala11-His12 (carnosine) indicating that carnosinase is the active enzyme. Both 111In-labeled peptides were shown to internalize into gastrin-releasing peptide-receptor-positive AR4-2J and PC-3 cells with similar high rates, which were independent of the radiometal. The biodistribution studies of [111In]-BZH1 and [111In]-BZH2 ([177Lu]-BZH2) in AR4-2J tumor-bearing rats showed specific and high uptake in gastrin-releasing peptide-receptor-positive organs and in the AR4-2J tumor. A fast clearance from blood and all of the nontarget organs except the kidneys was found. These radiopeptides were composed of the first pan-bombesin radioligands, which show great promise for the early diagnosis of tumors bearing not only gastrin-releasing peptide-receptors but also the other two bombesin receptor subtypes and may be of use in targeted radiotherapy of these tumors.

  11. Leukemic cell labeling with indium-111-oxine

    SciTech Connect

    Uchida, T.; Takagi, Y.; Matsuda, S.; Yui, T.; Ishibashi, T.; Kimura, H.; Kariyone, S.

    1984-01-01

    Leukemic cells were labeled with In-111-oxine in patients with acute leukemia. In vitro labeling studies revealed that labeling efficiency reached maximum 80.8 +- 3.6% (mean +- 1SD) by 2 times washes after 20 minutes incubation time. Cell viability was assessed by trypan blue exclusion test and in vitro culture of leukemic cells, which showed no cellular damage during labeling procedure. Elution of In-111 from the labeled cells was 10.0 +- 1.2% at 12 hours after labeling. For in vivo leukemic cell kinetic studies, more than 10/sup 8/ leukemic cells separated from Ficoll-Hypacque sedimentation were labeled by 30 minutes of In-111-oxine incubation and two times washes at 37/sup 0/C. In vivo studies were performed in 7 patients with acute myeloblastic, lymphoblastic leukemia and blastic crisis of chronic myelocytic leukemia. Labeled leukemic cells disappeared in single exponential fashion with half life of 9.6 to 31.8 hours. Total leukemic cell pool in peripheral circulation was calculated, which correlated well with peripheral leukemic cell counts (r=0.99). No relationship was observed between total leukemic cell pool and leukemic cell turnover rate. Migration patterns of labeled leukemic cells showed that pulmonary uptake was evident within 15 minutes after the infusion and returned to base-line. Splenic and hepatic uptake showed gradual increase up to 24 hours. Bone marrow accumulation was shown only in 2 cases. Presently, there are no suitable radionuclides for leukemic cell labeling. In-111-oxine labeled leukemic cells would overcome this difficulty.

  12. Indium 111 toxicity in the human lymphocyte

    SciTech Connect

    Silberstein, E.B.; Watson, S.; Mayfield, G.; Kereiakes, J.G.; Bullock, W.

    1985-05-01

    Indium-labeled lymphocytes were examined for response to a variety of mitogens, ability to synthesize immunoglobulins, mitotic index, and presence of chromosome aberrations at a range of exposures from 0.2 to 500 muCi/10(8) cells. Results of all four tests were found to be abnormal when the lymphocytes were labeled with /sup 111/In activities well within those employed for diagnostic testing.

  13. Accumulation of intimal platelets in cerebral arteries following experimental subarachnoid hemorrhage in cats

    SciTech Connect

    Haining, J.L.; Clower, B.R.; Honma, Y.; Smith, R.R.

    1988-07-01

    From 2 hours to 23 days following experimental subarachnoid hemorrhage, the accumulation of indium-111-labeled platelets on the intimal surface of the middle cerebral artery was studied in 23 cats. Subarachnoid hemorrhage was produced by transorbital rupture of the right middle cerebral artery. Of the 23 cats, 17 exhibited right middle cerebral artery/left middle cerebral artery radioactivity ratios of greater than 1.25. When these results were compared with those of 12 control cats, 0.001 less than p less than 0.005 (chi2 test). Thus, the results from the control and experimental groups are significantly different and indicate early (after 2 hours) preferential accumulation of intimal platelets in the ruptured right middle cerebral artery compared with the unruptured left middle cerebral artery and new platelet deposition continuing for up to 23 days. However, the experimental group did not reveal a clear pattern for platelet accumulation following subarachnoid hemorrhage. There was no simple correlation between the magnitude of the radioactivity ratios and the time after hemorrhage when the cats were killed although the ratios for 2 hours to 7 days seemed greater than those for 8 to 23 days. Assuming the pivotal role of platelets in the angiopathy of subarachnoid hemorrhage, the administration of antiplatelet agents as soon as possible following its occurrence may be of value.

  14. Effect of a selective thromboxane synthase inhibitor on arterial graft patency and platelet deposition in dogs

    SciTech Connect

    McDaniel, M.D.; Huntsman, W.T.; Miett, T.O.; Cronenwett, J.L.

    1987-08-01

    This study examined the effect of selective thromboxane synthase inhibition and nonselective cyclooxygenase inhibition on vascular graft patency and indium 111-labeled platelet deposition in 35 mongrel dogs undergoing carotid artery replacement with 4 mm X 4 cm polytetrafluoroethylene (PTFE) (one side) and Dacron (opposite side) end-to-end grafts. Aspirin-dipyridamole therapy improved one-week graft patency, from 46% in untreated dogs to 93% in treated dogs. Thromboxane synthase inhibition (U-63557A) improved graft patency in these dogs to 81%. Both drug treatments reduced platelet deposition on Dacron and PTFE grafts by 48% to 68% compared with control dogs. Dacron grafts accumulated significantly more platelets than PTFE grafts but had comparable patency rates. Low-dose aspirin therapy had no significant effect on either graft patency or platelet deposition. All treatment groups showed a 60% to 76% reduction in serum thromboxane B2, but only thromboxane synthase inhibitor treatment increased plasma 6-keto-prostaglandin F1 alpha by 100%. Selective thromboxane synthase inhibition improved small-caliber prosthetic graft patency to the same extent as did conventional cyclooxygenase inhibition in this preliminary study.

  15. Discrimination between platelet-mediated and coagulation-mediated mechanisms in a model of complex thrombus formation in vivo

    SciTech Connect

    Cadroy, Y.; Horbett, T.A.; Hanson, S.R.

    1989-04-01

    To study mechanisms of complex thrombus formation in vivo, and to compare the relative antithrombotic effects of anticoagulants and antiplatelet agents, a model was developed in baboons. Segments of collagen-coated tubing followed by two sequentially placed expansion chambers exhibiting disturbed flow patterns were exposed to native blood under laminar flow conditions. The device was incorporated for 1 hour into an exteriorized arteriovenous shunt in baboons under controlled blood flow (20 ml/min). Morphologic evaluation by scanning electron microscopy showed that thrombi associated with collagen were relatively rich in platelets but thrombi in the chambers were rich in fibrin and red cells. Deposition of indium 111-labeled platelets was continuously measured with a scintillation camera. Platelet deposition increased in a linear (collagen-coated segment) or exponential (chambers 1 and 2) fashion over time, with values after 40 minutes averaging 24.1 +/- 3.3 x 10(8) platelets (collagen segment), 16.7 +/- 3.4 x 10(8) platelets (chamber 1), and 8.4 +/- 2.4 x 10(8) platelets (chamber 2). Total fibrinogen deposition after 40 minutes was determined by using iodine 125-labeled baboon fibrinogen and averaged 0.58 +/- 0.14 mg in the collagen segment, 1.51 +/- 0.27 mg in chamber 1, and 0.95 +/- 0.25 mg in chamber 2. Plasma levels of beta-thromboglobulin (beta TG), platelet-factor 4 (PF4), and fibrinopeptide A (FPA) increased fourfold to fivefold after 60 minutes of blood exposure to the thrombotic device. Platelet deposition onto the collagen segment, chamber 1, and chamber 2 was linearly dependent on the circulating platelet count. Platelet accumulation in chamber 1 and chamber 2 was also dependent on the presence of the proximal collagen segment.

  16. The effect of ibuprofen on accumulation of /sup 111/In-labeled platelets and leukocytes in experimental myocardial infarction

    SciTech Connect

    Romson, J.L.; Hook, B.G.; Rigot, V.H.; Schork, M.A.; Swanson, D.P.; Lucchesi, B.R.

    1982-11-01

    To assess the ability of ibuprofen to influence the extent of platelet aggregation and leukocyte infiltration during acute myocardial infarction, autologous indium-111 (/sup 111/In)-labeled platelets or leukocytes were injected before 60 minutes of left circumflex coronary artery (LCx) occlusion, followed by 24 hours of reperfusion in the canine heart. Myocardial infarct size, as a percent of the area at risk, was reduced in the ibuprofen-treated group (12.5 mg/kg i.v. every 4 hours beginning 30 minutes before LCx occlusion) by 40%, from 48 +/- 4% in control animals to 29 +/- 4% in ibuprofen-treated dogs (p . 0.005). Quantification of the platelet-associated /sup 111/In radioactivity in irreversibly injured myocardium indicated that ibuprofen did not alter the accumulation of platelets in infarcted myocardium. In contrast, leukocyte accumulation in infarcted tissue was reduced significantly. In tissue samples with 0.41-0.60 gram infarct, the infarcted/normal ratio of leukocyte radioactivity was 12 +/- 2 in control dogs and 4 +/- 1 in ibuprofen-treated dogs, which represents a 67% reduction in leukocyte accumulation in ibuprofen-treated compared with control dogs. Similar reductions were found in other gram-infarct-weight categories. Although both platelets and leukocytes accumulate in infarcted canine myocardium, ibuprofen may exert its beneficial effect on ischemic myocardium by suppressing the inflammatory response associated with myocardial ischemia and infarction.

  17. Influence of endothelial cell seeding on platelet deposition and patency in small-diameter Dacron arterial grafts

    SciTech Connect

    Allen, B.T.; Long, J.A.; Clark, R.E.; Sicard, G.A.; Hopkins, K.T.; Welch, M.J.

    1984-01-01

    Serial platelet deposition, surface topography, and patency were evaluated in control (N . 28) and endothelial cell-seeded (N . 28) small-diameter (4 mm inner diameter) USCI Dacron grafts implanted in the carotid and femoral arteries of dogs. All dogs received aspirin (325 mg) daily for 2 weeks starting 24 hours prior to graft implantation. Endothelial cell seeding was performed by mixing suspensions of autologous endothelial cells that had been enzymatically harvested from segments of external jugular vein with blood that was used to preclot the prostheses. The platelet deposition on each graft was quantitated by means of indium 111-labeled platelets and technetium 99m-labeled red cells in a dual-isotope platelet-imaging technique. Platelet deposition on seeded grafts 24 hours after implantation was significantly higher than on the controls (p less than 0.05). Two weeks after implantation platelet deposition on seeded prostheses had decreased to a level significantly lower than that on the controls and continued to decline on serial studies up to 7 months. In contrast to seeded grafts, platelet accumulation on control grafts dramatically increased after the withdrawal of aspirin therapy and was associated with a sharp rise in control graft thromboses. Cumulative 7-month patency for seeded prostheses was significantly higher than for the controls (96% and 29%, respectively; p less than 0.001). We conclude that endothelial cell seeding in combination with short-term aspirin therapy is a simple, reliable diameter Dacron prostheses. Abrupt withdrawal of aspirin therapy may be contraindicated in nonseeded control grafts because it results in increased platelet deposition and thrombosis.

  18. Platelet Donation

    MedlinePlus

    ... donating platelets, can I still donate blood? What blood types should donate platelets? Can I donate plasma at ... Community Learn About Blood Blood Facts and Statistics Blood Types Blood Components What Happens to Donated Blood Blood ...

  19. Liver scintigraphy in veterinary medicine.

    PubMed

    Morandi, Federica

    2014-01-01

    The most common veterinary application of liver scintigraphy is for the diagnosis of portosystemic shunts (PSSs). There has been a continual evolution of nuclear medicine techniques for diagnosis of PSS, starting in the early 1980s. Currently, transplenic portal scintigraphy using pertechnetate or (99m)Tc-mebrofenin is the technique of choice. This technique provides both anatomical and functional information about the nature of the PSS, with high sensitivity and specificity. Hepatobiliary scintigraphy has also been used in veterinary medicine for the evaluation of liver function and biliary patency. Hepatobiliary scintigraphy provides information about biliary patency that complements finding in ultrasound, which may not be able to differentiate between biliary ductal dilation from previous obstruction vs current obstruction. Hepatocellular function can also be determined by deconvolutional analysis of hepatic uptake or by measuring the clearance of the radiopharmaceutical from the plasma. Plasma clearance of the radiopharmaceutical can be directly measured from serial plasma samples, as in the horse, or by measuring changes in cardiac blood pool activity by region of interest analysis of images. The objective of this paper is to present a summary of the reported applications of hepatobiliary scintigraphy in veterinary medicine.

  20. Extraction, radiolabeling, and in vivo catabolism of autologous-origin equine fibrinogen and platelets in the healthy and exercise-stressed horse

    SciTech Connect

    Coyne, C.P.

    1986-01-01

    Three separate techniques were evaluated for the extraction of autologous-origin fibrinogen from whole equine plasma. Rapid extraction of equine fibrinogen with ammonium sulfate-sodium phosphate buffer, in combination with saturated glycine buffer, provided the most practical means of obtaining a protein extract with the highest degree of biological activity and sufficiently high iodine-125 (/sup 125/I) radiolabeling efficiencies using monochloroiodine reagent (ICI). A technique was developed for the in vitro radiolabeling of equine platelets suspended in plasma. This entailed the use of the isotope, indium-111 (/sup 111/In), together with the lipophilic ligand, 2-(mercaptopyridine-N-oxide). This labeling technique achieved labeling efficiencies between 75% and 96%, and in vitro aggregability of /sup 111/In-merc radiolabeled platelets was comparable to that of unlabeled cell isolates. In the final phase of the investigation, autologous-origin /sup 125/I-labeled fibrinogen and /sup 111/In-labeled platelets were applied in a series of equine exercise physiology studies. Elimination of these two radiobiologicals was evaluated in the resting and exercise-stressed horse. Results from these investigations revealed no long-term influence of exercise conditioning on the in vivo kinetics of radiolabeled fibrinogen or platelets.

  1. Thallium 201 Scintigraphy

    PubMed Central

    McKillop, James H.

    1980-01-01

    The radioactive isotope thallium 201 behaves physiologically as a potassium analog, and when injected intravenously accumulates rapidly within the cells of many organs. Uptake of the isotope reflects both regional perfusion and sodium-potassium pump activity. The radionuclide emits 80 keV x-rays which are suitable for scintillation camera imaging. The main clinical application of 201TI scintigraphy has been in myocardial imaging. Abnormal uptake of the isotope results in a cold spot on the myocardial image. In patients with coronary artery disease, the differentiation of ischemic and infarcted myocardium is made by comparing images obtained after injecting the radionuclide at the peak of a maximal exercise test with those obtained after injection at rest. Abnormalities due to ischemia usually are seen only on the stress image whereas fixed defects in both rest and stress studies usually indicate areas of infarction or scarring. Some investigators believe that redistribution images obtained four to six hours after stress injection (without administering further 201TI) give the same information as a separate rest study. The sensitivity of stress imaging for detecting significant coronary disease is of the order of 80 percent to 95 percent, though computer processing of the images may be necessary to achieve the higher figure. The prediction of the extent of coronary disease from 201TI images is less reliable. An abnormal 201TI image is not entirely specific for coronary artery disease and the likelihood of an abnormal image being due to this diagnosis varies according to the clinical circumstances. The main clinical value of 201TI myocardial imaging is likely to be in the noninvasive screening of patients with atypical chest pain or with ambiguous findings on stress electrocardiographic tests. It has also proved useful in studying patients with variant angina or following a coronary bypass operation. It is doubtful whether the technique is clinically helpful in most

  2. [The position of scintigraphy in traumatology].

    PubMed

    Kaiser, C; Neck, K; Ritter, R; Glanzmann, C; Schwarz, H

    1978-12-01

    A report on the findings of skeletal scintigraphy in 80 cases of traumatic bone lesions is discussed. After a short survey on the physiological process in the activity ensilage, the assertion of the scintigraphy is compared to the X-ray. The indication which has been approved in practice is discussed and described. In correct indication scintigraphy is a valuable diagnostic measure and it may influence the procedure.

  3. Viability and functional integrity of washed platelets

    SciTech Connect

    Pineda, A.A.; Zylstra, V.W.; Clare, D.E.; Dewanjee, M.K.; Forstrom, L.A.

    1989-07-01

    The viability and functional integrity of saline- and ACD-saline-washed platelets were compared with those of unwashed platelets. After template bleeding time (TBT) was measured, 15 healthy volunteers underwent plateletpheresis and ingested 600 mg of aspirin. Autologous /sup 111/In-labeled platelets were transfused: unwashed (n = 5), washed with 0.9 percent saline solution (SS) (n = 5), and washed with a buffered 12.6 percent solution of ACD-A in 0.9 percent saline solution (n = 5). After transfusion, we measured TBT at 1, 4, and 24 hours; platelet survival at 10 minutes and 1, 4, and 24 hours and daily for 6 days; and the percentage of uptake in liver and spleen by quantitative whole-body radionuclide scintigraphy at 24 and 190 hours. We found that saline washing affected platelet recovery, 23.47 +/- 12 percent (p less than 0.001) as compared to 52.43 +/- 17 percent (p less than 0.002) for ACD-saline and 73.17 +/- 8 percent for control; that saline washing resulted in a greater liver uptake than control and ACD-saline-washed platelets (31.9 +/- 8% (p less than 0.001) vs 17.7 +/- 4.1 and 19.3 +/- 2.1% (p greater than 0.1), respectively); that, unlike control and ACD-saline-washed platelets, saline-washed platelets did not shorten bleeding time; and that neither type of washing affected survival. Although ACD-saline washing affects recovery, it also results in intact function, normal survival, higher recovery than SS platelets, and no significant liver uptake.

  4. Effects of 2450 MHz continuous wave microwave radiation and isothermal conduction on canine platelet aggregometry, survival and margination

    SciTech Connect

    Bushberg, J.T.

    1981-01-01

    The effect of 2450 MHz microwave radiation and isothermal conduction ex vivo exposures on canine platelets was analyzed in vitro by studying adenosine-5'-diphosphate activated aggregation and in vivo by studying the survival, distribution and physiological integrity of reinfused autologous Indium-111 labeled platelets. Platelet rich plasma (PRP) from eight healthy dogs was subjected to microwave irradiation at 10 MW/cm/sup 2/ and at 50 MW/cm/sup 2/ for 10, 100, 600, 900, 1800 seconds and at 100 MW/cm/sup 2/ for 10, 100, and 600 seconds. Aggregometry analysis was performed immediately after exposure and 10 minutes post-exposure. No significant perturbations were observed following microwave exposure of 10 MW/cm/sup 2/. At higher power densities six specific types of aggregation phenomena were demonstrated: (1) Hyperaggregation, (2) Decreased Velocity Reduced Hyperaggregation, (3) Recovery, (4) Decreased Velocity Delayed Hyperaggregation, (5) Reversible Afunctionality, and (6) Irreversible Afunctionality. The absence of equivalent aggregation responses with isothermal conduction heating (extraisothermal effects) was attributed to differences in heating rate and not to nonthermal microwave-specific effects. Scintigraphic and survival kinetic studies were performed following power density/exposure time combinations. PRP samples I and IV displayed normal survival half-times; however, exposure I resulted in a depressed 15-minute post-reinfusion circulating percentage (CP/sub 15/) of 29% compared to 61% for the control sample. Exposure of groups II and III resulted in a dramatic reduction in the CP/sub 15/ (i.e., 18% and 1.3% respectively) and survival half-times. Margination of the labeled platelets was divided between the spleen, liver and blood pool.

  5. Radionuclide scintigraphy of bacterial nephritis

    SciTech Connect

    Conway, J.J.; Weiss, S.C.; Shkolnik, A.; Yogev, R.; Firlit, C.; Traisman, E.S.

    1984-01-01

    Pyelonephritis is a leading cause of renal failure and is expected to cost as much as three billion dollars in 1984. The diagnosis of urinary tract infection is usually not difficult. However, localization of the infection within the renal parenchyma as opposed to the collecting system is much more difficult. Flank pain, fever, bacteiuria and evidence of parenchymal involvement by intravenous urography may be absent or unrecognized particularly in the infant. Ultrasound and Nuclear Medicine are advocated as better methods to define parenchymal involvement. Such definition is important in the consideration of treatment since parenchymal involvement of the kidney carries a much more ominous potential outcome than infection restricted to within the collecting system. 38 children with a clinical diagnosis of urinary tract infection were studied. 26 of the patients demonstrated abnormal renal parenchymal findings with Gallium-67 Citrate or Tc-99m Glucoheptonate scintigraphy. Intravenous urography was notably ineffective with only 5 of the 20 interpreted as abnormal due to parenchymal disease or decreased function. 11 were entirely normal while only 5 demonstrated scars or hydronephrosis. Only 10 of 17 patients demonstrated intranvesicoureteral reflux on x-ray or nuclear cystography. Ultrasound depicted 6 of 20 patients as having parenchymal abnormalities. Seven were normal. Nonspecific findings such as dilitation of the renal pelvis or renal enlargement was noted in 11 of the 20 patients. Radionuclide Scintigraphy is the most efficacious modality to detect since acute bacterial nephritis.

  6. Radionuclide bone scintigraphy in pediatric orthopedics

    SciTech Connect

    Conway, J.J.

    1986-12-01

    Radionuclide bone scintigraphy is highly sensitive and specific for diagnosing the musculoskeletal disorders of childhood. Conditions such as neonatal osteomyelitis, septic arthritis, diskitis of childhood, Legg-Calve-Perthes disease, the osteochondroses, the toddler's fracture, sports injuries, spondylolysis, myositis ossificians, and reflex sympathetic dystrophy are readily defined. High-quality state-of-the-art scintigraphy is essential in infants and young children. 64 references.

  7. Uptake of indium-111-labeled leukocytes by brain metastasis

    SciTech Connect

    Balachandran, S.; Husain, M.M.; Adametz, J.R.; Pallin, J.S.; Angtuaco, T.L.; Boyd, C.M.

    1987-04-01

    Uptake of indium-labeled leukocytes was seen in two cases of histologically proven brain metastasis. In one, this led to misdiagnosis of the lesion as an abscess. On histological evaluation, a large number of white blood cells or macrophages was seen at the neoplastic sites. Reasons for leukocyte accumulation around metastatic brain neoplasms are discussed. In contrast to the current reports that indium-labeled leukocyte scans can differentiate intracranial infection from tumor, these cases demonstrate their lack of specificity in the detection of brain abscess.

  8. In vivo dissolution measurement with indium-111 summation peak ratios

    SciTech Connect

    Jay, M.; Woodward, M.A.; Brouwer, K.R.

    1985-10-01

    Dissolution of (/sup 111/In)labeled tablets was measured in vivo in a totally noninvasive manner by using a modification of the perturbed angular correlation technique known as the summation peak ratio method. This method, which requires the incorporation of only 10-12 microCi into the dosage form, provided reliable dissolution data after oral administration of (/sup 111/In)lactose tablets. These results were supported by in vitro experiments which demonstrated that the dissolution rate as measured by the summation peak ratio method was in close agreement with the dissolution rate of salicylic acid in a (/sup 111/In)salicylic acid tablet. The method has the advantages of using only one detector, thereby avoiding the need for complex coincidence counting systems, requiring less radioactivity, and being potentially applicable to a gamma camera imaging system.

  9. Indium-111 leukocyte localization in infected prosthetic graft

    SciTech Connect

    Purnell, G.L.; Walker, C.W.; Allison, J.W.; Dalrymple, G.V. )

    1990-08-01

    Infective endocarditis can be difficult to prove, even in the face of strong clinical suspicion. A case in which standard methods of diagnosis failed to demonstrate endocarditis in a patient with recurrent Staphylococcus aureus bacteremia and porcine aortic valve is reported. An In-111 labelled leukocyte SPECT study demonstrated uptake in the aortic root and leaflets, and autopsy demonstrated vegetations on the leaflets. In-111 may prove useful in demonstrating endocarditis in patients with prosthetic valve infection.

  10. Indium-111 chloride imaging in the detection of infected prostheses

    SciTech Connect

    Sayle, B.A.; Fawcett, H.D.; Wilkey, D.J.; Cierny, G. III; Mader, J.T.

    1985-07-01

    Thirty-three patients with painful joint prostheses and a suspicion of infection were imaged with (/sup 111/In)chloride. A final diagnosis was established by culture in 19. Of these, 12 were categorized as true positives and three as true negatives. There were two false-positive studies, occurring in patients with knee prostheses. In both, the culture was obtained by aspiration. The sensitivity was 86%, specificity 60%, and accuracy 79%. Seventeen of the proven cases had bone imaging prior to (/sup 111/In)chloride imaging. All 17 static images were positive and were not helpful in differentiating loosening from infection. Using increased uptake on the blood-pool image as a criteria for infection, the sensitivity was 89%, but the specificity was 0. Adding flow studies made little difference in interpreting the blood-pool images. This study shows that (/sup 111/In)chloride imaging is more accurate in evaluating infection in prosthesis than bone imaging.

  11. Platelet associated antibodies

    MedlinePlus

    ... medlineplus.gov/ency/article/003552.htm Platelet-associated antibodies blood test To use the sharing features on ... JavaScript. This blood test shows if you have antibodies against platelets in your blood. Platelets are a ...

  12. Hysterosalpingo-radionuclide scintigraphy (HERS)

    SciTech Connect

    Iturralde, M.; Venter, P.F.

    1981-10-01

    A radionuclide procedure, hysterosalpingo-radionuclide scintigraphy (HERS), was designed to evaluate the migration of a particulate radioactive tracer from the vagina to the peritoneal cavity and ovaries as well as to image and functionally outline the patency of the pathways between these two extremes of the female reproductive system. Technetium-99m human albumin microspheres (99mTc-HAM) were deposited in the posterior fornices of patients who were divided into two specific groups. Group I consisted of patients who were to undergo different elective gynecologic operations, in which besides obtaining sequential images, radioactivity levels were measured in the removed organs and tissues. Group II consisted of patients referred by the Infertility Clinic for evaluation of their reproductive system pathways patency. In this latter group, HERS was compared with contrast hysterosalpingography (HSG) and peritoneoscopy (PCP). The results obtained from measurements of radioactivity levels on the removed surgical specimens and comparison with other conventional gynecologic diagnostic procedures provide accurate evidence of the migration of 99mTc-HAM from the vagina, through the uterus and tubes, to the peritoneal cavity and ovaries, and show that HERS is a simple noninvasive method for functionally imaging and assessing the patency of the female reproductive system pathways.

  13. Technical aspects of bone scintigraphy.

    PubMed

    Brown, M L; O'Connor, M K; Hung, J C; Hayostek, R J

    1993-07-01

    Optimal bone scintigraphy is obtained by using a current generation gamma camera with a high-resolution collimator, minimizing the patient-to-collimator distance, using scatter reduction techniques where possible, and obtaining a 500,000 to 1 million count image for 40-cm field of view camera. Hard copy images from an analog or digital formatter should be optimized to display all intensities either on the same images or, when necessary, to display the low count information on one image and the high count information on another. Additional images using different collimators, such as converging or pinhole collimators, and oblique and lateral views should be obtained when necessary to demonstrate or define the pathologic area. To optimize SPECT imaging, the following parameters should be used: a high-resolution collimator, a 128 x 128 acquisition matrix, and minimum separation between the patient and the collimator, which may require the use of an elliptic orbit. Between 64 and 128 views should be obtained, and depending on preference, the planar data should be prefiltered with a Butterworth, order 8-12 and a cutoff at 0.5 Nyquist. The data should then be reconstructed using a simple ramp filter. This method provides a good technique when one is first beginning to perform bone SPECT. Attenuation correction is not generally beneficial for SPECT bone studies, although sometimes weighted backprojection may improve image contrast and resolution. Finally, the use of volume rendering may help clarify the location of suspect lesions.

  14. Blood platelet kinetics and platelet transfusion.

    PubMed

    Aster, Richard H

    2013-11-01

    The discovery of citrate anticoagulant in the 1920s and the development of plastic packs for blood collection in the 1960s laid the groundwork for platelet transfusion therapy on a scale not previously possible. A major limitation, however, was the finding that platelet concentrates prepared from blood anticoagulated with citrate were unsuitable for transfusion because of platelet clumping. We found that this could be prevented by simply reducing the pH of platelet-rich plasma to about 6.5 prior to centrifugation. We used this approach to characterize platelet kinetics and sites of platelet sequestration in normal and pathologic states and to define the influence of variables such as anticoagulant and ABO incompatibility on post-transfusion platelet recovery. The "acidification" approach enabled much wider use of platelet transfusion therapy until alternative means of producing concentrates suitable for transfusion became available.

  15. Simultaneous pancreatic-renal transplant scintigraphy

    SciTech Connect

    Shulkin, B.L.; Dafoe, D.C.; Wahl, R.L.

    1986-12-01

    99mTc-DTPA scintigraphy was evaluated in seven patients as a technique to assess perfusion of the transplanted pancreas and kidney. Such scans provide high-quality images of both organs in both the flow phase and later phases. The radionuclide is readily available and its brief effective half-life allows repeated evaluations at short intervals. /sup 131/I-hippuran, the major radiopharmaceutical for renal transplant scintigraphy, does not allow visualization of the transplanted pancreas or evaluation of its blood supply. Although the blood glucose is a gross indicator of the function of the pancreatic allograft, pancreatic scintigraphy with 99mTc-DTPA in one case was capable of detecting graft dysfunction before elevation of the blood glucose occurred. While additional studies will be necessary to determine the predictive value of this test, 99mTc-DTPA is valuable for pancreatic-renal transplant evaluation.

  16. Colovesical fistula demonstrated on renal cortical scintigraphy.

    PubMed

    Stathaki, Maria; Vamvakas, Lampros; Papadaki, Emmanouela; Papadimitraki, Elisavet; Tsaroucha, Angeliki; Karkavitsas, Nikolaos

    2012-11-01

    A 70-year-old man with a history of weight loss, changes in bowel habits, and hematochezia had rectal adenocarcinoma. He was palliated with diverting colostomy, followed by radiochemotherapy. Bilateral hydronephrosis was found incidentally on lower abdominal CT scan. He underwent 99mTc dimercaptosuccinic acid scan prior to percutaneous nephrostomy tube placement. Apart from the renal cortex, scintigraphy showed activity in the ascending colon continuous to the activity of the bladder. This indicated urine extravasation on account of a colovesical fistula, complicating postoperative radiation treatment. Here we highlight the contribution of renal cortical scintigraphy in the detection of colovesical fistulas.

  17. Intraoperative scintigraphy for active small intestinal bleeding

    SciTech Connect

    Biener, A.; Palestro, C.; Lewis, B.S.; Katz, L.B. )

    1990-11-01

    Localizing active sites of bleeding within the small intestine remains a difficult task. Endoscopic, angiographic or scintigraphic studies may point to the small intestine as the site of blood loss, but at operation, without a palpable lesion, the exact site of bleeding remains elusive. Patients are managed at laparotomy with intraoperative endoscopy, angiography, multiple enterotomies, blind resections, or placement of an enterostomy. We describe two patients in whom intraoperative scintigraphy accurately identified active sites of bleeding in the small intestine when other modalities failed. Intraoperative scintigraphy is rapid, easy to perform and is an effective means of identifying active sites of bleeding within the small intestine.

  18. Guidelines for radioiodinated MIBG scintigraphy in children.

    PubMed

    Olivier, Pierre; Colarinha, Paula; Fettich, Jure; Fischer, Sibylle; Frökier, Jörgen; Giammarile, Francesco; Gordon, Isky; Hahn, Klaus; Kabasakal, Levent; Mann, Mike; Mitjavila, Mercedes; Piepsz, Amy; Porn, Ute; Sixt, Rune; van Velzen, Jeannette

    2003-05-01

    These guidelines on the use of radioiodinated (99m)Tc-MIBG scintigraphy in children, which summarise the views of the Paediatric Committee of the European Association of Nuclear Medicine, provide a framework which may prove helpful to nuclear medicine teams in daily practice. They have been influenced by the conclusions of the "Consensus Guidelines for MIBG Scintigraphy" (Paris, November 6, 1997) of the European Neuroblastoma Group and by those of the Oncological Committee of the French Society of Nuclear Medicine. The guidelines should be taken in the context of "good practice" and any local/national rules which apply to nuclear medicine examinations.

  19. Missed torsion in undescended testes detected by scintigraphy: testicular scintigraphy a decisive complementary tool.

    PubMed

    Kodali, Sunil Kumar; Abdullah, Zuhair Saleh; Sharma, Punit; Khan, Muhammad Umar; Naeem, Muhammad

    2013-01-01

    Torsion of undescended testis, although not uncommon, causes diagnostic difficulties. We here present testicular scintigraphy images of a typical case of torsion of an undescended inguinal testis with disparity between clinical and ultrasonography (USG) findings in the contralateral retractile testis.

  20. [In vitro platelet production].

    PubMed

    Dunois-Lardé, C; Baruch, D

    2011-04-01

    This review aims at presenting a state of the art on platelet functions, not only in well-characterized hemostasis and thrombosis, but also in various domains such as inflammation, immunity, angiogenesis, source of growth factors, metastasis and vascular remodelling. This multivalent phenotype of platelets suggests new potential applications of platelets. The second objective is to present new advances in platelet formation from megakaryocytes and direct platelet release, as initially shown by our group and more recently by others.

  1. Myocardial perfusion scintigraphy: the evidence

    PubMed Central

    Anagnostopoulos, C.; Cerqueira, M.; Ell, P. J.; Flint, E. J.; Harbinson, M.; Kelion, A. D.; Al-Mohammad, A.; Prvulovich, E. M.; Shaw, L. J.; Tweddel, A. C.

    2003-01-01

    This review summarises the evidence for the role of myocardial perfusion scintigraphy (MPS) in patients with known or suspected coronary artery disease. It is the product of a consensus conference organised by the British Cardiac Society, the British Nuclear Cardiology Society and the British Nuclear Medicine Society and is endorsed by the Royal College of Physicians of London and the Royal College of Radiologists. It was used to inform the UK National Institute of Clinical Excellence in their appraisal of MPS in patients with chest pain and myocardial infarction. MPS is a well-established, non-invasive imaging technique with a large body of evidence to support its effectiveness in the diagnosis and management of angina and myocardial infarction. It is more accurate than the exercise ECG in detecting myocardial ischaemia and it is the single most powerful technique for predicting future coronary events. The high diagnostic accuracy of MPS allows reliable risk stratification and guides the selection of patients for further interventions, such as revascularisation. This in turn allows more appropriate utilisation of resources, with the potential for both improved clinical outcomes and greater cost-effectiveness. Evidence from modelling and observational studies supports the enhanced cost-effectiveness associated with MPS use. In patients presenting with stable or acute chest pain, strategies of investigation involving MPS are more cost-effective than those not using the technique. MPS also has particular advantages over alternative techniques in the management of a number of patient subgroups, including women, the elderly and those with diabetes, and its use will have a favourable impact on cost-effectiveness in these groups. MPS is already an integral part of many clinical guidelines for the investigation and management of angina and myocardial infarction. However, the technique is underutilised in the UK, as judged by the inappropriately long waiting times and by

  2. [Osteoarticular scintigraphy in comparison with clinical evidence].

    PubMed

    del Puente, Antonio; Venditti, Carlo; Peluso, Rosario; Esposito, Antonella; Cimmino, Michele; De Luca Bossa, Rosa; Loi, Gabriella; Spanò, Angelo; Oriente, Alfonso; Oriente, Pasquale

    2003-01-01

    Bone scintigraphy is a technique which is often resorted to in diagnostic rheumatology. There are few data on the effective relevance of bone scintigraphy in the evaluation of chronic inflammatory diseases of the joints. The aim of this study was to compare the results of bone scintigraphy with clinical evidence in patients with rheumatoid arthritis or osteoarthritis. Seventy-five patients were submitted to total body bone scintigraphy (44 rheumatoid arthritis, 31 osteoarthritis). The nuclear medicine specialist indicated the list of joints showing uptake. For the same patients a rheumatologist indicated the number of affected joints. The laboratory and clinical data were recorded. The patients were first stratified according to the prevalence of the clinical evidence and scintigraphic uptake. The distribution was found to be not significant. Only 5.3% of patients showed no uptake. Thirty-three patients had no clinical evidence of disease; among these, 30 showed joint uptake. Considering only the patients with clinical evidence, 97.6% showed joint uptake. These results were confirmed even when the data were analyzed by sex, disease and therapy. Considering the patients with clinical evidence, the uptake/clinical ratio did not show any significant correlation. The number of joints with clinical evidence correlated with the erythrocyte sedimentation rate. The number of joints showing uptake correlated only with age. In conclusion, on average, scintigraphy, performed in patients with rheumatoid arthritis and osteoarthritis, highlights a significantly higher number of joints involved as compared to what would be expected on the basis of clinical evaluation. It remains to be defined whether this is an overestimation related to the characteristics of the scan or whether it is sign of a higher sensitivity in highlighting the site of inflammation. Against the latter hypothesis is the absence of correlation with the inflammatory indexes.

  3. A role for gamma scintigraphy in cancer immunology and immunotherapy.

    PubMed

    Perkins, A C; Pimm, M V

    1992-01-01

    Facilities for radiolabelling and gamma scintigraphy are largely restricted to nuclear medicine departments or specialised research institutions and are therefore not widely available to workers in cancer research. Despite this, there is growing interest in gamma scintigraphy, which can provide information relevant to the entire field of cancer immunology. This review discusses the present and future roles of gamma scintigraphy in respect of antibody-targeted, cell-mediated and cytokine therapy. The authors aim to show that gamma scintigraphy is an investigative tool of great potential.

  4. Efficacy of thyroid scintigraphy in the diagnosis of intrathoracic goiter

    SciTech Connect

    Park, H.M.; Tarver, R.D.; Siddiqui, A.R.; Schauwecker, D.S.; Wellman, H.N.

    1987-03-01

    For evaluation of the usefulness of thyroid scintigraphy in the diagnosis of intrathoracic goiter, we analyzed the results of radionuclide thyroid scintigraphy in 54 consecutive cases with suspected upper mediastinal masses. Intrathoracic goiters were found in 42. The sensitivity, specificity, and accuracy of the scintigraphy for intrathoracic goiter were 93% (39/42), 100% (12/12), and 94% (51/54), respectively. Scintigraphic morphology, scanning technique, and pitfalls are discussed. The results show that most intrathoracic goiters do have thyroid function and that radioiodine scintigraphy is a definitive and cost-effective diagnostic procedure for this disease.

  5. Esophageal transit scintigraphy in systemic sclerosis

    PubMed Central

    Kobylecka, Małgorzata; Olesińska, Marzena

    2016-01-01

    Systemic sclerosis is a rare connective tissue disease, distinctive features of which are fibrosis and microangiopathy. The esophagus is one of the most commonly involved internal organs. Most patients experience dysphagia, difficulties in swallowing and gastro-esophageal reflux. However, in up to one third of cases, the initial onset of esophageal disease may be clinically silent. There are several diagnostic modalities available for assessing both morphological and functional abnormalities of the esophagus. If structural abnormalities are suspected, endoscopy is the method of choice. Functional evaluation is best achieved with manometry. Both endoscopy and manometry are invasive techniques, with low patient acceptance. Barium-contrast study is well tolerated, but qualitative assessment of functional abnormalities is imprecise. Esophageal scintigraphy is an easy, non-invasive, sensitive and specific diagnostic modality. It can detect esophageal dysfunction even in asymptomatic patients. In patients already diagnosed with systemic sclerosis, scintigraphy is useful in evaluating severity and progression of the disease. PMID:27994270

  6. Esophageal transit scintigraphy in systemic sclerosis.

    PubMed

    Chojnowski, Marek; Kobylecka, Małgorzata; Olesińska, Marzena

    2016-01-01

    Systemic sclerosis is a rare connective tissue disease, distinctive features of which are fibrosis and microangiopathy. The esophagus is one of the most commonly involved internal organs. Most patients experience dysphagia, difficulties in swallowing and gastro-esophageal reflux. However, in up to one third of cases, the initial onset of esophageal disease may be clinically silent. There are several diagnostic modalities available for assessing both morphological and functional abnormalities of the esophagus. If structural abnormalities are suspected, endoscopy is the method of choice. Functional evaluation is best achieved with manometry. Both endoscopy and manometry are invasive techniques, with low patient acceptance. Barium-contrast study is well tolerated, but qualitative assessment of functional abnormalities is imprecise. Esophageal scintigraphy is an easy, non-invasive, sensitive and specific diagnostic modality. It can detect esophageal dysfunction even in asymptomatic patients. In patients already diagnosed with systemic sclerosis, scintigraphy is useful in evaluating severity and progression of the disease.

  7. Musculoskeletal scintigraphy of the equine athlete.

    PubMed

    Dyson, Sue

    2014-01-01

    Nuclear scintigraphic examination of equine athletes has a potentially important role in the diagnosis of lameness or poor performance, but increased radiopharmaceutical uptake (IRU) is not necessarily synonymous with pain causing lameness. Nuclear scintigraphy is highly sensitive to changes in bone turnover that may be induced by loading and knowledge of normal patterns of RU is crucial for accurate diagnosis. Blood pool images can be useful for identification of some soft tissue injuries, although acute bone injuries may also have intense IRU in blood pool images. Some muscle injuries may be associated with IRU in bone phase images. The use of scintigraphy together with other diagnostic imaging modalities has helped us to better understand the mechanisms of some musculoskeletal injuries. In immature racehorses, stress-related bone injury is a common finding and may be multifocal, whereas in mature sport horses, a very different spectrum of injuries may be identified. False-negative results are common with some injuries.

  8. Cervical venous reflux in dynamic brain scintigraphy.

    PubMed

    Hayt, D B; Perez, L A

    1976-01-01

    Cervical venous reflux, shown by dynamic brain scintigraphy, was investigated through three avenues of approach: (A) by reviewing 371 randomly chosen routine dynamic intracerebral bloodflow studies to estimate its incidence; (B) by correlative positive-contrast superior venacavography in patients with characteristic cervical venous reflux; and (C) by performing dynamic brain scintigraphy while utilizing various positional and physiologic maneuvers to attempt to produce cervical venous reflux in patients who did not exhibit this phenomenon on earlier examination. Although any obstruction of the superior vena cava or a properly timed Valsalva maneuver in selected patients can produce the scintigraphic picture of cervical venous reflux, in most cases it is a normal phenomenon due to incompetent or absent cervical venous valves.

  9. Adenosine thallium 201 myocardial perfusion scintigraphy

    SciTech Connect

    Verani, M.S. )

    1991-07-01

    Pharmacologic coronary vasodilation as an adjunct to myocardial perfusion imaging has become increasingly important in the evaluation of patients with coronary artery disease, in view of the large number of patients who cannot perform an adequate exercise test or in whom contraindications render exercise inappropriate. Adenosine is a very potent coronary vasodilator and when combined with thallium 201 scintigraphy produces images of high quality, with the added advantages of a very short half-life (less than 10 seconds) and the ability to adjust the dose during the infusion, which may enhance safety and curtail the duration of side effects. The reported sensitivity and specificity of adenosine thallium 201 scintigraphy for the detection of coronary artery disease are high and at least comparable with imaging after exercise or dipyridamole administration. 23 refs.

  10. Role of scintigraphy in urinary tract infection

    SciTech Connect

    Conway, J.J.

    1988-10-01

    There is controversy regarding the role of radiological imaging for urinary tract infection (UTI). The gold standard has been the intravenous pyelogram (IVP). Yet, the IVP has a very limited value with only about 25% of children with pyelonephritis demonstrating abnormalities. Ultrasound (US) has recently been advocated as a replacement for the poorly sensitive and poorly specific IVP. However, comparative studies between US and IVP indicate only an equivalent sensitivity and specificity. Cortical scintigraphy with Technetium-99m glucoheptonate (99mTc GH) or 99mTc dimercaptosuccinic acid (99mTc DMSA) has also been advocated as a means of differentiating parenchymal (pyelonephritis) from nonparenchymal (lower UTI) involvement in UTI. The clinical presentation may be misleading especially in the infant and child in whom an elevated temperature, flank pain, shaking chills, or an elevated sedimentation rate are often lacking. The clinician attempts to localize the site of infection for it has a direct bearing upon the therapy. A collecting system infection can often be eradicated with a single oral dose of an appropriate antibiotic, whereas renal parenchymal involvement requires IV therapy for an extended interval. Cortical scintigraphy can localize the site of infection with a high degree of accuracy. Recent studies report a sensitivity of 86% and specificity of 81% of pyelonephritis. This is in contrast to the IVP with a sensitivity of only 24% and US with a sensitivity of only 42%. The scintigraphic appearance of parenchymal infection of the kidney is a spectrum of minimal to gross defects reflecting the degree of histologic involvement that spans from a mild infection to frank abscess. Cortical scintigraphy can be used to monitor the evolution of scarring following infection. Cortical scintigraphy with 99mTc DMSA or 99mTc GH is the method of choice for the initial evaluation of UTI. 37 references.

  11. Bone scintigraphy in fluoride treated osteoporosis

    SciTech Connect

    Froelich, J.W.; Kleerekoper, M.; Parker, D.A.

    1985-05-01

    Quantitative bone scintigraphy was performed on 23 white females with post-menopausal osteoporosis and vertebral compression fractures. These patients were then entered into a randomized, double-blind clinical trial or sodium fluoride therapy (NaF=14, placebo=9) which included repeat bone scintigraphy every six months. Scintigraphic images were acquired for 500K counts per image over the total body with computer acquisition over the posterior thoracic and lumbar spine. Images were obtained on a wide field-of-view gamma camera two hours after injecting 15 mCi of Tc-99m MDP. Data analysis showed a significant reduction in the activity ratio of abnormal vertebral body to normal vertebral body in those patients treated with sodium fluoride (paired t-test p=0.0095). No significant change was observed in the control group of (p=0.142). These results suggest that sodium fluoride therapy promotes more rapid healing of osteoporotic vertebral fractures. They also demonstrate the utility of serial quantitative bone scintigraphy in assessing osteoporotic patients with vertebral compression fractures.

  12. The pathological basis for skeletal scintigraphy.

    PubMed

    Galasko, C S

    1975-08-01

    Skeletal scintigraphy, which has now been established as a useful and accurate method of detecting early skeletal metastases and assessing their response to treatment, has been investigated for its pathological basis. Histological examination of several hyndred necropsy specimens, from sixty-eight patients who died from malignant disease, showed a significant increase of osteoid and immature woven bone in the presence of metastatic cancer. Tumour-cell suspensions of the VX2 carcinoma were injected into the medullary cavity or on to the periosteal surface of the ilia or tibiae of New Zealand white rabbits. A combination of bone destruction and new bone formation, similar to the autopsy material, was seen. There were at least two mechanisms for the new bone production. Initially, intramembranous ossification was seen in the fibrous stroma surrounding the tumour. Once the cortex was involved and cortical bone destruction had occurred, large amounts of woven bone resembling fracture callus were laid down. The new bone had a markedly increased avidity for bone-seeking isotopes, indicating why skeletal scintigraphy was useful. A further twenty rabbits, in whose ilia the VX2 carcinoma was growing, were treated by local irradiation. When treatment was successful the tumour was destroyed, the production of new bone ceased, and the lesion lost its increased avidity for bone-seeking isotopes, indicating that skeletal scintigraphy could be used to assess the response of skeletal metastases to therapy.

  13. The omnipotent platelet.

    PubMed

    Steinberg, L A

    1996-03-01

    This information was derived from the increase in platelets of patients following fractures and/or bone surgery and in conjunction with a vast amount of published literature. The increase in numbers of platelets reflects the extent of bone involvement, especially noted in the hip, knee, post-coronary artery bypass graft, and multiple fractures. The role of the platelet in any and all tissues, i.e. soft tissue or bone, whether beneficial or detrimental, is multifunctional. The platelet responds to all physiologic and pathologic states and, if tissue involved is sufficient, the role of the platelet becomes obvious.

  14. Rhesus monkey platelets

    SciTech Connect

    Harbury, C.B.

    1986-03-01

    The purpose of this abstract is to describe the adenine nucleotide metabolism of Rhesus monkey platelets. Nucleotides are labelled with /sup 14/C-adenine and extracted with EDTA-ethanol (EE) and perchlorate (P). Total platelet ATP and ADP (TATP, TADP) is measured in the Holmsen Luciferase assay, and expressed in nanomoles/10/sup 8/ platelets. TR=TATP/TADP. Human platelets release 70% of their TADP, with a ratio of released ATP/ADP of 0.7. Rhesus platelets release 82% of their TADP, with a ratio of released ATP/ADP of 0.33. Thus, monkey platelets contain more ADP than human platelets. Thin layer chromatography of EE gives a metabolic ratio of 11 in human platelets and 10.5 in monkey platelets. Perchlorate extracts metabolic and actin bound ADP. The human and monkey platelets ratios were 5, indicating they contain the same proportion of actin. Thus, the extra ADP contained in monkey platelets is located in the secretory granules.

  15. The Platelet Proteome

    PubMed Central

    Senzel, Lisa; Gnatenko, Dmitri V.; Bahou, Wadie F.

    2010-01-01

    Purpose of review The proteome is the pool of proteins expressed at a given time and circumstance. The word “proteomics” summarizes several technologies for visualization, quantitation and identification of these proteins. Recent advances in these techniques are helping to elucidate platelet processes which are relevant to bleeding and clotting disorders, transfusion medicine and regulation of angiogenesis. Recent findings Over 1100 platelet proteins have been identified using proteomic techniques. Various subproteomes have been characterized, including platelet releasates (the “secretome”), alpha and dense granules, membrane and cytoskeletal proteins, platelet-derived microparticles, and the platelet “phosphoproteome”. Proteomic data about platelets have become increasingly available in integrated databases. Summary Proteomic experiments in resting and activated platelets have identified novel signaling pathways and secreted proteins which may represent therapeutic targets, as well as potential cancer biomarkers. PMID:19550320

  16. [Renal scintigraphy with 99mTc-penicillamine].

    PubMed

    Lichte, H; Hör, G

    1975-02-01

    By application of 99mTc-Penicillamine in renal scintigraphy excellent scintigraphies of the kidneys, especially by using the gamma-camera, can be obtained, even in case of damaged renal function, up to an increase of creatinine in serum of about 7 mg %.

  17. Platelets: handle with care.

    PubMed

    Thomas, S

    2016-10-01

    Platelets are delicate cells that require careful handling between collection, preparation and transfusion. This review addresses practical questions relating to platelet concentration, resting time after collection, total time and number of periods without agitation and temperature. The bags in which platelets are stored are made from gas-permeable plastic to allow sufficient oxygen for the platelets to maintain aerobic respiration. Manufacturers have assigned limits for platelet content and concentration, and these must not be exceeded. There is no strong evidence for or against the resting of platelets post-collection and pre-agitation, but platelets should not be over-wrapped during this period as this compromises gas exchange; a short rest period of up to 1 h may allow the separation of minor aggregates. It is necessary to transport platelet concentrates (e.g. from manufacturing site to hospital), but these periods without gas exchange must be limited to avoid excessive damage to the platelets. Current data support a total of 24 h of transportation per component but with no individual period lasting more than 8 h. Platelets need to be stored at 20-24 °C based on evidence that colder storage leads to irreversible changes on the platelet membrane, resulting in phagocytosis of the platelets following transfusion. Storage at warmer temperatures may lead to an increase in bacterial risk. On the basis of this review, the UK Guidelines for Blood Transfusion Services have been updated to ensure that platelets are handled in the most appropriate way to ensure that efficacious components are provided for patients.

  18. Diuretic renal scintigraphy in normal cats.

    PubMed

    Hecht, Silke; Lane, India F; Daniel, Gregory B; Morandi, Federica; Sharp, Dorothy E

    2008-01-01

    The purpose of this study was to develop a protocol for diuretic renal scintigraphy (renography) in cats and describe normal findings. 99mTc-DTPA renal scintigraphy was performed twice in 10 healthy cats. Furosemide or saline were injected 4.5 min after radiopharmaceutical administration for the diuretic or control scan, respectively. A dynamic acquisition was performed for 8 min. The following parameters were evaluated: (1) global and individual glomerular filtration rate (GFR); (2) shape of the time-activity curve (TAC); (3) time of peak (TOP); (4) individual kidney excretion half-time (T1/2) of the radiopharmaceutical; (5) percentage of maximum activity measured at the end of the study. Global GFR in the control studies (2.79 +/- 0.83 ml/min/kg, mean +/- SD) did not differ significantly from the diuretic scans (2.34 +/- 0.51 ml/min/kg). The shape of most (16/ 20) TAC of diuretic renograms was similar to those of control renograms. The TOP of the diuretic renogram curves was 3.06 +/- 0.58 min, and did not differ from that of the control scans (3.01 +/- 0.61 min). T1/2 of the diuretic renograms was significantly shorter (5.15 +/- 0.83 min) than that of the control renograms (6.31 +/- 1.50 min). A significantly lower percentage of maximum activity was present at the end of the study in diuretic renograms (median: 47.25%; range: 33.60-59.60%) compared with control renograms (63.40%; 30.00-69.40%). Diuretic renal scintigraphy is a noninvasive and fast procedure to perform in cats. The applicability of this technique needs to be investigated in patients with significantly impaired renal function and obstructive uropathies.

  19. Cat-scratch disease and bone scintigraphy.

    PubMed

    Ismaili-Alaoui, Nadia; Vuong, Valerie; Marcu-Marin, M; Sergent-Alaoui, Aline; Chevallier, Bertrand; de Labriolle-Vaylet, Claire

    2012-08-01

    Cat-scratch disease is a bacterial infection caused by Bartonella henselae. Bone involvement is rare. We describe the case of a 7-year-old boy with a systemic form of the disease. He presented with a 15-day history of fever, altered general condition, weight loss and cough, associated with back pain, and right-sided coxalgia. Bone scintigraphy with Tc-99m hydroxymethylene diphosphonate showed spinal involvement, the iliac crest, the right ankle, and the right first metatarsal. Magnetic resonance imaging confirmed these locations. He was positive for anti-Bartonella henselae. The fever regressed before treatment with rifampicin began, and he made a full recovery.

  20. Renal scintigraphy in the acute care setting.

    PubMed

    Sfakianaki, Efrosyni; Sfakianakis, George N; Georgiou, Mike; Hsiao, Bernard

    2013-03-01

    Renal scintigraphy is a powerful imaging method that provides both functional and anatomic information, which is particularly useful in the acute care setting. In our institution, for the past 2 decades, we have used a 25-minute renal diuretic protocol, technetium-99m ((99m)Tc) mercaptoacetyltriglycine with simultaneous intravenous injection of furosemide, for all ages and indications, including both native and transplant kidneys. As such, this protocol has been widely used in the workup of acutely ill patients. In this setting, there are common clinical entities which affect patients with native and transplant kidneys. In adult patients with native kidneys one of the most frequent reasons for emergency room visits is renal colic due to urolithiasis. Although unenhanced computed tomography is useful to assess the anatomy in cases of renal colic, it does not provide functional information. Time zero furosemide renal scintigraphy can do both and we have shown that it can effectively stratify patients with renal colic. To this end, 4 characteristic patterns of scintirenography have been identified, standardized, and consistently applied: no obstruction, partial obstruction (mild vs high grade), complete obstruction, and stunned (postdecompressed) kidney. With the extensive use of this protocol over the past 2 decades, a pattern of "regional parenchymal dysfunction" indicative of acute pyelonephritis has also been delineated. This information has proved to be useful for patients presenting with urinary tract infection and suspected pyelonephritis, as well as for patients who were referred for workup of renal colic but were found to have acute pyelonephritis instead. In instances of abdominal trauma, renal scintigraphy is uniquely suited to identify urine leaks. This is also true in cases of suspected leak following renal transplant or from other iatrogenic/postsurgical causes. Patients presenting with acute renal failure can be evaluated with renal scintigraphy. A

  1. Detection of gastrointestinal bleeding by radionuclide scintigraphy

    SciTech Connect

    Gupta, S.; Luna, E.; Kingsley, S.; Prince, M.; Herrera, N.

    1984-01-01

    Scanning with Technetium /sup 99m/ labeled autologous red blood cells was performed in 59 patients with clinical suspicion of acute and/or intermittent, chronic gastrointestinal bleeding. In 36 patients (61%), a definite site of bleeding could be demonstrated. A strong correlation with other modalities such as upper and lower gastrointestinal endoscopy, contrast angiography, and surgical exploration was found. Overall sensitivity of the procedure was 91%; specificity 100% and accuracy 93.3%. It is suggested that radionuclide scintigraphy provides a completely noninvasive, simple, and sensitive procedure which may be routinely used for the detection and localization of gastrointestinal bleeding.

  2. Platelet deposition at angioplasty sites and its relation to restenosis in human iliac and femoropopliteal arteries

    SciTech Connect

    Minar, E.; Ehringer, H.; Ahmadi, R.; Dudczak, R.; Leitha, T.; Koppensteiner, R.; Jung, M.; Stuempflen, A.

    1989-03-01

    The amount and time course of platelet accumulation at angioplasty sites and influence of these platelets on restenosis after percutaneous transluminal angioplasty (PTA) in peripheral arteries were determined in 92 patients, who received either a high or low dose of aspirin. Platelet deposition was quantitated by means of dual-radiotracer scintigraphy and calculation of a platelet accumulation index (PAI). The PAI was higher (P less than .05) 4-6 hours after PTA compared with that on subsequent days. There was a trend toward greater platelet accumulation in vessels with extensive dissection. Platelet accumulation at the PTA site occurred with both doses of aspirin, with no differences between the two dosage groups. Twenty-one of 67 patients who underwent PTA in the femoropopliteal segment developed restenosis during a median follow-up of 14 months. The median PAI at 4-6 and 22-24 hours after PTA was significantly less in these 21 patients than in the 46 without restenosis. The data suggest that use of antiplatelet agents to prevent platelet deposition after PTA may not be useful for prevention of restenosis.

  3. Endotoxin Interactions with Platelets

    DTIC Science & Technology

    1985-01-01

    irreversible aggregation of human platelets (Hamberg and Sainuelsson 1974; Hlamberg et al 1975). Acetylsalicylic acid , an inhibitor of cyclooxygenase aud...exposure to endotoxin (100 ttg/nil). To simulate the lipopolysac- charide of endotoxin, several different fatty acids were added individually to platelet...platelet lytic capability. Similarity, iflegaradt doses of ganima radiation 6wCo destroy fatty acid groups on lipid A (L. Bertok, personal communication

  4. Functional fractionation of platelets.

    PubMed

    Haver, V M; Gear, A R

    1981-02-01

    Studies of platelet populations suggest that they are heterogeneous in size, age, and metabolic parameters. In an attempt to correlate these parameters with efficiency of aggregation, a new technique, functional fractionation, was developed. Platelet populations are separated by their differential reactivity to aggregating agents. For example, low doses of ADP (0.1 to 0.7 microM) are added to stirred PRP, after which gentle centrifugation is used to remove aggregates from single unreacted platelets. The loose aggregates can be readily dispersed for comparison of the physical or biochemical properties of the reacted versus unreacted platelets. It was found that reactive platelets were larger (6.5 micrometer3) than unreacted platelets (5.51 micrometer3). No significant difference in density existed between the two populations, and no release of [14C]serotonin from prelabeled platelets occurred during functional fractionation. Scanning and transmission electron microscopy confirmed the size difference and revealed that in both populations platelets were structurally intact with a normal discoid shape and no significant difference in organelle content. Human platelets most reactive to ADP were also enriched in glycogen (3.6-fold), ATP (1.6-fold), and ADP (twofold), compared with less reactive cells. These "reactive" cells took up more 51[Cr] and contained 1.9 times more surface sialic acid. In an in vivo aging experiment, rats were injected with 75[Se]methionine. Shortly after labeling (1 day), the most reactive platelets possessed the highest amount of 75[Se]. These results reveal that functionally active platelets, which are also larger, are more active metabolically than less reactive platelets, possess a higher negative surface charge, and may be a younger population.

  5. Platelet size in man.

    PubMed

    Paulus, J M

    1975-09-01

    The shape and parameters of platelet size distributions were studied in 50 normal persons and 97 patients in order to test the proposed thesis that platelet size heterogeneity results mainly from aging in the circulation. This thesis was contradicted (1) by size distributions of age-homogeneous, newly-born cell populations which were lognormal with increased (instead of decreased) dispersion of volumes and (2) by the macrothrombocytosis found in some populations with normal age distribution. For these reasons, thrombocytopoiesis appeared to play the major role in determining platelet size. A model was built in which the volume variation of platelet territories due to megakaryocyte growth and membrane demarcation at each step of maturation was a random proportion of the previous value of the volume. This model explains the lognormal shape of both newborn and circulating platelet size distributions. It also implies that (1) the mean and standard deviation of platelet logvolumes depend on the rates of volume change of the individual platelet territories (growth rate minus demarcation rate) as well as on megakaryocyte maturation time; (2) platelet hyperdestruction causes an increase in the mean and dispersion of the rates of territory volume change; (3) Mediterranean macrothrombocytosis and some hereditary macrothrombocytotic thrombocytopenias or dysthrombocytopoieses reflect a diminished rate of territory demarcation, and (4) platelet size heterogeneity is caused mainly by the variations in territory growth and demarcation and not by aging in the circulation.

  6. Platelets enhance neutrophil transendothelial migration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Platelets are increasingly recognized as important mediators of inflammation in addition to thrombosis. While platelets have been shown to promote neutrophil (PMN) adhesion to endothelium in various inflammatory models, it is unclear whether platelets enhance neutrophil transmigration across inflame...

  7. Platelet additive solution - electrolytes.

    PubMed

    Azuma, Hiroshi; Hirayama, Junichi; Akino, Mitsuaki; Ikeda, Hisami

    2011-06-01

    Recent attention to solutions that replace most or all plasma in platelet concentrates, while maintaining satisfactory platelet function, is motivated by the potential of plasma reduction or depletion to mitigate various transfusion-related adverse events. This report considers the electrolytic composition of previously described platelet additive solutions, in order to draw general conclusions about what is required for platelet function and longevity. The optimal concentrations of Na(+) and Cl(-) are 69-115 mM. The presence of both K(+) and Mg(2+) in platelet suspension at nearly physiological concentrations (3-5mM and 1.5-3mM, respectively) is indispensable for good preservation capacity because both electrolytes are required to prevent platelet activation. In contrast to K(+) and Mg(2+), Ca(2+) may not be important because no free Ca(2+) is available in M-sol, which showed excellent platelet preservation capacity at less than 5% plasma concentration. The importance of bicarbonate (approximately 40 mM) can be recognized when the platelets are suspended in additive solution under less than 5% residual plasma concentration.

  8. Platelet Function Tests.

    PubMed

    Lordkipanidzé, Marie

    2016-04-01

    Traditionally developed for diagnosis of bleeding disorders, platelet function assays have become increasingly used in basic research on platelet physiology, in phenotype-genotype associations in bleeding disorders, in drug development as surrogate endpoints of efficacy of new antiplatelet therapy, and to an extent, in the monitoring of antiplatelet therapy in clinical practice to predict thrombotic and bleeding risk. A multiplicity of platelet function assays is available to measure the level of platelet activity in various settings. These include assays that are restricted to a specialized laboratory as well as point-of-care instruments meant to investigate platelet function at patient bedside. Unlike tests that determine a defined quantity or measurement of a clinical biomarker (e.g., cholesterol or blood pressure), platelet function testing assesses the dynamics of living cells, which immediately presents a series of unique problems to any laboratory or clinic. This article presents currently used platelet function assays and discusses important variables to take into account when performing these assays, including preanalytical issues and difficulties in interpreting platelet function test results.

  9. Alloimmune refractoriness to platelet transfusions.

    PubMed

    Sandler, S G

    1997-11-01

    Patients who are transfused on multiple occasions with red cells or platelets may develop platelet-reactive alloantibodies and experience decreased clinical responsiveness to platelet transfusion. This situation, conventionally described as "refractoriness to platelet transfusions," is defined by an unsatisfactory low post-transfusion platelet count increment. If antibodies to HLAs are detected, improved clinical outcomes may result from transfusions of HLA-matched or donor-recipient cross-matched platelets. Because refractoriness is an expected, frequently occurring phenomenon, prevention of HLA alloimmunization is an important management strategy. Prevention strategies include efforts to decrease the number of transfusions, filtration of cellular components to reduce the number of HLA-bearing leukocytes, or pretransfusion ultraviolet B irradiation of cellular components to decrease their immunogenicity. Other investigational approaches include reducing the expression of HLAs on transfused platelets, inducing a transient reticuloendothelial system blockade by infusions of specialized immunoglobulin products, or transfusing semisynthetic platelet substitutes (thromboerythrocytes, thrombospheres) or modified platelets (infusible platelet membranes, lyophilized platelets).

  10. The sticky platelet syndrome.

    PubMed

    Moncada, Benjamín; Ruíz-Arguelles, Guillermo J; Castillo-Martínez, Claudio

    2013-07-01

    The sticky platelets syndrome (SPS) is a procoagulant condition based on either arterial, venous, or capillary thrombi caused by hyperesponsive and hyperaggregable platelets. This is a frequent disease, which often remains clinically inapparent, until stressful events or combination with other factors increase the risk of developing SPS. The condition is due to a congenital platelet defect with autosomal dominant characteristics, leading to the increased platelet aggregability when they are challenged with epinephrine and adenosine diphosphate. Nowadays classification of this disorder is based on platelet reactivity to both ADP and epinephrine (SPS type 1), epinephrine alone (SPS type 2), and ADP alone (SPS type 3). The diagnoses of the syndrome depend on the functional aggregometer assay. This condition should be taken into account whenever a patient with thrombophilia is considered.

  11. Cisplatin triggers platelet activation.

    PubMed

    Togna, G I; Togna, A R; Franconi, M; Caprino, L

    2000-09-01

    Clinical observations suggest that anticancer drugs could contribute to the thrombotic complications of malignancy in treated patients. Thrombotic microangiopathy, myocardial infarction, and cerebrovascular thrombotic events have been reported for cisplatin, a drug widely used in the treatment of many solid tumours. The aim of this study is to explore in vitro cisplatin effect on human platelet reactivity in order to define the potentially active role of platelets in the pathogenesis of cisplatin-induced thrombotic complications. Our results demonstrate that cisplatin increases human platelet reactivity (onset of platelet aggregation wave and thromboxane production) to non-aggregating concentrations of the agonists involving arachidonic acid metabolism. Direct or indirect activation of platelet phospholipase A(2) appears to be implicated. This finding contributes to a better understanding of the pathogenesis of thrombotic complications occurring during cisplatin-based chemotherapy.

  12. Primary pericardial mesothelioma detected by gallium-67 scintigraphy

    SciTech Connect

    Nishikimi, T.; Ochi, H.; Hirota, K.; Ikuno, Y.; Oku, H.; Takeuchi, K.; Takeda, T.

    1987-07-01

    We present a case report of a 73-yr-old woman with progressive systemic sclerosis who showed extensive pericardial uptake of /sup 67/Ga by scintigraphy. At autopsy, primary pericardial mesothelioma was found.

  13. Platelet-collagen adhesion enhances platelet aggregation induced by binding of VWF to platelets

    SciTech Connect

    Laduca, F.M.; Bell, W.R.; Bettigole, R.E. State Univ. of New York, Buffalo )

    1987-11-01

    Ristocetin-induced platelet aggregation (RIPA) was evaluated in the presence of platelet-collagen adhesion. RIPA of normal donor platelet-rich plasma (PRP) demonstrated a primary wave of aggregation mediated by the binding of von Willebrand factor (VWF) to platelets and a secondary aggregation wave, due to a platelet-release reaction, initiated by VWF-platelet binding and inhibitable by acetylsalicylic acid (ASA). An enhanced RIPA was observed in PRP samples to which collagen had been previously added. These subthreshold concentrations of collagen, which by themselves were insufficient to induce aggregation, caused measurable platelet-collagen adhesion. Subthreshold collagen did not cause microplatelet aggregation, platelet release of ({sup 3}H)serotonin, or alter the dose-responsive binding of {sup 125}I-labeled VWF to platelets, which occurred with increasing ristocetin concentrations. However, ASA inhibition of the platelet release reaction prevented collagen-enhanced RIPA. These results demonstrate that platelet-collagen adhesion altered the platelet-release reaction induced by the binding of VWF to platelets causing a platelet-release reaction at a level of VWF-platelet binding not normally initiating a secondary aggregation. These findings suggest that platelet-collagen adhesion enhances platelet function mediated by VWF.

  14. Pathogen-Reduced, Platelet Additive Solution, Extended Stored Platelets (PREPS)

    DTIC Science & Technology

    2015-10-01

    trauma patients. References: 1. Slichter SJ, Harker LA. Preparation and storage of platelet concentrates . II. Storage variables influencing ...Storage variables influencing platelet viability and function. Br J Haematol 1976;34(3):403-419. 2. Becker GA, Tuccelli M, Kunicki T, et al. Studies of...platelet additive solution (PAS) to extend the life of stored platelets. Our project also aims to determine how long acceptable platelet viability can be

  15. Quantitative planar imaging in renal scintigraphy

    NASA Astrophysics Data System (ADS)

    Lárraga, J. M.; Martínez-Dávalos, A.; Martínez-Duncker, C.; Rodríguez, R. Herrera

    2002-08-01

    In this work we show the results of the implementation of the double energy window method (DEW) to correct for scatter and geometric mean of opposite image to correct for attenuation of radiation within the patient for absolute quantification of radiotracer in renal scintigraphy studies. We show that DEW method subestimates the scatter radiation within main energy window and that result in a 11% of maximun error for the determination of true activity of a renal kidney phantom. Moreover, in order to avoid transmission scans of patients we perform a Monte Carlo simulation (MC) for the determination of scatter component of the main energy window. The results of the MC simulation was validated with experimental data of emission studies.

  16. Radionuclide bone scintigraphy in sports injuries.

    PubMed

    Van der Wall, Hans; Lee, Allen; Magee, Michael; Frater, Clayton; Wijesinghe, Harindu; Kannangara, Siri

    2010-01-01

    Bone scintigraphy is one of the mainstays of molecular imaging. It has retained its relevance in the imaging of acute and chronic trauma and sporting injuries in particular. The basic reasons for its longevity are the high lesional conspicuity and technological changes in gamma camera design. The implementation of hybrid imaging devices with computed tomography scanners colocated with the gamma camera has revolutionized the technique by allowing a host of improvements in spatial resolution and anatomical registration. Both bone and soft-tissue lesions can be visualized and identified with greater and more convincing accuracy. The additional benefit of detecting injury before anatomical changes in high-level athletes has cost and performance advantages over other imaging modalities. The applications of the new imaging techniques will be illustrated in the setting of bone and soft-tissue trauma arising from sporting injuries.

  17. Cerebral scintigraphy--the phoenix rises again.

    PubMed Central

    Shepstone, B. J.

    1988-01-01

    This paper reviews the development of cerebral scintigraphy from its early days of planar imaging with simple technetium-99m labelled compounds to the recent revival of the technique in the form of positron-emission and single-photon emission tomography. A short explanation of instrumentation and radiopharmaceuticals is given as a prelude to a description of both techniques in normal and pathological situations. Particular emphasis is placed on the more readily-available single-photon emission-tomographic techniques using labelled amines in the functional investigation of disorders not readily diagnosed by computed tomography. Images Figure 2(a) Figure 3 Figure 4 Figure 5 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 PMID:3047720

  18. Platelet interaction with polymerizing fibrin.

    PubMed

    Niewiarowski, S; Regoeczi, E; Stewart, G J; Senyl, A F; Mustard, J F

    1972-03-01

    Interaction of washed pig, rabbit, or human platelets with fibrinogen was studied during its transition to fibrin using photometric, isotopic, and electron microscopic techniques. Untreated fibrinogen and fully polymerized fibrin had no detectable effect on platelets. Fibrinogen, incubated with low concentrations of reptilase or thrombin, formed intermediate products which readily became associated with platelets and caused their aggregation. Neutralization of the thrombin did not prevent this interaction. In the absence of fibrinogen, reptilase did not affect platelets. The interaction of polymerizing fibrin with platelets was accompanied by small losses of platelet constituents (serotonin, adenine nucleotides, platelet factor 4, and lactic dehydrogenase). This loss did not appear to be the result of the platelet release reaction. Inhibitors of the release reaction or of adenosine diphosphate (ADP)-induced aggregation did not prevent the interaction of platelets with polymerizing fibrin. Apyrase or prostaglandin E(1) (PGE(1)) reduced the extent of platelet aggregation by polymerizing fibrin, but the amount of protein associated with platelets was slightly increased. The interaction of polymerizing fibrin with platelets was completely inhibited by ethylenediaminetetraacetate (EDTA) or ethylene glycol bis (beta-aminoethyl ether) N, N,N',N'-tetraacetic acid (EGTA).Fibers formed in solutions of polymerizing fibrin were larger in the presence than in the absence of washed platelets, suggesting that platelets affect fibrin polymerization. The adherence of platelets to polymerizing fibrin may be responsible for the establishment of links between platelets and fibrin in hemostatic plugs and thrombi.

  19. Gallium 67 scintigraphy in glomerular disease

    SciTech Connect

    Bakir, A.A.; Lopez-Majano, V.; Levy, P.S.; Rhee, H.L.; Dunea, G.

    1988-12-01

    To evaluate the diagnostic usefulness of gallium 67 scintigraphy in glomerular disease, 45 patients with various glomerulopathies, excluding lupus nephritis and renal vasculitis, were studied. Persistent renal visualization 48 hours after the gallium injection, a positive scintigram, was graded as + (less than), ++ (equal to), and +++ (greater than) the hepatic uptake. Positive scintigrams were seen in ten of 16 cases of focal segmental glomerulosclerosis, six of 11 cases of proliferative glomerulonephritis, and one case of minimal change, and one of two cases of membranous nephropathy; also in three of six cases of sickle glomerulopathy, two cases of diabetic neuropathy, one of two cases of amyloidosis, and one case of mild chronic allograft rejection. The 25 patients with positive scans were younger than the 20 with negative scans (31 +/- 12 v 42 +/- 17 years; P less than 0.01), and exhibited greater proteinuria (8.19 +/- 7.96 v 2.9 +/- 2.3 S/d; P less than 0.01) and lower serum creatinine values (2 +/- 2 v 4.1 +/- 2.8 mg/dL; P less than 0.01). The amount of proteinuria correlated directly with the intensity grade of the gallium image (P less than 0.02), but there was no correlation between the biopsy diagnosis and the outcome of the gallium scan. It was concluded that gallium scintigraphy is not useful in the differential diagnosis of the glomerular diseases under discussion. Younger patients with good renal function and heavy proteinuria are likely to have a positive renal scintigram regardless of the underlying glomerulopathy.

  20. Platelet Adhesion under Flow

    PubMed Central

    Ruggeri, Zaverio M.

    2011-01-01

    Platelet adhesive mechanisms play a well-defined role in hemostasis and thrombosis, but evidence continues to emerge for a relevant contribution to other pathophysiological processes including inflammation, immune-mediated responses to microbial and viral pathogens, and cancer metastasis. Hemostasis and thrombosis are related aspects of the response to vascular injury, but the former protects from bleeding after trauma while the latter is a disease mechanism. In either situation, adhesive interactions mediated by specific membrane receptors support the initial attachment of single platelets to cellular and extracellular matrix constituents of the vessel wall and tissues. In the subsequent steps of thrombus growth and stabilization, adhesive interactions mediate platelet to platelet cohesion (aggregation) and anchoring to the fibrin clot. A key functional aspect of platelets is their ability to circulate in a quiescent state surveying the integrity of the inner vascular surface, coupled to a prompt reaction wherever alterations are detected. In many respects, therefore, platelet adhesion to vascular wall structures, to one another or to other blood cells are facets of the same fundamental biological process. The adaptation of platelet adhesive functions to the effects of blood flow is the main focus of this review. PMID:19191170

  1. Platelets in Critical Illness.

    PubMed

    Levi, Marcel

    2016-04-01

    In patients with critical illness, thrombocytopenia is a frequent laboratory abnormality. However frequent this may occur, a low platelet count is not an epiphenomenon, but a marker with further significance. It is always important to assess the proper cause for thrombocytopenia in critically ill patients because different underlying disorders may precipitate different diagnostic and therapeutic management strategies. Platelets are part of the first-line defense of the body against bleeding; hence, thrombocytopenia may increase the risk of hemorrhage. In case of systemic inflammatory syndromes, such as the response to sepsis, disseminated intravascular platelet activation may occur. This will contribute to microvascular failure and thereby play a role in the development of organ dysfunction. Platelets are circulating blood cells that will normally not interact with the intact vessel wall but that may swiftly respond to endothelial disruption (which is often part of the pathogenesis of critical illness) by adhering to subendothelial structures, followed by interaction with each other, thereby forming a platelet aggregate. The activated platelet (phospholipid) membrane may form a suitable surface on which further coagulation activation may occur. A low platelet count is a strong and independent predictor of an adverse outcome in critically ill patients, thereby facilitating a simple and practically risk assessment in these patients and potentially guiding the use of complex or expensive treatment strategies.

  2. Limitations of indium leukocyte imaging for the diagnosis of spine infections

    SciTech Connect

    Whalen, J.L.; Brown, M.L.; McLeod, R.; Fitzgerald, R.H. Jr. )

    1991-02-01

    The usefulness of indium-111 white blood cell (WBC) scintigraphy in the detection of spine sepsis was studied in 22 patients who had open or percutaneous biopsies for microbiologic diagnosis. The indium images in 18 patients with vertebral infection were falsely negative in 15 (83%) and truly positive in 3 (17%). All four patients with negative cultures and histology had true-negative scans. The indium-111 WBC imaging results yielded a sensitivity of 17%, a specificity of 100%, and an accuracy rate of 31%. Prior antibiotic therapy was correlated with a high incidence of false-negative scans and photon-deficient indium-111 WBC uptake. The usefulness of indium-111 WBC scintigraphy for the diagnosis of vertebral infection may be limited to those patients who have not been treated with antibiotics previously.

  3. Platelet-delivered therapeutics.

    PubMed

    Lyde, R; Sabatino, D; Sullivan, S K; Poncz, M

    2015-06-01

    We have proposed that modified platelets could potentially be used to correct intrinsic platelet defects as well as for targeted delivery of therapeutic molecules to sights of vascular injury. Ectopic expression of proteins within α-granules prior to platelet activation has been achieved for several proteins, including urokinase, factor (F) VIII, and partially for FIX. Potential uses of platelet-directed therapeutics will be discussed, focusing on targeted delivery of urokinase as a thromboprophylactic agent and FVIII for the treatment of hemophilia A patients with intractable inhibitors. This presentation will discuss new strategies that may be useful in the care of patients with vascular injury as well as remaining challenges and limitations of these approaches.

  4. Platelet aggregation test

    MedlinePlus

    ... disorders Uremia (a result of kidney failure ) Von Willebrand disease (a bleeding disorder) Risks There is very little ... vasculitis Platelet count Polycythemia vera Prerenal azotemia Von Willebrand disease Review Date 1/27/2015 Updated by: Yi- ...

  5. Platelets and diabetes mellitus.

    PubMed

    Santilli, Francesca; Simeone, Paola; Liani, Rossella; Davì, Giovanni

    2015-07-01

    Platelet activation plays a key role in atherothrombosis in type 2 diabetes mellitus (T2DM) and increased in vivo platelet activation with enhanced thromboxane (TX) biosynthesis has been reported in patients with impairment of glucose metabolism even in the earlier stages of disease and in the preclinical phases. In this regards, platelets appear as addresses and players carrying and transducing metabolic derangement into vascular injury. The present review critically addresses key pathophysiological aspects including (i) hyperglycemia, glycemic variability and insulin resistance as determinants and predictors of platelet activation, (ii) inflammatory mediators derived from platelets, such as soluble CD40 ligand, soluble CD36, Dickkopf-1 and probably soluble receptor for advanced glycation-end-products (sRAGE), which expand the functional repertoire of platelets from players of hemostasis and thrombosis to powerful amplifiers of inflammation by promoting the release of cytokines and chemokines, cell activation, and cell-cell interactions; (iii) molecular mechanisms underpinning the less-than-expected antithrombotic protection by aspirin (ASA), despite regular antiplatelet prophylaxis at the standard dosing regimen, and (iv) stratification of patients deserving different antiplatelet strategies, based on the metabolic phenotype. Taken together, these pathophysiological aspects may contribute to the development of promising mechanism-based therapeutic strategies to reduce the progression of atherothrombosis in diabetic subjects.

  6. Platelets and wound healing.

    PubMed

    Nurden, Alan T; Nurden, Paquita; Sanchez, Mikel; Andia, Isabel; Anitua, Eduardo

    2008-05-01

    Platelets help prevent blood loss at sites of vascular injury. To do this, they adhere, aggregate and form a procoagulant surface favoring thrombin generation and fibrin formation. In addition, platelets express and release substances that promote tissue repair and influence processes such as angiogenesis, inflammation and the immune response. They contain large secretable pools of biologically active proteins, while newly synthesized active metabolites are also released. Although anucleate, activated platelets possess a spliceosome and can synthesize tissue factor and interleukin-1beta. The binding of secreted proteins within a developing fibrin mesh or to the extracellular matrix can create chemotactic gradients favoring the recruitment of stem cells, stimulating cell migration and differentiation, and promoting repair. The therapeutic use of platelets in a fibrin clot has a positive influence in clinical situations requiring rapid healing. Dental implant surgery, orthopaedic surgery, muscle and tendon repair, skin ulcers, hole repair in eye surgery and cardiac surgery are situations where the use of autologous platelets accelerates healing. We now review the ways in which platelets participate in these processes.

  7. Nitric oxide released from activated platelets inhibits platelet recruitment.

    PubMed Central

    Freedman, J E; Loscalzo, J; Barnard, M R; Alpert, C; Keaney, J F; Michelson, A D

    1997-01-01

    Vessel injury and thrombus formation are the cause of most ischemic coronary syndromes and, in this setting, activated platelets stimulate platelet recruitment to the growing thrombus. Recently, a constitutive nitric oxide synthase (NOS) has been identified in human platelets. To further define the capacity of platelets to produce nitric oxide (NO), as well as to study the role of this NO in platelet recruitment, we adapted a NO-selective microelectrode for use in a standard platelet aggregometer, thereby permitting simultaneous measurement of platelet aggregation and NO production. Treatment of platelets with the NO synthase inhibitor -NG-nitroarginine methyl ester (L-NAME), reduced NO production by 92+/-8% in response to 5 microM ADP compared to control but increased aggregation by only 15+/-2%. In contrast, L-NAME had a more pronounced effect on platelet recruitment as evidenced by a 35+/-5% increase in the extent of aggregation, a 33+/-3% decrease in cyclic GMP content, and a 31+/-5% increase in serotonin release from a second recruitable population of platelets added to stimulated platelets at the peak of NO production. To study platelet recruitment accurately, we developed an assay that monitors two platelet populations simultaneously. Nonbiotinylated platelets were incubated with L-NAME or vehicle and activated with ADP. At peak NO production, biotinylated platelets were added. As measured by three-color flow cytometry, there was a 56+/-11% increase in the number of P selectin- positive platelets in the nonbiotinylated population treated with L-NAME as compared to control. When biotinylated platelets were added to the L-NAME-treated nonbiotinylated population, the number of P selectin positive biotinylated plate-lets increased by 180+/-32% as compared to biotinylated platelets added to the control. In summary, stimulated platelets produce NO that modestly inhibits platelet activation but markedly inhibits additional platelet recruitment. These data suggest

  8. Platelet preservation: agitation and containers.

    PubMed

    van der Meer, Pieter F; de Korte, Dirk

    2011-06-01

    For platelets to maintain their in vitro quality and in vivo effectiveness, they need to be stored at room temperature with gentle agitation in gas-permeable containers. The mode of agitation affects the quality of the platelets, and a gentle method of agitation, either a circular or a flat bed movement, provides the best results. Tumblers or elliptical agitators induce platelet activation and subsequent damage. As long as the platelets remain in suspension, the agitation speed is not important. Agitation of the platelet concentrates ensures that the platelets are continuously oxygenated, that sufficient oxygen can enter the storage container and that excess carbon dioxide can be expelled. During transportation of platelet concentrates, nowadays over long distances where they are held without controlled agitation, platelets may tolerate a certain period without agitation. However, evidence is accumulating that during the time without agitation, local hypoxia surrounding the platelets may induce irreversible harm to the platelets. Over the decades, more gas-permeable plastics have been used to manufacture platelet containers. The use of different plastics and their influence on the platelet quality both in vitro and in vivo is discussed. The improved gas-permeability has allowed the extension of platelet storage from 3 days in the early 1980s, to currently at least 7 days. In the light of new developments, particularly the introduction of pathogen reduction techniques, the use of platelet additive solutions and the availability of improved automated separators, further (renewed) research in this area is warranted.

  9. Renal scintigraphy following angiotensin converting enzyme inhibition in the diagnosis of renovascular hypertension (captopril scintigraphy)

    SciTech Connect

    Sfakianakis, G.N. )

    1989-09-01

    This article describes the pathophysiology and primary causes of renovascular hypertension (RVH). No historical or physical finding is specific in the diagnosis of RVH, although onset of hypertension before the age of 30 years may suggest the possible presence of RVH. The physiology of the kidney is described along with the biochemistry of angiotensin converting enzyme inhibitors. The main thrust of the article is nuclear medicine techniques useful in the diagnosis of this disease. Several diagnositic methods are described but captopril scintigraphy is presented as a method that may give more optimal results in the diagnosis of RVH.

  10. Giant Platelets in Platelet Donors – A Blessing in Disguise?

    PubMed Central

    Choudhury, Nabajyoti; Ray, Deepanjan

    2015-01-01

    Introduction Inherited thrombocytopenias, including inherited giant platelet disorders (IGPD) are relatively rare, but their prevalence is probably underestimated. Harris platelet syndrome, the most common IGPD reported from Indian subcontinent, mostly from eastern part, is characterised by a low platelet count, high mean platelet volume (MPV) and absence of bleeding. Aim A short study was conducted to assess the prevalence of giant platelets in voluntary donors of single donor platelets (SDP) and analyse the effect of transfusion of such SDPs in patients. Materials and Methods Voluntary donors of SDPs were screened as per standard guidelines prior to the procedure. A complete blood count (including MPV) along with a peripheral smear was done. A total of 45 donors were screened for plateletpheresis. Following plateletpheresis from these donors, a platelet count from the collection bag was done after one hour. The SDP was transfused as a single unit or divided into two and transfused to the same patient at two different occasions, as per clinical need. Platelet counts on pateints were done after one hour and the platelet recovery was noted. Results Out of the 45 donors who were screened, 30 (66.67%) were found to have giant platelets. It was observed that the pre procedure platelet counts in donors having giant platelets were relatively low (1.5 -1.7 lacs) and so also the platelet yield (2.7-3x1011) compared to donors who did not, but the post transfusion platelet recovery was greater. Conclusion Since presence of giant platelets has been seen to be common in the Eastern part of India, a peripheral smear examination should always be considered during screening of plateletpheresis donors to avoid rejecting donors with giant platelets whose platelet counts are given falsely low by autoanalysers. PMID:26266124

  11. Platelets and platelet-like particles mediate intercellular RNA transfer

    PubMed Central

    Risitano, Antonina; Beaulieu, Lea M.; Vitseva, Olga

    2012-01-01

    The role of platelets in hemostasis and thrombosis is clearly established; however, the mechanisms by which platelets mediate inflammatory and immune pathways are less well understood. Platelets interact and modulate the function of blood and vascular cells by releasing bioactive molecules. Although the platelet is anucleate, it contains transcripts that may mirror disease. Platelet mRNA is only associated with low-level protein translation; however, platelets have a unique membrane structure allowing for the passage of small molecules, leading to the possibility that its cytoplasmic RNA may be passed to nucleated cells. To examine this question, platelet-like particles with labeled RNA were cocultured with vascular cells. Coculture of platelet-like particles with activated THP-1, monocytic, and endothelial cells led to visual and functional RNA transfer. Posttransfer microarray gene expression analysis of THP-1 cells showed an increase in HBG1/HBG2 and HBA1/HBA2 expression that was directly related to the transfer. Infusion of wild-type platelets into a TLR2-deficient mouse model established in vivo confirmation of select platelet RNA transfer to leukocytes. By specifically transferring green fluorescent protein, we also observed external RNA was functional in the recipient cells. The observation that platelets possess the capacity to transfer cytosolic RNA suggests a new function for platelets in the regulation of vascular homeostasis. PMID:22596260

  12. Investigation of platelet function and platelet disorders using flow cytometry.

    PubMed

    Rubak, Peter; Nissen, Peter H; Kristensen, Steen D; Hvas, Anne-Mette

    2016-01-01

    Patients with thrombocytopenia or platelet disorders are at risk of severe bleeding. We report the development and validation of flow cytometry assays to diagnose platelet disorders and to assess platelet function independently of platelet count. The assays were developed to measure glycoprotein levels (panel 1) and platelet function (panel 2) in sodium citrated blood. Twenty healthy volunteers and five patients diagnosed with different platelet disorders were included. Glycoprotein expression levels of the receptors Ia, Ib, IIb, IIIa and IX were measured and normalised with forward scatter (FS) as a measurement of platelet size. Platelet function was assessed by CD63, P-selectin and bound fibrinogen in response to arachidonic acid, adenosine diphosphate (ADP), collagen-related peptide, ristocetin and thrombin receptor-activation peptide-6. All patients except one with suspected δ-granule defect showed aberrant levels of glycoproteins in panel 1. Glanzmann's thrombasthenia and genetically verified Bernard-Soulier syndrome could be diagnosed using panel 1. All patients showed reduced platelet function according to at least one agonist. Using panel 2 it was possible to diagnose Bernard-Soulier syndrome, δ-granule defect and GPVI disorder. By combining the two assays, we were able to diagnose different platelet disorders and investigate platelet function independent of platelet count.

  13. Reproducibility of Manual Platelet Estimation Following Automated Low Platelet Counts

    PubMed Central

    Al-Hosni, Zainab S; Al-Khabori, Murtadha; Al-Mamari, Sahimah; Al-Qasabi, Jamal; Davis, Hiedi; Al-Lawati, Hatim; Al-Riyami, Arwa Z

    2016-01-01

    Objectives Manual platelet estimation is one of the methods used when automated platelet estimates are very low. However, the reproducibility of manual platelet estimation has not been adequately studied. We sought to assess the reproducibility of manual platelet estimation following automated low platelet counts and to evaluate the impact of the level of experience of the person counting on the reproducibility of manual platelet estimates. Methods In this cross-sectional study, peripheral blood films of patients with platelet counts less than 100 × 109/L were retrieved and given to four raters to perform manual platelet estimation independently using a predefined method (average of platelet counts in 10 fields using 100× objective multiplied by 20). Data were analyzed using intraclass correlation coefficient (ICC) as a method of reproducibility assessment. Results The ICC across the four raters was 0.840, indicating excellent agreement. The median difference of the two most experienced raters was 0 (range: -64 to 78). The level of platelet estimate by the least-experienced rater predicted the disagreement (p = 0.037). When assessing the difference between pairs of raters, there was no significant difference in the ICC (p = 0.420). Conclusions The agreement between different raters using manual platelet estimation was excellent. Further confirmation is necessary, with a prospective study using a gold standard method of platelet counts. PMID:27974955

  14. Arteriovenous fistula stent infection diagnosed with radiolabelled leucocyte scintigraphy.

    PubMed

    Yoo, Jeong Rae; Heo, Sang Taek; Kim, Miyeon; Kim, Hyun Woo; Chang, Jee Won; Song, Heesung

    2015-07-01

    Infectious complications of haemodialysis in patients with arteriovenous fistula stent are rare. In addition, patients with low-grade infection are more difficult to diagnose. Here, we report the first case of low-grade infection of an arteriovenous fistula stent diagnosed using (99m)Tc-hexamethylpropylene amine oxime (HMPAO)-labelled leucocyte scintigraphy. A 62-year-old man with end-stage renal disease was referred for prolonged fever. We performed (99m)Tc-HMPAO-labelled leucocyte scintigraphy following a work-up according to fever of unknown origin. A focal uptake on the left forearm compatible with the arteriovenous fistula stent insertion site was shown, and the stent was removed. (99m)Tc-HMPAO-labelled leucocyte scintigraphy could be a suitable method for assessing vascular stent infection in low-grade fever.

  15. In-111-labeled leukocyte scintigraphy in suspected orthopedic prosthesis infection: comparison with other imaging modalities

    SciTech Connect

    Magnuson, J.E.; Brown, M.L.; Hauser, M.F.; Berquist, T.H.; Fitzgerald, R.H. Jr.; Klee, G.G.

    1988-07-01

    When infection of prosthetic orthopedic implants is suspected, optimal management requires accurate confirmation or exclusion of infection. The authors retrospectively studied 98 patients with possible infection who underwent scanning with indium-111-labeled white blood cells (WBCs) and subsequently underwent surgery within 14 days. At surgery, 50 patients had infections, as determined by means of culture or histologic results. The diagnostic accuracy of In-111 scanning was compared with that of plain radiography, arthrography, three-phase bone scanning, and various clinical and laboratory findings classically associated with infection. Positive findings on In-111 WBC scans and elevated erythrocyte sedimentation rates were found to be the most predictive variables in the diagnosis of septic prostheses (P less than or equal to .001 and P less than or equal to .002, respectively). Likelihood ratio analysis more clearly demonstrated the superiority of In-111 WBC scanning, with positive and negative scans yielding likelihood ratios of 5.0 and 0.16, respectively.

  16. Complement Activation Alters Platelet Function

    DTIC Science & Technology

    2013-10-01

    mice and mice transfused with Syk inhibitor-treated platelets . Platelet lodging was remarkably decreased in lungs of mice transfused with Syk...AD_________________ Award Number: W81XWH-12-1-0523 TITLE: Complement Activation Alters Platelet ...30September2012–29September2013 4. TITLE AND SUBTITLE Complement Activation Alters Platelet Function 5a. CONTRACT NUMBER W81XWH-12-1-0523 5b. GRANT NUMBER

  17. Recovery of Platelet Count among Apheresis Platelet Donors

    PubMed Central

    Radhakrishnan, Krishnamoorthy; Anandan, Ashwin; Panicker, Vinod Kumar

    2016-01-01

    Introduction Increase in awareness regarding use of single donor platelets and the availability of technology has resulted in increased platelet pheresis procedures. The interval between two succesive plateletpheresis donations is much less compared to whole blood donations. Plateletpheresis procedures are associated with short term and long term adverse events. The effect of plateletpheresis on haematopoietic system remains significant. Aim To study the recovery of platelet count to baseline in plateletpheresis donors. Materials and Methods Fifty, first time apheresis donors were followed for platelet count recovery. Platelet count was measured before donation and at 30 minutes, 48 hours, 7th day and 14th day post-donation. Donor platelet count recovery to baseline was observed during the two week period. Results were analysed statistically, p<0.05 was considered statistically significant. Results Platelet count recovered to baseline by 7th day post-donation in 50% of donors in groups I (Pre-donation platelet count 1.5 lacs/μl to 2.2 lacs/μl) and II (Donors with platelet count >2.2 lacs/μl to 2.75 lacs/μl), 30% of donors in group III (Donors with platelet count >2.75 lacs/μl to 3.5 lacs/μl) of the donors. Donor’s platelet count recovered to baseline in 85% of donors by day 14 in across the three groups. Recruitment of platelets from spleen was observed in donors with pre-donation platelet count on the lower limit of normal. Conclusion By day 7, donor’s platelet count recovered to baseline in majority of the donors. Allowing enough recovery periods for donor platelet count, the minimum interval between two apheresis donations can be 7 days till more prospective studies conclude on the frequency and minimum interval between plateletpheresis donations. PMID:28208861

  18. Lyophilized Platelets: Challenges and Opportunities

    DTIC Science & Technology

    2011-05-01

    and protozoan infections; alloimmunization resulting in refracto- riness to future platelet transfusions; and graft-versus-host disease . The...for preparation of lyophilized platelets has recently been described.7 Freeze-dried platelets retain native von Willebrand factor-mediated adhesion

  19. Radionuclide Esophageal Transit Scintigraphy in Primary Hypothyroidism

    PubMed Central

    Khan, Shoukat H; Madhu, Vijay P; Rather, Tanveer A; Laway, Bashir A

    2017-01-01

    Background/Aims Esophageal dysmotility is associated with gastrointestinal dysmotility in various systemic and neuroregulatory disorders. Hypothyroidism has been reported to be associated with impaired motor function in esophagus due to accumulation of glycosaminoglycan hyaluronic acid in its soft tissues, leading to changes in various contraction and relaxation parameters of esophagus, particularly in the lower esophageal sphincter. In this study we evaluated esophageal transit times in patients of primary hypothyroidism using the technique of radionuclide esophageal transit scintigraphy. Methods Thirty-one patients of primary hypothyroidism and 15 euthyroid healthy controls were evaluated for esophageal transit time using 15–20 MBq of Technetium-99m sulfur colloid diluted in 10–15 mL of drinking water. Time activity curve was generated for each study and esophageal transit time was calculated as time taken for clearance of 90% radioactive bolus from the region of interest encompassing the esophagus. Esophageal transit time of more than 10 seconds was considered as prolonged. Results Patients of primary hypothyroidism had a significantly increased mean esophageal transit time of 19.35 ± 20.02 seconds in comparison to the mean time of 8.25 ± 1.71 seconds in healthy controls (P < 0.05). Esophageal transit time improved and in some patients even normalized after treatment with thyroxine. A positive correlation (r = 0.39, P < 0.05) albeit weak existed between the serum thyroid stimulating hormone and the observed esophageal transit time. Conclusions A significant number of patients with primary hypothyroidism may have subclinical esophageal dysmotility with prolonged esophageal transit time which can be reversible by thyroxine treatment. Prolonged esophageal transit time in primary hypothyroidism may correlate with serum thyroid stimulating hormone levels. PMID:27444283

  20. Reactions Induced by Platelet Transfusions

    PubMed Central

    Kiefel, Volker

    2008-01-01

    Summary Platelet transfusions play a central role in therapeutic regimens for patients with hematologic/oncologic diseases who develop severe thrombocytopenia either in the course of their disease or following cytostatic therapy. Like other blood components, platelet transfusions have achieved a high degree of safety as far as transmission of viral diseases is concerned. However, transfusion of platelet concentrates is accompanied by a high frequency of febrile and anaphylactoid reactions. In rare cases, recipients of platelet concentrates are threatened by severe reactions as septic complications due to bacterial contamination of platelet concentrates, transfusion-related acute lung injury and severe anaphylactic episodes. PMID:21512624

  1. Cbl proteins in platelet activation.

    PubMed

    Buitrago, Lorena; Tsygankov, Alexander; Sanjay, Archana; Kunapuli, Satya P

    2013-01-01

    Platelets play a fundamental role in hemostasis. Their functional responses have to be tightly controlled as any disturbance may lead to bleeding disorders or thrombosis. It is thus important to clearly identify and understand the signaling mechanisms involved in platelet function. An important role of c-Cbl and Cbl-b ubiquitin ligases in platelet functional responses and in hematological malignancies has been recently described. Cbl proteins perform negative and positive regulation of several signaling pathways in platelets. In this review, we explore the role of Cbl proteins in platelet functional responses.

  2. Human Platelet Senescence.

    DTIC Science & Technology

    1976-04-30

    s by thP Spleen. We have recently made the interest inro o!bservat ion that the spleen preferentially sequesters mega- thrombocytes (o,7) (se...follow:ini th,’ inj,.cti(,n ,f anti-platelet antihody. Electron microscopy of blood from pati. with micrnthr’bteocyte, peaks reveal very small intact

  3. Platelet transport in microchannels

    NASA Astrophysics Data System (ADS)

    Reyssat, Mathilde; Le Goff, Anne; Blin, Antoine; Pujos, Justine; Magniez, Aurélie; Baruch, Dominique

    2013-11-01

    Blood platelets are small enucleated cells responsible for the arrest of bleeding. These cells have the ability to tether and translocate on injured vascular endothelium, thanks to a specific interaction between a receptor of their membrane and a protein expressed by the cells composing the inner wall of the vessel, the von Willebrand factor (VWF). Others cells have such abilities of rolling. Leucocytes, for example, translocate on surface due to a specific interaction between selectin molecules and their respective glycoprotein ligands. These kinds of cells present two modes of transport: they can either be advected by the flux, or translocate on surfaces due to specific ligand-receptor interactions. Our work consists first in studying experimentally the transport of platelets along a microchannel and then in modeling this particular cell transport. Due to these two modes of transport along a channel, platelets adhering to the surface are not equally distributed along the channel axis. We describe the evolution of the density of platelets with time and distance.

  4. Cavernous hemangioma. Why is peripheral filling at scintigraphy so rare

    SciTech Connect

    Drane, W.E.; Weatherby, E. III

    1987-10-01

    Peripheral filling at dynamic CT occurs frequently with cavernous hemangiomas, yet this phenomenon is a rare finding on Tc-99m RBC imaging. A case of peripheral filling of a cavernous hemangioma with scintigraphy is reported and the rationale for its infrequent occurrence is discussed.

  5. Platelet satellitism: an ultrastructural study.

    PubMed Central

    Payne, C. M.

    1981-01-01

    The ultrastructural morphology of platelet-polymorph (platelet-polymorphonuclear leukocyte) rosettes was investigated in EDTA-anticoagulated blood obtained from two patients who exhibited the phenomenon of platelet satellitism. Most of the platelet profiles were attached to the polymorph surface by broad areas of contact. Examination of these broad areas of contact at high magnification revealed an intercellular material of low electron density. This material appeared to form strands, which bridged the intercellular space and spanned the entire area formed by the apposing plasma membranes. Phagocytosis of entire platelets was only observed in 1 case. The platelet profiles that participated in rosette formation revealed a large number of glycogen particles, compared with unattached platelets. Ultrastructural examination of "stress" platelets obtained from five normal subjects treated with steroids similarly showed a large number of glycogen particles, although no rosette formation or phagocytosis of platelets was observed. The etiology of platelet satellitism is discussed. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:7223859

  6. Typing for human platelet alloantigens.

    PubMed

    Juji, T; Saji, H; Satake, M; Tokunaga, K

    1999-01-01

    Antibodies to platelet alloantigens, and sometimes to isoantigens, induce severe clinical problems such as neonatal alloimmune thrombocytopenia (NAIT), post-transfusion purpura (PTP) and refractoriness to platelet transfusions (PTR). For example, NAIT affects approximately 1 in 5,000 live births. It is essential, therefore, to screen pregnant women for platelet antibodies in order to save babies' lives. Almost 40 years ago, two platelet alloantigen systems were discovered using relatively simple methods, namely the platelet agglutination test and the complement fixation test. However, these methods were not sensitive enough to identify all antibodies in mothers and patients, even in those with severe clinical problems. Tremendous effort has been devoted to establish more sensitive and reliable methods. In recent years, excellent new serological and immunochemical methods have been established and several new platelet antigen systems have been discovered. Simultaneously, newly developed molecular genetic techniques have been introduced for the typing and analysis of human platelet alloantigen systems. These methods allow DNA typing for cases in which serological typing is not available. In this article, the history of studies on human platelet alloantigen systems and isoantigens, the nomenclature of platelet alloantigen systems and their alleles, the present status of antibody detection and typing techniques and, finally, ethnic variations in platelet antigen profiles are reviewed.

  7. Effects of hormones on platelet aggregation.

    PubMed

    Farré, Antonio López; Modrego, Javier; Zamorano-León, José J

    2014-04-01

    Platelets and their activation/inhibition mechanisms play a central role in haemostasis. It is well known agonists and antagonists of platelet activation; however, during the last years novel evidences of hormone effects on platelet activation have been reported. Platelet functionality may be modulated by the interaction between different hormones and their platelet receptors, contributing to sex differences in platelet function and even in platelet-mediated vascular damage. It has suggested aspects that apparently are well established should be reviewed. Hormones effects on platelet activity are included among them. This article tries to review knowledge about the involvement of hormones in platelet biology and activity.

  8. Human Platelet Senescence Study.

    DTIC Science & Technology

    1980-03-01

    ability to measure certain enzymes to their oxidation-reduc other enzymes which can be measured by o phosphatase , acid phosphatase , chymotryp...alkaline sin, trypsin, esterases (17)); M use of n A or wheat germ agglutinin in the second etect specific carbohydrate constituents. We have...Von Willebrand factor. Nurden and Caen also demonstrated that GPI was rich in sialic acid (5) and probably responsible for the platelets’ surface

  9. Hypothermia and Platelet Dysfunction

    DTIC Science & Technology

    2007-11-02

    cardiopulmonary bypass during cardiac surgery, other major surgery, multiple trauma, cold exposure, and neonatal cold injury.1Ŗ The hemorrhagic diathesis...associated with hypothermic cardiopulmonary bypass during cardiac surgery is considered to be primarily a platelet function defect.I6,17,23 We have...cardiopulmonary bypass during cardiac surgery.,8,24 Consistent with this data, other investigators have recently reported that normothermic cardiopulmonary

  10. [Platelet count in the cat].

    PubMed

    Moritz, A; Hoffmann, C

    1997-11-01

    The technique of collecting blood samples is primarily responsible for the appearance of platelet-agglomeration in cats. Blood obtained by the conventional way ("one syringe technology", drips of blood) caused in 52% of the cases an activation of the large and therefore active thrombocytes however. Rejection of the first 2-5 ml blood for the platelet count ("two syringe technology") reduced the rate of platelet-agglomeration significantly. No big differences in platelet-agglomeration were found with regard to the place used for collecting blood (V. cephalica antebrachii/V. jugularis). Platelet-agglutination was observed with Li-Heparin, K-EDTA, Na-Citrat or ACD anticoagulated blood samples. Citrat (Na-Citrat, ACD) seemed to have a stabilizing effect on feline thrombocytes as has been described for human thrombocytes. The platelet count in cats should be performed within 30 minutes.

  11. 123I-metaiodobenzylguanidine myocardial scintigraphy in Parkinson's disease

    PubMed Central

    Orimo, S; Ozawa, E; Nakade, S; Sugimoto, T; Mizusawa, H

    1999-01-01

    OBJECTIVES—123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy is clinically used to estimate local myocardial sympathetic nerve damage in some forms of heart disease, autonomic nerve disturbance in diabetic neuropathy, and disturbance of the autonomic nervous system in neurodegenerative disease. In the present study, examinations were performed to clarify (1) the proportion of cardiac sympathetic nerve disturbance in Parkinson's disease, (2) the usefulness of 123I-MIBG myocardial scintigraphy to detect sympathetic nerve disturbances compared with autonomic function tests, (3) cardiac function in patients who have a decreased MIBG uptake in 123I-MIBG myocardial scintigraphy, (4) the usefulness of 123I-MIBG myocardial scintigraphy to differentiate Parkinson's disease from the other neurological diseases mimicking it.
METHODS—123I-MIBG myocardial scintigraphy was performed, together with autonomic function tests and cardiac examinations in 46 patients with Parkinson's disease and 25 patients with vascular parkinsonism, essential tremor, or multiple system atrophy.
RESULTS—In an anterior image study, the average count per pixel in heart to mediastinum (H/M) ratio decreased in 80% of the patients with Parkinson's disease in the early phase and 84% in the late phase. The mean H/M ratio in Parkinson's disease was significantly lower than that in controls and the other diseases. The H/M ratio tended to decrease with the disease progression. In almost half of the patients in Hoehn and Yahr stage I, the H/M ratio was already decreased. The sympathetic skin response in upper and lower limbs, head up tilt test, and coefficient of variation of R-R interval were abnormal in 17%, 31%, 30%, and 17% of the patients, respectively. All the patients with abnormal autonomic functions were in Hoehn and Yahr stage III, IV, or V. Echocardiography showed normal left ventricular function. Twenty four hour Holter electrocardiography detected no serious arrhythmias except

  12. Human blood platelets at microgravity

    NASA Technical Reports Server (NTRS)

    Surgenor, D. MACN.; Ausprunk, D.; Blevins, D.; Chao, F. C.; Curby, W.

    1987-01-01

    A set of freshly collected and separated human platelet suspensions were transported, in three types of plastic containers, on a 6 day, 2 hr mission of the orbiter Columbia to study the effect of prolonged exposure of human blood cells to microgravity. A controlled environment at a temperature of 22 + or - 1 deg with air flow was provided and another set of samples held on the ground acted as controls. Paired comparisons of platelets at ug versus controls at lxg revealed superior platelet survival at microgravity. When viewed in terms of plastic type, ug platelets in containers fabricated from PVC-TOTM displayed the best overall postflight viability.

  13. Platelet effects on ovarian cancer.

    PubMed

    Davis, Ashley N; Afshar-Kharghan, Vahid; Sood, Anil K

    2014-06-01

    Growing understanding of the role of thrombocytosis, high platelet turnover, and the presence of activated platelets in the circulation in cancer progression and metastasis has brought megakaryocytes into focus. Platelet biology is essential to hemostasis, vascular integrity, angiogenesis, inflammation, innate immunity, wound healing, and cancer biology. However, before megakaryocyte/platelet-directed therapies can be considered for clinical use, understanding of the mechanism and biology of paraneoplastic thrombocytosis in malignancy is required. Here, we provide an overview of the clinical implications, biological significance, and mechanisms of paraneoplastic thrombocytosis in the context of ovarian cancer.

  14. Platelets can enhance vascular permeability.

    PubMed

    Cloutier, Nathalie; Paré, Alexandre; Farndale, Richard W; Schumacher, H Ralph; Nigrovic, Peter A; Lacroix, Steve; Boilard, Eric

    2012-08-09

    Platelets survey blood vessels, searching for endothelial damage and preventing loss of vascular integrity. However, there are circumstances where vascular permeability increases, suggesting that platelets sometimes fail to fulfill their expected function. Human inflammatory arthritis is associated with tissue edema attributed to enhanced permeability of the synovial microvasculature. Murine studies have suggested that such vascular leak facilitates entry of autoantibodies and may thereby promote joint inflammation. Whereas platelets typically help to promote microvascular integrity, we examined the role of platelets in synovial vascular permeability in murine experimental arthritis. Using an in vivo model of autoimmune arthritis, we confirmed the presence of endothelial gaps in inflamed synovium. Surprisingly, permeability in the inflamed joints was abrogated if the platelets were absent. This effect was mediated by platelet serotonin accumulated via the serotonin transporter and could be antagonized using serotonin-specific reuptake inhibitor antidepressants. As opposed to the conventional role of platelets to microvascular leakage, this demonstration that platelets are capable of amplifying and maintaining permeability adds to the rapidly growing list of unexpected functions for platelets.

  15. Overview of platelet physiology and laboratory evaluation of platelet function.

    PubMed

    Rodgers, G M

    1999-06-01

    Appropriate laboratory testing for the platelet-type bleeding disorders hinges on an adequate assessment in the history and physical examination. Patients with histories and screening laboratory results consistent with coagulation disorders (hemophilia, disseminated intravascular coagulation) are not appropriate candidates for platelet function testing. In contrast, patients with a lifelong history of platelet-type bleeding symptoms and perhaps a positive family history of bleeding would be appropriate for testing. Figure 6 depicts one strategy to evaluate these patients. Platelet morphology can easily be evaluated to screen for two uncommon qualitative platelet disorders: Bernard-Soulier syndrome (associated with giant platelets) and gray platelet syndrome, a subtype of storage pool disorder in which platelet granulation is morphologically abnormal by light microscopy. If the bleeding disorder occurred later in life (no bleeding with surgery or trauma early in life), the focus should be on acquired disorders of platelet function. For those patients thought to have an inherited disorder, testing for vWD should be done initially because approximately 1% of the population has vWD. The complete vWD panel (factor VIII coagulant activity, vWf antigen, ristocetin cofactor activity) should be performed because many patients will have abnormalities of only one particular panel component. Patients diagnosed with vWD should be classified using multimeric analysis to identify the type 1 vWD patients likely to respond to DDAVP. If vWD studies are normal, platelet aggregation testing should be performed, ensuring that no antiplatelet medications have been ingested at least 1 week before testing. If platelet aggregation tests are normal and if suspicion for an inherited disorder remains high, vWD testing should be repeated. The evaluation of thrombocytopenia may require bone marrow examination to exclude primary hematologic disorders. If future studies with thrombopoietin assays

  16. [STRUCTURAL CHARACTERIZATION OF PLATELETS AND PLATELET-DERIVED MICROVESICLES].

    PubMed

    Ponomareva, A A; Nevzorova, T A; Mordakhanova, E R; Andrianova, I A; Litvinov, R I

    2016-01-01

    Platelets are the anucleated blood cells, wich together with the fibrin stop bleeding (hemostasis). Cellular microvesicles are membrane-surrounded microparticles released into extracellular space upon activation and/or apoptosis of various cells. Platelet-derived macrovesicles from the major population of circulating blood microparticles that play an important role in hemostasis and thrombosis. Despite numerous studies on the pathophysiology of platelet-derived macrovesicles, mechanisms of their formation and structural details remain poorly understood. Here we investigated the ultrastructure of parental platelets and platelet-derived microvesicles formed in vitro by quiescent cells as well as by cells stimulated with one of the following activators: arachidonic acid, ADP, thrombin, calcium ionophore A23187. Using transmission electron microscopy of human platelets and isolated microvesicles, we analyzed the intracellular origin, steps of formation, structural diversity, and size distributions of the subcellular particles. We have revealed that thrombin, unlike other stimuli, not only induced vesiculation of the plasma membrane but also caused break-up of the cells followed by formation of microparticles that are comparable with microvesicles by size. A fraction of these microparticles contained cellular organelles surrounded by a thin membrane. The size of platelet-derived macrovesicles varied from 30 nm to 500 nm, however, the size distributions depended on the nature of a cell-activating stimulus. The results obtained provide new information about the formation of platelet-derived macrovesicles and their structural diversity, wich is important to understand their multiple functions in normal and disease states.

  17. ROC analysis of diagnostic performance in liver scintigraphy.

    PubMed

    Fritz, S L; Preston, D F; Gallagher, J H

    1981-02-01

    Studies on the accuracy of liver scintigraphy for the detection of metastases were assembled from 38 sources in the medical literature. An ROC curve was fitted to the observed values of sensitivity and specificity using an algorithm developed by Ogilvie and Creelman. This ROC curve fitted the data better than average sensitivity and specificity values in each of four subsets of the data. For the subset dealing with Tc-99m sulfur colloid scintigraphy, performed for detection of suspected metastases and containing data on 2800 scans from 17 independent series, it was not possible to reject the hypothesis that interobserver variation was entirely due to the use of different decision thresholds by the reporting clinicians. Thus the ROC curve obtained is a reasonable baseline estimate of the performance potentially achievable in today's clinical setting. Comparison of new reports with these data is possible, but is limited by the small sample sizes in most reported series.

  18. Absorbed dose to the fetus during bone scintigraphy

    SciTech Connect

    Hedrick, W.R.; DiSimone, R.N.; Wolf, B.H.; Langer, A.

    1988-07-01

    The authors observed the uptake of radiopharmaceutical and calculated absorbed dose in fetuses of two patients who underwent bone scintigraphy with technetium-99m methylene diphosphonate. Dose estimates per administered activity were 17 mrad/mCi (4.6 microGy/MBq) for an 8-week-old fetus and 9.7 mrad/mCi (2.6 microGy/MBq) for an 18-week-old fetus. Neither fetus demonstrated radionuclide uptake above maternal background levels. The uterine activity showed rapid clearance, with an effective half-life of 12 minutes after reaching a maximum within 1 minute after injection. Major contribution to fetal dose comes from the presence of the radionuclide in the maternal bladder. The authors conclude that bone scintigraphy performed unknowingly in pregnant individuals presents negligible increased risk to the fetus.

  19. Bone scintigraphy of hip joint effusions in children

    SciTech Connect

    Kloiber, R.; Pavlosky, W.; Portner, O.; Gartke, K.

    1983-05-01

    Thirty-eight children with hip pain of acute onset were studied by bone scintigraphy. Nine patients had diminished radiotracer deposition involving the entire proximal femoral ossification center. This could be related to infarction or compression of blood supply by a tense joint effusion. Eight of these patients had joint aspiration confirming the presence of an effusion. Five patients had follow-up studies after aspiration, and femoral-head uptake reverted to normal in all but one which subsequently proved to be infarcted. A photopenic zone was seen on blood pool images in 10 patients, many of whom were also aspirated of fluid. Bone scintigraphy is useful in the diagnosis of joint effusions and can give information as to the state of perfusion of the femoral head. Follow-up studies after aspiration can differentiate infarction from reversible ischemia.

  20. Pulmonary scintigraphy in fibrosing mediastinitis due to histoplasmosis

    SciTech Connect

    Park, H.M.; Jay, S.J.; Brandt, M.J.; Holden, R.W.

    1981-04-01

    The pulmonary scintigraphic findings from our patients with fibrosing mediastinitis due to histoplasmosis are reported. The ventilation/perfusion (V/Q) mismatch mimicked pulmonary emboli. However, in these cases the chest radiographs and/or gallium-67 scintigraphy were abnormal, suggesting mediastinal or hilar disease. Awareness of the nonembolic conditions that can result in V/Q mismatches is important in the interpretation of lung scans.

  1. Pulmonary scintigraphy and the diagnosis of pulmonary embolism. A perspective

    SciTech Connect

    Polak, J.F.; McNeil, B.J.

    1984-09-01

    The authors attempt to demonstrate those circumstances for which perfusion scintigraphy, by itself, or in combination with ventilation scintiscanning, offers the best adjunctive information in excluding or confirming the presence of pulmonary embolism. They then identify those circumstances in which scintiscanning does not or cannot contribute significantly to the medical decision-making process. In these cases, the use of pulmonary angiography or possibly peripheral venography is not only recommended but, if warranted clinically, is absolutely necessary.

  2. Statin induced myopathy does not show up in MIBI scintigraphy.

    PubMed

    Lupattelli, G; Palumbo, B; Sinzinger, H

    2001-05-01

    Statin induced myopathy is the most commonly seen side effect in users of this family of drugs. Their different forms present with either creatine phosphokinase (CK) elevation or not, signs of in vivo oxidation injury or not or a combination of both. The pathogenetic background, however, still remains obscure. As MIBI, beside myocardial and tumour scintigraphy, is useful in detecting muscle metabolic abnormalities, an increased uptake of MIBI in the diseased muscular segments could be expected. We investigated seven patients (five males, two females; aged 36-56 years) with statin induced myopathy with either elevated CK, isoprostanes or muscle pains at varying combinations. MIBI whole-body imaging was done immediately, the patients still being on the respective statin. Sixteen patients (six males, 10 females) suffering from lung or breast cancer and being on statins served as controls. No uptake abnormalities in any muscular segment either in the patients or the control group were seen. Thus, MIBI scintigraphy is not useful, apparently, in diagnosing and eventually localizing statin induced myopathy. These findings indicate that MIBI scintigraphy is of no help for diagnosis and gaining further insight into statin induced myopathy.

  3. Thallium-201 myocardial scintigraphy in acute myocardial infarction and ischemia

    SciTech Connect

    Wackers, F.J.

    1982-04-01

    Thallium-201 scintigraphy provides a sensitive and reliable method of detecting acute myocardial infarction and ischemia when imaging is performed with understanding of the temporal characteristics and accuracy of the technique. The results of scintigraphy are related to the time interval between onset of symptoms and time of imaging. During the first 6 hr after chest pain almost all patients with acute myocardial infarction and approximately 50% of the patients with unstable angina will demonstrate /sup 201/TI pefusion defects. Delayed imaging at 2-4 hr will permit distinction between ischemia and infarction. In patients with acute myocardial infarction, the size of the perfusion defect accurately reflects the extent of the infarcted and/or jeopardized myocardium, which may be used for prognostic stratification. In view of the characteristics of /sup 201/TI scintigraphy, the most practical application of this technique is in patients in whom myocardial infarction has to be ruled out, and for early recognition of patients at high risk for complications.

  4. Incidental diagnosis of pregnancy on bone and gallium scintigraphy

    SciTech Connect

    Palestro, C.J.; Malat, J.; Collica, C.J.; Richman, A.H.

    1986-03-01

    Bone and gallium scintigraphy were performed as part of the diagnostic workup of a 21-yr-old woman who presented at our institution with a history of progressively worsening low back pain over a 1-wk period of time. The angiographic phase of the bone scan demonstrated a well-defined radionuclide blush within the pelvis just cephalad to the urinary bladder with persistent hyperemia noted in the blood-pool image. We attribute these findings to a uterine blush secondary to the pronounced uterine muscular hyperplasia, hyperemia, and edema that accompany pregnancy. Gallium scintigraphy demonstrated intense bilateral breast accumulation of the imaging agent in a typical doughnut pattern which is commonly found in the prelactating and lactating breast. Also demonstrated was apparent gallium accumulation in the placenta. This case is presented to emphasize the radionuclide findings that occur during pregnancy, particularly the incidental finding of radionuclide blush during the angiographic phase of a radionuclide scintigraphy which should alert the nuclear physician to the possibility of pregnancy in a woman of childbearing age.

  5. Platelets: production, morphology and ultrastructure.

    PubMed

    Thon, Jonathan N; Italiano, Joseph E

    2012-01-01

    Platelets are anucleate, discoid cells, roughly 2-3 μm in diameter that function primarily as regulators of hemostasis, but also play secondary roles in angiogensis and innate immunity. Although human adults contain nearly one trillion platelets in circulation that are turned over every 8-10 days, our understanding of the mechanisms involved in platelet production is still incomplete. Platelets stem from large (30-100 μm) nucleated cells called megakaryocytes that reside primarily in the bone marrow. During maturation megakaryocytes extend long proplatelet elongations into sinusoidal blood vessels from which platelets ultimately release. During this process, platelets develop a number of distinguishable structural elements including: a delimited plasma membrane; invaginations of the surface membrane that form the open canalicular system (OCS); a closed-channel network of residual endoplasmic reticulum that form the dense tubular system (DTS); a spectrin-based membrane skeleton; an actin-based cytoskeletal network; a peripheral band of microtubules; and numerous organelles including α-granules, dense-granules, peroxisomes, lysosomes, and mitochondria. Proplatelet elongation and platelet production is an elaborate and complex process that defines the morphology and ultrastructure of circulating platelets, and is critical in understanding their increasingly numerous and varied biological functions.

  6. Deciphering the human platelet sheddome

    PubMed Central

    Fong, Karen P.; Barry, Colin; Tran, Anh N.; Traxler, Elizabeth A.; Wannemacher, Kenneth M.; Tang, Hsin-Yao; Speicher, Kaye D.; Blair, Ian A.; Speicher, David W.; Grosser, Tilo

    2011-01-01

    Activated platelets shed surface proteins, potentially modifying platelet function as well as providing a source of bioactive fragments. Previous studies have identified several constituents of the platelet sheddome, but the full extent of shedding is unknown. Here we have taken a global approach, analyzing protein fragments in the supernate of activated platelets using mass spectroscopy and looking for proteins originating from platelet membranes. After removing plasma proteins and microparticles, 1048 proteins were identified, including 69 membrane proteins. Nearly all of the membrane proteins had been detected previously, but only 10 had been shown to be shed in platelets. The remaining 59 are candidates subject to confirmation. Based on spectral counts, protein representation in the sheddome varies considerably. As proof of principle, we validated one of the less frequently detected proteins, semaphorin 7A, which had not previously been identified in platelets. Surface expression, cleavage, and shedding of semaphorin 7A were demonstrated, as was its association with α-granules. Finally, cleavage of semaphorin 7A and 12 other proteins was substantially reduced by an inhibitor of ADAM17, a known sheddase. These results define a subset of membrane proteins as sheddome candidates, forming the basis for further studies examining the impact of ectodomain shedding on platelet function. PMID:20962327

  7. Biologic nanoparticles and platelet reactivity

    PubMed Central

    Miller, Virginia M; Hunter, Larry W; Chu, Kevin; Kaul, Vivasvat; Squillace, Phillip D; Lieske, John C; Jayachandran, Muthuvel

    2009-01-01

    Aim Nanosized particles (NPs) enriched in hydroxyapatite and protein isolated from calcified human tissue accelerate occlusion of endothelium-denuded arteries when injected intravenously into rabbits. Since platelet aggregation and secretory processes participate in normal hemostasis, thrombosis and vascular remodeling, experiments were designed to determine if these biologic NPs alter specific platelet functions in vitro. Methods Platelet-rich plasma was prepared from citrate anticoagulated human blood. Platelet aggregation and ATP secretion were monitored in response to thrombin receptor agonists peptide (10 μM) or convulxin (50 μg/ml) prior to and following 15 min incubation with either control solution, human-derived NPs, bovine-derived NPs or crystals of hydroxyapatite at concentrations of 50 and 150 nephelometric turbidity units. Results Incubation of platelets for 15 min with either human- or bovine-derived NPs reduced aggregation induced by thrombin receptor activator peptide and convulxin in a concentration-dependent manner. Hydroxyapatite caused a greater inhibition than either of the biologically derived NPs. Human-derived NPs increased ATP secretion by unstimulated platelets during the 15 min incubation period. Conclusion Effects of bovine-derived and hydroxyapatite NPs on basal release of ATP were both time and concentration dependent. These results suggest that biologic NPs modulate both platelet aggregation and secretion. Biologically derived NPs could modify platelet responses within the vasculature, thereby reducing blood coagulability and the vascular response to injury. PMID:19839809

  8. Platelets, inflammation and tissue regeneration.

    PubMed

    Nurden, Alan T

    2011-05-01

    Blood platelets have long been recognised to bring about primary haemostasis with deficiencies in platelet production and function manifesting in bleeding while upregulated function favourises arterial thrombosis. Yet increasing evidence indicates that platelets fulfil a much wider role in health and disease. First, they store and release a wide range of biologically active substances including the panoply of growth factors, chemokines and cytokines released from a-granules. Membrane budding gives rise to microparticles (MPs), another active participant within the blood stream. Platelets are essential for the innate immune response and combat infection (viruses, bacteria, micro-organisms). They help maintain and modulate inflammation and are a major source of pro-inflammatory molecules (e.g. P-selectin, tissue factor, CD40L, metalloproteinases). As well as promoting coagulation, they are active in fibrinolysis; wound healing, angiogenesis and bone formation as well as in maternal tissue and foetal vascular remodelling. Activated platelets and MPs intervene in the propagation of major diseases. They are major players in atherosclerosis and related diseases, pathologies of the central nervous system (Alzheimers disease, multiple sclerosis), cancer and tumour growth. They participate in other tissue-related acquired pathologies such as skin diseases and allergy, rheumatoid arthritis, liver disease; while, paradoxically, autologous platelet-rich plasma and platelet releasate are being used as an aid to promote tissue repair and cellular growth. The above mentioned roles of platelets are now discussed.

  9. Effect of histocompatibility factors on pulmonary retention of indium-111-labeled granulocytes

    SciTech Connect

    Dutcher, J.P.; Riggs, C. Jr.; Fox, J.J.; Johnston, G.S.; Norris, D.; Wiernik, P.H.; Schiffer, C.A. )

    1990-04-01

    Granulocyte transfusions are associated with a number of side effects including febrile transfusion reactions and occasionally pulmonary infiltrates. There is evidence that the presence of preformed antibodies may be a cause of these complications. In this study, allogeneic 111Indium-labeled granulocytes were used to evaluate the pulmonary retention of radioactivity in alloimmunized and non-alloimmunized patients in an attempt to assess antibody effect on granulocyte migration. After injection of labeled allogeneic granulocytes into neutropenic patients, the ratios of lung to heart activity were calculated for the first 30 min of scanning. There was significantly greater retention of radioactivity from cells in the lungs of patients who were alloimmunized, having both lymphocytotoxic (anti-HLA) and leuko-agglutinating antibodies, compared to the activity in the lungs of non-alloimmunized patients (P less than .001) or of patients receiving autologous granulocytes (P less than .001). This study demonstrates that labeled, mismatched granulocytes may be retained in the lungs for a significantly longer time in patients with preformed antibodies. This implies that transfusion of large numbers of such mismatched granulocytes, i.e., granulocyte transfusions, may also be retained in the lungs of alloimmunized patients, which could lead to pulmonary compromise. Therefore, granulocyte transfusions from random donors should not be given to alloimmunized patients.

  10. Distribution and imaging of Indium-111 labelled circulating immune complexes (CIC) in humans

    SciTech Connect

    Wirquin, E.; Bruneau, C.; Cinotti, L.; Sobel, A.; Meignan, M.

    1984-01-01

    The clearance of labelled CIC has been widely used to investigate the phagocytic function of the reticuloendothelial system in humans. Many of these studies have been performed with red blood cells (RBC) sensitized with IgG anti Rh and labelled with Cr-51, so that no image of the distribution of these CIC has been presented up to now. The authors obtained such images by using In-111 instead of Cr-51, and compared the values of the clearances provided by each label in 9 normal controls. The In-111 procedure included camera imaging on spleen, liver, heart, lungs and kidneys. Local kinetic-curves were obtained on each organ: 1) The blood clearance values were similar with In-111 (T 1/2 = 23.3 +- 6.4 min) or Cr-51 (T 1/2 = 21.4 +- 4.9); 2) The heart clearance (T 1/2 = 26.6 +- 8.3 min) was not significantly different from the blood T1/.2; 3) There was no uptake of sensitized RBC in lungs and kidneys; 4) Sensitized RBC were mostly cleared by the spleen and T1/2 values were homogenous (20.3 +- 3.8 min); and 5) Sensitized RBC were retained in the liver in 8 out of 9 cases and subsequently released in 5, indicating sequestration without phagocytosis. The variability of the results made it difficult to establish a norm, possibly due to small variations in sensitization, insufficient to influence the spleen T1/2. The authors conclude that sensitized RBC labelled with Cr-51 or In-111 may be used equally well. By camera imaging, the authors identified an hepatic Fc function and could determine the respective role of spleen and liver. IgG sensitized RBC, like their IgM counterparts, were sequestered and released by the liver.

  11. Kinetics of indium-111-labeled leukemic cells in patients with acute non-lymphocytic leukemia

    SciTech Connect

    Suzuki, Y.; Yamauchi, K.

    1984-01-01

    The kinetics of autologous leukemic cells labeled with In-111 oxine were studied in 5 patients with acute myeloblastic leukemia (AML) and one patient with acute premyelocytic leukemia (APL), and kinetics of OKM1 monoclonal antibody-treated leukemic cells were studied in one patient with acute monoblastic leukemia (AMoL). Recoveries of 33.7 +- 23.3%(range, 22.0 to 48.1%) were achieved at 10min after injection of In-111 oxine labeled leukemic cells in AML and APL patients. However, in a patient with AMoL recovery of 12.3% was only achieved at 10min after injection of OKM1-treated leukemic cells. Clearance of the activity from blood was rapid up to one in all patients. The clearance curve of the activity in 5 AML patients showed a hump or a plateau from one to 5hr after injection of labeled leukemic cells. In APL patient and AMoL patient, however, this hump or plateau was not noted. In AML and APL patients the activity over the spleen was higher than that of over the liver at from 30min to 3hr after and showed a plateau or gradual rising thereafter. In a patient with AMoL, the hepatic activity was higher than the splenic activity at 30min after, but thereafter the latter became higher than the former. Liver activity curves showed transient fall at 3hr after and then gradual uprising in all patients. In a patient with APL, high activity was noted over the kidneys. This rose to a maximum after 3hr and then decreased rapidly. Since In-111 oxine stays firmly attached to the cells in spite of the possibility of radiation damage in a long-term survey, it seems an ideal label for studying leukemic cell kinetics.

  12. In vitro effects on Indium-111-Oxine labeled leukocytes functions of N-etilmycin

    SciTech Connect

    Iacovo, R.D.; Perna, M.; Esposito, G.; Polese, C.; Frizzi, L.

    1985-05-01

    In order to study in vitro chemotaxis, phagocytosis and bactericydal efficiencies of granulocytes (PMN) and monocytes (Mo) of cancer patients with solid tumours, the authors have undertaken the evaluation of a method of measuring PMN and Mo chemotaxis with modified Boyden chambers, using In-111-oxine. The tests were performed in order to evaluate the interference of N-etilmycin with leukocyte functions, a currently fashionable antibiotic used in the treatment of gram-negative infections. The results both compare well with the visual method and are objective. Cancer patients, disease-free for a minimum of one year, were compared and evidenced normal chemotaxis and normal controls. No difference between the two groups was found (20.46% of those tested). The addition of N-etilmy-cin (6..mu..g/ml) to PMN and Mo further decreased the chemotaxis from 20.46% to 16.07% (t=2.81, P=0.0102). The addition of 30..mu..g/ml further decreased the chemotaxis from the mean control values to 5.925% (t=4.55,P 1%). The use of N-etilmycin in disease-free cancer patients should be avoided in the possible event of tumour enhancement.

  13. Indium-111-antimyosin and iodine-123-MIBG studies in early assessment of doxorubicin cardiotoxicity

    SciTech Connect

    Carrio, I.; Estorch, M.; Berna, L.

    1995-11-01

    Detection of myocyte cell damage with {sup 111}In-antimyosin and impairment of adrenergic neuron function with MIBG during doxorubicin administration may provide early identification of patients at risk of significant functional impairment. We studied 36 cancer patients who underwent chemotherapy, including doxorubicin, to assess MIBG and {sup 111}In-antimyosin uptake in the course of doxorubicin administration. MIBG scans, antimyosin scans and ejection fraction measurements were performed before chemotherapy, at intermediate cumulative doses and at maximal cumulative doses of doxorubicin. MIBG uptake was quantified by a heart-to-mediastinum ratio and antimyosin uptake was quantified by a heart-to-lung ratio. All patients had absent antimyosin uptake (mean ratio 1.40 {+-} 0.06) with normal MIBG uptake (ratio 1.85 {+-} 0.29) before chemotherapy; ejection fraction was 61% {+-} 8%. With a 240-300 mg/m{sup 2} dose of doxorubicin, an increase in antimyosin uptake was observed with a ratio of 1.85 {+-} 0.2 (p < 0.01), whereas a similar degree of MIBG uptake was observed (mean ratio of 1.80 {+-} 0.2, p = ns); ejection fraction was 59% {+-} 5% (p = ns). At 420-600 mg/m{sup 2}, increased antimyosin uptake was observed with a ratio of 2.02 {+-} 0.3 (p < 0.01), and a decrease in MIBG uptake was also observed (mean ratio of 1.76 {+-} 0.2, p < 0.05); ejection fraction was 52% {+-} 8% (p < 0.05). Patients with more intense antimyosin uptake at intermediate doses tended to be those with more severe functional impairment at maximal cumulative doses. At cumulative doses of 420-600 mg/m{sup 2}, antimyosin and MIBG studies detect cell damage and impaired adrenergic neuron activity in patients with maintained or slightly decreased ejection fraction. 33 refs., 3 figs., 2 tabs.

  14. Imaging focal sites of bacterial infection in rats with indium-111-labeled chemotactic peptide analogs

    SciTech Connect

    Fischman, A.J.; Pike, M.C.; Kroon, D.; Fucello, A.J.; Rexinger, D.; ten Kate, C.; Wilkinson, R.; Rubin, R.H.; Strauss, H.W. )

    1991-03-01

    Four DTPA-derivatized chemotactic peptide analogs: ForNleLFNleYK-DTPA (P1), ForMLFNH(CH2)6NH-DTPA (P2), ForNleLFK(NH2)-DTPA (P3), and ForNleLFK-DTPA (P4), were synthesized and evaluated for in vitro bioactivity and receptor binding. The peptides were radiolabeled with 111In by transchelation and their biodistribution determined in rats at 5, 30, 60 and 120 min after injection. Localization at sites of infection was determined by scintillation camera imaging in animals with deep-thigh infection due to Escherichia coli. Images were recorded from 5 min to 2 hr after injection. All peptides maintained biologic activity (EC50 for O2-production by human PMN's: 3-150 nM) and the ability to bind to the oligopeptide chemoattractant receptor on human PMN's (EC50 for binding: 7.5-50 nM); biologic activity and receptor binding were highly correlated (r = 0.99). For all the peptides, blood clearance was rapid (half-lives: 21.5, 33.1, 31.6, and 28.7 min for P1, P2, P3, and P4, respectively). Biodistributions of the individual peptides were similar with low levels of accumulation in the heart, lung, liver, spleen, and gastrointestinal tract. In the kidney, P1 had much greater accumulation than other organs. All peptides yielded high quality images of the infection sites within 1 hr of injection. This study demonstrates that 111In-labeled chemotactic peptide analogs were effective agents for the external imaging of focal sites of infection.

  15. Indium-111 leukocyte scanning. False-negative study in a renal abscess

    SciTech Connect

    Kumar, R.; Bedi, D.G.; Fawcett, H.D.; Winsett, M.Z.; Fagan, C.J.

    1986-04-01

    A 33-year-old man had clinical features of a right renal abscess. Results of excretory urography and ultrasonography showed a focal complex mass lesion in the right kidney. An In-111 leukocyte scan failed to detect the right renal abscess, which later was aspirated under CT guidance and explored surgically. The role of In-111 leukocyte imaging in the detection of intra-abdominal abscesses, with limitations of the procedure, is discussed.

  16. Colonic localization of indium-111 labeled leukocytes in active Behcet's disease

    SciTech Connect

    Harre, R.G.; Conrad, G.R.; Seabold, J.E.

    1988-06-01

    A patient with known Behcet's disease demonstrated intense colonic localization of In-111 labeled leukocytes. Gastrointestinal involvement had not been previously manifested, but extensive colonic inflammation was documented by endoscopy. This case illustrates the utility of In-111 labeled leukocyte imaging for detecting active bowel disease in a debilitated patient with documented Behcet's vasculitis.

  17. False-positive indium-111 labeled leukocyte scintigram in a patient with a painful hip prosthesis

    SciTech Connect

    Feldman, N.; Makler, P.T. Jr.; Alavi, A.

    1986-01-01

    A Tronzo hip prosthesis is designed to elicit an inflammatory reaction in order to promote prosthesis stability. A three-phased bone scan and Ga-67 imaging in conjunction with physical examination and laboratory findings failed to demonstrate evidence for osteomyelitis in a patient with a painful hip prosthesis, in whom images obtained with In-111-labeled leukocytes were positive. This observation demonstrated that the interpretation of the latter technique in demonstrating inflammation can cause a false impression of an infectious process.

  18. Skeletal photopenic appearance of Paget's disease with indium-111 white blood cell imaging

    SciTech Connect

    Borin, B.F.; Abghari, R.; Sarkissian, A.

    1987-10-01

    A case of focal decreased skeletal uptake with In-111 labeled white blood cells representing Paget's disease is reported. Although uncommon, other causes for skeletal photon deficient areas using In-111 white blood cells have been described. To the authors' knowledge, this finding representing Paget's disease has not been previously described.

  19. Distribution of DNA strand breaks produced by iodine-123 and indium-111 in synthetic oligodeoxynucleotides.

    PubMed

    Karamychev, V N; Reed, M W; Neumann, R D; Panyutin, I G

    2000-01-01

    Antigene radiotherapy, a procedure based on delivery of short-range Auger-electron-emitting radioisotopes to target genes via sequence-specific triplex-forming oligonucleotides, has been successfully demonstrated in vitro using the well-studied radionuclide 125I. To proceed with in vivo trials, Auger electron emitters with shorter half-lives than 125I are required. Here we report a study of the efficiency and distribution of sequence-specific DNA strand breaks produced by decay of 123I and mIIn. 123I and 111In were introduced into triplex-and duplex-forming oligodeoxyribonucleotides (ODNs) through carbohydrate linkers of various lengths. Labeling with radioiodine was performed through tributylstannylbenzamide intermediates while 111In was attached via DTPA. The Auger-emitter-labeled ODNs were hybridized to a single-stranded DNA target, to form duplexes. After decay accumulation, the target DNA samples were assayed for strand breaks using a sequencing gel-electrophoresis technique. For the first time, we observed footprints of DNA strand breaks produced by 123I and 111In. Most of the breaks were located within 10 nucleotides from the decay site. The yield of strand breaks per decay varies; decay of 111In breaks DNA almost 10 times more effectively than decay of 123I. Both 123I and 111In are less effective in breaking DNA strands than 121I, which reflects the higher total energy of the Auger decay process of 125I.

  20. Dual isotope study of iodine-125 and indium-111-labeled antibody in athymic mice

    SciTech Connect

    Carney, P.L.; Rogers, P.E.; Johnson, D.K. )

    1989-03-01

    Monoclonal antibody B72.3 was coupled to a benzylisothiocyanate derivative of diethylenetriaminepentaacetic acid (DTPA). The maximum substitution achievable without loss of immunoreactivity was three DTPA groups per immunoglobulin molecule. The resulting conjugate was labeled with {sup 111}In by brief incubation with {sup 111}InCl{sub 3}, giving a mean radiochemical yield of {sup 111}In-labeled antibody of 96%. The ({sup 111}In)B72.3 preparation was mixed with an ({sup 125}I) B72.3 preparation, obtained by the chloramine-T method, and the mixture administered to athymic mice bearing subcutaneous LS174T colon carcinoma xenografts. There were no significant differences (p greater than 0.1) in the biodistributions of the two labels at 1, 2, 5, and 7 days postinjection. These results are contrasted with prior studies showing elevated levels of {sup 111}In in liver, spleen, and kidneys using B72.3-DTPA conjugates prepared via the bicyclic anhydride. It is concluded that protein cross-linking and/or the formation of unstable chelate sites in anhydride coupled conjugates underlie these disparities.

  1. Platelet coagulation-protein interactions.

    PubMed

    Walsh, Peter N

    2004-08-01

    The biochemical mechanisms by which activated platelets participate in exposing receptors for the assembly of enzyme-cofactor-substrate complexes at all stages of the blood coagulation cascade are reviewed. Information derived from studies conducted during the last 30 years supports the concept that the initiation of blood coagulation is triggered by exposure of tissue factor at injury sites, leading to the generation of minute quantities of thrombin (limited by tissue factor pathway inhibitor), sufficient to activate platelets, factors XI, VIII, and V, and trigger the consolidation pathway (i.e., the sequential activation of factors XI, IX, X, and prothrombin on the activated platelet surface), leading to the generation of sufficient thrombin to convert fibrinogen to fibrin and effect hemostasis. Platelets localize coagulation to the hemostatic thrombus and protect coagulation enzymes from inhibition by both plasma and platelet inhibitors (e.g., protease nexin 2), thus preventing disseminated intravascular coagulation.

  2. Platelets and angiogenesis in malignancy.

    PubMed

    Sierko, Ewa; Wojtukiewicz, Marek Z

    2004-02-01

    There is increasing evidence that platelets play an important role in the process of tumor angiogenesis. Thrombocytosis is a frequent finding in cancer patients (10-57%). Although the mechanisms underlying thrombocytosis are not yet fully elucidated, tumor-derived factors with thrombopoietin-like activity and growth factors, platelet-derived microparticles, and factors secreted from bone marrow endothelial cells, as well as growth factors released by megakaryocytes (acting via an autocrine loop), are postulated to influence this process. The progression of cancer is associated with hypercoagulability, which results from direct influences of tumor cells and diverse indirect mechanisms. Activated platelets serve as procoagulant surfaces amplifying the coagulation reactions. It is well known that hemostatic proteins are involved in different steps of the angiogenic process. Furthermore, platelets adhering to endothelium facilitate adhesion of mononuclear cells (which exert various proangiogenic activities) to endothelial cells and their transmigration to the extravascular space. It was also documented that platelets induce angiogenesis in vivo. Platelets are a rich source of proangiogenic factors. They also store and release angiogenesis inhibitors. In addition, platelets express surface growth factor receptors, which may regulate the process of angiogenesis. Platelets also contribute directly to the process of basement membrane and extracellular matrix proteolysis by releasing proteinases, or indirectly via inducing endothelial cells and tumor cells to release proteolytic enzymes, as well as through the proteolytic activities of platelet-derived growth factors. The multidirectional activities of platelets in the process of new blood vessel formation during tumor development and metastasis formation may create the possibility of introducing antiplatelet agents for antiangiogenic therapy in cancer patients. Thus far experimental studies employing inhibitors of

  3. Analyzing the platelet proteome.

    PubMed

    García, Angel; Zitzmann, Nicole; Watson, Steve P

    2004-08-01

    During the last 10 years, mass spectrometry (MS) has become a key tool for protein analysis and has underpinned the emerging field of proteomics. Using high-throughput tandem MS/MS following protein separation, it is potentially possible to analyze hundreds to thousands of proteins in a sample at a time. This technology can be used to analyze the protein content (i.e., the proteome) of any cell or tissue and complements the powerful field of genomics. The technology is particularly suitable for platelets because of the absence of a nucleus. Cellular proteins can be separated by either gel-based methods such as two-dimensional gel electrophoresis or one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis followed by liquid chromatography (LC) -MS/MS or by multidimensional LC-MS/MS. Prefractionation techniques, such as subcellular fractionations or immunoprecipitations, can be used to improve the analysis. Each method has particular advantages and disadvantages. Proteomics can be used to compare the proteome of basal and diseased platelets, helping to reveal information on the molecular basis of the disease.

  4. Platelet function and constituents of platelet rich plasma.

    PubMed

    Pelletier, M H; Malhotra, A; Brighton, T; Walsh, W R; Lindeman, R

    2013-01-01

    Platelet Rich Plasma (PRP) therapies require blood to be processed prior to application, however, the full assessment of the output of platelet sequestration devices is lacking. In this study the products of the Autologous Fluid Concentrator (Circle BiologicsTM, Minneapolis, MN) and the Gravitational Platelet Separation System (GPS, Biomet, Warsaw, IN, USA) were evaluated in terms of platelet viability and PRP constituents. The AFC and GPS produced 6.4 (±1.0) ml and 6.3 (±0.4) ml of PRP, with platelet recovery of 46.4% (±14.7%) and 59.8% (±24.2%) producing fold increases of platelets of 4.19 (±1.62) and 5.19 (±1.62), respectively. Fibrinogen concentration was increased above baseline PPP produced with the AFC. pH was lower for both of the processed samples than for whole blood. White Blood Cell count was increased around 5 fold. Functional tests showed preserved viability with both devices. This represents essential knowledge that every treating physician should have before they can confidently administer PRP therapy produced by any method. These are the first published results of platelet function for the GPS system and the first performance results of the AFC system. The PRP produced is classified according to broad classifications as Leukocyte-PRP (L-PRP) for both devices.

  5. Shiga toxin binds to activated platelets.

    PubMed

    Ghosh, S A; Polanowska-Grabowska, R K; Fujii, J; Obrig, T; Gear, A R L

    2004-03-01

    Hemolytic uremic syndrome (HUS) is associated with acute renal failure in children and can be caused by Shiga toxin (Stx)-producing Escherichia coli. Thrombocytopenia and formation of renal thrombi are characteristic of HUS, suggesting that platelet activation is involved in its pathogenesis. However, whether Shiga toxin directly activates platelets is controversial. The present study evaluates if potential platelet sensitization during isolation by different procedures influences platelet interaction with Shiga toxin. Platelets isolated from sodium citrate anticoagulated blood were exposed during washing to EDTA and higher g forces than platelets prepared from acid-citrate-dextrose (ACD) plasma. Platelet binding of Stx was significantly higher in EDTA-washed preparations relative to ACD-derived platelets. Binding of Stx was also increased with ACD-derived platelets when activated with thrombin (1 U mL-1) and exposure of the Gb3 Stx receptor was detected only on platelets subjected to EDTA, higher g forces or thrombin. EDTA-exposed platelets lost their normal discoid shape and were larger. P-selectin (CD62P) exposure was significantly increased in EDTA-washed preparations relative to ACD-derived platelets, suggesting platelet activation. Taken together, these results suggest that direct binding of Stx occurs only on 'activated' platelets rather than on resting platelets. The ability of Stx to interact with previously activated platelets may be an important element in understanding the pathogenesis of HUS.

  6. Radioimmune assay of human platelet prostaglandin synthetase

    SciTech Connect

    Roth, G.J.; Machuga, E.T.

    1982-02-01

    Normal platelet function depends, in part, on platelet PG synthesis. PG synthetase (cyclo-oxygenase) catalyzes the first step in PG synthesis, the formation of PGH/sub 2/ from arachidonic acid. Inhibition of the enzyme by ASA results in an abnormality in the platelet release reaction. Patients with pparent congenital abnormalities in the enzyme have been described, and the effects have been referred to as ''aspirin-like'' defects of the platelet function. These patients lack platelet PG synthetase activity, but the actual content of PG synthetase protein in these individuals' platelets is unknown. Therefore an RIA for human platelet PG synthetase would provide new information, useful in assessing the aspirin-like defects of platelet function. An RIA for human platelet PG synthetase is described. The assay utilizes a rabbit antibody directed against the enzyme and (/sup 125/I)-labelled sheep PG synthetase as antigen. The human platelet enzyme is assayed by its ability to inhibit precipitation of the (/sup 125/I)antigen. The assay is sensitive to 1 ng of enzyme. By the immune assay, human platelets contain approximately 1200 ng of PG synethetase protein per 1.5 mg of platelet protein (approximately 10/sup 9/ platelets). This content corresponds to 10,000 enzyme molecules per platelet. The assay provides a rapid and convenient assay for the human platelet enzyme, and it can be applied to the assessment of patients with apparent platelet PG synthetase (cyclo-oxygenase) deficiency.

  7. Platelet Interaction with Innate Immune Cells

    PubMed Central

    Kral, Julia Barbara; Schrottmaier, Waltraud Cornelia; Salzmann, Manuel; Assinger, Alice

    2016-01-01

    Summary Beyond their traditional role in haemostasis and thrombosis, platelets are increasingly recognised as immune modulatory cells. Activated platelets and platelet-derived microparticles can bind to leukocytes, which stimulates mutual activation and results in rapid, local release of platelet-derived cytokines. Thereby platelets modulate leukocyte effector functions and contribute to inflammatory and immune responses to injury or infection. Platelets enhance leukocyte extravasation, differentiation and cytokine release. Platelet-neutrophil interactions boost oxidative burst, neutrophil extracellular trap formation and phagocytosis and play an important role in host defence. Platelet interactions with monocytes propagate their differentiation into macrophages, modulate cytokine release and attenuate macrophage functions. Depending on the underlying pathology, platelets can enhance or diminish leukocyte cytokine production, indicating that platelet-leukocyte interactions represent a fine balanced system to restrict excessive inflammation during infection. In atherosclerosis, platelet interaction with neutrophils, monocytes and dendritic cells accelerates key steps of atherogenesis by promoting leukocyte extravasation and foam cell formation. Platelet-leukocyte interactions at sites of atherosclerotic lesions destabilise atherosclerotic plaques and promote plaque rupture. Leukocytes in turn also modulate platelet function and production, which either results in enhanced platelet destruction or increased platelet production. This review aims to summarise the key effects of platelet-leukocyte interactions in inflammation, infection and atherosclerosis. PMID:27226790

  8. Platelets effects on tumor growth.

    PubMed

    Goubran, Hadi A; Stakiw, Julie; Radosevic, Mirjana; Burnouf, Thierry

    2014-06-01

    Unlike other blood cells, platelets are small anucleate structures derived from marrow megakaryocytes. Thought for almost a century to possess solely hemostatic potentials, platelets, however, play a much wider role in tissue regeneration and repair and interact intimately with tumor cells. On one hand, tumor cells induce platelet aggregation (TCIPA), known to act as the trigger of cancer-associated thrombosis. On the other hand, platelets recruited to the tumor microenvironment interact, directly, with tumor cells, favoring their proliferation, and, indirectly, through the release of a wide palette of growth factors, including angiogenic and mitogenic proteins. In addition, the role of platelets is not solely confined to the primary tumor site. Indeed, they escort tumor cells, helping their intravasation, vascular migration, arrest, and extravasation to the tissues to form distant metastasis. As expected, nonspecific or specific inhibition of platelets and their content represents an attractive novel approach in the fight against cancer. This review illustrates the role played by platelets at primary tumor sites and in the various stages of the metastatic process.

  9. Platelets in inflammation and infection.

    PubMed

    Jenne, Craig N; Kubes, Paul

    2015-01-01

    Although platelets are traditionally recognized for their central role in hemostasis, many lines of research clearly demonstrate these rather ubiquitous blood components are potent immune modulators and effectors. Platelets have been shown to directly recognize, sequester and kill pathogens, to activated and recruit leukocytes to sites of infection and inflammation, and to modulate leukocyte behavior, enhancing their ability to phagocytose and kill pathogens and inducing unique effector functions, such as the production of Neutrophil Extracellular Traps (NETs). This multifaceted response to infection and inflammation is due, in part, to the huge array of soluble mediators and cell surface molecules expressed by platelets. From their earliest origins as primordial hemocytes in invertebrates to their current form as megakaryocyte-derived cytoplasts, platelets have evolved to be one of the key regulators of host intravascular immunity and inflammation. In this review, we present the diverse roles platelets play in immunity and inflammation associated with autoimmune diseases and infection. Additionally, we highlight recent advances in our understanding of platelet behavior made possible through the use of advanced imaging techniques that allow us to visualize platelets and their interactions, in real-time, within the intact blood vessels of a living host.

  10. Failure of Gallium-67 scintigraphy to identify reliably noninfectious interstitial nephritis: concise communication

    SciTech Connect

    Graham, G.D.; Lundy, M.M.; Moreno, A.J.

    1983-07-01

    Gallium-67 scintigraphy has been reported to be useful in the diagnosis of noninfectious interstitial nephritis. We studied 12 patients with Ga-67 citrate that were diagnosed as having noninfectious interstitial nephritis on renal biopsy. Only seven of the twelve patients with interstitial nephritis on biopsy were scan-positive. Gallium-67 scintigraphy may not reliably identify noninfectious interstitial nephritis.

  11. Incidental detection of a bleeding gastrointestinal stromal tumor on Tc-99m red blood cell scintigraphy.

    PubMed

    Santhosh, Sampath; Bhattacharya, Anish; Gupta, Vikas; Singh, Rajinder; Radotra, Bishan Dass; Mittal, Bhagwant Rai

    2012-10-01

    The role of 99m-technetium labeled red blood cell (RBC) scintigraphy in acute gastro-intestinal bleed is well-established. The authors report a case of a bleeding gastrointestinal stromal tumor (GIST) incidentally discovered on Tc-99m RBC scintigraphy.

  12. Studies on Human Platelet Gangliosides

    PubMed Central

    Marcus, Aaron J.; Ullman, Harris L.; Safier, Lenore B.

    1972-01-01

    Gangliosides, glycosphingolipids which contain sialic acid, were studied in human platelets. They represented 0.5% of the platelet lipids and accounted for 6% of the total neuraminic acid content of platelets. Three major ganglioside fractions were identified and characterized. Ganglioside I was hematoside (G6) and comprised 92% of the platelet gangliosides. It contained glucose, galactose, and sialic acid in molar ratios of 1:1:1 and no hexosamine. The major fatty acid was behenate (22:0). Ganglioside I was also identified in isolated platelet granules and membranes. Ganglioside II (5%) contained glucose, galactose, sialic acid, and hexosamines (molar ratios 1:2:1:1). The hexosamines were glucosamine (72%) and galactosamine (28%). It was therefore designated as ganglioside lacto-N-neotetraose. Ganglioside III (2%) contained disialosyllactosyl ceramide (G3A) as well as two other gangliosides which could not be precisely characterized. Gangliosides I, II, and III were susceptible to the action of Clostridium perfringens neuraminidase as evidenced by full recovery of sialic acid in its free form after incubation. Neutral platelet glycolipids were qualitatively examined by thin-layer chromatography. The major component was lactosyl ceramide. Interactions of gangliosides I and III and serotonin-14C were examined in an equilibrium dialysis system at 4°C. The gangliosides bound serotonin-14C in relatively small quantities, whereas control lipids were negative. The binding was essentially unchanged by reverse dialysis, ultracentrifugation and subsequent thin-layer chromatography. The results are comparable to the previously observed nonmetabolic interactions between whole platelets and serotonin in the cold. It is suggested that the orientation and specific distribution of platelet membrane glycolipids may be important determinants of the unique surface properties of platelets. Images PMID:4341436

  13. Platelet function in Takotsubo cardiomyopathy.

    PubMed

    Núñez-Gil, Iván J; Bernardo, Esther; Feltes, Gisela; Escaned, Javier; Mejía-Rentería, Hernán D; De Agustín, José Alberto; Vivas, David; Nombela-Franco, Luis; Jiménez-Quevedo, Pilar; Macaya, Carlos; Fernández-Ortiz, Antonio

    2015-05-01

    Takotsubo cardiomyopathy (TK) includes a transient left ventricular dysfunction without obstructive coronary disease, sometimes after stressful situations with elevated cathecolamines. Since catecholamines activate platelets we aimed to study the platelet influence in a TK setting. We included 32 patients with a TK diagnosis, 13 with an acute coronary syndrome (ACS) and 18 healthy volunteers. Once consent informed was obtained, blood samples were extracted and processed (at admission and after 3 months follow-up). Clinical, ecg, echocardiographic and angiographic features were thoroughly recorded.Previous treatment before admission was similar between groups. No differences were observed in clinical features or any of the acute markers studied regarding platelet reactivity between TK compared to ACS. After follow-up, aggregation levels and platelet reactivity showed differences, mainly due to the antithrombotic therapy prescribed at discharge, but similar to volunteers. Circulating epinephrine during the acute phase was significantly higher in TK (p < 0.001). Patients with higher levels of epinephrine had elevated platelet activation and aggregation after 3 months. No differences were observed in Takotsubo acute platelet aggregation compared to patients with ACS, in spite of higher blood levels of adrenaline. Takotsubo patients had elevated platelet aggregation and activation compared with ACS patients at 3 months follow-up because they were less frequently on chronic clopidogrel and ASA. However, they had similar platelet aggregation and activation levels to healthy volunteers despite treatment with low-dose ASA. Takotsubo patients who had higher levels of adrenaline in the acute phase displayed increased platelet reactivity during follow-up.

  14. Diffuse Hepatic and Spleen Uptake of Tc-99m MDP on Bone Scintigraphy Resembling Liver-Spleen Scintigraphy in a Patient of Plasma Cell Tumor.

    PubMed

    Ravanbod, Mohammad Reza; Nemati, Reza; Javadi, Hamid; Nabipour, Iraj; Assadi, Majid

    2014-01-01

    The present case demonstrates a diffuse intense hepatic and, to a lesser degree, spleen, Tc-99m MDP uptake on a routine bone scintigraphy resembling liver-spleen imaging. A 49-year-old female with a history of anaplastic plasma cell tumor and suffering from bone pain was referred for bone scintigraphy to evaluate possible bone metastases. The bone scintigraphy showed diffuse hepatic and spleen uptake of Tc-99m MDP resembling liver-spleen imaging. Furthermore, bone uptake of Tc-99m MDP was significantly diminished and there were no abnormal foci throughout the skeleton. The bone scintigraphy of the present case of an anaplastic plasma cell tumor suggests the possible presence of amyloidosis.

  15. Value of bone scintigraphy for detection and ageing of vertebral fractures in patients with severe osteoporosis and correlation between bone scintigraphy and mineral bone density.

    PubMed

    Kucukalic-Selimovic, Elma; Begic, Amela

    2004-01-01

    Osteoporosis is the most common of the metabolic bone diseases, and is an important cause of morbidity in the elderly. Bone scintigraphy is used to detect skeletal lesions at the earliest possible time, to monitor the course of the skeletal discase and to evaluate the metabolic activity of skeletal lesions. The aim of this study was to determine, by using the bone scan age of vertebral fractures in patients with severe osteoporosis, and make correlation between bone scintigraphy and mineral bone density. Material and methods 30 female patients were studied with bone scintigraphy after BMD.BMD was measurred with DEXA Hologic QDR 4500 Elite System. Correlation between T-score and uptake of radiofarmaceutical (Tc-99mMDP) was 0.849, and it was high. Intensity of uptake of Tc-99m MDP scintigraphy is an accurate method for the detection and ageing of fractures in osteoporotic patients.

  16. Thallium-201 scintigraphy of the suppressed thyroid: an alternative for iodine-123 scanning after TSH stimulation

    SciTech Connect

    Corstens, F.; Huysmans, D.; Kloppenborg, P.

    1988-08-01

    Thallium-201 scintigraphy of the thyroid gland suppressed by autonomous nodule was compared with /sup 123/I scintigraphy after TSH stimulation. In all patients, similar images were obtained by both methods. In 20 patients, the contralateral lobe was visualized on both scans and in 14 of these, the upper pole of the ipsilateral lobe was also visualized. In one patient, neither /sup 123/I scanning after TSH nor /sup 201/TI scintigraphy showed any extranodular tissue. This study suggests that /sup 201/TI scintigraphy is a reliable alternative for scanning after TSH. It is a relatively simple method, not inducing any TSH-related allergic reactions. Iodine uptake in extranodular tissue is not stimulated and therefore, /sup 201/TI scintigraphy and radioiodine therapy can be combined on one day, without increasing the risk of radiation damage to the normal thyroid tissue with a resultant post-treatment hypothyroidism.

  17. Platelet and red blood cell indices in Harris platelet syndrome.

    PubMed

    Naina, Harris V K; Harris, Samar

    2010-01-01

    Inherited thrombocytopenias, including inherited giant platelet disorders (IGPD) or macro thrombocytopenias are relatively rare, but their prevalence is likely underestimated from complexities of diagnosis and a spectrum of subclinical phenotypes. Harris platelet syndrome (HPS) is the most common IGPD reported from the Indian subcontinent. Of note there are an increased number of hemoglobinopathies reported from the geographic location. We analysed red blood cell and platelet indices of blood donors with HPS from the north eastern part of India and compared them with blood indices of blood donors of south India. We found a statistically significant lower platelet count in blood donors with HPS (median, range) 132 (71-267) vs. 252 (160-478) as compared to donors from south India (P < 0.001). Mean platelet volume (MPV) was higher in donors with HPS 13.1, (range 12-21.9 fl) as compared to donors from south India 7.35 (range 6-9.2 fl) (P < 0.001). This study showed that blood donors with HPS had a low median platelet bio-mass 0.17 (0.10-0.38%) vs. 0.19 (0.13-0.28%) in donors from south India. The platelet distribution width (PDW) was 17.4 (14.9-19.6) in donors with HPS vs. 16.38 (15.2-18.5) in south Indian blood donors (P < 0.001). Thirty-three donors with HPS had a normal platelet count with MPV more than 12 fL. Only donors with HPS had giant platelets and thrombocytopenia on peripheral blood smear examination. None of these donors had Dohle body inclusion in their leukocytes. Compared to donors from south India, donors with HPS had a significantly lower hemoglobin 13.8 (12-16.3 gm/dL) vs. 14.8 (12-18) respectively (P < 0.001) while red distribution width (RDW) was higher in HPS 13.6 (11.5-16.7) vs. 12.8 (11.4-15.1). However we did not find any statistically significant difference in MCV, MCH, MCHC between the two groups. Peripheral blood smear did not show any obvious abnormal red blood cell morphology. In the blood donors with HPS we found a statistically higher MPV

  18. The Platelet Function Defect of Cardiopulmonary Bypass.

    DTIC Science & Technology

    1992-11-24

    fibrinolytic and coagulation systems occur during CPB,1 a platelet function defect is generally considered to be the primary CPB-induced hemostatic...platelets.39 OKM5 (provided by Dr. Patricia Rao, Ortho Diagnostic Systems , Raritan, NJ) is directed against platelet membrane GPIV.40 Flow Cytometric...22 after degranulation.7-14-16-18 Utilizing washed platelet systems , Nieuwenhuis et al.14 found a modest increase during CPB of the platelet

  19. Autologous platelet-labeling in thrombocytopenia

    SciTech Connect

    Sinzinger, H.; Virgolini, I.; Vinazzer, H. )

    1990-11-01

    Field studies performed with peripheral platelets obtained from 6 male volunteers aged 23 to 29 years revealed an extraordinary dependence of labeling efficiency on incubation time and platelet concentration after {sup 111}In-oxine platelet labeling. Since the monitoring of in vivo-platelet function in patients with thrombocytopenia may cause problems due to insufficient labeling results and homologous platelets may show a different in vivo behaviour to autologous ones, we have searched for the minimal amount of platelets necessary to allow appropriate labeling and imaging in patients with thrombocytopenia. In 15 patients with untreated thrombocytopenia aged 14 to 79 years demonstrating a mean peripheral platelet count of 2.509 +/- 1.45 x 10(4) cells/microliters autologous {sup 111}In-oxine platelet labeling was performed. The results indicate that approximately 1 x 10(8) (concentrated) platelets/ml are necessary to obtain an adequate labeling efficiency and recovery. This platelet concentration can be easily achieved by drawing one more Monovette of whole blood per each 5 x 10(4) platelets/microliter peripheral platelet count less than 2 x 10(5)/microliter. It is concluded, that calculation of the required number of platelets in advance, variation of the blood volume drawn and the volume of incubation buffer allow informative, qualitative and quantitative results using autologous platelets. The method presented effectively circumvents the requirement of homologous platelets for radiolabeling in thrombocytopenia.

  20. Perfusion Scintigraphy and Patient Selection for Lung Volume Reduction Surgery

    PubMed Central

    Chandra, Divay; Lipson, David A.; Hoffman, Eric A.; Hansen-Flaschen, John; Sciurba, Frank C.; DeCamp, Malcolm M.; Reilly, John J.; Washko, George R.

    2010-01-01

    Rationale: It is unclear if lung perfusion can predict response to lung volume reduction surgery (LVRS). Objectives: To study the role of perfusion scintigraphy in patient selection for LVRS. Methods: We performed an intention-to-treat analysis of 1,045 of 1,218 patients enrolled in the National Emphysema Treatment Trial who were non–high risk for LVRS and had complete perfusion scintigraphy results at baseline. The median follow-up was 6.0 years. Patients were classified as having upper or non–upper lobe–predominant emphysema on visual examination of the chest computed tomography and high or low exercise capacity on cardiopulmonary exercise testing at baseline. Low upper zone perfusion was defined as less than 20% of total lung perfusion distributed to the upper third of both lungs as measured on perfusion scintigraphy. Measurements and Main Results: Among 284 of 1,045 patients with upper lobe–predominant emphysema and low exercise capacity at baseline, the 202 with low upper zone perfusion had lower mortality with LVRS versus medical management (risk ratio [RR], 0.56; P = 0.008) unlike the remaining 82 with high perfusion where mortality was unchanged (RR, 0.97; P = 0.62). Similarly, among 404 of 1,045 patients with upper lobe–predominant emphysema and high exercise capacity, the 278 with low upper zone perfusion had lower mortality with LVRS (RR, 0.70; P = 0.02) unlike the remaining 126 with high perfusion (RR, 1.05; P = 1.00). Among the 357 patients with non–upper lobe–predominant emphysema (75 with low and 282 with high exercise capacity) there was no improvement in survival with LVRS and measurement of upper zone perfusion did not contribute new prognostic information. Conclusions: Compared with optimal medical management, LVRS reduces mortality in patients with upper lobe–predominant emphysema when there is low rather than high perfusion to the upper lung. PMID:20538961

  1. Platelet serotonin modulates immune functions.

    PubMed

    Mauler, M; Bode, C; Duerschmied, D

    2016-01-01

    This short review addresses immune functions of platelet serotonin. Platelets transport serotonin at a high concentration in dense granules and release it upon activation. Besides haemostatic, vasotonic and developmental modulation, serotonin also influences a variety of immune functions (mediated by different serotonin receptors). First, platelet serotonergic effects are directed against invading pathogens via activation and proliferation of lymphocytes, modulation of cytokine release, and recruitment of neutrophils to sites of acute inflammation by induction of selectin expression on endothelial cells. Second, serotonin levels are elevated in autoimmune diseases, such as asthma or rheumatoid arthritis, and during tissue regeneration after ischemia of myocardium or brain. Specific antagonism of serotonin receptors appears to improve survival after myocardial infarction or sepsis and to attenuate asthmatic attacks in animal models. It will be of great clinical relevance if these findings can be translated into human applications. In conclusion, targeting immune modulatory effects of platelet serotonin may provide novel therapeutic options for common health problems.

  2. Skeletal Scintigraphy in Radiation-Induced Fibrosis With Lymphedema.

    PubMed

    Wang, Jieqi; Iranmanesh, Arya M; Oates, M Elizabeth

    2017-03-01

    Despite increasing reliance on CT, MRI, and FDG PET/CT for oncological imaging, whole-body skeletal scintigraphy remains a frontline modality for staging and surveillance of osseous metastatic disease. We present a 54-year-old woman with metastatic breast cancer who received palliative external-beam radiation to the left ilium. Serial follow-up Tc-MDP bone scans demonstrated progressive soft-tissue uptake in her left lower extremity, extending from thigh to leg, with associated enlargement and skin thickening, consistent with lymphedema related to radiation-induced fibrosis. Correlative abdominopelvic CT scans confirmed fibrotic changes in the left thigh.

  3. Three-phase bone scintigraphy in Pellegrini-Stieda disease.

    PubMed

    Liu, R S; Chou, C S; Yeh, S H

    1987-01-01

    In a patient with Pellegrini-Stieda disease, radiographs of the knees were unremarkable at the time the three-phase bone scintigraphy was abnormal. The results of follow-up radiographs three months later remained normal in the left knee, where local steroid injection was given, but revealed typical positive results in the right knee with no treatment. The three-phase bone scintigraphic pattern is rather typical and antedates the radiographic changes. Thus, the radionuclide technique would provide a useful procedure for the early diagnosis and treatment of Pellegrini-Stieda disease.

  4. Radiation hazards from horses undergoing scintigraphy using technetium-99m.

    PubMed

    Whitelock, R G

    1997-01-01

    This paper quantifies the extent of the radiation hazard to personnel from horses undergoing scintigraphy using technetium99m methylene diphosphonate (99Tcm-MDP). From the data produced it is possible to derive safe working protocols which are comfortably within the legislated limits for whole body doses as set out in the Ionising Radiations Regulations 1985. Measurements were made of the surface and environmental activities which result from individuals undergoing scintigraphic evaluation and also from urine contaminated bedding. The use of both high and low activities in the assessment of the radiation hazard to personnel and owners is considered.

  5. Gallium scintigraphy in a case of tuberculous trochanteric bursitis.

    PubMed

    Kawamura, Etsushi; Kawabe, Joji; Tsumoto, Chikako; Hayashi, Takehiro; Oe, Ai; Kurooka, Hiroko; Kotani, Jin; Higashiyama, Shigeaki; Tsushima, Hiroyuki; Habu, Daiki; Shiomi, Susumu

    2007-06-01

    We report a 67-year-old woman with systemic lupus erythematosus and systemic disseminated tuberculosis affecting the femoral trochanteric bursae, a site rarely affected by tuberculosis. For quantification of the inflammation with gallium-67 scintigraphy, we calculated the radioisotope count ratio in the most inflamed areas, the right lateral thorax and bursa of the right greater trochanter. Systemic scanning with this modality allowed evaluation of the extent of lesions and simple quantitative determination of the severity of inflammation, yielding information useful for the follow-up of the patient during the course of tuberculosis treatment.

  6. Rare case of thoracic kidney detected by renal scintigraphy

    PubMed Central

    Natarajan, Aravintho; Agrawal, Archi; Purandare, Nilendu; Shah, Sneha; Rangarajan, Venkatesh

    2016-01-01

    Intrathoracic kidney is a rare congenital abnormality with lowest frequency among all renal ectopias. Patients with thoracic kidneys are usually asymptomatic, and the condition is usually discovered incidentally during radiological evaluation for other conditions or during thoracic surgery. We report a case of a 62-year-old male who was referred to our department for renal scintigraphy for a nonvisualized left kidney on ultrasonography report. Both Tc-99m dimercaptosuccinic acid and diethylenetriaminepentaacetic acid scans revealed a left thoracic kidney which was confirmed by CT scan of the thorax and abdomen. PMID:27385896

  7. Complement Activation Alters Platelet Function

    DTIC Science & Technology

    2014-10-01

    Negative T cells than B6.lpr mice. This suggests that the absence of PF4 alleviates some tissue damage in the lupus prone mice. 6...mice with PF4-/- mice may alleviate multi organ dysfunction in Lupus prone mice. Reportable Outcomes Nothing to report Conclusions We have...dysfunction in lupus models. We have evaluated the relationship between Syk and platelets and have thus far identified a role for Syk in platelet lodging in

  8. Future innovations in anti-platelet therapies

    PubMed Central

    Barrett, N E; Holbrook, L; Jones, S; Kaiser, W J; Moraes, L A; Rana, R; Sage, T; Stanley, R G; Tucker, K L; Wright, B; Gibbins, J M

    2008-01-01

    Platelets have long been recognized to be of central importance in haemostasis, but their participation in pathological conditions such as thrombosis, atherosclerosis and inflammation is now also well established. The platelet has therefore become a key target in therapies to combat cardiovascular disease. Anti-platelet therapies are used widely, but current approaches lack efficacy in a proportion of patients, and are associated with side effects including problem bleeding. In the last decade, substantial progress has been made in understanding the regulation of platelet function, including the characterization of new ligands, platelet-specific receptors and cell signalling pathways. It is anticipated this progress will impact positively on the future innovations towards more effective and safer anti-platelet agents. In this review, the mechanisms of platelet regulation and current anti-platelet therapies are introduced, and strong, and some more speculative, potential candidate target molecules for future anti-platelet drug development are discussed. PMID:18587441

  9. Unraveling mechanisms that control platelet production.

    PubMed

    Italiano, Joseph E

    2013-02-01

    Platelets are formed by giant precursor cells called megakaryocytes that reside within the bone marrow. The generation of platelets, and their release into the bloodstream by megakaryocytes, requires a complex series of remodeling events powered by the cytoskeleton to result in the release of many platelets from a single megakaryocyte. Abnormalities in this process can result in thrombocytopenia (low platelet count) and can lead to increased risk of bleeding. This review describes the process of platelet production in detail and discusses new insights into novel platelet biology.

  10. Detection of platelet alloimmunity with a platelet-associated IgG assay

    SciTech Connect

    Myers, T.J.; Kim, B.K.; Steiner, M.; Bishop, J.; Baldini, M.G.

    1981-06-01

    A quantitative immunofluorescence PA-IgG assay was used to detect alloimmunity to platelets. The assay identified serum alloantibodies in 10 out of 14 multitransfused patients and for two of three infants with neonatal thrombocytopenia. The correct separation of all multitransfused patients into alloimmune and nonalloimmune groups by the PA-IgG assay was substantiated with chromium-51-labeled platelet survival studies. The allogeneic nature of the serum antibodies was demonstrated by progressive absorption of the antibody with increasing numbers of allogeneic platelets but not with autologous platelets. The sensitivity of the PA-IgG assay for detection of serum alloantibodies was superior to that of platelet aggregation, platelet serotonin release, and lymphocytotoxicity testing. In dilution experiments with alloimmune serum, elevated levels of serum PA-IgG could still be detected on donor platelets when platelet aggregation and serotonin release tests became negative. Platelet survival studies with selected platelets performed in the 10 alloimmunized, multitransfused patients confirmed the results of the PA-IgG assays, predicting alloimmunity to the donor platelets. In contrast, platelet aggregation, platelet serotonin release, and lymphocytotoxicity testing indicated alloimmunity for 50% or less of the patients. Reduced platelet survival times were also seen with HLA A- and HLA B-matched donor platelets when donor-recipient incompatibility was demonstrated by the PA-IgG assay. Thus the PA-IgG assay provides a sensitive method to detect serum platelet alloantibodies and may offer a technique in platelet crossmatching.

  11. Impact of reticulated platelets on antiplatelet response to thienopyridines is independent of platelet turnover.

    PubMed

    Stratz, Christian; Nührenberg, Thomas; Amann, Michael; Cederqvist, Marco; Kleiner, Pascal; Valina, Christian M; Trenk, Dietmar; Neumann, Franz-Josef; Hochholzer, Willibald

    2016-10-28

    Reticulated platelets are associated with impaired antiplatelet response to thienopyridines. It is uncertain whether this interaction is caused by a decreased drug exposure due to high platelet turnover reflected by elevated levels of reticulated platelets or by intrinsic properties of reticulated platelets. This study sought to investigate if the impact of reticulated platelets on early antiplatelet response to thienopyridines is mainly caused by platelet turnover as previously suggested. Elective patients undergoing coronary intervention were randomised to loading with clopidogrel 600 mg or prasugrel 60 mg (n=200). Adenosine diphosphate (ADP)-induced platelet reactivity was determined by impedance aggregometry before, at 30, 60, 90, and 120 minutes and at day 1 after loading. Immature platelet count was assessed as marker of reticulated platelets by flow cytometry. Platelet reactivity increased with rising levels of immature platelet count in both groups. This effect was more distinctive in patients on clopidogrel as compared to patients on prasugrel. Overall, immature platelet count correlated well with on-treatment platelet reactivity at all time-points (p < 0.001). These correlations did not change over time in the entire cohort as well as in patients treated with clopidogrel or prasugrel indicating an effect independent of platelet turnover (comparison of correlations 120 minutes/day 1: p = 0.64). In conclusion, the association of immature platelet count with impaired antiplatelet response to thienopyridines is similar early and late after loading. This finding suggests as main underlying mechanism another effect of reticulated platelets on thienopyridines than platelet turnover.

  12. Acute pyelonephritis resulting in intense vascular blush during dynamic renal scintigraphy

    PubMed Central

    Joshi, Prathamesh; Deshpande, Sushil; Kulkarni, Mukta; Shetkar, Shubhangi

    2016-01-01

    A thirty-year-old male underwent Tc-99m diethylenetriaminepentaacetic acid renal scintigraphy for evaluation of gross hydronephrosis of left kidney. The perfusion phase revealed an intense vascular blush in left renal fossa. The uptake phase of scintigraphy revealed the absence of tracer uptake in left kidney. Contrast-enhanced computed tomography (CECT) was performed for evaluating the cause of vascular blush. CECT demonstrated features suggestive of acute pyelonephritis (APN) involving lower pole of the hydronephrotic left kidney, corresponding to the site of vascular blush seen on renal scintigraphy. The postnephrectomy specimen confirmed the diagnosis of APN suggested on CECT. PMID:26917903

  13. Congenital renal anomaly: evaluation with 99mTc-dimercaptosuccinic acid renal scintigraphy.

    PubMed

    Hosokawa, S; Kawamura, J; Tomoyoshi, T; Yoshida, O

    1983-05-01

    Technetium 99m-2,3, dimercaptosuccinic acid (99mTc-DMSA) preferentially accumulates in the renal cortex, demonstrating functioning cortical mass. We used 99mTc-DMSA renal scintigraphy in ten patients with horseshoe kidneys and five patients with unilateral fused kidneys. The results show that 99mTc-DMSA renal scintigraphy reliably establishes the diagnosis of horseshoe kidney and clearly shows the isthmus, which is very essential for proper management. The technique also aids in the definitive assessment of separate kidney function and of total radionuclide uptake is possible using 99mTc-DMSA scintigraphy.

  14. Uremic Leontiasis Ossea in a Patient With Chronic Renal Insufficiency Demonstrated on Bone Scintigraphy.

    PubMed

    Han, Yeon-Hee; Jeong, Hwan-Jeong; Lim, Seok Tae; Sohn, Myung-Hee

    2016-08-01

    A 37-year-old woman with chronic renal insufficiency underwent bone scintigraphy to evaluate renal osteodystrophy (ROD). Markedly increased uptakes were shown in the maxilla and the mandible, which suggested extensive maxillary and mandibular hypertrophy. CT image revealed that diffuse bony thickening and ground-glass appearance in the skull, maxilla, and mandible with poor distinction of the corticomedullary junction. Whole-body bone scintigraphy images also demonstrated various skeletal characteristics of ROD. This case emphasizes the utility of bone scintigraphy for the surveillance of the whole body in ROD.

  15. 123I-Metaiodobenzylguanidine Myocardial Scintigraphy in Lewy Body-Related Disorders: A Literature Review

    PubMed Central

    Chung, Eun Joo; Kim, Sang Jin

    2015-01-01

    Lewy body-related disorders are characterized by the presence of Lewy bodies and Lewy neurites, which have abnormal aggregations of α-synuclein in the nigral and extranigral areas, including in the heart. 123I-metaiodobenzylguanidine (MIBG) scintigraphy is a well-known tool to evaluate cardiac sympathetic denervation in the Lewy body-related disorders. MIBG scintigraphy showed low uptake of MIBG in the Lewy body-related disorders, including Parkinson’s disease, dementia with Lewy bodies, pure autonomic failure and rapid eye movement sleep behavior disorder. This review summarizes previous results on the diagnostic applications of MIBG scintigraphy in Lewy body-related disorders. PMID:26090077

  16. Congenital renal anomaly: evaluation with 99mTc-dimercaptosuccinic acid renal scintigraphy

    SciTech Connect

    Hosokawa, S.; Kawamura, J.; Tomoyoshi, T.; Yoshida, O.

    1983-05-01

    Technetium 99m-2,3, dimercaptosuccinic acid (99mTc-DMSA) preferentially accumulates in the renal cortex, demonstrating functioning cortical mass. We used 99mTc-DMSA renal scintigraphy in ten patients with horseshoe kidneys and five patients with unilateral fused kidneys. The results show that 99mTc-DMSA renal scintigraphy reliably establishes the diagnosis of horseshoe kidney and clearly shows the isthmus, which is very essential for proper management. The technique also aids in the definitive assessment of separate kidney function and of total radionuclide uptake is possible using 99mTc-DMSA scintigraphy.

  17. Dynamic light scattering can determine platelet function

    NASA Astrophysics Data System (ADS)

    Lee, Nathan

    2011-10-01

    Platelet transfusions are life-saving procedures for patients who are bleeding or undergoing chemotherapy. The effectiveness of transfusions depends on the number of platelets transfused and the platelet function. Platelet function correlates with proportion of discoid to activated platelets, morphology response to temperature stress, and inversely correlates with microparticle content. ThromboLUX is a novel device that determines platelet function by measuring all of these characteristics using dynamic light scattering (DLS). During periods of stress, such as decreased temperature, cytoskeletal rearrangements will cause normal, discoid platelets to activate and become spiny spheres. The formation of pseudopods of various lengths facilitates the clotting cascade and also increases the apparent size of platelets. ThromboLUX uses a 37-20-37 C temperature cycle that mimics the bleeding, storage, and transfusion process. As the temperature fluctuates, DLS will measure the changing platelet hydrodynamic radius and the size of any microparticles present. ThromboLUX analysis of platelet concentrates in vitro would allow determination of high platelet function units before transfusion and would therefore improve transfusion outcomes and patient safety. This study examined how DLS is able to distinguish between discoid and activated platelets as well as measure the parameters that contribute to high platelet function.

  18. Relationships between platelet counts, platelet volumes and reticulated platelets in patients with ITP: evidence for significant platelet count inaccuracies with conventional instrument methods.

    PubMed

    Diquattro, M; Gagliano, F; Calabrò, G M; Tommasi, M; Scott, C S; Mancuso, G; Palma, B; Menozzi, I

    2009-04-01

    The platelet count has a primary role in the diagnosis and treatment of idiopathic thrombocytopenic purpura (ITP). This study analysed the accuracy of ITP patient platelet counts determined by Abbott CD-Sapphire (impedance/optical) and Bayer Advia 120 (optical) analyses, compared with a reference immunoplatelet method. Instrument platelet estimates showed broad equivalence in the higher range of observed values, but significant discrepancies against the immunoplatelet count were seen when platelet counts were <10 x 10(9)/l. CD-Sapphire mean platelet volume (MPV) results revealed increased (>12 fl) platelet volumes in eight of eight ITP patients with counts of <20 x 10(9)/l compared with 6/6 and 5/13 patients with platelet counts of 20-50 and >50 x 10(9)/l. In contrast, Bayer Advia MPV values showed no relationship with the platelet count. Increased reticulated platelets were associated with an increasing CD-Sapphire MPV (R(2) = 0.61) and a decreasing platelet count. High (>40%) reticulated platelet values were seen in 9/9 patients with immunoplatelet counts of <20 x 10(9)/l compared with 0/19 patients with platelet counts above 20 x 10(9)/l. There may be a need for caution in the interpretation of platelet counts in ITP patients obtained with conventional instrument methods, and therapeutic decisions should ideally be validated by reference immunoplatelet procedures.

  19. Platelet function tests: a comparative review.

    PubMed

    Paniccia, Rita; Priora, Raffaella; Liotta, Agatina Alessandrello; Abbate, Rosanna

    2015-01-01

    In physiological hemostasis a prompt recruitment of platelets on the vessel damage prevents the bleeding by the rapid formation of a platelet plug. Qualitative and/or quantitative platelet defects promote bleeding, whereas the high residual reactivity of platelets in patients on antiplatelet therapies moves forward thromboembolic complications. The biochemical mechanisms of the different phases of platelet activation - adhesion, shape change, release reaction, and aggregation - have been well delineated, whereas their complete translation into laboratory assays has not been so fulfilled. Laboratory tests of platelet function, such as bleeding time, light transmission platelet aggregation, lumiaggregometry, impedance aggregometry on whole blood, and platelet activation investigated by flow cytometry, are traditionally utilized for diagnosing hemostatic disorders and managing patients with platelet and hemostatic defects, but their use is still limited to specialized laboratories. To date, a point-of-care testing (POCT) dedicated to platelet function, using pertinent devices much simpler to use, has now become available (ie, PFA-100, VerifyNow System, Multiplate Electrode Aggregometry [MEA]). POCT includes new methodologies which may be used in critical clinical settings and also in general laboratories because they are rapid and easy to use, employing whole blood without the necessity of sample processing. Actually, these different platelet methodologies for the evaluation of inherited and acquired bleeding disorders and/or for monitoring antiplatelet therapies are spreading and the study of platelet function is strengthening. In this review, well-tried and innovative platelet function tests and their methodological features and clinical applications are considered.

  20. Platelet function tests: a comparative review

    PubMed Central

    Paniccia, Rita; Priora, Raffaella; Alessandrello Liotta, Agatina; Abbate, Rosanna

    2015-01-01

    In physiological hemostasis a prompt recruitment of platelets on the vessel damage prevents the bleeding by the rapid formation of a platelet plug. Qualitative and/or quantitative platelet defects promote bleeding, whereas the high residual reactivity of platelets in patients on antiplatelet therapies moves forward thromboembolic complications. The biochemical mechanisms of the different phases of platelet activation – adhesion, shape change, release reaction, and aggregation – have been well delineated, whereas their complete translation into laboratory assays has not been so fulfilled. Laboratory tests of platelet function, such as bleeding time, light transmission platelet aggregation, lumiaggregometry, impedance aggregometry on whole blood, and platelet activation investigated by flow cytometry, are traditionally utilized for diagnosing hemostatic disorders and managing patients with platelet and hemostatic defects, but their use is still limited to specialized laboratories. To date, a point-of-care testing (POCT) dedicated to platelet function, using pertinent devices much simpler to use, has now become available (ie, PFA-100, VerifyNow System, Multiplate Electrode Aggregometry [MEA]). POCT includes new methodologies which may be used in critical clinical settings and also in general laboratories because they are rapid and easy to use, employing whole blood without the necessity of sample processing. Actually, these different platelet methodologies for the evaluation of inherited and acquired bleeding disorders and/or for monitoring antiplatelet therapies are spreading and the study of platelet function is strengthening. In this review, well-tried and innovative platelet function tests and their methodological features and clinical applications are considered. PMID:25733843

  1. CD8+ T cells induce platelet clearance in the liver via platelet desialylation in immune thrombocytopenia

    PubMed Central

    Qiu, Jihua; Liu, Xuena; Li, Xiaoqing; Zhang, Xu; Han, Panpan; Zhou, Hai; Shao, Linlin; Hou, Yu; Min, Yanan; Kong, Zhangyuan; Wang, Yawen; Wei, Yu; Liu, Xinguang; Ni, Heyu; Peng, Jun; Hou, Ming

    2016-01-01

    In addition to antiplatelet autoantibodies, CD8+ cytotoxic T lymphocytes (CTLs) play an important role in the increased platelet destruction in immune thrombocytopenia (ITP). Recent studies have highlighted that platelet desialylation leads to platelet clearance via hepatocyte asialoglycoprotein receptors (ASGPRs). Whether CD8+ T cells induce platelet desialylation in ITP remains unclear. Here, we investigated the cytotoxicity of CD8+ T cells towards platelets and platelet desialylation in ITP. We found that the desialylation of fresh platelets was significantly higher in ITP patients with positive cytotoxicity of CD8+ T cells than those without cytotoxicity and controls. In vitro, CD8+ T cells from ITP patients with positive cytotoxicity induced significant platelet desialylation, neuraminidase-1 expression on the platelet surface, and platelet phagocytosis by hepatocytes. To study platelet survival and clearance in vivo, CD61 knockout mice were immunized and their CD8+ splenocytes were used. Platelets co-cultured with these CD8+ splenocytes demonstrated decreased survival in the circulation and increased phagocytosis in the liver. Both neuraminidase inhibitor and ASGPRs competitor significantly improved platelet survival and abrogated platelet clearance caused by CD8+ splenocytes. These findings suggest that CD8+ T cells induce platelet desialylation and platelet clearance in the liver in ITP, which may be a novel mechanism of ITP. PMID:27321376

  2. Current status of additive solutions for platelets.

    PubMed

    Alhumaidan, Hiba; Sweeney, Joseph

    2012-01-01

    The storage of platelets in additive solution (PAS) had lagged behind red cell concentrates, especially in North America. The partial or complete removal of anticoagulated plasma and storage of platelet concentrates in AS presents many advantages. The PAS can be formulated to optimize aerobic metabolism or decrease platelet activation, thus abrogating the platelet storage lesion and potentially improving in vivo viability. Plasma removal has been shown to reduce allergic reactions and the plasma harvested could contribute to the available plasma pool for transfusion or fractionation. PAS coupled to pathogen reduction technology results in a platelet product of equivalent hemostatic efficacy to conventionally stored platelets. Given the above, the likely future direction of platelet storage will be in new generation designer PAS with an extended shelf life and a superior safety profile to plasma stored platelets. J. Clin. Apheresis, 2012. © 2012 Wiley Periodicals, Inc.

  3. [Activation and inhibitory mechanisms of blood platelets].

    PubMed

    Suzuki-Inoue, Katsue

    2014-07-01

    Exposure of platelets to subendothelial matrices initiates physiological hemostasis and pathological thrombosis. Under high shear stress, von Willebrand factor bridges newly exposed collagen to glycoprotein (GP) Ib on platelets. This initial tethering facilitates association between the collagen receptor GPVI and collagen, which generates tyrosine kinase-dependent activation signals, followed by release of secondary mediators and integrin activation. Activated integrin can bind to their ligands including fibrinogen. The released secondary mediators, ADP and thromboxane A2, activate integrin of flowing platelets, which enables formation of platelet thrombi by binding of activated flowing platelets and adhered platelets to collagen via binding between activated aIIbbeta3 integrin and fibrinogen. Platelets also have inhibitory mechanisms, which help to prevent unwanted platelet activation in vivo.

  4. Effect of photodynamic therapy on mouse platelets

    NASA Astrophysics Data System (ADS)

    Zhou, Chuannong; Chi, Shunji; Deng, Jinsheng; Zhang, Hua; Liang, Junlin; Ha, Xian-wen

    1993-06-01

    Normal mice received hematoporphyrin derivative (HpD) i.v. prior to red light irradiation and the platelet-rich plasma was prepared and irradiated by red light. The platelets were processed for EM examination and stereological analysis. It was shown the 16 hrs after irradiation almost all platelets were necrotized; 8 hours after irradiation about one fourth of the platelets were necrotized and the remaining were considerably damaged. Immediately after irradiation a small number of platelets became necrotic and most other platelets were swollen and deformated, showing significantly increased mean area, perimeter and short axis, and mean cell volume and cell surface area. The findings indicate that platelets are highly sensitive to PDT action and can be directly and rapidly damaged by PDT even in the absence of vascular endothelial cells. The early platelet photoactivation may play an important role in the initiation of early vascular damage and microcirculatory alterations induced by PDT in vivo.

  5. The role of scintigraphy in the lameness evaluation.

    PubMed

    Steckel, R R

    1991-08-01

    Bone scanning to help diagnose orthopedic disease has been used in human patients for over two decades. The value of this diagnostic tool has been well established in helping to identify a variety of musculoskeletal conditions. It has only recently been used by veterinarians for more accurate characterization of equine musculoskeletal disease. The technique offers the major advantage of increased sensitivity over standard radiographic imaging. The case material illustrated here shows that except for consistent identification of bone cysts, most of the pathologic changes to the horse's musculoskeletal system that might cause lameness are detected on bone scans. Many acute bone diseases can be diagnosed by scintigraphy that cannot be discerned by radiographs until the condition has become chronic: Because of their body size, these conditions may not be diagnosed at all in horses. Scintigraphy in horses offers the other major advantage of affording accurate imaging of the upper limbs, pelvis, and vertebral column without general anesthesia. Therefore, it has a final advantage of increased safety over conventional radiography because it eliminates the need to perform general anesthesia to study these areas. In the author's experience, if abnormal uptake of isotope in the upper limbs, pelvis or spine is not observed, general anesthesia to radiograph those areas is not warranted. A second major benefit of scintigraphic imaging is to differentiate mixed lameness conditions in which the component of bone disease must be separated from that of soft tissues to arrive at a rational course of treatment or prognosis. Finally, for athletic horses suspected of having lameness due to localized myositis, scintigraphy not only allows confirmation of muscle inflammation but also identifies the muscle bellies injured reasonably accurately so that specific local treatment may be given. Nuclear imaging of equine skeletal disease is an option that should be employed more frequently by

  6. Patterning surfaces for controlled platelet adhesion and detection of dysfunctional platelets.

    PubMed

    Ye, Wei; Shi, Qiang; Wong, Shing-Chung; Hou, Jianwen; Shi, Hengchong; Yin, Jinghua

    2013-06-01

    Platelets play a fundamental role in thrombus formation and in the pathogenesis of arterial thrombosis. Patterning surfaces for controlled platelet adhesion paves the way for adhesion and activation mechanisms in platelets and detection of platelet functional defects. Here, a new and simple method based on controlled polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) on the surface of styrene-block-(ethylene-co-butylene)-block-styrene (SEBS) is shown. The competition between polymerization and degradation enables platelet adhesion on SEBS to be switched on and off. The adhesive sites of the platelets can be down to single cell level, and the dysfunctional platelets can be quantitatively detected.

  7. Platelet Activation: The Mechanisms and Potential Biomarkers

    PubMed Central

    Yun, Seong-Hoon; Sim, Eun-Hye; Goh, Ri-Young; Park, Joo-In

    2016-01-01

    Beyond hemostasis and thrombosis, an increasing number of studies indicate that platelets play an integral role in intercellular communication, mediating inflammatory and immunomodulatory activities. Our knowledge about how platelets modulate inflammatory and immunity has greatly improved in recent years. In this review, we discuss recent advances in the pathways of platelet activation and potential application of platelet activation biomarkers to diagnosis and prediction of disease states. PMID:27403440

  8. Selection of donor platelets for alloimmunized patients using a platelet-associated IgG assay

    SciTech Connect

    Myers, T.J.; Kim, B.K.; Steiner, M.; Baldini, M.G.

    1981-09-01

    A quantitative immunofluorescence platelet-associated immunoglobulin-G (PA-IgG) assay was used to detect alloimmunity to platelets in 8/12 multitransfused patients and to perform platelet crossmatching in the 8 alloimmunized patients. The correct separation of multitransfused patients into alloimmune and nonalloimmune groups was substantiated with chromium-51-labeled platelet survival studies. For 5 alloimmunized patients, compatible and incompatible donor platelets were demonstrated by PA-IgG crossmatching and were confirmed by platelet survival studies. With the other 3 alloimmunized patients, only Pa-IgG incompatible donor platelets were found. Survival studies with 5 of these incompatible donor platelets showed markedly reduced survival times on 4 occasions. Pa-IgG compatible donor platelets survived 3.5 to 8.7 days, while Pa-IgG incompatible platelets showed survival times of 0.1 to 2.4 days.

  9. Dengue platelets meet Sir Arthur Conan Doyle.

    PubMed

    Bray, Paul F

    2013-11-14

    In this issue of Blood, Hottz et al provide compelling evidence that dengue virus (DV) induces (1) platelet synthesis of interleukin-1b (IL-1b); (2) platelet-derived IL-1b–containing microvesicles (MVs) that increase vascular permeability; and (3) DV-triggered inflammasome activation in platelets.

  10. 21 CFR 864.6675 - Platelet aggregometer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... shape and platelet aggregation following the addition of an aggregating reagent to a platelet rich... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Platelet aggregometer. 864.6675 Section 864.6675...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6675...

  11. 21 CFR 864.6675 - Platelet aggregometer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... shape and platelet aggregation following the addition of an aggregating reagent to a platelet rich... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Platelet aggregometer. 864.6675 Section 864.6675...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6675...

  12. Multiscale model of platelet translocation and collision

    NASA Astrophysics Data System (ADS)

    Wang, Weiwei; Mody, Nipa A.; King, Michael R.

    2013-07-01

    The tethering of platelets on the injured vessel surface mediated by glycoprotein Ibα (GPIbα) - Von Willebrand factor (vWF) bonds, as well as the interaction between flowing platelets and adherent platelets, are two key events that take place immediately following blood vessel injury. This early-stage platelet deposition and accumulation triggers the initiation of hemostasis, a self-defensive mechanism to prevent the body from excessive blood loss. To understand and predict this complex process, one must integrate experimentally determined information on the mechanics and biochemical kinetics of participating receptors over very small time frames (1-1000 μs) and length scales (10-100 nm), to collective phenomena occurring over seconds and tens of microns. In the present study, a unique three dimensional multiscale computational model, Platelet Adhesive Dynamics (PAD), was applied to elucidate the unique physics of (i) a non-spherical, disk-shaped platelet interacting and tethering onto the damaged vessel wall followed by (ii) collisional interactions between a flowing platelet with a downstream adherent platelet. By analyzing numerous simulations under different physiological conditions, we conclude that the platelet's unique spheroid-shape provides heterogeneous, orientation-dependent translocation (rolling) behavior which enhances cell-wall interactions. We also conclude that platelet-platelet near field interactions are critical for cell-cell communication during the initiation of microthrombi. The PAD model described here helps to identify the physical factors that control the initial stages of platelet capture during this process.

  13. Automatic detection of immature platelets for decision making regarding platelet transfusion indications for pediatric patients.

    PubMed

    Saigo, Katsuyasu; Sakota, Yasuyuki; Masuda, Yukako; Matsunaga, Kyoko; Takenokuchi, Mariko; Nishimura, Kunihiro; Sugimoto, Takeshi; Sakurai, Kosuke; Hashimoto, Makoto; Yanai, Tomoko; Hayakawa, Akira; Takeshima, Yasuhiro; Nomura, Tsutomu; Kubota, Yoshitsugu; Kumagai, Shunichi

    2008-04-01

    Immature or reticulated platelets are known as a clinical marker of thrombopoiesis. Recently, an automatic method was established to detect reticulated platelets as immature platelet fraction (IPF) by means of hematology analyzer XE-2100. We assessed the effects of IPF detection after chemotherapy for various pediatric malignant disorders of 16 patients. Our results indicate that IPF should be considered a useful marker of imminent platelet recovery so that unnecessary platelet transfusion can be avoided.

  14. Nurse exposure doses resulted from bone scintigraphy patient

    NASA Astrophysics Data System (ADS)

    Tunçman, Duygu; Kovan, Bilal; Poyraz, Leyla; ćapali, Veli; Demir, Bayram; Türkmen, Cüneyt

    2016-03-01

    Bone scintigraphy is used for displaying the radiologic undiagnosed bone lesions in nuclear medicine. It's general indications are researching bone metastases, detection of radiographically occult fractures, staging and follow-up in primary bone tumors, diagnosis of paget's disease, investigation of loosening and infection in orthopedic implants. It is applied with using 99mTc labeled radiopharmaceuticals (e.g 99m Tc MDP,99mTc HEDP and 99mTc HMDP). 20 -25 mCi IV radiotracer was injected into vein and radiotracer emits gamma radiation. Patient waits in isolated room for about 3 hours then a gamma camera scans radiation area and creates an image. When some patient's situation is not good, patients are hospitalized until the scanning because of patients' close contact care need. In this study, measurements were taken from ten patients using Geiger Muller counter. After these measurements, we calculated nurse's exposure radiations from patient's routine treatment, examination and emergency station.

  15. Altered biodistribution of radiopharmaceuticals used in bone scintigraphy.

    PubMed

    Zuckier, Lionel S; Martineau, Patrick

    2015-01-01

    Bone scintigraphy has remained a mainstay of clinical nuclear medicine for more than 4 decades. Extensive medical literature has developed surrounding the etiology and significance of alterations in distribution of bone radiopharmaceuticals. Altered biodistribution may be of a global nature, reflecting altered partition of radiopharmaceutical between bone and soft tissues, or more focal, reflecting regional abnormalities, including those related to bone or soft tissues. A third category of alterations in the distribution of bone radiopharmaceuticals is those due to errors and blunders, colloquially termed "artifactual" in the medical imaging literature. Being cognizant of these unexpected abnormalities, and understanding their etiology, will prepare the reader to more readily appreciate the significance of these findings when encountered in clinical practice.

  16. Spontaneous perforation of common bile duct in a pediatric patient: application of hepatobiliary scintigraphy.

    PubMed

    Joodi, Marjan; Norouzbeigi, Nasim; Rad, Mohammad Ali Ghodsi; Shojaeian, Reza; Kakhki, Vahid Reza Dabbagh; Sadeghi, Ramin

    2012-10-01

    We report a case of spontaneous biliary perforation in a 21-month old female pediatric patient with the presenting symptoms of abdominal distension, jaundice, and umbilical hernia. Hepatobiliary scintigraphy showed tracer accumulation in the peritoneal cavity. Preliminary diagnosis of spontaneous biliary perforation was confirmed during surgery. After surgical repair of the biliary leakage, the patient recovered fully. This case shows the importance of hepatobiliary scintigraphy in patients suspicious for this condition.

  17. [Imaging of hyperparathyroidism-Ultrasonography and 99mTc-MIBI scintigraphy-].

    PubMed

    Kawabe, Joji; Higashiyama, Shigeaki; Yoshida, Atsushi; Kotani, Kohei; Shiomi, Susumu

    2016-06-01

    Treatments for primary hyperparathyroidism due to adenoma, hyperplasia and carcinoma and secondary hyperparathyroidism are mainly surgical resections of them. Accurate imaging diagnoses of the existences and the regions are very important for reductions of invasiveness. We describe ultrasonography and (99m)Tc-MIBI scintigraphy of hyperparathyroidism. We explain an advantage, a disadvantage and diagnosability of these modalities. We mention utilities of SPECT/CT, too. We show echogram and (99m)Tc-MIBI scintigraphy images about 3 cases of hyperparathyroidism.

  18. Bone scintigraphy of severe hypercalcemia following simvastatin induced rhabdomyolysis

    PubMed Central

    Mirza, Zubair B.; Hu, Sophia; Amorosa, Louis F.

    2016-01-01

    Summary Simvastatin induced rhabdomyolysis with renal failure is a well reported clinical entity with hyperkalemia recognized as a life threatening risk. The risk of delayed hypercalcemia during the recovery of renal function is not well appreciated as this varies in severity and can be caused by multiple mechanisms. We present a patient with high dose simvastatin induced rhabdomyolysis leading to late onset of severe hypercalcemia due to calcium phosphate deposition in muscles diagnosed by distinctive bone scintigraphy. A 60-year-old Asian male was admitted to the hospital for profound weakness one week following the initiation of simvastatin 80 mg daily post myocardial infarction. His clinical course was complicated by contrast nephropathy. One week later, he developed progressive weakness in all his extremities and inability to raise his head and eat. Simvastatin was discontinued at this point. CPK elevation to greater than 425,000 U was found, consistent with rhabdomyolysis. He became oliguric requiring hemodialysis. Muscle biopsy showed severe muscle necrosis and type 2 fiber atrophy. One month later, he developed hypercalcemia with suppressed intact PTH and 1, 25(OH) D levels. Whole body bone scintigraphy showed calcium phosphate deposition throughout his musculature. His calcium levels normalized in 1 week on hemodialysis. This patient’s experience illustrates the marked risk of delayed severe hypercalcemia from rhabdomyolysis due to dissolution of myocellular calcium phosphate deposits. It also provides an opportunity to review the different mechanisms of hypercalcemia especially in statin induced rhabdomyolysis. Recognition of this phenomenon is critical for appropriate follow up and treatment of such patients. PMID:28228795

  19. Characterization of multiple acquired portosystemic shunts using transplenic portal scintigraphy.

    PubMed

    Morandi, Federica; Sura, Patricia A; Sharp, Dorothy; Daniel, Gregory B

    2010-01-01

    We describe the scintigraphic patterns observed in 14 patients with confirmed multiple portosystemic shunts imaged via transplenic portal scintigraphy. Parameters evaluated included presence of multiple anomalous vessels, presence of hepatofugal flow caudal to spleen, and/or to cranial margin of the kidneys, slow absorption resulting in longer spleen to heart transit time, and presence of biphasic or fragmented bolus. Twenty-eight additional patients, 14 with a confirmed single portocaval and 14 with a portoazygos shunt, were used for comparison. Nine of 14 (64.3%) patients with multiple shunts had multiple vessels, five (35.7%) had a biphasic bolus, 13 (92.9%) had hepatofugal flow caudal to the cranial margin of the kidneys. In all single portocaval shunts, a single anomalous vessel was identified. None had hepatofugal flow caudal to the border of the kidneys. Among portoazygos shunts, 4/14 (28.6%) had flow caudal to the injection site. Six portoazygos and one portocaval shunts had biphasic bolus. Median transit time from spleen to heart was significantly longer (1.9 s) in patients with multiple shunts than in patients with a portocaval shunt (1.0 s), but not in patients with a portoazygos shunt (1.3 s). Although a distinct plexus of anomalous vessels is not detected in all patients with multiple shunts imaged using transplenic portal scintigraphy, findings of hepatofugal flow caudal to the margin of the kidneys, and longer transit time compared with single portocaval shunts were characteristic. Flow caudal to the splenic injection site but cranial to the kidneys and biphasic bolus can also be seen with a single congenital shunt.

  20. Evaluation of antral motility in humans using manometry and scintigraphy.

    PubMed Central

    Jones, K; Edelbroek, M; Horowitz, M; Sun, W M; Dent, J; Roelofs, J; Muecke, T; Akkermans, L

    1995-01-01

    Recent studies suggest that scintigraphy can be used to evaluate non-invasively antral motility in humans, although scintigraphic techniques have not yet been compared with more conventional measurements of intraluminal pressures by manometry. Simultaneous scintigraphic and manometric measurements of antral motility were performed in nine healthy volunteers. After intubation with a sleeve/sidehole catheter which incorporated five pressure sideholes located at 1.5 cm intervals spanning the antrum, each subject ingested 100 g minced beef labelled with 100 MBq 99mTc-chicken liver and 150 ml water. Between 40-43, 60-63, 80-83, and 100-103 minutes after meal ingestion, radioisotopic data were acquired in two second frames. Time-activity curves showing antral 'contractions' resulting from wall motion were derived by drawing small regions of interest over the antrum to coincide with the position of the antral manometric sideholes. Scintigraphic contraction rates approximated 3/minute, whereas antral pressure waves that occluded the lumen were less frequent (p < 0.01 for all), particularly in the proximal antrum. The amplitude of wall motion, evaluated scintigraphically, and the amplitude of pressure waves were both inversely related to the distance from the pylorus (r > -0.32, p < 0.05) and antral volume r > -0.29 (p < 0.05). There were significant relationships between the amplitude of contractions assessed scintigraphically and the number of lumen-occlusive antral pressure waves in the distal antrum (r -0.48, p < 0.05) but not in the more proximal antral regions. It is concluded that scintigraphy can detect antral wall motion with greater sensitivity than manometry, particularly in the proximal antrum. As manometry gives information on the amplitude as well as the temporal and spatial organisation of those contractions which result in lumen occlusion, the combination of scintigraphic and manometric techniques in the evaluation of antral motility shows considerable

  1. Thyroid scintigraphy findings in 2096 cats with hyperthyroidism.

    PubMed

    Peterson, Mark E; Broome, Michael R

    2015-01-01

    Thyroid scintigraphy is currently the reference standard for diagnosing and staging cats with hyperthyroidism, but few studies describing the scintigraphic characteristics in a large number of cats have been reported. The objective of this study was to better characterize thyroid scintigraphy findings by evaluating 2096 consecutive cats with hyperthyroidism that were referred over a 3.5-year period. Of these cats, 2068 (98.7%) had a high thyroid-to-salivary ratio (>1.5), whereas 2014 (96.1%) were found to have a high thyroid-to-background ratio (>6.1). When the patterns of the cats' thyroid disease were recorded, 665 (31.7%) had unilateral disease, 1060 (50.6%) had bilateral-asymmetric disease (two thyroid lobes unequal in size), 257 (12.3%) had bilateral-symmetric disease (both lobes similar in size), and 81 (3.9%) had multifocal disease (≥3 areas of increased radionuclide uptake). The number of areas of (99m) TcO(-) 4 uptake in the 2096 cats ranged from 1 to 6 (median, 2), located in the cervical area in 2057 (98.1%), thoracic inlet in 282 (13.5%), and in the thoracic cavity in 115 (5.5%). Ectopic thyroid tissue (e.g. lingual or mediastinal) was diagnosed in 81 (3.9%) cats, whereas thyroid carcinoma was suspected in 35 (1.7%) of the cats. The results of this study support conclusions that most hyperthyroid cats have unilateral or bilateral thyroid nodules, but that multifocal disease will develop in a few cats that have ectopic thyroid disease or thyroid carcinoma. Both ectopic thyroid disease and thyroid carcinoma are relatively uncommon in hyperthyroid cats, with a respective prevalence of ∼4% and ∼2% in this study.

  2. Exploratory studies of extended storage of apheresis platelets in a platelet additive solution (PAS).

    PubMed

    Slichter, Sherrill J; Corson, Jill; Jones, Mary Kay; Christoffel, Todd; Pellham, Esther; Bailey, S Lawrence; Bolgiano, Doug

    2014-01-09

    To evaluate the poststorage viability of apheresis platelets stored for up to 18 days in 80% platelet additive solution (PAS)/20% plasma, 117 healthy subjects donated platelets using the Haemonetics MCS+, COBE Spectra (Spectra), or Trima Accel (Trima) systems. Control platelets from the same subjects were compared with their stored test PAS platelets by radiolabeling their stored and control platelets with either (51)chromium or (111)indium. Trima platelets met Food and Drug Administration poststorage platelet viability criteria for only 7 days vs almost 13 days for Haemonetics platelets; ie, platelet recoveries after these storage times averaged 44 ± 3% vs 49 ± 3% and survivals were 5.4 ± 0.3 vs 4.6 ± 0.3 days, respectively. The differences in storage duration are likely related to both the collection system and the storage bag. The Spectra and Trima platelets were hyperconcentrated during collection, and PAS was added, whereas the Haemonetics platelets were elutriated with PAS, which may have resulted in less collection injury. When Spectra and Trima platelets were stored in Haemonetics' bags, poststorage viability was significantly improved. Platelet viability is better maintained in vitro than in vivo, allowing substantial increases in platelet storage times. However, implementation will require resolution of potential bacterial overgrowth during storage.

  3. Renal anomalies in patients with turner syndrome: Is scintigraphy superior to ultrasound?

    PubMed

    Hamza, Rasha T; Shalaby, Mennatallah H; Hamed, Laith S; Abdulla, Dunya B A; Elfekky, Sahar M; Sultan, Omar M

    2016-02-01

    Renal anomalies are present in up to 30% of patients with Turner syndrome (TS). Renal ultrasound (U/S) detects anatomical renal anomalies only while renal scintigraphy detects anomalies, detects early renal malfunction, and estimates glomerular filtration rate (GFR). Thus, we aimed to assess frequency of renal abnormalities detected by scintigraphy in comparison to renal U/S in TS patients. Ninety TS patients were subjected to auxological assessment, measurement of serum creatinine; and renal U/S and scintigraphy. Renal U/S detected renal anomalies in 22.22% of patients versus 17.78 % detected by scintigraphy (P = 0.035). Scintigraphy detected renal functional abnormalities in 44.44% of patients in the form of subnormal total GFR, abnormal renogram curve pattern, improper tracer handling and perfusion; and difference in split renal function >10% between both kidneys. Patients with a 45,X karyotype had more renal functional abnormalities (56%) than those with mosaic karyotype (33.33%), P = 0.04. In conclusion, renal scintigraphy is not superior to U/S in detection of renal anomalies but is a reliable method for early detection of renal malfunction in TS patients especially those with 45,X to ensure early management to offer a better quality of life.

  4. Platelet count and platelet indices in women with preeclampsia

    PubMed Central

    AlSheeha, Muneera A; Alaboudi, Rafi S; Alghasham, Mohammad A; Iqbal, Javed; Adam, Ishag

    2016-01-01

    Background Although the exact pathophysiology of preeclampsia is not completely understood, the utility of different platelets indices can be utilized to predict preeclampsia. Objective To compare platelet indices, namely platelet count (PC), mean platelet volume (MPV), platelet distribution width (PDW), and PC to MPV ratio in women with preeclampsia compared with healthy controls. Setting Qassim Hospital, Kingdom of Saudi Arabia. Design A case–control study. Sixty preeclamptic women were the cases and an equal number of healthy pregnant women were the controls. Results There was no significant difference in age, parity, and body mass index between the study groups. Sixteen and 44 of the cases were severe and mild preeclampsia, respectively. There was no significant difference in PDW and MPV between the preeclamptic and control women. Both PC and PC to MPV ratios were significantly lower in the women with preeclampsia compared with the controls. There was no significant difference in the PC, PDW, MPV, and PC to MPV ratio when women with mild and severe preeclampsia were compared. Using receiver operating characteristic (ROC) curves, the PC cutoff was 248.0×103/µL for diagnosis of pre-eclampsia (P=0.019; the area under the ROC curve was 62.4%). Binary regression suggests that women with PC <248.010×103/µL were at higher risk of preeclampsia (odds ratio =2.2, 95% confidence interval =1.08–4.6, P=0.03). The PC/MPV cutoff was 31.2 for diagnosis of preeclampsia (P=0.035, the area under the ROC curve was 62.2%). Conclusion PC <248.010×103/µL and PC to MPV ratio 31.2 are valid predictors of preeclampsia. PMID:27920548

  5. Pooled platelet concentrates: an alternative to single donor apheresis platelets?

    PubMed

    Pietersz, R N I

    2009-10-01

    Three types of platelet concentrates (PC) are compared: PC either processed with the platelet-rich plasma (PRP) or the Buffy coat (BC) method from whole blood units and PC obtained by apheresis. Leuko-reduction (LR) pre-storage is advocated to improve quality of the PC during storage and reduce adverse reactions in recipients. Standardization of methods allow preparation of PC with comparable yields of approximately 400 x 10(9) platelets in pooled non-LR-PRP, approximately 370 x 10(9) in pooled LR-BC-PC and in LR apheresis PC the number of platelets can be targeted on 350 x 10(9) or more with devices of various manufacturers. While viral transmission can be prevented by outstanding laboratory tests, the risk of bacterial contamination should be reduced by improved arm disinfection, deviation of the first 20-30 ml of blood and culture or rapid detection assays of the PC pre-issue. In a large prospective multicenter trial no significant difference was observed between cultures of apheresis PC (n = 15,198): 0.09% confirmed positive units versus 0.06% in pooled BC-PC (n = 37,045), respectively. Though platelet activation as measured by CD62 expression may differ in vitro in PC obtained with various apheresis equipment, and also between PC processed with the two whole blood methods there is scarce literature about the clinical impact of these findings. In conclusion the final products of LR-PC derived from whole blood or obtained by apheresis can be comparable, provided the critical steps of the processing method are identified and covered and the process is in control.

  6. A large renal pelvic diverticulum, presenting incomplete excretion during tc-99m MAG-3 scintigraphy and tracer accumulation on tc-99m DMSA scintigraphy; a case report.

    PubMed

    Turgut, Bulent; Erselcan, Taner; Ozdemir, Semra; Hasbek, Zekiye; Tosun, H Bayram; Topaktas, Seher

    2004-12-01

    This case report illustrates the dynamic and static renal scintigraphic images of a patient with an unusual large diverticulum of the renal pelvis. The initial diagnosis by intravenous pyelography (IVP) and ultrasonographic (US) examination was a renal pelvic diverticulum of the left kidney, and the patient was referred to the nuclear medicine department for exploration of the effect of the pelvic diverticulum on renal functions. We performed dynamic renal scintigraphy with technetium-99m (Tc-99m) labeled mercaptoacetyl triglycine (MAG-3) and static renal scintigraphy with Tc-99m labeled dimercaptosuccinic acid (DMSA). In dynamic renal scintigraphy, bilaterally normal concentration function was observed. While right kidney excretion function was normal, an incomplete excretion pattern was seen on the left side. Complete urinary flow obstruction occurred approximately at the 10th minute of the acquisition, which did not seem to respond to the i.v. furosemide application. However, when only the renal cortex was included in the region of interest, the obstructive pattern disappeared. In static renal scintigraphy, a large renal pelvic diverticulum localized antero-medially was clearly visualized in the left-anterior oblique projection, most probably due to accumulation of radiopharmaceutical inside it. This case showed that a renal pelvic diverticulum should be thought of when an incomplete excretion pattern is seen on dynamic renal scintigraphy. Using only a cortical region of interest may also help to distinguish other types of obstructive pattern from diverticulum. Additionally, Tc-99m DMSA scintigraphy may show diverticulum localization with antero-oblique projections in addition to routine projections.

  7. Mean Platelet Volume and Platelet Immunofluorescence as Indicators of Platelet Compatibility.

    DTIC Science & Technology

    1983-02-23

    Studies were performed to determine if the increase in MPV was due to the presence of alloantibodies or if it was due to ABO isoagglutinins anti-A and...blood group types (Tables IA and 1B). Sera from donors with blood group type 0 containing anti-A and anti-B isoagglutinins always caused type A...platelets to swell (range 7-24%) (Table 1A). Mixtures of B and 0 platelets with sera containing anti-A and anti-B isoagglutinins demonstrated no change or

  8. Hemolysis after ABO-incompatible platelet transfusions.

    PubMed

    Chow, M P; Yung, C H; Hu, H Y; Tzeng, C H

    1991-08-01

    An 18 year old girl, with acute myeloid leukemia, developed progressive hemolysis after receiving multiple transfusions with ABO-incompatible platelets. It was caused by passive transfusion of anti-A and -B isoagglutinin from the donor plasma. Her hemoglobin level returned to normal after giving group compatible or pooled and reduced volume platelet concentrates. Transfusing group-incompatible platelets is not contraindicated, but donor plasma reduction should be considered for those patients who need prolonged platelet support. Testing for isoagglutinin titer in group O donors is an alternate method to reduce the incidence of plasma-induced hemolysis in group-incompatible platelet transfusions.

  9. Acetal phosphatidic acids: novel platelet aggregating agents.

    PubMed

    Brammer, J P; Maguire, M H; Walaszek, E J; Wiley, R A

    1983-05-01

    1 Palmitaldehyde, olealdehyde and linolealdehyde acetal phosphatidic acids induced rapid shape change and dose-dependent biphasic aggregation of human platelets in platelet-rich plasma; aggregation was reversible at low doses and irreversible at high doses of the acetal phosphatidic acids. The palmitaldehyde congener elicited monophasic dose-dependent aggregation of sheep platelets in platelet-rich plasma.2 The threshold concentration for palmitaldehyde acetal phosphatidic acid (PGAP)-induced platelet aggregation was 2.5-5 muM for human platelets and 0.25-0.5 muM for sheep platelets. PGAP was 4-5 times as potent versus human platelets as the olealdehyde and linolealdehyde acetal phosphatidic acids, which were equipotent.3 PGAP-induced irreversible aggregation of [(14)C]-5-hydroxytryptamine ([(14)C]-5-HT)-labelled human platelets in platelet-rich plasma was accompanied by release of 44.0+/-2.4% (s.e.) of the platelet [(14)C]-5-HT; reversible aggregation was not associated with release. In contrast, PGAP-induced release of [(14)C]-5-HT-labelled sheep platelets was dose-dependent.4 The adenosine diphosphate (ADP) antagonist, 2-methylthio-AMP, and the cyclo-oxygenase inhibitor, aspirin, abolished PGAP-induced second phase aggregation and release in human platelets but did not affect the first, reversible, phase of aggregation. Both the first and second phases of PGAP-induced aggregation were abolished by chlorpromazine, by the phospholipase A(2) inhibitor, mepacrine, and by nmolar concentrations of prostaglandin E(1) (PGE(1)); these agents abolished the second, but not the first phase of ADP-induced aggregation.5 The related phospholipids, lecithin, lysolecithin and phosphatidic acid, at <100 muM, neither induced aggregation of human platelets in platelet-rich plasma, nor modified PGAP-induced aggregation; 1-palmityl lysophosphatidic acid elicited aggregation of human platelets at a threshold concentration of 100 muM.6 It is concluded that the acetal phosphatidic acids

  10. Platelet actively cooled thermal management devices

    NASA Astrophysics Data System (ADS)

    Mueggenburg, H. H.; Hidahl, J. W.; Kessler, E. L.; Rousar, D. C.

    1992-07-01

    An overview of 28 years of actively-cooled platelet thermal management devices design and development history is presented. Platelet devices are created by bonding together thin metal sheets (platelets) which contain chemically-etched coolant pasages. The bonding process produces an intricate and precise matrix of coolant passages and structural walls contained within a monolithic structure. Thirteen specific applications for platelet thermal management devices are described. These devices are cooled using convective, film, and transpiration cooling techniques. Platelet thermal management devices have been fabricated from a variety of metals, cooled with a variety of fluids, and operated at heat fluxes up to 200 Btu/sq in.-sec.

  11. Evidence that platelet buoyant density, but not size, correlates with platelet age in man.

    PubMed

    Mezzano, D; Hwang, K; Catalano, P; Aster, R H

    1981-01-01

    Following infusion of 51Cr-labeled autologous platelets into normal subjects, high-density (HD) and low-density (LD) platelet cohorts were isolated by prolonged centrifugation in isosmotic arabino-galactan (Stractan). Specific radio-activity of LD platelets declined rapidly post-infusion (T1/2 = 1.5 days), but specific radioactivity of HD platelets remained constant or increased over a 3--4-day period and gradually declined for 6--7 days thereafter. These differences were exaggerated when platelet cohorts enriched in LD or HD cells by slow centrifugation in high-density albumin were labeled and transfused. Mean survival of a platelet cohort enriched with HD cells was significantly (P less than 0.02) shorter (7.73 days) than that of a cohort enriched with LD cells (9.33) days). In normal subjects treated with aspirin, capacity for thromboxane synthesis was regained more rapidly (P less than 0.05) in LD than in HD platelets. HD and LD platelets differed only slightly in mean volume (HD platelets = 7.57 mu3, LD platelets = 6.87 mu3, 0.05 less than P less than 0.01). We believe the most logical interpretation of these findings is that under normal conditions in man, newly formed platelets are less dense on the average than total platelets and become more dense as they age in the circulation. Thus, specific radioactivity of LD platelets declines rapidly as these platelets move into a more dense compartment and are replaced by newly formed, unlabelled cells; specific radioactivity of HD platelets remains constant or increases as labelled platelets enter this compartment in numbers equal to or greater than the number leaving it at the end of their life span. The similarity in mean volumes of LD and HD platelets suggests that platelet size is unrelated to platelet age under normal conditions.

  12. Evidence that platelet buoyant density, but not size, correlates with platelet age in man

    SciTech Connect

    Mezzano, D.; Hwang, K.; Catalano, P.; Aster, R.H.

    1981-01-01

    Following infusion of 51Cr-labeled autologous platelets into normal subjects, high-density (HD) and low-density (LD) platelet cohorts were isolated by prolonged centrifugation in isosmotic arabino-galactan (Stractan). Specific radio-activity of LD platelets declined rapidly post-infusion (T1/2 . 1.5 days), but specific radioactivity of HD platelets remained constant or increased over a 3--4-day period and gradually declined for 6--7 days thereafter. These differences were exaggerated when platelet cohorts enriched in LD or HD cells by slow centrifugation in high-density albumin were labeled and transfused. Mean survival of a platelet cohort enriched with HD cells was significantly (P less than 0.02) shorter (7.73 days) than that of a cohort enriched with LD cells (9.33) days). In normal subjects treated with aspirin, capacity for thromboxane synthesis was regained more rapidly (P less than 0.05) in LD than in HD platelets. HD and LD platelets differed only slightly in mean volume (HD platelets . 7.57 mu3, LD platelets . 6.87 mu3, 0.05 less than P less than 0.01). We believe the most logical interpretation of these findings is that under normal conditions in man, newly formed platelets are less dense on the average than total platelets and become more dense as they age in the circulation. Thus, specific radioactivity of LD platelets declines rapidly as these platelets move into a more dense compartment and are replaced by newly formed, unlabelled cells; specific radioactivity of HD platelets remains constant or increases as labelled platelets enter this compartment in numbers equal to or greater than the number leaving it at the end of their life span. The similarity in mean volumes of LD and HD platelets suggests that platelet size is unrelated to platelet age under normal conditions.

  13. Splenic release of platelets contributes to increased circulating platelet size and inflammation after myocardial infarction.

    PubMed

    Gao, Xiao-Ming; Moore, Xiao-Lei; Liu, Yang; Wang, Xin-Yu; Han, Li-Ping; Su, Yidan; Tsai, Alan; Xu, Qi; Zhang, Ming; Lambert, Gavin W; Kiriazis, Helen; Gao, Wei; Dart, Anthony M; Du, Xiao-Jun

    2016-07-01

    Acute myocardial infarction (AMI) is characterized by a rapid increase in circulating platelet size but the mechanism for this is unclear. Large platelets are hyperactive and associated with adverse clinical outcomes. We determined mean platelet volume (MPV) and platelet-monocyte conjugation (PMC) using blood samples from patients, and blood and the spleen from mice with AMI. We further measured changes in platelet size, PMC, cardiac and splenic contents of platelets and leucocyte infiltration into the mouse heart. In AMI patients, circulating MPV and PMC increased at 1-3 h post-MI and MPV returned to reference levels within 24 h after admission. In mice with MI, increases in platelet size and PMC became evident within 12 h and were sustained up to 72 h. Splenic platelets are bigger than circulating platelets in normal or infarct mice. At 24 h post-MI, splenic platelet storage was halved whereas cardiac platelets increased by 4-fold. Splenectomy attenuated all changes observed in the blood, reduced leucocyte and platelet accumulation in the infarct myocardium, limited infarct size and alleviated cardiac dilatation and dysfunction. AMI-induced elevated circulating levels of adenosine diphosphate and catecholamines in both human and the mouse, which may trigger splenic platelet release. Pharmacological inhibition of angiotensin-converting enzyme, β1-adrenergic receptor or platelet P2Y12 receptor reduced platelet abundance in the murine infarct myocardium albeit having diverse effects on platelet size and PMC. In conclusion, AMI evokes release of splenic platelets, which contributes to the increase in platelet size and PMC and facilitates myocardial accumulation of platelets and leucocytes, thereby promoting post-infarct inflammation.

  14. Platelet Cryopreservation Using Dimethyl Sulfoxide,

    DTIC Science & Technology

    plateletpheresis methods or cell separators. In recent studies, the corrected count increment following 66 transfusions of frozen platelets collected using the...Haemonetics Model 30 processor (Haemonetics Corp., Natick, Mass.) was 12,3000 (range 0-36,800) compared to a mean CCI of 11,7000 (0-34,900) using manual plateletpheresis technique (N = 211).

  15. Platelets and viruses: an ambivalent relationship.

    PubMed

    Flaujac, Claire; Boukour, Siham; Cramer-Bordé, Elisabeth

    2010-02-01

    Thrombocytopenia is a frequent complication of viral infections providing evidence that interaction of platelets with viruses is an important pathophysiological phenomenon. Multiple mechanisms are involved depending on the nature of the viruses involved. These include immunological platelet destruction, inappropriate platelet activation and consumption, and impaired megakaryopoiesis. Viruses bind platelets through specific receptors and identified ligands, which lead to mutual alterations of both the platelet host and the viral aggressor. We have shown that HIV-1 viruses are internalized specifically in platelets and megakaryocytes, where they can be either sheltered, unaltered (with potential transfer of the viruses into target organs), or come in contact with platelet secretory products leading to virus destruction and facilitated platelet clearance. In this issue, we have reviewed the various pathways that platelets use in order to interact with viruses, HIV and others. This review also shows that more work is still needed to precisely identify platelet roles in viral infections, and to answer the challenge of viral safety in platelet transfusion.

  16. Signaling during platelet adhesion and activation

    PubMed Central

    Li, Zhenyu; Delaney, M. Keegan; O’Brien, Kelly A.; Du, Xiaoping

    2011-01-01

    Upon vascular injury, platelets are activated by adhesion to adhesive proteins like von Willebrand factor and collagen, or by soluble platelet agonists like ADP, thrombin, and thromboxane A2. These adhesive proteins and soluble agonists induce signal transduction via their respective receptors. The various receptor-specific platelet activation signaling pathways converge into common signaling events, which stimulate platelet shape change, granule secretion, and ultimately induce the “inside-out” signaling process leading to activation of the ligand binding function of integrin αIIbβ3. Ligand binding to integrin αIIbβ3 mediates platelet adhesion and aggregation and triggers “outside-in” signaling, resulting in platelet spreading, additional granule secretion, stabilization of platelet adhesion and aggregation, and clot retraction. It has become increasingly evident that agonist-induced platelet activation signals also crosstalk with integrin “outside-in” signals to regulate platelet responses. Platelet activation involves a series of rapid positive feedback loops that greatly amplify initial activation signals, and enable robust platelet recruitment and thrombus stabilization. Recent studies have provided novel insight into the molecular mechanisms of these processes. PMID:21071698

  17. Evidence of platelet activation in multiple sclerosis

    PubMed Central

    Sheremata, William A; Jy, Wenche; Horstman, Lawrence L; Ahn, Yeon S; Alexander, J Steven; Minagar, Alireza

    2008-01-01

    Objective A fatality in one multiple sclerosis (MS) patient due to acute idiopathic thrombocytopenic purpura (ITP) and a near fatality in another stimulated our interest in platelet function abnormalities in MS. Previously, we presented evidence of platelet activation in a small cohort of treatment-naive MS patients. Methods In this report, 92 normal controls and 33 stable, untreated MS patients were studied. Platelet counts, measures of platelet activation [plasma platelet microparticles (PMP), P-selectin expression (CD62p), circulating platelet microaggragtes (PAg)], as well as platelet-associated IgG/IgM, were carried out. In addition, plasma protein S activity was measured. Results Compared to controls, PMP were significantly elevated in MS (p < 0.001) and CD62p expression was also markedly elevated (p < 0.001). Both are markers of platelet activation. Platelet-associated IgM, but not IgG, was marginally elevated in MS (p = 0.01). Protein S in MS patients did not differ significantly from normal values. Conclusion Platelets are significantly activated in MS patients. The mechanisms underlying this activation and its significance to MS are unknown. Additional study of platelet activation and function in MS patients is warranted. PMID:18588683

  18. Numerical simulation of platelet margination in microcirculation

    NASA Astrophysics Data System (ADS)

    Zhao, Hong; Shaqfeh, Eric

    2009-11-01

    The adhesion of platelets to vascular walls is the first step in clotting. This process critically depends on the preferential concentration of platelets near walls. The presence of red blood cells, which are the predominant blood constituents, is known to affect the steady state platelet concentration and the dynamic platelet margination, but the underlying mechanism is not well understood to-day. We use a direct numerical simulation to study the platelet margination process, with particular emphasis on the Stokesian hydrodynamic interactions among red cells, platelets, and vessel walls. Well-known mechanical models are used for the shearing and bending stiffness of red cell membranes, and the stiffer platelets are modeled as rigid discoids. A boundary integral formulation is used to solve the flow field, where the numerical solution procedure is accelerated by a parallel O(N N) smooth particle-mesh Ewald method. The effects of red cell hematocrit and deformability will be discussed.

  19. Thrombocytopenia and platelet transfusion in the neonate.

    PubMed

    Cremer, Malte; Sallmon, Hannes; Kling, Pamela J; Bührer, Christoph; Dame, Christof

    2016-02-01

    Neonatal thrombocytopenia is widespread in preterm and term neonates admitted to neonatal intensive care units, with up to one-third of infants demonstrating platelet counts <150 × 10(9)/L. Thrombocytopenia may arise from maternal, placental or fetal/neonatal origins featuring decreased platelet production, increased consumption, or both mechanisms. Over the past years, innovations in managing neonatal thrombocytopenia were achieved from prospectively obtained clinical data on thrombocytopenia and bleeding events, animal studies on platelet life span and production rate and clinical use of fully automated measurement of reticulated platelets (immature platelet fraction). This review summarizes the pathophysiology of neonatal thrombocytopenia, current management including platelet transfusion thresholds and recent developments in megakaryopoietic agents. Furthermore, we propose a novel index score for bleeding risk in thrombocytopenic neonates to facilitate clinician's decision-making when to transfuse platelets.

  20. Quantitative bone and 67Ga scintigraphy in the differentiation of necrotizing external otitis from severe external otitis

    SciTech Connect

    Uri, N.; Gips, S.; Front, A.; Meyer, S.W.; Hardoff, R. )

    1991-06-01

    Qualitative technetium Tc 99m bone scintigraphy using phosphate compounds and gallium 67 scintigraphy were described as a helpful means in diagnosing necrotizing external otitis (NEO). They were, however, claimed to be nonspecific. Quantitative Tc 99m methylene diphosphonate bone scintigraphy and gallium 67 scintigraphy were performed in eight patients with NEO and in 20 patients with severe external otitis, in order to prove usefulness of scintigraphy in the diagnosis of NEO. Ratios of lesion to nonlesion for bone scintigraphy were 1.67 {plus minus} 0.16 in patients with NEO and 1.08 {plus minus} 0.09 in patients with severe external otitis, and for gallium 67 scintigraphy they were 1.35 {plus minus} 0.24 in NEO patients and 1.05 {plus minus} 0.03 in patients with severe external otitis. There was no difference in uptake between diabetic patients with severe external otitis and nondiabetic patients. The scintigraphic studies were also evaluated using a qualitative scoring method (scores 0 to +4), according to the intensity of the radiopharmaceutical uptake. This method was found to be inferior in the diagnosis of NEO compared with the quantitative method. We conclude that lesion-to-nonlesion ratios greater than 1.5 and 1.3 on bone and gallium 67 scintigraphy, respectively, are indicative of NEO. Quantitative bone scintigraphy, which is quicker to perform, may be used as a single imaging modality for the diagnosis of NEO.

  1. Mean platelet volume as an indicator of platelet rejuvenation following bone-marrow transplantation. Master's thesis

    SciTech Connect

    Seanger, D.G.

    1986-07-01

    Thrombocytopenia of unpredictable duration and severity is an expected outcome of the radiation/chemotherapy protocols performed prior to bone-marrow transplantation. Serial evaluation of the platelet count and mean platelet volume of patients diagnosed with acute leukemia demonstrated the mean platelet volume to increase into reference limits 24 to 40 hours prior to a rise in the platelet count in those patients whose bone-marrow successfully responded to induction chemotherapy. Serial platelet counts and measurements of mean platelet volume were performed on 31 patients following bone marrow transplantation. Numerous platelet transfusions, together with sustained thrombocytopenia, inhibited accurate assessment of 29 of 31 patients. Two patients, however, demonstrated a rise in the mean platelet volume prior to an increase in the platelet count. Both of these patients received no platelet transfusions during the period preceding or following the rise in the platelet count. It was proposed that the serial evaluation of the mean platelet volume may assist practitioners in the decision-making process of deciding whether platlet transfusions are required, or an increase in the number of circulating platelets is imminent. A decision not to transfuse would have the direct benefit of decreasing patient costs, in conjunction with eliminating a potential source for the development of an antibody against platelets.

  2. Platelet Function Tests in Bleeding Disorders.

    PubMed

    Lassila, Riitta

    2016-04-01

    Functional disorders of platelets can involve any aspect of platelet physiology, with many different effects or outcomes. These include platelet numbers (thrombocytosis or thrombocytopenia); changes in platelet production or destruction, or capture to the liver (Ashwell receptor); altered adhesion to vascular injury sites and/or influence on hemostasis and wound healing; and altered activation or receptor functions, shape change, spreading and release reactions, procoagulant and antifibrinolytic activity. Procoagulant membrane alterations, and generation of thrombin and fibrin, also affect platelet aggregation. The above parameters can all be studied, but standardization and quality control of assay methods have been limited despite several efforts. Only after a comprehensive clinical bleeding assessment, including family history, information on drug use affecting platelets, and exclusion of coagulation factor, and tissue deficits, should platelet function testing be undertaken to confirm an abnormality. Current diagnostic tools include blood cell counts, platelet characteristics according to the cell counter parameters, peripheral blood smear, exclusion of pseudothrombocytopenia, whole blood aggregometry (WBA) or light transmission aggregometry (LTA) in platelet-rich plasma, luminescence, platelet function analysis (PFA-100) for platelet adhesion and deposition to collagen cartridges under blood flow, and finally transmission electron microscopy to exclude rare structural defects leading to functional deficits. The most validated test panels are included in WBA, LTA, and PFA. Because platelets are isolated from their natural environment, many simplifications occur, as circulating blood and interaction with vascular wall are omitted in these assays. The target to reach a highly specific platelet disorder diagnosis in routine clinical management can be exhaustive, unless needed for genetic counseling. The elective overall assessment of platelet function disorder

  3. Platelet quantification and growth factor analysis from platelet-rich plasma: implications for wound healing.

    PubMed

    Eppley, Barry L; Woodell, Jennifer E; Higgins, Joel

    2004-11-01

    Growth factors released from activated platelets initiate and modulate wound healing in both soft and hard tissues. A recent strategy to promote the wound-healing cascade is to prepare an autologous platelet concentrate suspended in plasma, also known as platelet-rich plasma, that contains growth factors and administer it to wound sites. The purpose of this study was to quantitate platelet number and growth factors released from a prepared platelet concentrate. Whole blood was drawn from 10 healthy patients undergoing cosmetic surgery and concentrated into platelet-rich plasma. Platelet counts on whole blood and platelet-rich plasma were determined using a Cell-Dyn 3200. Platelet-derived growth factor-BB, transforming growth factor-beta1, vascular endothelial growth factor, endothelial growth factor, and insulin-like growth factor-1 were measured in the platelet-rich plasma using the enzyme-linked immunosorbent assay method. In addition, platelet activation during the concentration procedure was analyzed by measuring P selectin values in blood serum. An 8-fold increase in platelet concentration was found in the platelet-rich plasma compared with that of whole blood (baseline whole blood, 197 +/- 42 x 10 platelets/microl; platelet concentrate, 1600 +/- 330 x 10 platelets/microl). The concentration of growth factors also increased with increasing platelet number. However, growth factor concentration varied from patient to patient. On average for the whole blood as compared with platelet-rich plasma, the platelet-derived growth factor-BB concentration increased from 3.3 +/- 0.9 ng/ml to 17 +/- 8 ng/ml, transforming growth factor-beta1 concentration increased from 35 +/- 8 ng/ml to 120 +/- 42 ng/ml, vascular endothelial growth factor concentration increased from 155 +/- 110 pg/ml to 955 +/- 1030 pg/ml, and endothelial growth factor concentration increased from 129 +/- 61 pg/ml to 470 +/- 320 pg/ml. No increase was found for insulin-like growth factor-1. In addition, no

  4. [Pathogen inactivation of platelets: organization consequences for platelet transfusion].

    PubMed

    Chavarin, P; DePutter, C; Boussoulade, F; Acquart, S; Vidal, M; Argaud, C; Fabrigli, P; Garraud, O

    2011-08-01

    In the past few years, pathogen reduction technologies for labile blood products have been part of the enhancement of global transfusion safety regarding residual risks of transmitting infectious pathogens. Having carried out a feasibility study for the implementation of pathogen inactivation of platelet concentrates by means of the amotosalen/HCl/UVA (Intercept™) technology, and participated to a reinforced haemovigilance study, we took the opportunity to analyze the organization consequences for platelet concentrates inventory and distribution. This impact study first indicated that those novel needs forced the blood donation service, as well as the labile blood product preparation laboratory, to review and improve practices; secondly, it showed that the routine implementation has little (no major) consequence in the overall organization, independently of the economic consequences (not covered here).

  5. Influence of Oxidative Stress on Stored Platelets

    PubMed Central

    2016-01-01

    Platelet storage and its availability for transfusion are limited to 5-6 days. Oxidative stress (OS) is one of the causes for reduced efficacy and shelf-life of platelets. The studies on platelet storage have focused on improving the storage conditions by altering platelet storage solutions, temperature, and materials. Nevertheless, the role of OS on platelet survival during storage is still unclear. Hence, this study was conducted to investigate the influence of storage on platelets. Platelets were stored for 12 days at 22°C. OS markers such as aggregation, superoxides, reactive oxygen species, glucose, pH, lipid peroxidation, protein oxidation, and antioxidant enzymes were assessed. OS increased during storage as indicated by increments in aggregation, superoxides, pH, conjugate dienes, and superoxide dismutase and decrements in glucose and catalase. Thus, platelets could endure OS till 6 days during storage, due to the antioxidant defense system. An evident increase in OS was observed from day 8 of storage, which can diminish the platelet efficacy. The present study provides an insight into the gradual changes occurring during platelet storage. This lays the foundation towards new possibilities of employing various antioxidants as additives in storage solutions. PMID:26949396

  6. Trehalose lyophilized platelets for wound healing.

    PubMed

    Pietramaggiori, Giorgio; Kaipainen, Arja; Ho, David; Orser, Cindy; Pebley, Walter; Rudolph, Alan; Orgill, Dennis P

    2007-01-01

    Fresh platelet preparations are utilized to treat a wide variety of wounds, although storage limitations and mixed results have hampered their clinical use. We hypothesized that concentrated lyophilized and reconstituted platelet preparations, preserved with trehalose, maintain and possibly enhance fresh platelets' ability to improve wound healing. We studied the ability of a single dose of trehalose lyophilized and reconstituted platelets to enhance wound healing when topically applied on full-thickness wounds in the genetically diabetic mouse. We compared these results with the application of multiple doses of fresh platelet preparations and trehalose lyophilized and reconstituted platelets as well as multiple doses of vascular endothelial growth factor (VEGF) and wounds left untreated. Trehalose lyophilized and reconstituted platelets, in single and multiple applications, multiple applications of fresh platelets and multiple applications of VEGF increased granulation tissue deposition, vascularity, and proliferation when compared with untreated wounds, as assessed by histology and immunohistochemistry. Wounds treated with multiple doses of VEGF and a single dose of freeze-dried platelets reached 90% closure faster than wounds left untreated. A single administration of trehalose lyophilized and reconstituted platelet preparations enhanced diabetic wound healing, therefore representing a promising strategy for the treatment of nonhealing wounds.

  7. Detection of microbial contamination in platelets

    NASA Astrophysics Data System (ADS)

    Berg, Tracy L.; Leparc, German; Huffman, Debra E.; Gennaccaro, Angela L.; Garcia-Lopez, Alicia; Klungness, Greta; Stephans, Christie; Garcia-Rubio, Luis H.

    2005-03-01

    In the United States, approximately 100 patients develop fatal sepsis associated with platelet transfusions every year. Current culture methods take 24-48 hours to acquire results, which in turn decrease the shelf life of platelets. Many of the microorganisms that contaminate platelets can replicate easily at room temperature, which is the necessary storage temperature to keep platelets functional. Therefore, there is a need for in-situ quality control assessment of the platelet quality. For this purpose, a real time spectrophotometric technique has been developed. The Spectral Acquisition Processing Detection (SAPD) method, comprised of a UV-vis spectrophotometer and modeling algorithms, is a rapid method that can be performed prior to platelet transfusion to decrease the risk of bacterial infection to patients. The SAPD method has been used to determine changes in cell suspensions, based on size, shape, chemical composition and internal structure. Changes in these cell characteristics can in turn be used to determine microbial contamination, platelet aging and other physiologic changes. Detection limits of this method for platelet suspensions seeded with bacterial contaminants were identified to be less than 100 cfu/ml of sample. Bacterial counts below 1000 cfu/ml are not considered clinically significant. The SAPD method can provide real-time identification of bacterial contamination of platelets affording patients an increased level of safety without causing undue strain on laboratory budgets or personnel while increasing the time frame that platelets can be used by dramatically shortening contaminant detection time.

  8. Thrombospondin-induced adhesion of human platelets.

    PubMed Central

    Tuszynski, G P; Kowalska, M A

    1991-01-01

    Washed human unactivated platelets attached and spread on thrombospondin (TSP)-coated microtiter plates. Platelet adhesion was promoted by divalent cations Mn2+, Mg2+, and Ca2+ as compared to buffer having all divalent cations complexed with EDTA. TSP-dependent adhesion was inhibited by anti-TSP fab fragments, an anti-TSP monoclonal antibody, an RGD-containing peptide, complex-specific anti-glycoprotein (GP)IIb-IIIa monoclonal antibodies (A2A9 or AP-2) and anti-VLA-2 monoclonal antibodies (6F1 and Gi9), but not by rabbit preimmune fab fragments, mouse IgG, an anti-GPIIIa monoclonal antibody, or monoclonal antibodies against either the human vitronectin receptor, glycocalicin, or GPIV. At saturating concentrations, anti-GPIIb-IIIa inhibited adhesion by 40-60%. Glanzman's thrombasthenic platelets, which lack GPIIb-IIIa, adhered to TSP to the same extent as anti-GPIIb-IIIa-treated normal platelets or 40-60% as well as untreated normal platelets. Antibody 6F1 (5-10 micrograms/ml) inhibited platelet adhesion of both normal and thrombasthenic platelets by 84-100%. Both VLA-2 antibodies also inhibited collagen-induced platelet adhesion, but had no effect on fibronectin-induced adhesion of normal platelets. These data indicate that platelets specifically adhere to TSP and that this adhesion is mediated through GPIIb-IIIa and/or VLA-2. Images PMID:2010551

  9. Effect of sildenafil on platelet function and platelet cGMP of patients with erectile dysfunction.

    PubMed

    Akand, M; Gencer, E; Yaman, Ö; Erişgen, G; Tekin, D; Özdiler, E

    2015-12-01

    To investigate the effect of sildenafil on platelet function and cyclic guanosine monophosphate (cGMP) levels in patients with erectile dysfunction, we evaluated the association between erectile function and platelet responses after administration of 100 mg sildenafil. Erectile responses were monitored after 8 daily doses of the drug. Adenosine diphosphate (ADP) and collagen-induced platelet aggregation and simultaneous adenosine triphosphate (ATP) release and cGMP levels were determined before and after sildenafil therapy. Basal levels for platelet aggregation, ATP release and cGMP were compared with age-matched controls. There was no difference among basal levels of platelet responses between patients and controls, except for ADP-induced platelet aggregation (P = 0.04). It was significantly higher in the patient group. Analysis of the responses to sildenafil revealed that for the patients who showed a positive erectile response, there was a significant increase in platelet cGMP (P = 0.028) and a decrease in ADP-induced platelet aggregation (P = 0.04). However, for those who showed a negative or poor erectile response, there was no change in platelet cGMP levels and platelet functions. Sildenafil did not affect collagen-induced platelet responses although cGMP levels of the responders increased. It is concluded that sildenafil increases platelet cGMP in the patients with positive erectile response. Therefore, it has been speculated that platelet cGMP may be used as an index for erectile response.

  10. Complement Activation Alters Platelet Function

    DTIC Science & Technology

    2015-12-01

    2004; Danese et al., 2003). Recent studies have demonstrated a role for platelets in the development of both innate and adaptive immune responses...mediated modulation of adaptive immunity. A communication link between innate and adaptive immune compartments. Immunity 19:9-19. 4. Fleming, S.D., M...Monestier, and G.C. Tsokos. 2004. Accelerated ischemia/reperfusion- induced injury in autoimmunity-prone mice. Journal of immunology 173:4230-4235

  11. Platelets: cell proliferation and atherosclerosis.

    PubMed

    Ross, R

    1979-04-01

    Intimal smooth muscle proliferation is the hallmark of the lesions of atherosclerosis. Endothelial injury is postulated to precede this intimal smooth muscle proliferative response, which is mediated by a potent mitogenic factor derived from adherence, aggregation, and release by platelets at sites of endothelial injury. Smooth muscle proliferation is accompanied by varying amounts of connective tissue formation and intracellular and extracellular lipid deposition, dependent upon the risk factors encountered in each patient. The platelet-derived mitogen (PF) is a stable, cationic, relatively low molecular weight (10,000-30,000) protein that has been partially purified by ion exchange chromotography and gel filtration. Less than 100 ng of PF/ml culture medium can stimulate sparse 3T3 cells or smooth muscle cells, but not endothelial cells, to undergo multiple cell divisions in the presence of 5% cell-free, plasma-derived serum. The latter contains no mitogenic activity. The interaction of the platelet mitogen and plasma-derived components, including lipoproteins, plays a critical role in smooth muscle proliferation in vitro and in vivo in the induction of the lesions of atherosclerosis.

  12. The impact of platelet transfusion characteristics on posttransfusion platelet increments and clinical bleeding in patients with hypoproliferative thrombocytopenia.

    PubMed

    Triulzi, Darrell J; Assmann, Susan F; Strauss, Ronald G; Ness, P M; Hess, John R; Kaufman, Richard M; Granger, Suzanne; Slichter, Sherrill J

    2012-06-07

    Platelet characteristics, such as platelet dose, platelet source (apheresis vs pooled), platelet donor-recipient ABO compatibility, and duration of platelet storage, can affect posttransfusion platelet increments, but it is unclear whether these factors impact platelet transfusion efficacy on clinical bleeding. We performed secondary analyses of platelet transfusions given in the prospective randomized Platelet Dose Study, which included 1272 platelet-transfused hematology-oncology patients who received 6031 prophylactic platelet transfusions. The primary outcome of these analyses was time from first transfusion to first World Health Organization ≥ grade 2 bleeding. Platelet transfusion increments were assessed at 0.25 to 4 hours and 16 to 32 hours after platelet transfusion. There were 778 patients evaluable for analysis of time to bleeding. Adjusted models showed that randomized dose strategy, platelet source, ABO compatibility, and duration of storage did not predict this outcome. Platelet increments were generally higher for transfusions of apheresis platelets, ABO-identical platelets, and platelets stored 3 days versus 4 to 5 days. Thus, although platelet source, ABO compatibility, and duration of storage exert a modest impact on both absolute and corrected posttransfusion platelet increments, they have no measurable impact on prevention of clinical bleeding. This trial was registered at www.clinicaltrials.gov as #NCT00128713.

  13. Vesicoureteral Reflux Detected with 99mTc-DTPA Renal Scintigraphy during Evaluation of Renal Function

    PubMed Central

    Manevska, Nevena; Stojanoski, Sinisa; Majstorov, Venjamin; Pop-Gjorcheva, Daniela; Zdraveska, Nikolina; Kuzmanovska, Dafina

    2016-01-01

    BACKGROUND: Radionuclide techniques, as direct radionuclide cystography and 99mTc-DMSA scintigraphy, have been used in evaluation of vesicoureteral reflux (VUR) and reflux nephropathy (RN) in children. Dynamic 99mTc-DTPA scintigraphy is reserved for evaluation of differential renal function and obstruction in children, where hydronephrosis is detected by ultrasonography (US) pre- or postnatally. CASE REPORT: Six year old boy was prenatally diagnosed with bilateral hydronephrosis. Postnatal, severe bilateral VUR was detected by voiding urethrocytography. US and 99mTc-DTPA scintigraphy performed in the first month of life showed small left kidney that participated with 2% in the global renal function. Bilateral cutaneous ureterostomy has been performed in order to obtain good renal drainage and promote optimal renal growth. Twelve months later, classic antireflux procedure was done. Control 99mTc-DTPA scintigraphy, 5 ys after antireflux surgery, revealed persisting radioactivity during the diuretic phase, in the left kidney that indicated antireflux procedure failure with VUR reappearance. CONCLUSION: 99mTc-DTPA scintigraphy is the first method of choice for long-term monitoring of individual kidney function in children with VUR and other congenital urinary tract anomalies. Additionally, it can be used as indirect radionuclide cystography when rising of radioactivity in the kidney region, during the diuretic phase can indicate presence of VUR. PMID:27275347

  14. Clinical utility of bone scintigraphy in patients with limb pain of suspected musculoskeletal origin

    PubMed Central

    Ferrari, Robert

    2015-01-01

    Objective To determine the clinical utility of bone scintigraphy in patients with limb pain of suspected musculoskeletal origin. Material and Methods All patients aged ≥18 years who were referred for diagnosis and management of limb pain were diagnosed on the basis of history, physical examination, and investigations excluding bone scintigraphy. After the presumptive diagnosis was made (the pre-test diagnosis), all subjects underwent bone scintigraphy, or if they had a previous bone scintigram for their pain condition, the results of that scintigram were reviewed. Then, the pre-test diagnosis was reviewed in light of the bone scintigraphy findings and repeat clinical assessment as needed. The post-test diagnosis was considered either as unchanged diagnosis or changed diagnosis for the region or regions of interest. Results There were 118 females (54.8%) and 97 males (45.2%). The mean age of the entire group was 36±8.1 years (range: 18–87 years). The mean duration of the symptoms was 17.4±11.2 months (range: 1–264 months). Of the 215 subjects, 212 had a bone scintigram. Of these 212 subjects, none had a changed diagnosis. Conclusion In the evaluation of limb pain of suspected musculoskeletal origin, scintigraphy is unlikely to alter the pre-test diagnosis or affect treatment decisions after history, physical examination, and non-scintigraphic investigations. The clinical utility of scinitigraphy in this setting is low. PMID:27708914

  15. Use of thallium-201 redistribution scintigraphy in the preoperative differentiation of reversible and nonreversible myocardial asynergy.

    PubMed

    Rozanski, A; Berman, D S; Gray, R; Levy, R; Raymond, M; Maddahi, J; Pantaleo, N; Waxman, A D; Swan, H J; Matloff, J

    1981-11-01

    Thallium-201 (201Tl) redistribution scintigraphy might differentiate reversibly from nonreversibly asynergic myocardial segments and thus predict the response of these segments to coronary artery bypass grafting (CABG). To test this hypothesis, 25 consecutive patients undergoing CABG, preoperative stress-redistribution 201Tl scintigraphy, and both pre- and postoperative resting equilibrium radionuclide ventriculography were evaluated. For both types of scintigraphic study, each patient was imaged in the same three views. Because of the effects of CABG on septal motion, this region was considered separately. Postoperative improvement was noted in 54% of 72 preoperative asynergic segments. Improvement was common not only in hypokinetic but also in akinetic and dyskinetic segments, and occurred in a similar proportion of studies performed early (less than 2 weeks) or late (3-6 months) after CABG. Thallium-201 redistribution scintigraphy was highly predictive of the pattern of postoperative asynergy: The redistribution pattern was normal in 90% of segments with reversible asynergy and abnormal in 76% of segments with nonreversible asynergy. The presence or absence of pathologic Q waves was less sensitive in this differentiation. Septal segments, however, frequently demonstrated abnormal wall motion postoperatively, despite normal 201Tl redistribution scintigraphy. Resting left ventricular ejection fraction (LVEF) was generally unchanged postoperatively, but in some patients with multiple areas of reversible asynergy it did improve. Thus, 201Tl redistribution scintigraphy appears to reliably distinguish viable from nonviable asynergic myocardial zones, and predicts the response of these segments to CABG.

  16. Comparison of dipyridamole-echocardiography with dipyridamole-thallium scintigraphy for the diagnosis of myocardial ischemia

    SciTech Connect

    Perin, E.C.; Moore, W.; Blume, M.; Hernandez, G.; Dhekne, R.; DeCastro, C.M. )

    1991-06-01

    After an intravenous infusion of dipyridamole (0.56 mg/kg), the authors performed both echocardiography and thallium scintigraphy in 63 patients who were referred for known or suspected coronary artery disease. Of those patients, 25 returned for coronary arteriography within 1 month after the tests, thus forming the study group for this report. Sensitivity for detection of coronary artery disease, when analyzed region-by-region, was 80% for thallium scintigraphy and 57% for echocardiography, whereas specificity was 85% and 98%, respectively. When evaluating individual patients for the presence or absence of ischemia, they found a sensitivity of 95% for scintigraphy and 58% for echocardiography; corresponding specificities were 50% and 100%. By using arteriography as the gold standard for comparison, it appears that thallium scintigraphy has a significantly higher sensitivity but lower specificity for the detection of coronary artery disease than does echocardiography. Echocardiography may, however, be a useful adjunct to thallium scintigraphy in the evaluation of patients with coronary artery disease.

  17. Clinical applications of oro-pharyngo-oesophageal scintigraphy in the study of dysphagia

    PubMed Central

    Fattori, B; Grosso, M; Ursino, F; Matteucci, F; Mancini, V; Rizza, E; Mattone, V; Mariani, G; Nacci, A

    2007-01-01

    Summary The diagnostic approach to patients with dysphagia is well established and relies mainly on videofluoroscopy and endoscopy. Oro-pharyngo-oesophageal scintigraphy permits both a functional and a semi-quantitative study of the various stages of swallowing. Moreover, by means of this investigation, it is possible to estimate the amount of inhaled bolus. Oro-pharyngo-oesophageal scintigraphy with 99mTc-nanocolloid has been found to be easy to use, economical, well tolerated and, supplying precise indications regarding the extent of the swallowing disorder, then permits a better clinical definition of the patient. The limitations of swallowing scintigraphy are: poor definition in visualizing anatomic structures and low specificity when used as the only diagnostic test. Scintigraphy plays an important role in the diagnosis and follow-up of dysphagia, and its use, together with other diagnostic techniques, increases diagnostic accuracy. In this study, the role of oro-pharyngo-oesophageal scintigraphy has been analysed in patients with post-surgical, neurological and oesophageal dysphagia. PMID:17957850

  18. Therapeutic platelet reduction: Use in postsplenectomy thrombocytosis

    PubMed Central

    Negi, Gita; Talekar, Manjubala S.; Verma, Sanjiv Kumar; Rehmani, Babar; Gupta, Vibha; Agarwal, Amit; Harsh, Meena

    2015-01-01

    Therapeutic platelet reduction is an effective modality for the reduction of platelet count in patients with treatment of extreme thrombocytosis resulting from a variety of primary and secondary causes of thrombocytosis, which may be associated with thrombotic or hemorrhagic complications of varying degrees. These cases when symptomatic fall into the ASFA Category II indication for therapeutic platelet apheresis procedure. Here, we report a case of postsplenectomy secondary thrombocytosis presenting with extremely high platelet counts and subsequent thrombosis in the shunt and successful treatment after therapeutic platelet reduction. The case is being presented to bring forth the fact that therapeutic platelet reduction is an easy procedure that gives quick and good results and also to bring to the attention of transfusion specialists an associated but as yet unreported procedural finding. PMID:25722581

  19. Mean platelet volume in acute rheumatic fever.

    PubMed

    Sert, Ahmet; Aypar, Ebru; Odabas, Dursun

    2013-01-01

    Acute rheumatic fever (ARF) is still an endemic disease, especially among school-aged children in developing countries. Mean platelet volume (MPV), which is commonly used as a measure of platelet size, indicates the rate of platelet production and platelet activation. We aimed to investigate MPV in children with ARF. The study population consisted of 40 children with ARF (32 patients with carditis and 8 patients without carditis) and 40 healthy control subjects. White blood cell (WBC) and platelet counts were significantly higher and MPV values were significantly lower in patients with ARF during the acute stage when compared to controls. Erythrocyte sedimentation rate (ESR) and C-reactive protein values significantly decreased in patients with ARF after the treatment when compared to baseline, whereas MPV values increased. MPV values were negatively correlated with ESR and WBC, and platelet counts. In conclusion, during the acute stage of ARF, MPV values were lower when compared to controls.

  20. Nouvelle cuisine: platelets served with inflammation.

    PubMed

    Kapur, Rick; Zufferey, Anne; Boilard, Eric; Semple, John W

    2015-06-15

    Platelets are small cellular fragments with the primary physiological role of maintaining hemostasis. In addition to this well-described classical function, it is becoming increasingly clear that platelets have an intimate connection with infection and inflammation. This stems from several platelet characteristics, including their ability to bind infectious agents and secrete many immunomodulatory cytokines and chemokines, as well as their expression of receptors for various immune effector and regulatory functions, such as TLRs, which allow them to sense pathogen-associated molecular patterns. Furthermore, platelets contain RNA that can be nascently translated under different environmental stresses, and they are able to release membrane microparticles that can transport inflammatory cargo to inflammatory cells. Interestingly, acute infections can also result in platelet breakdown and thrombocytopenia. This report highlights these relatively new aspects of platelets and, thus, their nonhemostatic nature in an inflammatory setting.

  1. The Role of Platelets in Venous Thromboembolism.

    PubMed

    Montoro-García, Silvia; Schindewolf, Marc; Stanford, Sophia; Larsen, Ole Halfdan; Thiele, Thomas

    2016-04-01

    Multiple factors contribute to the risk of venous thromboembolism (VTE). Platelets have attracted much interest in arterial cardiovascular disease, whereas their role in VTE has received much less attention. Recent evidence suggests that platelets may play a more important role in VTE than previously anticipated. This review discusses the mechanisms that link platelets with venous thrombotic disease and their potential applications as novel risk factors for VTE. In addition, animal studies and randomized clinical trials that highlight the potential effect of antiplatelet therapy in venous thrombosis are evaluated to assess the role of platelets in VTE. The clinical significance of platelets for VTE risk assessment in specific patient cohorts and their role as a suitable therapeutic target for VTE prevention is acknowledged. The role of platelets in VTE is a promising field for future research.

  2. Anti-platelets in diabetes management.

    PubMed

    Grantham, N M; Magliano, D J; Tai, G; Cohen, N; Shaw, J E

    2010-06-01

    This study aimed to determine the prevalence of anti-platelet use, and the extent to which contraindications to anti-platelet therapy prevent its use, in 726 diabetic patients attending a private clinic. Among those who reported a history of cardiovascular disease (CVD), 87.1% were on anti-platelet therapy. Of those without prior CVD but with at least one CVD risk factor, 59.8% were not on anti-platelet therapy, but only 7.1% of these had a contraindication to anti-platelet therapy. This study showed that high usage of anti-platelet therapy in diabetic patients with prior CVD is achievable, and that contraindications did not explain low use in those without prior CVD.

  3. Blood platelet aggregation and personality traits.

    PubMed

    Jenkins, C D; Thomas, G; Olewine, D; Zyzanski, S J; Simpson, M T; Hames, C G

    1975-12-01

    Changes in blood platelet aggregation may precipitate episodes of arterial occlusive diseases. Little is known, however, regarding the influence of psychological traits, emotional states and other behavioral stressors on platelet aggregation phenomena. This study examined 46 healthy college men at rest and after submaximal treadmill exercise. Associations were found between the duration of platelet aggregation and a number of scores from the California Psychological Inventory and self-administered anxiety scales. The more socially adequate, poised and dominant persons--those with more mature ego development and less overt anxiety--had platelets with more prolonged aggregation reactions to the in vitro introduction of noradrenalin. Irreversible aggregation of platelets occurred more regularly to lower in vitro concentrations of noradrenalin in platelet samples drawn from subjects who were less anxious and tended to be more rigidly defensive. It is premature to attempt to derive clinical implications from this exploratory work, but some implications for the design of future research are discussed.

  4. Bone marrow scintigraphy and computed tomography in myloproliferative disease

    SciTech Connect

    Goldsmith, S.J.; Gilbert, H.S.; Hermann, G.

    1985-05-01

    Peripheral bone marrow (BM) expansion in myeloproliferative disease (MPD) is demonstrated by scintigraphy (scint) with Technetium 99m sulfur colloid (TSC) or Indium III chloride (In). Computed tomography (CT) of the normal adult medullary cavity yields negative attenuation coefficients (AC) which become positive when BM fat is replaced. BM scint and CT of the medullary cavity are obtained in 23 studies in 21 pts: 6 polycythemia vera (PCV), 6 post PCV myeloid metaplasis (MyM), 4 agnogenic MyM, 3 myelodysplasia with refractory anemia, 1 acute myelocytic leukemia and 1 chronic myelocytic with acute leukemic transformation. AC were measured for BM cavity of lower extremities at each third of the femur and tibia. Values ranged from -89 to +289 Hounsfield units. The results are presented in this paper. There was agreement between SCINT and CT in 83% pts and segments. 80% of MB segments with + AC had scint identified BM. BM biopsy of the iliac crest demonstrated fibrosis or blast proliferation in pts with +AC rather than hypercellularity or osteosclerosis. The highest AC values (>200) were seen in pts with blast proliferation and fibrosis. Decreased BM scint visualization and +CT AC correlated with BM fibrosis and may reflect replacement of BM elements or decreased RES function. BM scint and CT are useful to monitor MPD and select BM sites for biopsy.

  5. Applicability of the Appropriate use Criteria for Myocardial Perfusion Scintigraphy

    PubMed Central

    de Oliveira, Anderson; Rezende, Maria Fernanda; Corrêa, Renato; Mousinho, Rodrigo; Azevedo, Jader Cunha; Miranda, Sandra Marina; Oliveira, Aline Ribeiro; Gutterres, Ricardo Fraga; Mesquita, Evandro Tinoco; Mesquita, Cláudio Tinoco

    2014-01-01

    Background Appropriateness Criteria for nuclear imaging exams were created by American College of Cardiology (ACC) e American Society of Nuclear Cardiology (ASNC) to allow the rational use of tests. Little is known whether these criteria have been followed in clinical practice. Objective To evaluate whether the medical applications of myocardial perfusion scintigraphy (MPS) in a private nuclear medicine service of a tertiary cardiology hospital were suitable to the criteria of indications proposed by the American medical societies in 2005 and 2009 and compare the level of indication of both. Methods We included records of 383 patients that underwent MPS, November 2008 up to February 2009. Demographic characteristics, patient's origin, coronary risk factors, time of medical graduation and appropriateness criteria of medical applications were studied. The criteria were evaluated by two independent physicians and, in doubtful cases, defined by a medical expert in MPS. Results Mean age was 65 ± 12 years. Of the 367 records reviewed, 236 (64.3%) studies were performed in men and 75 (20.4%) were internee. To ACC 2005, 255 (69.5%) were considered appropriate indication and 13 (3.5%) inappropriate. With ACC 2009, 249 (67.8%) were considered appropriate indications and 13 (5.2%) inappropriate. Conclusions We observed a high rate of adequacy of medical indications for MPS. Compared to the 2005 version, 2009 did not change the results. PMID:25252163

  6. Size Dependent Platelet Subpopulations: Relationship of Platelet Volume to Ultrastructure Enzymatic Activity, and Function.

    DTIC Science & Technology

    1983-03-10

    of the present apheresis instruments to separate the larger more functional platelets from the smaller ones. The selective isolation of large... PLATELET VOLUME T. -(U) BOSTON UNIV MA SCHOOL OF I MEDICINE C B THOMPSON ET RL 10 MAR 83 BUSM-93-89 UNIIDN919CA89 /68 6ilfflfllflflflflll l...N00014-79-C-0168 TECHNICAL REPORT NO. 83-08 SIZE DEPENDENT PLATELET SUBPOPULATIONS: RELATIONSHIP OF PLATELET VOLUME TO ULTRASTRUCTURE. ENZYMATIC ACTIVITY

  7. Extending The Shelf Life Of Blood Platelets

    NASA Technical Reports Server (NTRS)

    Surgenor, Douglas M.

    1988-01-01

    New method of storing human blood platelets extends vitality for transfusions. Packaged as suspension in sterile liquid in plastic blood bags. Each bag placed between pair of plastic grids, and rubberbands placed around sandwich thus formed to hold together. Stored upright in open air or in container through which air pumped at rate of at least 45 L/min. Ensures that platelets receive ample oxygen and expiratory carbon dioxide form platelets removed before pH drops to harmful levels.

  8. Status Report on Cryopreservation of Human Platelets.

    DTIC Science & Technology

    1979-03-27

    Platelets." In: Erythrocytes, Path.44:678, 1965. lets contributed to our excellent re- Thrombocytes and Leukocytes. Eds. * suits. The observations in...the methodsof measurement: 80% when the platelet counts were made by phase microscopy ,85% by Coulter counter, and 60% by the Technicon. These... microscopy , 85’/ by Coulter counter, and 60% by the Technicon. These platelets had 5 1 Cr survival values in viv’o about 50’le of those observed for

  9. Platelet mimicry: The emperor's new clothes?

    PubMed

    Moghimi, Seyed Moein; Hunter, Alan Christy; Peer, Dan

    2016-01-01

    Here we critically examine whether coating of nanoparticles with platelet membranes can truly disguise them against recognition by elements of the innate immune system. We further assess whether the "cloaking technology" can sufficiently equip nanoparticles with platelet-mimicking functionalities to include in vivo targeting of damaged blood vessels and binding to platelet-adhering opportunistic pathogens. We present views for improved, and pharmaceutically viable nanoparticle design strategies.

  10. Platelet Glycoprotein lb-1X and Malignancy

    DTIC Science & Technology

    2010-09-01

    of mouse models of platelet dysfunction in the progression of cancer to metastatic disease . During the next year we propose to examine the relevance...spread of metastatic disease represents a fundamental change in significantly shortening the life span of patients with breast cancer. Thus...von Willebrand factor (vWF) and thrombin, illustrating platelet GP Ib-IX as a major initiator of platelet thrombus formation in the arterial

  11. Platelet Glycoprotein Ib-IX and Malignancy

    DTIC Science & Technology

    2010-09-01

    cancer to metastatic disease . During the next year we propose to examine the relevance of platelet receptors in models of spontaneous metastasis. A...the prognosis for recovery from breast cancer cannot be under emphasized. Indeed, the spread of metastatic disease represents a fundamental change in...IX have been identified, including von Willebrand factor (vWF) and thrombin, illustrating platelet GP Ib-IX as a major initiator of platelet thrombus

  12. Unexpected Tc-99m labelled erythrocyte scintigraphy finding of a patient with suspicion of active bleeding into renal haematoma.

    PubMed

    Koç, Zehra Pinar; Balci, Tansel Ansal; Celiker, Hüseyin

    2011-08-11

    A 36-year-old male patient with suspicion of active bleeding into renal haematoma loge was sent to our clinic for Tc-99m labelled erythrocyte scintigraphy. Scintigraphy showed no active bleeding to renal haematoma but coexisting active haemorrhage of stomach which was confirmed as erosive bulbitis with further endoscopy.

  13. Traumatic retroperitoneal hematoma illustrated on Tc-99m methylene diphosphonate bone scintigraphy in a patient presenting with a fall.

    PubMed

    Nguyen, Huong Van; Chiam, Quee Li; Dixson, Hugh; Goddard, Kim A

    2007-08-01

    Retroperitoneal haematoma is rarely described in the context of bone scintigraphy, as it is usually an incidental discovery on bone scan carried out for another purpose. We report a case of a right retroperitoneal haematoma detected on Tc-99m-methylene diphosphonate bone scintigraphy taken in an elderly patient presenting with a mechanical fall and a right acetabular fracture.

  14. The role of RNA uptake in platelet heterogeneity.

    PubMed

    Clancy, Lauren; Beaulieu, Lea M; Tanriverdi, Kahraman; Freedman, Jane E

    2017-03-09

    The role of platelets in regulating vascular homeostasis has expanded beyond mediation of haemostasis and thrombosis. The discovery of platelet RNA and the presence of subpopulations of platelets containing varying amounts of RNA suggest a role for platelet transcripts in vascular function. As the RNA in anucleated platelets is biologically functional and may transfer to other vascular cells, we hypothesised that platelet RNA diminishes over the lifespan of the platelet with diminishing platelet size due to horizontal cellular transfer. The purpose of this study is to determine if platelet RNA variance is the result of horizontal cellular transfer between platelets and other vascular cells. Utilising platelet sorting and RNA sequencing, we found that smaller platelets contained a more diverse set of transcripts than larger platelets. Further investigation using fluorescence imaging, gene expression analyses and in vitro and in vivo modelling revealed that platelets take up RNA from other vascular cells in a complex manner, revealing a dynamic role for platelets in modulating vascular homeostasis through bidirectional RNA transfer. The resultant RNA profile heterogeneity suggests unique functional roles for platelets dependent on size and complexity. This study expands our basic understanding of platelet function and heterogeneity and is the first to evaluate endogenous vascular RNA uptake and its relation to platelet processes. Our findings describe a novel endogenous phenomenon that can help elucidate the platelet's role in these non-thrombotic and haemostatic fields, as well as present potential for diagnostic and therapeutic development.

  15. Platelet function tests, independent of platelet count, are associated with bleeding severity in ITP.

    PubMed

    Frelinger, Andrew L; Grace, Rachael F; Gerrits, Anja J; Berny-Lang, Michelle A; Brown, Travis; Carmichael, Sabrina L; Neufeld, Ellis J; Michelson, Alan D

    2015-08-13

    Immune thrombocytopenia (ITP) patients with similarly low platelet counts differ in their tendency to bleed. To determine if differences in platelet function in ITP patients account for this variation in bleeding tendency, we conducted a single-center, cross-sectional study of pediatric patients with ITP. Bleeding severity (assessed by standardized bleeding score) and platelet function (assessed by whole blood flow cytometry) with and without agonist stimulation was evaluated in 57 ITP patients (median age, 9.9 years). After adjustment for platelet count, higher levels of thrombin receptor activating peptide (TRAP)-stimulated percent P-selectin- and activated glycoprotein (GP)IIb-IIIa-positive platelets were significantly associated with a lower bleeding score, whereas higher levels of immature platelet fraction (IPF), TRAP-stimulated platelet surface CD42b, unstimulated platelet surface P-selectin, and platelet forward light scatter (FSC) were associated with a higher bleeding score. Thus, platelet function tests related to platelet age (IPF, FSC) and activation through the protease activated receptor 1 (PAR1) thrombin receptor (TRAP-stimulated P-selectin, activated GPIIb-IIIa, and CD42b), independent of platelet count, are associated with concurrent bleeding severity in ITP. These tests may be useful markers of future bleeding risk in ITP.

  16. Response of Northern Elephant Seal platelets to pressure and temperature changes: a comparison with human platelets.

    PubMed

    Field, Cara L; Tablin, Fern

    2012-08-01

    Mammalian blood platelets are activated by physiological agonists such as collagen or thrombin, or by physical stimuli such as cold temperatures and rapid decompression. Marine mammals regularly experience cold temperatures, high pressures and rapid decompression while diving, yet do not appear to suffer from thrombotic events during routine dive activity. We evaluated the effects of cold temperature and high pressure excursions on Northern Elephant Seal (NES) platelets and compared NES platelet response to that of human platelets subjected to identical stimuli. NES platelets undergo cold-induced activation when chilled to 4 °C, and 3 distinct phase transitions can be measured using Fourier Transform Infrared Spectroscopy. NES platelet membrane lipid composition was determined using thin layer chromatography and NES platelets were found to have three times the amount of cholesterol (21% by weight) as human platelets. When exposed to high pressure-rapid decompression excursion, NES platelets did not undergo morphological shape change nor bind increased amounts of fibrinogen, while human platelets were significantly activated by the same excursion. These results demonstrate that while NES platelets are activated by the physical stimulus of cold temperatures, they are resistant to decompression-induced activation. We suggest that the composition of NES platelet membranes may play an important role in preventing pressure-related activation.

  17. Platelet activation of platelet concentrates derived from buffy coat and apheresis methods.

    PubMed

    Ali, Soleimany Ferizhandy

    2011-02-01

    Preparation for storage may cause platelet activation. The quality of platelet concentrates plays an important role in transfusion therapy. Platelet concentrates are produced by different centrifugation methods; buffy coat (buffy coat-derived platelet concentrates-BC) and plateletpheresis (apheresis-derived platelet concentrates-APC). Their quality was assessed using the following parameters: platelet, WBC and RBC counts pH, volume, platelet factor 4 (PF4) and Annexin V. The present paper compares the quality of both platelet preparations in vitro. In this experimental study, 30 platelet concentrates were harvested with the Haemonetics MCS plus and 30 units via the buffy coat (BC) method. The percentages of Annexin V expression, PF4 levels, platelet, WBC and RBC counts, pH and volume were measure immediately after collection and after 3 days of storage. During storage for up to 3 days, BC units displayed, no significant pH or RBC, difference in comparison with apheresis preparations (p>0.05). During storage for up to 3 days, BC units displayed a significant increase in the PF4 and Annexin V expression, compared to the apheresis preparations on day three (p<0.05). The kinetics of PF4 and Annexin V levels are influenced by the method used to prepare platelets for storage. The different levels of PF4 and Annexin V in BCs and APCs clearly demonstrates a progressive activation of BC platelets exceeding that of APC. However, in vivo studies should be performed to confirm these findings.

  18. Mean platelet volume in patients with fibromyalgia.

    PubMed

    Haliloğlu, S; Carlioglu, A; Sahiner, E; Karaaslan, Y; Kosar, A

    2014-10-01

    Fibromyalgia is a syndrome characterised by chronic widespread pain at multiple tender points, as well as joint stiffness and systemic symptoms. The aetiology and pathogenesis of fibromyalgia still remain unclear, although many contributory factors have been suggested. The presence of some common features between fibromyalgia and cardiovascular risk factors (e.g. depression and sleep disturbance) led to question of whether there is there a relationship between fibromyalgia and cardiovascular disease and/or atherosclerosis. Mean platelet volume, which is a determinant of platelet activation, is a newly emerging independent risk factor for cardiovascular disease.The present study was designed to evaluate levels of mean platelet volume in patients with fibromyalgia; the study population consisted of 283 individuals with this syndrome, who were compared with 72 healthy controls. Erythrocyte sedimentation rate, C-reactive protein, white blood cell count, platelet count and mean platelet volume levels were retrospectively recorded via the computerised patient database. The levels of mean platelet volume were significantly higher in the fibromyalgia group than in the control group (8.09 ± 0.84 fl and 7.73 ± 0.65 fl, respectively, p < 0.001). There were no statistical differences between groups with regard to platelet count and other parameters. These results suggest that an early atherosclerosis marker, mean platelet volume, is elevated in patients with fibromyalgia. This indicates increased platelet activation and therefore a higher risk of future cardiovascular disease.

  19. Platelet antibodies in idiopathic thrombocytopenic purpura.

    PubMed Central

    Veenhoven, W A; Van der Schans, G S; Nieweg, H O

    1980-01-01

    An immunofluorescence (IF) technique for the detection of antibodies was applied to idiopathic thrombocytopenic purpura (ITP). Serum platelet antibodies were found in thirteen out of twenty-two patients (59 percent) with active disease, but in only four out of fifteen patients (27 percent) who had attained remission. Direct tests for platelet-associated IgG were positive in 36 and 44 percent of these patients respectively. In two cases IgM was observed on the patients' platelet membranes. C3 was not detedted on patients' platelets. Platelet-associated IgG was also found in several other disorders and its occurrence is not therefore diagnostic of ITP. In addition, serum platelet antibodies do not indicate specifically ITP as they may also be due to previous isoimmunization. Antibodies in the sera of patients with ITP generally did not fix Clq and in most cases bound to platelets only in the presence of EDTA. In contrast, isoantibodies often fixed Clq and they had equal affinity for platelets suspended in ACD or EDTA plasma. This was confirmed by quantitative data on IgG binding by platelets obtained by measuring 125-I-labelled protein A uptake. The simplicity of the IF technique permits its routine application and the technique may give useful information with respect to the nature of the antibodies. It must, however, be considered of limited value in the diagnosis of ITP. PMID:6991171

  20. Modulatory effect of coffee on platelet function.

    PubMed

    Bhaskar, Shobha; Rauf, Arun A

    2010-01-01

    Blood platelets play a major role in cardiovascular disease (CVD) and thrombosis. Conflicting information exists regarding the effect of coffee consumption on the cardiovascular system. We have investigated whether the consumption of moderate amount of coffee affect platelet functions and primary hemostasis in vivo in normal and high fat diet fed rats. Coffee fed group showed significant (P < 0.05) decrease in mean platelet volume, platelet crit and platelet distribution width as compared to high fat diet (HFD) group. The concentration of malondialdehyde in platelets increased in atherosclerotic group indicates the increased thromboxane A2 (TXA2) production from membrane arachidonic acid and it was decreased in coffee treated group. Platelet aggregation studies with ADP, collagen, arachidonic acid and epinephrine showed significant (P < 0.05) decrease in aggregation in coffee fed group. Scanning electron microscopic studies revealed that platelet aggregation tendency increased in HFD group and was reduced in coffee fed group. These results indicate that coffee is active in inhibiting platelet aggregation, a critical step involved in thrombosis.

  1. [Cardiology. Platelet function testing for clinicians].

    PubMed

    Pellaton, Cyril; Eeckhout, Eric; Silvain, Johanne; Montalescot, Gilles; Collet, Jean-Phillipe

    2014-01-15

    Platelet P2YI2 receptor inhibition with clopidogrel, prasugrel or ticagrelor plays a key role to prevent recurrent ischaemic events after percutaneous coronary intervention in acute coronary syndromes or elective settings. The degree of platelet inhibition depends on the antiplatelet medication used and is influenced by clinical and genetic factors. A concept of therapeutic window exists. On one side, efficient anti-aggregation is required in order to reduce cardio-vascular events. On the other side, an excessive platelet inhibition represents a risk of bleeding complications. This article describes the current knowledge about some platelet function tests and genetic tests and summarises their role in the clinical practice.

  2. Cancer and Thrombosis: The Platelet Perspective

    PubMed Central

    Meikle, Claire K. S.; Kelly, Clare A.; Garg, Priyanka; Wuescher, Leah M.; Ali, Ramadan A.; Worth, Randall G.

    2017-01-01

    Platelets are critical to hemostatic and immunological function, and are key players in cancer progression, metastasis, and cancer-related thrombosis. Platelets interact with immune cells to stimulate anti-tumor responses and can be activated by immune cells and tumor cells. Platelet activation can lead to complex interactions between platelets and tumor cells. Platelets facilitate cancer progression and metastasis by: (1) forming aggregates with tumor cells; (2) inducing tumor growth, epithelial-mesenchymal transition, and invasion; (3) shielding circulating tumor cells from immune surveillance and killing; (4) facilitating tethering and arrest of circulating tumor cells; and (5) promoting angiogenesis and tumor cell establishment at distant sites. Tumor cell-activated platelets also predispose cancer patients to thrombotic events. Tumor cells and tumor-derived microparticles lead to thrombosis by secreting procoagulant factors, resulting in platelet activation and clotting. Platelets play a critical role in cancer progression and thrombosis, and markers of platelet-tumor cell interaction are candidates as biomarkers for cancer progression and thrombosis risk. PMID:28105409

  3. Ultrastructural studies of the gray platelet syndrome.

    PubMed

    White, J G

    1979-05-01

    The gray platelet syndrome (GPS) is a rare inherited disorder in which peripheral blood platelets are relatively large, vacuolated, and almost devoid of cytoplasmic granulation. In the present study we have evaluated the ultrastructure and cytochemistry of platelets from 2 patients with the GPS to determine precisely which organelles are missing from their cells. The findings indicate that gray platelets contain normal numbers of mitochondria, dense bodies, peroxisomes, and lysosomes but specifically lack alpha-granules. Preliminary studies of megakaryocytes from 1 of the 2 patients suggest that the defect in granule formation may lie at the level of the Golgi zone.

  4. Identification of platelet refractoriness in oncohematologic patients

    PubMed Central

    Ferreira, Aline Aparecida; Zulli, Roberto; Soares, Sheila; de Castro, Vagner; Moraes-Souza, Helio

    2011-01-01

    OBJECTIVES: To identify the occurrence and the causes of platelet refractoriness in oncohematologic patients. INTRODUCTION: Platelet refractoriness (unsatisfactory post-transfusion platelet increment) is a severe problem that impairs the treatment of oncohematologic patients and is not routinely investigated in most Brazilian services. METHODS: Forty-four episodes of platelet concentrate transfusion were evaluated in 16 patients according to the following parameters: corrected count increment, clinical conditions and detection of anti-platelet antibodies by the platelet immunofluorescence test (PIFT) and panel reactive antibodies against human leukocyte antigen class I (PRA-HLA). RESULTS: Of the 16 patients evaluated (median age: 53 years), nine (56%) were women, seven of them with a history of pregnancy. An unsatisfactory increment was observed in 43% of the transfusion events, being more frequent in transfusions of random platelet concentrates (54%). Platelet refractoriness was confirmed in three patients (19%), who presented immunologic and non-immunologic causes. Alloantibodies were identified in eight patients (50%) by the PIFT and in three (19%) by the PRA-HLA. Among alloimmunized patients, nine (64%) had a history of transfusion, and three as a result of pregnancy (43%). Of the former, two were refractory (29%). No significant differences were observed, probably as a result of the small sample size. CONCLUSION: The high rate of unsatisfactory platelet increment, refractoriness and alloimmunization observed support the need to set up protocols for the investigation of this complication in all chronically transfused patients, a fundamental requirement for the guarantee of adequate management. PMID:21437433

  5. Effect of photodynamic therapy on mouse platelets

    NASA Astrophysics Data System (ADS)

    Zhou, Chuannong; Chi, Shunji; Deng, Jinsheng; Zhang, Hua; Liang, Junlin; Ha, Xian-wen

    1993-03-01

    Normal mice received hematoporphyrin derivative (10 mg/kg iv) immediately, 24 or 48 hrs prior to red light irradiation. The blood was collected and the platelet-rich plasma was irradiated by red light (100 J/cm2). The platelets were fixed immediately, 8 or 16 hrs after irradiation, and processed for EM examination. In comparison with those of control mice, the platelets of all experimental mice showed structural changes: 16 hrs after irradiation all platelets were necrotized; 8 hrs after irradiation almost one fourth of the platelets were necrotized and the remaining were considerably damaged; immediately after irradiation a small number of platelets became necrotic and most other platelets were swollen and deformed, often with many cytoplasmic projections and considerable dilatation of the canalicular membrane system. Our findings provided a clear evidence that platelets are highly sensitive to PDT action and can be directly and rapidly injured by PDT even in the absence of vascular endothelial cells. Our results give firm support to the hypothesis that both endothelial cells and platelets may play an important role in the initiation of early vascular damage and microcirculatory alterations induced by PDT in vivo.

  6. Aging of platelets stored for transfusion.

    PubMed

    Smethurst, Peter A

    2016-09-01

    A goal of platelet storage is to maintain the quality of platelets from the point of donation to the point of transfusion - to suspend the aging process. This effort is judged by clinical and laboratory measures with varying degrees of success. Recent work gives encouragement that platelets can be maintained ex vivo beyond the current 5 -7 day shelf life whilst maintaining their quality, as measured by posttransfusion recovery and survival. However, additional measures are needed to validate the development of technologies that may further reduce the aging of stored platelets, or enhance their hemostatic properties.

  7. A simple method for activating the platelets used in microfluidic platelet aggregation tests: Stirring-induced platelet activation

    PubMed Central

    Lee, Hoyoon; Kim, Gyehyu; Lim, Chaeseung; Lee, ByoungKwon; Shin, Sehyun

    2016-01-01

    High-shear stimulation is well known as one of the key factors affecting platelet activation and aggregation, which can lead to the formation of a thrombus. In one of our previous studies, we introduced migration distance-based platelet function analysis in a microfluidic system. In this study, we set out to examine the effects of stirring on shear-induced platelet activation and aggregation in a chamber system by using a rotating stirrer. We found that the rotating stirrer caused not only rotational shear flow but also a strong radial secondary flow. The latter flow led to efficient mixing in the chamber. Moreover, the rotational flow led to the generation of shear stress, the magnitude of which can be controlled to activate the platelets. Activated platelets tend to aggregate themselves. The maximum platelet aggregation was observed at a critical shear rate of 3100 s−1, regardless of the stirrer shape. Furthermore, the time taken to attain maximum aggregation was significantly shortened when using a wide stirrer (30 s) instead of a narrow one (180 s). When using a flat stirrer, the non-uniform shear field in the chamber system was resolved with the radial secondary flow-induced mixing; thus, most of the platelets were homogenously activated. The stirring-induced platelet activation mechanism was experimentally confirmed in a microfluidic system for a platelet aggregation test while monitoring the migration distance until the microfluidic channel is occluded. Our findings indicate that the present system, consisting of a rotating stirrer and a confined chamber, provides effective shear stimulation for activating platelets and inducing platelet aggregates. PMID:28058084

  8. A simple method for activating the platelets used in microfluidic platelet aggregation tests: Stirring-induced platelet activation.

    PubMed

    Lee, Hoyoon; Kim, Gyehyu; Lim, Chaeseung; Lee, ByoungKwon; Shin, Sehyun

    2016-11-01

    High-shear stimulation is well known as one of the key factors affecting platelet activation and aggregation, which can lead to the formation of a thrombus. In one of our previous studies, we introduced migration distance-based platelet function analysis in a microfluidic system. In this study, we set out to examine the effects of stirring on shear-induced platelet activation and aggregation in a chamber system by using a rotating stirrer. We found that the rotating stirrer caused not only rotational shear flow but also a strong radial secondary flow. The latter flow led to efficient mixing in the chamber. Moreover, the rotational flow led to the generation of shear stress, the magnitude of which can be controlled to activate the platelets. Activated platelets tend to aggregate themselves. The maximum platelet aggregation was observed at a critical shear rate of 3100 s(-1), regardless of the stirrer shape. Furthermore, the time taken to attain maximum aggregation was significantly shortened when using a wide stirrer (30 s) instead of a narrow one (180 s). When using a flat stirrer, the non-uniform shear field in the chamber system was resolved with the radial secondary flow-induced mixing; thus, most of the platelets were homogenously activated. The stirring-induced platelet activation mechanism was experimentally confirmed in a microfluidic system for a platelet aggregation test while monitoring the migration distance until the microfluidic channel is occluded. Our findings indicate that the present system, consisting of a rotating stirrer and a confined chamber, provides effective shear stimulation for activating platelets and inducing platelet aggregates.

  9. Iodine-131 metaiodobenzylguanidine scintigraphy for the location of neuroblastoma: preliminary experience in ten cases

    SciTech Connect

    Geatti, O.; Shapiro, B.; Sisson, J.C.; Hutchinson, R.J.; Mallette, S.; Eyre, P.; Beierwaltes, W.H.

    1985-07-01

    Ten patients with histologically proven neuroblastoma were studied by (/sup 131/I)MIBG scintigraphy. Tumor uptake of the radiopharmaceutical showed a spectrum varying from no uptake in one case, to slight uptake in two, moderate uptake in two and intense uptake in five cases. Iodine-131 MIBG scintigraphy was more effective in demonstrating the extent of neuroblastoma spread than were conventional bone scan and CT in one patient, equal to these modalities in four cases, almost equal in two cases and significantly inferior in three cases. These preliminary results suggest that (/sup 131/I)MIBG scintigraphy is useful in detecting the presence and delineating the distribution of neuroblastoma and may, in certain cases, have therapeutic potential.

  10. Pre- and postcaptopril renal scintigraphy as a screening test for renovascular hypertension in children.

    PubMed

    Abdulsamea, Sameh; Anderson, Peter; Biassoni, Lorenzo; Brennan, Eileen; McLaren, Clare A; Marks, Stephen D; Roebuck, Derek J; Selim, Sabry; Tullus, Kjell

    2010-02-01

    We studied the ability of pre- and postcaptopril renal scintigraphy to predict renovascular disease (RVD) in children. Retrospective review of medical notes and radiology reports of all hypertensive children who had had both pre- and postcaptopril renal scintigraphy with [(99m)Tc] dimercaptosuccinic acid (DMSA) and/or [(99m)Tc] mercaptoacetyltriglycine (MAG3) and digital subtraction angiography (DSA). 81 children aged 1-18 (median 10) years were studied with 62% (51) having a diagnosis of RVD. Main renal artery disease, intrarenal disease, and both main and intrarenal artery disease were present in 25, 14, and 12 patients respectively. The isotope study accurately diagnosed RVD, confirmed by DSA, in 47% (24 of 51) children, with eight false positive studies. The sensitivity, specificity, and positive and negative predictive values of the isotope study to predict RVD were 48%, 73%, 76%, and 51%, respectively. Pre- and postcaptopril renal scintigraphy was unable to predict RVD in children.

  11. Scintigraphy with 99mTc(V)-DMSA in monitoring patients with inflammatory bowel disease.

    PubMed

    Javadi, Hamid; Amiriani, Taghi; Mirkarimi, HoneySadat; Besharat, Sima; Semnani, Shahriar; Abedi, Jamshid; Seyedabadi, Mohammad; Assadi, Majid

    2013-01-01

    The clinical significance of pentavalent technetium-99m dimercaptosuccinic acid (99mTc(V)-DMSA) scintigraphy in diagnosing inflammatory bowel disease (IBD) has not yet been fully elucidated. The aim of this prospective paper was to study the above. This study included 54 patients, 22 females and 32 males (mean age: 36.68±11.49; range: 18-63 years) with IBD who came to our clinics for follow-up and were examined clinically by colonoscopy and 99mTc(V)-DMSA scintigraphy. On the follow-up studies, five patients (9.25%) relapsed, and 49 (90.74%) remained at a steady condition. There was a good correlation between the scintigraphic results and the clinical and colonoscopy data of the patients (P<0.05). In conclusion, our results indicated that 99mTc(V)DMSA scintigraphy can be complementary to colonoscopy for the diagnostic evaluation of IBD.

  12. Physiologic and pathologic changes of platelets in pregnancy.

    PubMed

    Valera, Marie-Cecile; Parant, Olivier; Vayssiere, Christophe; Arnal, Jean-François; Payrastre, Bernard

    2010-01-01

    Platelets are key players in haemostasis and thrombus formation. Defects affecting platelets during pregnancy can lead to heterogeneous complications, such as thrombosis, first trimester miscarriage and postpartum haemorrhage. The incidence of complications is increased in women who have heritable platelet function disorders. Modifications of platelet count or platelet functions during normal pregnancy and preeclampsia will be summarized and the management of pregnant women with heritable platelet function disorders will be discussed.

  13. Platelet function in the postprandial period

    PubMed Central

    2012-01-01

    Background Postprandial hyperlipidemia and hyperglycemia have been related to cardiovascular events. Among different underlying mechanisms platelet activation seems to be responsible too. No comparable data between various tests in normo- vs. hyperlipidemics before and at different time intervals are available after a fat meal. We aimed to compare 9 of them within the same patients at several time points in postprandial hyperlipidemia. Results For some tests baseline values between the groups were significantly different (TXB2, platelet sensitivity, sedimentation and WU-test). However, hyperlipidemia revealed a variable influence on the tests examined. Some of the available tests apparently sensitive to show platelet activation reflect the increase in triglycerides (TG), such as the sedimentation index. ADP-induced platelet aggregatory activity in count adjusted washed isolated platelet samples during postprandial hyperlipidemia indicates mildly enhanced platelet activity, but does not seem to induce significant changes in aggregation. In patients with severe hypertriglyceridemia (> 400 mg/dl fasting) changes in platelet function are more pronounced due to delayed decay and may last up to 16 hours paralleling TG reaching the prevalue. The overwhelming majority of platelet function tests do not significantly respond to postprandial hyperlipidemia. The correlation between the tests applied is poor. For standardization purpose, platelet aggregation tests, aimed to examine proaggregatory capacity in atherosclerosis, should only be performed at the same time of the day after a fasting period > 6 hours. The great variation in preanalytical work-up on comparison of various tests, large number of platelet tests available and their respective potential value are discussed. Conclusions At present, the suspicion that platelet function is significantly activated in the postprandial period cannot be supported by any of the tests used. The information provided is valuable to

  14. Evaluation of platelet turnover by flow cytometry.

    PubMed

    Salvagno, G L; Montagnana, M; Degan, M; Marradi, P L; Ricetti, M M; Riolfi, P; Poli, G; Minuz, P; Santonastaso, C L; Guidi, G C

    2006-05-01

    The number of circulating newly produced platelets depends on the thrombopoietic capacity of bone marrow as well as platelet removal from the bloodstream. Flow cytometric analysis with thiazole orange (TO), a fluorescent dye that crosses platelet membranes and binds intracellular RNA, has been used to measure circulating reticulated platelets (RPs) with high RNA content as an index of platelet turnover. We first assessed the specificity of TO flow cytometry and then applied this method in the diagnosis of thrombocytopenia caused by impaired platelet production or increased destruction. We also explored the utility of TO flow cytometry to predict thrombocytopoiesis after chemotherapy-induced bone marrow aplasia. Venous blood, anticoagulated with K(2)EDTA, was incubated with 0.6 microg/ml TO plus an anti-GPIIIa monoclonal antibody. The mean percentage of RPs in control subjects (n = 23) was 6.13 +/- 3.09%. RPs were 10.41 +/- 9.02% in patients (n = 10) with hematological malignancies during aplasia induced by chemotherapy and a significant increase in RPs (35.45 +/- 6.11%) was seen in the recovery phase. In 10 patients with idiopathic thrombocytopenic purpura, the percentage of TO positive platelets was 67.81 +/- 18.79 (P < 0.001 vs. controls). In patients with thrombocytopenia associated with hepatic cirrhosis (n = 21; 21.04 +/- 16.21%, P < 0.001 vs. controls) or systemic lupus erythematosus (n = 6, 29.08 +/- 15.57%; P < 0.001 vs. controls) increases in TO-stained platelets were also observed. Measurement of TO positive platelets may be a reliable tool for the laboratory identification of platelet disorders, with a higher sensitivity than measurement of platelet volume. Measurement of RPs may also prove useful to recognize the underlying pathogenetic mechanisms in thrombocytopenia.

  15. Hereditary sideroblastic anemia with associated platelet abnormalities.

    PubMed

    Soslau, G; Brodsky, I

    1989-12-01

    A 62 year old male (R.H.) presented with a mild anemia (Hb 11-12 gm%) and a history of multiple hemorrhagic episodes. The marrow had 40-50% sideroblasts. Marrow chromosomes were normal. His wife was hematologically normal, while one daughter, age 30 years, had a sideroblastic anemia (Hb 11-12 gm%) with 40-50% sideroblasts in the marrow. Her anemia was first noted at age 15 years. Administration of vitamin B6 did not correct the anemia in either the father or daughter. Platelet abnormalities inherited jointly with this disorder are described for the first time. Both R.H. and his daughter had prolonged bleeding times, with normal PTT, PT times, fVIII:C, fVIII:Ag levels, and vWF multimers, which may rule out a von Willebrand's disease. They have normal platelet numbers but abnormally low platelet adhesiveness and greatly depressed ADP, collagen, and epinephrine responsiveness. Response to ristocetin was in the low normal range, and aggregation with thrombin was normal. While desmopressin completely normalized R.H.'s bleeding time, none of these platelet parameters were improved. No differences in the SDS PAGE protein patterns of RH platelets could be detected in comparison to normal samples. His platelets took up and released serotonin (5HT) normally, and electron micrographs defined no morphological abnormalities. However, no ATP was released from platelets activated with collagen, and when followed by thrombin about fourfold greater ATP was released by control platelets as compared to RH platelets. The dense granule fraction derived from RH platelets contained about 20% the level of ATP, 40% the level of ADP, and 50% the level of 5HT detected in a normal sample. The results indicate that the bleeding disorder is related to a non-classical heritable storage pool defect. The connection between the inherited sideroblastic anemia and platelet defects is obscure.

  16. An incidental detection of aortic aneurysm on Tc-99m MAG3 renal scintigraphy.

    PubMed

    Sadic, Murat; Demirel, Koray; Koca, Gökhan; Atilgan, Hasan Ikbal; Korkmaz, Meliha

    2013-01-01

    A 71-year-old man with newly diagnosed hypertension was referred for Technetium-99m mercaptoacetyltriglycine (Tc-99m MAG3) renal scintigraphy to evaluate the recent onset of impairment in renal functions. Dynamic imaging revealed activity flow which was suspicious for aortic aneurysm (AA) with a concurrent decrease in left renal blood flow. CT angiography of the thoracoabdominal aorta confirmed that this area corresponded to AA. The purpose of this report was to present the first case of incidental detection of AA on Tc-99m MAG3 scintigraphy and highlight the importance of correlative imaging for the diagnosis of abnormal radioactivity accumulation in the region of vascular structures.

  17. Complementary roles of brain scintigraphy and computed tomography in multiple sclerosis

    SciTech Connect

    Moreno, A.J.; Brown, J.M.; Waller, S.F.; Lundy, M.M.; Brown, T.J.

    1983-12-01

    Cerebral computed tomography, with and without iodinated contrast, revealed the appearance and evolution of lesions in a 32-year-old man with multiple sclerosis. Two areas were enhanced with contrast, with one showing a mild mass effect and rim of enhancement. Serial brain scintigraphy using technetium-/sub 99m/ glucoheptonate, following the computed tomography, showed the appearance and regression of corresponding regions of increased uptake. Computed tomography one day prior to brain scintigraphy failed to demonstrate a region of increased accumulation of radiotracer. One week later, however, evidence of a corresponding unenhanced defect was noted on computed tomography. Clinical correlation is given additionally.

  18. Bone scintigraphy in the initial staging of patients with renal-cell carcinoma: concise communication

    SciTech Connect

    Rosen, P.R.; Murphy, K.G.

    1984-03-01

    The records of 40 consecutive patients who received bone scintigraphy in conjunction with the initial evaluation and staging of renal-cell carcinoma were reviewed to determine the role of bone imaging in this clinical context. Bone scintigrams were positive in three out of 40 patients at the time of diagnosis. In view of the low yield of bone imaging, it appears that routine scintigraphy is unwarranted in the absence of skeletal symptoms before the diagnosis of renal lesions. The presence of a positive bone image did not alter the indication for nephrectomy.

  19. Unusual appearance for urinary bladder obstruction detected with 99mTc-MDP bone scintigraphy.

    PubMed

    Wright, Chadwick L; Sharma, Akash

    2015-12-01

    Unanticipated but clinically significant nonosseous findings can be detected during routine bone scintigraphy. We present a case of an 83-year-old man who presented with a pathologic fracture of the right femur. Whole-body bone scintigraphy for osseous staging revealed intense radiotracer accumulation in the kidneys and ureters but no activity within the urinary bladder. The patient had not voided for 14 hours. A Foley catheter was inserted, and more than 2000 mL of urine was drained, most consistent with urinary bladder obstruction. Subsequent repeat images demonstrated marked reduction of the renal and ureteral activity with trace activity in the urinary bladder.

  20. Miscellaneous indications in bone scintigraphy: metabolic bone diseases and malignant bone tumors.

    PubMed

    Cook, Gary J R; Gnanasegaran, Gopinath; Chua, Sue

    2010-01-01

    The diphosphonate bone scan is ideally suited to assess many global, focal or multifocal metabolic bone disorders and there remains a role for conventional bone scintigraphy in metabolic bone disorders at diagnosis, investigation of complications, and treatment response assessment. In contrast, the role of bone scintigraphy in the evaluation of primary malignant bone tumors has reduced with the improvement of morphologic imaging, such as computed tomography and magnetic resonance imaging. However, an increasing role for (18)F-fluorodeoxyglucose positron emission tomography and positron emission tomography/computed tomography is emerging as a functional assessment at diagnosis, staging, and neoadjuvant treatment response assessment.

  1. Incidental vesicocolic fistula on routine bone scintigraphy: Value of additional delayed images and direct radionuclide cystography.

    PubMed

    Sohn, Myung-Hee; Tae Lim, Seok; Jin Jeong, Young; Wook Kim, Dong; Jeong, Hwan-Jeong; Yim, Chang-Yeol

    2010-09-01

    An unexpected vesicocolic fistula can be detected incidentally on routine bone scintigraphy. A 55-year-old man who had a radical colectomy for carcinoma of the sigmoid colon 1 year previously underwent bone scintigraphy to evaluate bone metastasis. Whole-body images showed an abnormal accumulation of radioactivity in the right lower quadrant of the abdomen, but the radioactivity did not precisely define a structure. Additional delayed images obtained after 15 and 24 hours of the initial image localized a vesicocolic fistula. Subsequent radionuclide cystography confirmed leakage of the radioactivity from the bladder.

  2. Myocardial Scintigraphy in the Evaluation of Cardiac Events in Patients without Typical Symptoms

    PubMed Central

    Smanio, Paola Emanuela Poggio; Silva, Juliana Horie; Holtz, João Vitor; Ueda, Leandro; Abreu, Marilia; Marques, Carlindo; Machado, Leonardo

    2015-01-01

    Background Cardiovascular disease is a leading cause of death in the world and in Brazil. Myocardial scintigraphy is an important noninvasive method for detecting ischemia in symptomatic patients, but its use in asymptomatic ones or those with atypical symptoms is yet to be defined. Objective To verify the presence of major cardiac events in asymptomatic patients or those with atypical symptoms (atypical chest pain or dyspnea) that underwent myocardial scintigraphy (MS), over a period of 8 years. Secondary objectives were to identify cardiac risk factors associated with myocardial scintigraphy abnormalities and possible predictors for major cardiac events in this group. Methods This was a retrospective, observational study using the medical records of 892 patients that underwent myocardial scintigraphy between 2005 and 2011 and who were followed until 2013 for assessment of major cardiac events and risk factors associated with myocardial scintigraphy abnormalities. Statistical analysis was performed by Fisher’s exact test, logistic regression and Kaplan-Meyer survival curves, with statistical significance being set at p ≤ 0.05. Results Of the total sample, 52.1% were men, 86.9% were hypertensive, 72.4% had hyperlipidemia, 33.6% were diabetic, and 12.2% were smokers; 44.5% had known coronary artery disease; and 70% had high Framingham score, 21.8% had moderate and 8% had low risk. Of the myocardial scintigraphies, 58.6% were normal, 26.1% suggestive of fibrosis and 15.3% suggestive of ischemia. At evolution, 13 patients (1.5%) had non-fatal myocardial infarction and six individuals (0.7%) died. The group with normal myocardial scintigraphy showed longer period of time free of major cardiac events, non-fatal myocardial infarction (p = 0.036) and death. Fibrosis in the myocardial scintigraphy determined a 2.4-fold increased risk of non-fatal myocardial infarction and five-fold higher risk of death (odds ratio: 2.4 and 5.7, respectively; p = 0.043). Conclusion The

  3. Scintigraphy of infected total hip arthroplasty (THA): A canine model

    SciTech Connect

    Merkel, K.D.; Brown, M.L.; Fitzgerald, R.H.; Dewanjee, M.K.

    1984-01-01

    Differentiating low-grade sepsis from aseptic loosening of an orthopedic prosthesis is difficult. This study was designed to compare the ability of Tc-99m-HMDP, Ga-67, and In-111 leukocytes (WC) to differentiate low-grade sepsis from aseptic THA component loosening in a canine model. A canine THA was implanted in 14 dogs. Six dogs were given infected femoral components by injecting 10/sup 5/ colony-forming units of Staphylococcus aureus into the femoral canal 6y0 to 90 seconds prior to cementing. Four dogs had an aseptic loose femoral component, and four dogs had an aseptic tight femoral component (control). At six months all dogs were evaluated with X-ray, lab scintigraphy, and tissue quantitation of each tracer. Diagnosis was confirmed by histology and quantitative microbiology. White blood cell counts and differentials were normal in all dogs, and in only one out of six infected dogs was the sedimentation rate abnormal. X-rays were interpreted as possible infection in five dogs and probable infection in only one dog. In-111 WBC scans were more accurate than sequential Tc-Ga scans (sensitivity 94% vs 61%, specificity 86% vs 71% accuracy 90% vs 67%). Quantitative counting of gamma camera data and tissue samples demonstrated significantly (P < .01) higher accumulation of In-111 WBC about the infected than the loose or control component. No significant difference was demonstrated between the loose and septic components with TC-HMDP or Ga. These results correlate well and confirm our clinical data that In-111 WBC scanning is accurate and useful in the workup of the painful orthopedic prosthesis.

  4. Expansion of the neonatal platelet mass is achieved via an extension of platelet lifespan

    PubMed Central

    Liu, Zhi-Jian; Hoffmeister, Karin M.; Hu, Zhongbo; Mager, Donald E.; Ait-Oudhia, Sihem; Debrincat, Marlyse A.; Pleines, Irina; Josefsson, Emma C.; Kile, Benjamin T.; Italiano, Joseph; Ramsey, Haley; Grozovsky, Renata; Veng-Pedersen, Peter; Chavda, Chaitanya

    2014-01-01

    The fetal/neonatal hematopoietic system must generate enough blood cells to meet the demands of rapid growth. This unique challenge might underlie the high incidence of thrombocytopenia among preterm neonates. In this study, neonatal platelet production and turnover were investigated in newborn mice. Based on a combination of blood volume expansion and increasing platelet counts, the platelet mass increased sevenfold during the first 2 weeks of murine life, a time during which thrombopoiesis shifted from liver to bone marrow. Studies applying in vivo biotinylation and mathematical modeling showed that newborn and adult mice had similar platelet production rates, but neonatal platelets survived 1 day longer in circulation. This prolonged lifespan fully accounted for the rise in platelet counts observed during the second week of murine postnatal life. A study of pro-apoptotic and anti-apoptotic Bcl-2 family proteins showed that neonatal platelets had higher levels of the anti-apoptotic protein Bcl-2 and were more resistant to apoptosis induced by the Bcl-2/Bcl-xL inhibitor ABT-737 than adult platelets. However, genetic ablation or pharmacologic inhibition of Bcl-2 alone did not shorten neonatal platelet survival or reduce platelet counts in newborn mice, indicating the existence of redundant or alternative mechanisms mediating the prolonged lifespan of neonatal platelets. PMID:24599546

  5. Expansion of the neonatal platelet mass is achieved via an extension of platelet lifespan.

    PubMed

    Liu, Zhi-Jian; Hoffmeister, Karin M; Hu, Zhongbo; Mager, Donald E; Ait-Oudhia, Sihem; Debrincat, Marlyse A; Pleines, Irina; Josefsson, Emma C; Kile, Benjamin T; Italiano, Joseph; Ramsey, Haley; Grozovsky, Renata; Veng-Pedersen, Peter; Chavda, Chaitanya; Sola-Visner, Martha

    2014-05-29

    The fetal/neonatal hematopoietic system must generate enough blood cells to meet the demands of rapid growth. This unique challenge might underlie the high incidence of thrombocytopenia among preterm neonates. In this study, neonatal platelet production and turnover were investigated in newborn mice. Based on a combination of blood volume expansion and increasing platelet counts, the platelet mass increased sevenfold during the first 2 weeks of murine life, a time during which thrombopoiesis shifted from liver to bone marrow. Studies applying in vivo biotinylation and mathematical modeling showed that newborn and adult mice had similar platelet production rates, but neonatal platelets survived 1 day longer in circulation. This prolonged lifespan fully accounted for the rise in platelet counts observed during the second week of murine postnatal life. A study of pro-apoptotic and anti-apoptotic Bcl-2 family proteins showed that neonatal platelets had higher levels of the anti-apoptotic protein Bcl-2 and were more resistant to apoptosis induced by the Bcl-2/Bcl-xL inhibitor ABT-737 than adult platelets. However, genetic ablation or pharmacologic inhibition of Bcl-2 alone did not shorten neonatal platelet survival or reduce platelet counts in newborn mice, indicating the existence of redundant or alternative mechanisms mediating the prolonged lifespan of neonatal platelets.

  6. Cryopreservation of buffy-coat-derived platelet concentrates in dimethyl sulfoxide and platelet additive solution.

    PubMed

    Johnson, L N; Winter, K M; Reid, S; Hartkopf-Theis, T; Marks, D C

    2011-04-01

    Platelets prepared in plasma can be frozen in 6% dimethyl sulfoxide (Me(2)SO) and stored for extended periods at -80°C. The aim of this study was to reduce the plasma present in the cryopreserved product, by substituting plasma with platelet additive solution (PAS; SSP+), whilst maintaining in vitro platelet quality. Buffy coat-derived pooled leukoreduced platelet concentrates were frozen in a mixture of SSP+, plasma and 6% Me(2)SO. The platelets were concentrated, to avoid post-thaw washing, and frozen at -80°C. The cryopreserved platelet units (n=9) were rapidly thawed at 37°C, reconstituted in 50% SSP+/plasma and stored at 22°C. Platelet recovery and quality were examined 1 and 24h post-thaw and compared to the pre-freeze samples. Upon thawing, platelet recovery ranged from 60% to 80%. However, there were differences between frozen and liquid-stored platelets, including a reduction in aggregation in response to ADP and collagen; increased CD62P expression; decreased viability; increased apoptosis and some loss of mitochondrial membrane integrity. Some recovery of these parameters was detected at 24h post-thaw, indicating an extended shelf-life may be possible. The data suggests that freezing platelets in 6% Me(2)SO and additive solution produces acceptable in vitro platelet quality.

  7. Transfusion of ABO-mismatched platelets leads to early platelet refractoriness.

    PubMed

    Carr, R; Hutton, J L; Jenkins, J A; Lucas, G F; Amphlett, N W

    1990-07-01

    Forty-three consecutive patients previously unexposed to platelets and undergoing treatment for acute leukaemia or autografting for relapsed Hodgkin's lymphoma were randomized to receive transfused platelets of either their own ABO group (OG) or of a major mismatched group (MMG). The 26 evaluable patients were equally distributed between the two study groups. Nine of 13 (69%) MMG patients became refractory with a median onset at transfusion 7 (15 d), compared with only one of 13 (8%) OG patients (P = 0.001). Refractoriness was associated with the formation of high titre isoagglutinins, anti-HLA and platelet specific antibodies. In one patient refractoriness appeared to be due to high titre isoagglutinins alone. Six other patients developed an increase in isoagglutinin titre sufficient to adversely affect platelet increments. Patients receiving ABO-mismatched platelets had a higher incidence of anti-HLA antibodies (5 v. 1) and platelet specific antibodies (4 v. 1). ABO-mismatched platelets transfused prior to the onset of refractoriness resulted in increments similar to those achieved by ABO-matched platelets. The study demonstrates that ABO-mismatched platelets are as effective as matched platelets in patients with low titre isoagglutinins requiring only few transfusions. However, the greater incidence of early refractoriness induced in MMG patients indicates that ABO-mismatched platelets should not be given to patients with marrow failure requiring long-term support.

  8. Reelin is a platelet protein and functions as a positive regulator of platelet spreading on fibrinogen.

    PubMed

    Tseng, Wei-Lien; Huang, Chien-Ling; Chong, Kowit-Yu; Liao, Chang-Huei; Stern, Arnold; Cheng, Ju-Chien; Tseng, Ching-Ping

    2010-02-01

    Abnormalities of platelet functions have been linked to reelin-impaired neuronal disorders. However, little attention has been given to understanding the interplay between reelin and platelet. In this study, reelin was found to present in the human platelets and megakaryocyte-like leukemic cells. Reelin-binding assays revealed that extracellular reelin can interact with platelets through the receptor belonging to the low density lipoprotein receptor gene family. The reelin-to-platelet interactions enhance platelet spreading on fibrinogen concomitant with the augmentation of lamellipodia formation and F-actin bundling. In contrast, reelin has no effect on integrin alphaIIbbeta3 activation and agonist-induced platelet aggregation. Molecular analysis revealed that the up-regulation of Rac1 activity and the inhibition of protein kinase C delta-Thr505 phosphorylation are important for reelin-mediated enhancement of platelet spreading on fibrinogen. These findings demonstrate for the first time that reelin is present in platelets and the reelin-to-platelet interactions play a novel role in platelet signaling and functions.

  9. [Platelet allo-antibodies identification strategies for preventing and managing platelet refractoriness].

    PubMed

    Basire, A; Picard, C

    2014-11-01

    Platelet refractoriness is a serious complication for patients receiving recurrent platelet transfusions, which can be explained by non-immune and immune causes. Human Leukocyte Antigens (HLA) allo-immunization, especially against HLA class I, is the major cause for immune platelet refractoriness. To a lesser extent, allo-antibodies against specific Human Platelet Antigen (HPA) are also involved. Pregnancy, transplantation and previous transfusions can lead to allo-immune reaction against platelet antigens. After transfusion, platelet count is decreased by accelerated platelet destruction related to antibodies fixation on incompatible platelet antigens. New laboratory tests for allo-antibodies identification were developed to improve sensibility and specificity, especially with the LUMINEX(®) technology. The good use and interpretation of these antibodies assays can improve strategies for platelet refractoriness prevention and management with a patient adapted response. Compatible platelets units can be selected according to their identity with recipient typing or immune compatibility regarding HLA or HPA antibodies or HLA epitope compatibility. Prospective studies are needed to further confirm the clinical benefit of new allo-antibodies identification methods and consensus strategies for immune platelet refractoriness management.

  10. Relation of platelet density to platelet age: survival of low- and high-density 111indium-labeled platelets in baboons

    SciTech Connect

    Savage, B.; McFadden, P.R.; Hanson, S.R.; Harker, L.A.

    1986-08-01

    The relationship between platelet density and platelet age has been studied using continuous linear Percoll density gradients and 111In-labeling of autologous platelets in baboons. To investigate changes in platelet density during senescence in the circulation, baboons were infused with 111In-labeled autologous platelets, and blood was collected at one hour postinfusion and twice daily thereafter for six days. Platelets were isolated from these samples in high yield (greater than 95%) and separated in continuous linear Percoll density gradients following density equilibrium centrifugation. Although at one hour postinfusion the density distribution of radiolabeled platelets coincided closely with the distribution of the total platelet population, a detectable symmetrical shift toward higher densities was observed after five days. The relative specific radioactivity (RSR) of high-density platelets (1.064 to 1.067 g/mL) decreased at a slower rate than that of the total platelet population (platelets of all densities), whereas the RSR of low-density platelets (1.053 to 1.056 g/mL) showed a more immediate and rapid decrease. These results give rise to one of two interpretations: (1) low-density platelets have a shorter survival time than more dense platelets and are therefore cleared from the circulation at a faster rate, or (2) platelets of all densities increase in density upon aging in the circulation. To determine the explanation for changing RSR of different density fractions we studied the in vivo disappearance characteristics of low- and high-density 111In-labeled platelets. There were no significant differences between the mean survival times of low-density platelets (5.0 +/- 0.49 days, +/- 1 SD, n = 6), high-density platelets (4.9 +/- 0.56 days, n = 6), or control platelets representing platelets of all densities (4.9 +/- 0.38 days, n = 6).

  11. The omnipotent platelet. Part II: Further observations.

    PubMed

    Steinberg, L A

    1997-07-01

    Observation of platelet responses during acute injury or pathology can provide important information. The initial response is thrombocytopenia followed by thrombocytosis. In the case of injury with negative X-ray and appropriate thrombocytosis, a bone scan is indicated. The platelet responds like a sedimentation rate, which indicates the course of the injury or pathology.

  12. Synthetic materials for platelet quality control.

    PubMed

    Lott, J A; Hartzell, R K; Longberry, J

    1983-01-01

    At present, the quality control of platelet counting by semi-automated and automated methods does not meet ideal standards. Controls prepared from human or animal platelets have limited stability, and some synthetic platelet controls that are available do not have the size distribution of fresh platelets. The platelet control materials described here are wholly synthetic; however, their particle size distribution is like that of normal human platelets, and the dispersing medium has the viscosity and surface tension of plasma. Two types of products are described. The first type are dilutions of the synthetic platelets which are handled like 3000-fold dilutions of platelet-rich plasma and are intended for direct use on instruments like the Coulter ZBI. The two dilution levels gave counts of about 50,000 and 200,000/microL on the Coulter ZBI and were found to be stable for at least 30 days at - 20C, 4C, and 37C, and at least eight months at 25C. The second type of product is handled like whole blood and is intended for direct use on instruments like the Coulter Model S-Plus. This product gave counts of about 200,000/microL and was found to be stable for at least 120 days at - 20C, 4C, 25C, and 37C. Freezing at - 20C produced some aggregates that dispersed after thawing and standing for several days prior to testing.

  13. Daily prickly pear consumption improves platelet function.

    PubMed

    Wolfram, R; Budinsky, A; Efthimiou, Y; Stomatopoulos, J; Oguogho, A; Sinzinger, H

    2003-07-01

    Prickly pear is traditionally used by Pima Indians as a dietary nutrient against diabetes mellitus. We examined the effect of daily consumption of 250 g in 8 healthy volunteers and 8 patients with mild familial heterozygous hypercholesterolemia on various parameters of platelet function. Beside its action on lipids and lipoproteins, prickly pear consumption significantly reduced the platelet proteins (platelet factor 4 and beta-thromboglobulin), ADP-induced platelet aggregation and improved platelet sensitivity (against PGI2 and PGE1) in volunteers as well as in patients. Also plasma 11-DH-TXB2 and the WU-test showed a significant improvement in both patients and volunteers. In contrast, collagen-induced platelet aggregation and the number of circulating endothelial cells showed a significant response in patients only. No influence of prickly pear ingestion on peripheral platelet count was monitored. The dietary run-in period did not influence any of the parameters of haemostasis examined. No sex difference was seen. Prickly pear may induce at least part of its beneficial actions on the cardiovascular system via decreasing platelet activity and thereby improving haemostatic balance.

  14. Fractal and Euclidean descriptors of platelet shape.

    PubMed

    Kraus, Max-Joseph; Neeb, Heiko; Strasser, Erwin F

    2014-01-01

    Platelet shape change is a dynamic membrane surface process that exhibits remarkable morphological heterogeneity. Once the outline of an irregular shape is identified and segmented from a digital image, several mathematical descriptors can be applied to numerical characterize the irregularity of the shapes surface. 13072 platelet outlines (PLO) were segmented automatically from 1928 microscopic images using a newly developed algorithm for the software product Matlab R2012b. The fractal dimension (FD), circularity, eccentricity, area and perimeter of each PLO were determined. 972 PLO were randomly assigned for computer-assisted manual measurement of platelet diameter as well as number, width and length of filopodia per platelet. FD can be used as a surrogate parameter for determining the roughness of the PLO and circularity can be used as a surrogate to estimate the number and length of filopodia. The relationship between FD and perimeter of the PLO reveals the existence of distinct groups of platelets with significant structural differences which may be caused by platelet activation. This new method allows for the standardized continuous numerical classification of platelet shape and its dynamic change, which is useful for the analysis of altered platelet activity (e.g. inflammatory diseases, contact activation, drug testing).

  15. Clinica use of platelet additive solutions.

    PubMed

    van Rhenen, Dick J

    2007-12-01

    Randomised clinical trial (RCT) to study the clinical efficacy and safety of new platelet products using platelet additive solutions are scarce. In this paper a number of recent RCT's is discussed. It can be the start of a development where new transfusion products enter a RCT before the product is applied in clinical practice.

  16. Short-term exposure of platelets to glucose impairs inhibition of platelet aggregation by cyclooxygenase inhibitors.

    PubMed

    Kobzar, Gennadi; Mardla, Vilja; Samel, Nigulas

    2011-01-01

    Aspirin treatment reduces cardiovascular events and deaths in high-risk non-diabetic patients, but not in patients suffering from diabetes. In these patients, hyperglycemia has been found to cause reduced platelet sensitivity to aspirin. It is supposed that long-term exposure of platelets to glucose leads to non-enzymatic glycosylation and impairs aspirin inhibition of platelet aggregation. On the other hand, short-term exposure of platelets to glucose also attenuates the effect of aspirin on platelets. The aim of the present work was to analyse the effect of short-term exposure of glucose on the inhibition of platelet aggregation by aspirin and other cyclooxygenase (COX) inhibitors. Already a 15 min exposure of platelets to glucose impaired aspirin inhibition of the platelet aggregation induced by collagen, thrombin, adenosine diphosphate (ADP), and arachidonic acid (AA). Aspirin inhibition of platelet aggregation in platelet-rich plasma (PRP) was attenuated by 5.6, 11.2, 16.8, and 22.4 mM of glucose in a concentration-dependent way. The same effect was observed with indomethacin and acetaminophen used as cyclooxygenase inhibitors instead of aspirin. N-methyl-L-arginine, an inhibitor of nitric oxide synthase, prevented the effect of glucose on aspirin, indomethacin and acetaminophen inhibition of platelet aggregation. Other monosaccharides, for example fructose and galactose, impaired aspirin inhibition as did glucose. Lactic acid (0.1, 0.2, 0.4, 0.8 mM), the end product of anaerobic glycolysis in platelets, impaired the inhibition of platelet aggregation with aspirin in a concentration-dependent way but did not affect indomethacin. It is suggested that lactic acid might be a mediator of the effect of glucose on aspirin inhibition in platelets.

  17. Dynamic adhesion of eryptotic erythrocytes to immobilized platelets via platelet phosphatidylserine receptors.

    PubMed

    Walker, Britta; Towhid, Syeda T; Schmid, Evi; Hoffmann, Sascha M; Abed, Majed; Münzer, Patrick; Vogel, Sebastian; Neis, Felix; Brucker, Sara; Gawaz, Meinrad; Borst, Oliver; Lang, Florian

    2014-02-01

    Glucose depletion of erythrocytes triggers suicidal erythrocyte death or eryptosis, which leads to cell membrane scrambling with phosphatidylserine exposure at the cell surface. Eryptotic erythrocytes adhere to endothelial cells by a mechanism involving phosphatidylserine at the erythrocyte surface and CXCL16 as well as CD36 at the endothelial cell membrane. Nothing has hitherto been known about an interaction between eryptotic erythrocytes and platelets, the decisive cells in primary hemostasis and major players in thrombotic vascular occlusion. The present study thus explored whether and how glucose-depleted erythrocytes adhere to platelets. To this end, adhesion of phosphatidylserine-exposing erythrocytes to platelets under flow conditions was examined in a flow chamber model at arterial shear rates. Platelets were immobilized on collagen and further stimulated with adenosine diphosphate (ADP, 10 μM) or thrombin (0.1 U/ml). As a result, a 48-h glucose depletion triggered phosphatidylserine translocation to the erythrocyte surface and augmented the adhesion of erythrocytes to immobilized platelets, an effect significantly increased upon platelet stimulation. Adherence of erythrocytes to platelets was blunted by coating of erythrocytic phosphatidylserine with annexin V or by neutralization of platelet phosphatidylserine receptors CXCL16 and CD36 with respective antibodies. In conclusion, glucose-depleted erythrocytes adhere to platelets. The adhesive properties of platelets are augmented by platelet activation. Erythrocyte adhesion to immobilized platelets requires phosphatidylserine at the erythrocyte surface and CXCL16 as well as CD36 expression on platelets. Thus platelet-mediated erythrocyte adhesion may foster thromboocclusive complications in diseases with stimulated phosphatidylserine exposure of erythrocytes.

  18. Function of eltrombopag-induced platelets compared to platelets from control patients with immune thrombocytopenia.

    PubMed

    Haselboeck, Johanna; Kaider, Alexandra; Pabinger, Ingrid; Panzer, Simon

    2013-04-01

    Data on the in vivo function of platelets induced by the thrombopoietin receptor agonist eltrombopag are scarce. To assess a possible influence of eltrombopag we compared platelet function of eltrombopag-treated immune thrombocytopenia (ITP) patients (group 1; n=10) after treatment response to that from control ITP patients (group 2; n=12). We further analysed platelet function at baseline and after one, three, and four weeks of eltrombopag treatment and estimated daily changes of platelet function during the eltrombopag-induced platelet rise. The formation of platelet-monocyte aggregates (PMA), P-selectin expression [MFI], and platelet adhesion under high shear conditions (surface coverage, SC) in vivo and after in vitro addition of agonists (ADP, TRAP-6, Collagen) were similar between both groups after response to eltrombopag treatment. Only TRAP-6 induced a lower SC in the eltrombopag group (p=0.03). All platelet function parameters except for Collagen-induced P-selectin expression changed significantly during treatment with eltrombopag. PMA, naïve and after addition of ADP or TRAP-6 increased with increasing platelet counts. P-selectin expression decreased, when measured without and upon addition of ADP, increased in the presence of TRAP-6, and remained unchanged after addition of Collagen. SC increased during the eltrombopag-induced platelet rise. All significant changes of platelet function correlated to changes in platelet counts. Two patients developed venous thromboses during eltrombopag treatment, but no association with any distinct single platelet function parameter or combinations thereof was identifiable. Thus, eltrombopag-induced platelets function similar to those from control ITP patients without discernible increased hyper-reactivity.

  19. Increased platelet adhesion under flow conditions is induced by both thalassemic platelets and red blood cells.

    PubMed

    Goldschmidt, Neta; Spectre, Galia; Brill, Alexander; Zelig, Orly; Goldfarb, Ada; Rachmilewitz, Eliezer; Varon, David

    2008-11-01

    Thromboembolic complications are not uncommon in thalassemia. Previous studies suggest increased platelet aggregation and a potential role of pathological changes in the red blood cell (RBC) lipid membrane, induced by oxidative stress. In the present study, platelet adhesion and the effect of thalassemic RBC on platelet adhesion under flow conditions were evaluated, using the Cone and Plate (let) Analyzer(CPA). Twenty-two beta-thalassemia patients and 22 blood type-matched healthy controls were studied. An increased platelet adhesion (% surface coverage, SC), was observed in patients as compared to controls (p < 0.05). When platelet count and haematocrit were normalized by autologous reconstitution, a significant increase in platelet aggregation (average size, AS) was observed (p < 0.05). Increased platelet adhesion (SC and AS), was demonstrated in six patients with a history of thrombosis as compared to 16 patients without any history of thrombosis (p < or = 0.007) and in 17 splenectomized patients as compared to five non-splenectomized patients (p = 0.003). In reconstitution studies, thalassemic RBC mixed with normal platelet-rich plasma significantly increased platelet adhesion compared to normal RBC (SC p < 0.03, AS p < 0.02). Thalassemic platelets reconstituted with normal RBC, had increased aggregation (AS, p < 0.004) in comparison with normal platelets. The results indicate that increased platelet adhesion in beta-thalassemia is induced by both platelets and RBC. Increased platelet adhesion correlated with clinical thrombotic events and thus may suggest a mechanism of thrombosis in thalassemic patients. The potential application of the CPA in identifying thalassemic patients with high risk for thrombosis should be studied prospectively in a larger cohort of patients.

  20. EXTENDED STORAGE OF BUFFY-COAT PLATELET CONCENTRATES IN PLASMA OR A PLATELET ADDITIVE SOLUTION

    PubMed Central

    Slichter, Sherrill J.; Bolgiano, Doug; Corson, Jill; Jones, Mary Kay; Christoffel, Todd; Bailey, S. Lawrence; Pellham, Esther

    2014-01-01

    Background Platelet concentrates prepared from whole blood in the U.S. are made using the platelet-rich-plasma (PRP) method. The platelet concentrates must be made within 8 hours of blood collection and stored for only 5 days. In Europe and Canada, platelet concentrates are made using the buffy-coat (BC) method from whole blood held overnight at 22°C and storage times may be up to 7 days. Our studies were designed to determine how long BC platelets can be stored in plasma or Plasmalyte while meeting the FDA’s post-storage viability criteria. Study Design, Materials, And Methods Normal subjects donated whole blood that was stored at 22°C for 22 ± 2 hours prior to preparation of BC platelets. Platelets were stored for 5 to 8 days in either plasma or Plasmalyte concentrations of 65% or 80%. Radiolabeled autologous stored versus fresh platelet recoveries and survivals were assessed as well as post-storage in vitro assays. Results BC platelets stored in either plasma or 65% Plasmalyte met FDA post-storage platelet recovery criteria for 7 days but survivals for only 6 days, while storage in 80% Plasmalyte gave very poor results. Both stored platelet recoveries and survivals correlated with the same donor’s fresh results, but the correlation was much stronger between recoveries than survivals. In vitro measures of extent of shape change, morphology score, and pH best predicted post-storage platelet recoveries, while annexin V binding best predicted platelet survivals. Conclusion BC platelets stored in either plasma or 65% Plasmalyte meet FDA’s post-storage viability criteria for 6 days. PMID:24673482

  1. Proteomic approaches to dissect platelet function: half the story

    PubMed Central

    Gnatenko, Dmitri V.; Perrotta, Peter L.; Bahou, Wadie F.

    2006-01-01

    Platelets play critical roles in diverse hemostatic and pathologic disorders and are broadly implicated in various biological processes that include inflammation, wound healing, and thrombosis. Recent progress in high-throughput mRNA and protein profiling techniques has advanced our understanding of the biological functions of platelets. Platelet proteomics has been adopted to decode the complex processes that underlie platelet function by identifying novel platelet-expressed proteins, dissecting mechanisms of signal or metabolic pathways, and analyzing functional changes of the platelet proteome in normal and pathologic states. The integration of transcriptomics and proteomics, coupled with progress in bioinformatics, provides novel tools for dissecting platelet biology. In this review, we focus on current advances in platelet proteomic studies, with emphasis on the importance of parallel transcriptomic studies to optimally dissect platelet function. Applications of these global profiling approaches to investigate platelet genetic diseases and platelet-related disorders are also addressed. PMID:16926286

  2. Relationship between potential platelet activation and LCS

    NASA Astrophysics Data System (ADS)

    Shadden, Shawn

    2010-11-01

    In the study of blood flow, emphasis is often directed at understanding shear stress at the vessel wall due to its potentially disruptive influence on the endothelium. However, it is also known that shear stress has a potent effect on platelet activation. Platelet activation is a precursor for blood clotting, which in turn is the cause of most forms of death. Since most platelets are contained in the flow domain, it is important to consider stresses acting on the platelet as they are convected. Locations of high stress can correspond to boundaries between different dynamic regions and locations of hyperbolic points in the Eulerian sense. In the computation of LCS, strain in typically considered in the Lagrangian sense. In this talk we discuss the relationship between locations of potential platelet activation due to increased stress and locations of LCS marking increase Lagrangian deformation.

  3. Platelet bioreactor-on-a-chip.

    PubMed

    Thon, Jonathan N; Mazutis, Linas; Wu, Stephen; Sylman, Joanna L; Ehrlicher, Allen; Machlus, Kellie R; Feng, Qiang; Lu, Shijiang; Lanza, Robert; Neeves, Keith B; Weitz, David A; Italiano, Joseph E

    2014-09-18

    Platelet transfusions total >2.17 million apheresis-equivalent units per year in the United States and are derived entirely from human donors, despite clinically significant immunogenicity, associated risk of sepsis, and inventory shortages due to high demand and 5-day shelf life. To take advantage of known physiological drivers of thrombopoiesis, we have developed a microfluidic human platelet bioreactor that recapitulates bone marrow stiffness, extracellular matrix composition,micro-channel size, hemodynamic vascular shear stress, and endothelial cell contacts, and it supports high-resolution live-cell microscopy and quantification of platelet production. Physiological shear stresses triggered proplatelet initiation, reproduced ex vivo bone marrow proplatelet production, and generated functional platelets. Modeling human bone marrow composition and hemodynamics in vitro obviates risks associated with platelet procurement and storage to help meet growing transfusion needs.

  4. Platelet storage pool deficiency in Jacobsen syndrome.

    PubMed

    White, James G

    2007-11-01

    Jacobsen syndrome and Paris-Trousseau Syndrome share similar congenital anomalies, thrombocytopenia, giant platelet alpha granules resulting from fusion of smaller organelles, and an 11q terminal deletion at 11q23.3. Similarities in the two cohorts have suggested that the Paris-Trousseau Syndrome is a variant of Jacobsen syndrome, or the same disorder. The present study has pointed out a significant difference between the two syndromes. Platelets from six patients with Jacobsen syndrome were markedly diminished in serotonin adenine nucleotide rich dense bodies, indicating the presence of platelet storage pool deficiency. Since platelet dense bodies are reported to be normal in size, number and distribution in the Paris-Trousseau Syndrome, the presence of platelet storage pool deficiency in six patients evaluated in the present study may distinguish the two disorders.

  5. [Platelet antigens: immunology and immuno-allergology].

    PubMed

    de Sousa, J C; Palma-Carlos, A G

    1996-02-01

    Platelet immunology allows the understanding of clinical findings in a genetic and serologic basis. Blood platelets bear common antigens and same specific antigens, classified in five groups (HPA 1 to 5), that are localized on membrane glycoproteins Ia, Ib alpha, IIb and IIIa. Antiplatelet autoimmunization is generally due to IgG antibodies against membrane complexes IIb/IIIa or Ib/lX. Antiplatelet alloimmunization, clinically resulting in Posttransfusion Purpura and Neonatal Thrombocytopenia is more frequently associated with anti-IIb/IIIa antibodies, either anti-HPA-1a or HPA-1b. Finally, platelet participation in immunoallergic reactions is discussed, focusing both platelet activation by allergen itself and platelet recruitment by other inflammatory cells.

  6. Contact- and agonist-regulated microvesiculation of human platelets.

    PubMed

    Zhang, Yanjun; Liu, Xiao; Liu, Li; Zaske, Ana-Maria; Zhou, Zhou; Fu, Yuanyuan; Yang, Xi; Conyers, Jodie L; Li, Min; Dong, Jing-fei; Zhang, Jianning

    2013-08-01

    After exposure to an agonist, platelets are activated and become aggregated. They also shed membrane microparticles that participate in the pathogenesis of thrombosis, hyper-coagulation and inflammation. However, microvesiculation can potentially disrupt the integrity of platelet aggregation by shedding the membrane receptors and phosphatidylserine critical for forming and stabilising a platelet clot. We tested the hypothesis that adhesion and microvesiculation are functions of different subsets of platelets at the time of haemostasis by real-time monitoring of agonist-induced morphological changes and microvesiculation of human platelets.We identified two types of platelets that are adherent to fibrinogen: a high density bubble shape (HDBS) and low-density spread shape (LDSS). Adenosine diphosphate (ADP) predominantly induced HDBS platelets to vesiculate, whereas LDSS platelets were highly resistant to such vesiculation. Thrombin-receptor activating peptide (TRAP) stabilised platelets against microvesiculation by promoting a rapid HDBS-to-LDSS morphological transition. These activities of ADP and TRAP were reversed for platelets in suspension, independent of an engagement integrin αIIbβ3. As the result of membrane contact, LDSS platelets inhibited the microvesiculation of HDBS platelets in response to ADP. Aspirin and clopidogrel inhibited ADP-induced microvesiculation through different mechanisms. These results suggest that platelet aggregation and microvesiculation occur in different subsets of platelets and are differently regulated by agonists, platelet-platelets and platelet-fibrinogen interactions.

  7. Cangrelor attenuates coated-platelet formation.

    PubMed

    Norgard, Nicholas B; Hann, Callie L; Dale, George L

    2009-01-01

    P2Y(12) inhibitors were introduced clinically as effective inhibitors of adenosine-5'-diphosphate (ADP) mediated platelet activation and aggregation. This class of pharmacological agents has enjoyed considerable success. Cangrelor is a recently developed P2Y(12) inhibitor that has the advantage of being an active drug not requiring metabolic conversion, although it is not orally available. Coated-platelets are a subclass of activated platelets generated on dual agonist activation with collagen plus thrombin; the primary hallmark of coated-platelets is their ability to support prothrombinase activity. Interestingly, we recently observed that the relatively weak agonist ADP potentiates the production of coated-platelets by the very strong agonists collagen plus thrombin, a previously unknown role for ADP. The authors sought in this study to determine if P2Y(12) inhibitors, such as cangrelor, were capable of attenuating this augmentation of coated-platelet generation. Cangrelor, at physiologically relevant concentrations, was able to eliminate the ADP-dependent increase in coated-platelet production with an IC(50) of 1.4 nM. Cangrelor, however, had no effect on thrombin-dependent platelet activation as measured by P-selectin expression. Although this in vitro study does not address the question of whether the effectiveness of cangrelor in vivo is partially due to an attenuation of coated-platelet production in addition to its documented antiaggregatory effects, it does reveal an unexpected action of cangrelor. Additional studies will be required to determine if all P2Y(12) inhibitors are equally effective in attenuating coated-platelet production.

  8. Qualitative disorders of platelets and megakaryocytes.

    PubMed

    Nurden, A T

    2005-08-01

    Qualitative disorders of platelet function and production form a large group of rare diseases which cover a multitude of genetic defects that by and large have as a common symptom, excessive mucocutaneous bleeding. Glanzmann thrombasthenia, is enabling us to learn much about the pathophysiology of integrins and of how alphaIIb beta3 functions. Bernard-Soulier syndrome, an example of macrothrombocytopenia, combines the production of large platelets with a deficit or non-functioning of the major adhesion receptor of platelets, the GPIb-IX-V complex. Amino acid substitutions in GPIb alpha, may lead to up-regulation and spontaneous binding of von Willebrand factor as in Platelet-type von Willebrand disease. In disorders with defects in the MYH9 gene, macrothrombocytopenias are linked to modifications in kidney, eye or ear, whereas other inherited thrombocytopenias variously link a low platelet count with a propensity to leukemia, skeletal defects, learning impairment, and abnormal red cells. Defects of secretion from platelets include an abnormal alpha-granule formation as in the gray platelet syndrome (with marrow myelofibrosis), and of organelle biogenesis in the Hermansky-Pudlak and Chediak-Higashi syndromes where platelet dense body defects are linked to abnormalities of other lysosomal-like organelles including melanosomes. Finally, defects involving surface receptors (P2Y(12), TPalpha) for activating stimuli, of proteins essential for signaling pathways (including Wiskott-Aldrich syndrome), and of platelet-derived procoagulant activity (Scott syndrome) show how studies on platelet disorders are helping unravel the pathways of primary hemostasis.

  9. Platelet derivatives in regenerative medicine: an update.

    PubMed

    De Pascale, Maria Rosaria; Sommese, Linda; Casamassimi, Amelia; Napoli, Claudio

    2015-01-01

    Prior preclinical and clinical studies support the use of platelet-derived products for the treatment of soft and hard tissue lesions. These regenerative effects are controlled by autocrine and paracrine biomolecules including growth factors and cytokines contained in platelet alpha granules. Each growth factor is involved in a phase of the healing process, such as inflammation, collagen synthesis, tissue granulation, and angiogenesis collectively promoting tissue restitution. Platelet derivatives have been prepared as platelet-rich plasma, platelet gel, platelet-rich fibrin, and platelet eye drops. These products vary in their structure, growth factors, composition, and cytokine concentrations. Here, we review the current use of platelet-derived biological products focusing on the rationale for their use and the main requirements for their preparation. Variation in the apparent therapeutic efficacy may have resulted from a lack of reproducible, standardized protocols for preparation. Despite several individual studies showing favorable treatment effects, some randomized controlled trials as well as meta-analyses have found no constant clinical benefit from the application of platelet-derived products for prevention of tissue lesions. Recently, 3 published studies in dentistry showed an improvement in bone density. Seven published studies showed positive results in joint regeneration. Five published studies demonstrated an improvement in the wound healing, and an improvement of eye epithelial healing was observed in 2 reports. Currently, at least 14 ongoing clinical trials in phase 3 or 4 have been designed with large groups of treated patients (n > 100). Because the rationale of the therapy with platelet-derived compounds is still debated, a definitive insight can be acquired only when these large randomized trials will be completed.

  10. Effect of low dose acetylsalicylic acid on the frequency and hematologic activity of left ventricular thrombus in anterior wall acute myocardial infarction

    SciTech Connect

    Kuepper, A.J.V.; Verheugt, F.W.; Peels, C.H.; Galema, T.W.; den Hollander, W.; Roos, J.P.

    1989-04-15

    In this prospective, randomized, placebo-controlled trial the effect of 100 mg acetylsalicylic acid (ASA) once daily on the incidence, hematologic activity and embolic potential of left ventricular (LV) thrombosis was studied in 100 consecutive patients with a first anterior wall acute myocardial infarction (AMI). Patients were randomized to ASA or placebo less than 12 hours after onset of symptoms. Heparin, 5,000 IU subcutaneously twice daily, was given to all patients during immobilization. Echocardiography was performed less than 24 hours, 48 to 72 hours and 1, 2, and 12 weeks after AMI. LV thrombosis was detected by echocardiography in 30 (33%) of the 92 evaluable patients (15 patients given ASA and 15 given placebo). Indium-111 platelet scintigraphy was done in 17 of the 22 patients with an LV thrombus at the second week echocardiogram. Among 7 ASA-treated patients, 4 had positive images; among 10 placebo patients, 5 had positive images. LV thrombus resolution was noted in 3 of 9 patients with a positive scan and in 5 of 8 patients with a negative platelet scan. In 7 of 10 ASA-treated patients and 5 of 12 placebo-treated patients thrombus resolution was observed (difference not significant). Systemic embolism occurred in 2 patients, both given ASA, during the first week after AMI. Thus, low dose ASA has no effect on the incidence, hematologic activity and embolic potential of LV thrombosis in anterior wall AMI.

  11. Inhibitory effect of trichothecene mycotoxins on bovine platelets stimulated by platelet activating factor.

    PubMed Central

    Gentry, P A; Ross, M L; Bondy, G S

    1987-01-01

    Several species of fungi, which infect cereals and grains, can produce a class of compounds, known as trichothecene mycotoxins, which is characterized by a substituted epoxy-trichothecene ring structure. Cattle are susceptible to intoxication from feeds contaminated with T-2 toxin, one of the more potent trichothecene mycotoxins, while swine refuse to ingest feed contaminated with T-2 toxin. The bovine platelet has been used as a model cell system to evaluate the effects of T-2 toxin and its natural metabolites, HT-2 toxin and T-2 tetraol, on cell function in vitro. Due to the lipophilic nature of these mycotoxins, a biologically active phospholipid was used to stimulate the platelets in the presence and absence of the toxins. The mycotoxin T-2 toxin and its major metabolite HT-2 toxin inhibited platelet activating factor-stimulated bovine platelets, suspended in homologous plasma, in a concentration but not time dependent manner. Significant inhibition of platelet function (p less than 0.01) occurred with 135 ng T-2 toxin per 10(6) platelets and with 77 ng HT-2 toxin per 10(6) platelets. These mycotoxins exerted an additive inhibitory effect on the platelet aggregation response. In contrast, the minor metabolite T-2 tetraol had no inhibitory effect on platelet function and had no influence on the responses of T-2 toxin or HT-2 toxin when the mycotoxins were present together in the platelet suspensions.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3453270

  12. The effects of drugs used in anaesthesia on platelet membrane receptors and on platelet function.

    PubMed

    Kozek-Langenecker, Sibylle A

    2002-06-01

    Platelet dysfunctions are known origins of perioperative bleeding disorders which are a major concern in the management of surgical patients. Among multiple factors, interactions of drugs used in anaesthesia with platelets have been implicated to aggravate the risk of haemorrhagic complications. This paper reviews in vitro and in vivo studies which have examined the effects of inhalational, intravenous, and local anaesthetics, opioids, and muscle relaxants on platelets. A brief summary of platelet physiology, function tests, and flow cytometric assessment of membrane receptors is included. Although the results of many studies have been conflicting, it appears that halothane, sevoflurane, and propofol inhibit platelet function in a reversible and dose-related manner at concentrations used clinically. Ilalothane affects the intracellular activating second messenger inositol triphosphate, platelet calcium homeostasis, thromboxane A2 formation, and the inhibiting signal transduction pathway including cyclic adenosine monophosphate. The proposed platelet inhibiting mechanism of sevoflurane involves the suppression of thromboxane A2 formation. Propofol appears to cause platelet dysfunctions by inhibiting calcium mobilisation upon agonist stimulation. Nitrous oxide causes a modest suppression of calcium mobilisation. An interaction of local anaesthetics with components in the platelet membrane appears to account for their inhibiting effect, but only at concentrations far higher than that found during clinical use. A clinically relevant antithrombotic effect of regional anaesthesia has been observed, though. Isoflurane, enflurane, desflurane, barbiturates, etomidate, opioids, and muscle relaxants seem to have negligible effects on platelets at therapeutic concentrations. Anaesthetists should be aware of the potential impairment of the coagulation profile by anaesthetic agents.

  13. Meta-iodobenzylguanidine scintigraphy in neuroblastoma--a comparison with conventional X-ray and ultrasound

    SciTech Connect

    Mueller-Gaertner, H.W.Er.; Erttmann, R.; Helmke, K. )

    1986-01-01

    To evaluate the accuracy of meta-iodobenzylguanidine (MIBG) imaging in comparison with bone X-ray and ultrasound, 15 patients with histologically verified neuroblastoma were investigated using 123- or 131MIBG scintigraphy. 123MIBG and 131MIBG are used as the abbreviations for 123-iodine-labeled-MIBG and 131-iodine-labeled-MIBG, respectively. Either 7.4 MBq 131MIBG (n = 4) or 111-185 MBq 123MIBG (n = 11) was applied, and scans were performed 24 and 48 h PI. Anatomical orientation was provided in selected cases by single-photon emission CT or scintigraphy of other organs. X-ray procedures or ultrasound depicted 27 neuroblastoma manifestations (primary tumors and metastatic deposits); 24 of these (89%) were identified by MIBG scintigraphy. Of 42 primary neuroblastomas and metastatic deposits, 27 (64%) were detected by corresponding bone X-ray or ultrasound. The 15 neuroblastoma lesions depicted solely by MIBG scans were mainly (80%) situated in the skeletal system. Because of the pronounced physiological MIBG uptake by liver tissue, detection of intrahepatic or perihepatic tumor involvement is difficult. MIBG scintigraphy is a safe and noninvasive means of locating a wide range of neuroblastoma lesions. Its main diagnostic advantage in comparison with bone X-ray lies in the detection of bone marrow infiltration.

  14. Gastric emptying scintigraphy results in children are affected by age, anthropometric factors, and study duration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A standardized 4-hour adult-based gastric emptying scintigraphy (GES) protocol is increasingly being used in children to evaluate for gastroparesis. We sought to determine the effect of age, anthropometrics, and study duration on GES results using this protocol in children. Retrospective review of c...

  15. Collar Osteophytes Mimicking Osteonecrosis in Planar Bone Scintigraphy and Usefulness of SPECT/CT Images.

    PubMed

    Juang, Jr-Jian; Chen, Yi-Hsing; Tsai, Shih-Chuan; Lin, Wan-Yu

    2017-03-01

    The use of prednisolone is one major risk factor for osteonecrosis in patients with systemic lupus erythematosus. Bone scintigraphy can be a diagnostic tool for early diagnosis. We present a case who had collar osteophytes at the bilateral femoral heads, which mimicked osteonecrosis in the planar bone scintigram. An SPECT/CT scan avoided this pitfall and increased the diagnostic accuracy for osteonecrosis.

  16. Evaluation of gadolinium compounds potentially suitable for magnetic resonance using Gd-153 scintigraphy

    SciTech Connect

    Engelstad, B.; Huberty, J.; White, D.; Wynne, C.; Ramos, E.; Goldberg, H.

    1985-05-01

    Gd-153 is not customarily considered for scintigraphy, yet it: 1) is available at acceptable cost, 2) has a 242 day half-life suitable for prolonged animal studies and 3) has 97 keV (40%) and 103 keV (59%) photopeaks suitable for conventional scintigraphy. Gd-153 (10-15 ..mu..Ci; 370-555 kBq) was administered to normal rats in 5 forms: 1) carrier 0.1 mmole/kg Gd-EIDA (diethyl iminodiacetic acid), 2) tracer (<.1 umole/kg) Gd-EIDA, 3) tracer Gd-ISIDA (diisopropyl iminodiacetic acid), 4) tracer GdCl/sub 3/, and 5) tracer Gd-DTPA. Scintigraphy, performed continuously for 90 minutes following intravenous injection and at intervals at up to 2 weeks, depicted: 1) rapid, partial hepatobiliary and renal clearance of tracer Gd-EIDA and Gd-ISIDA; 2) slow blood clearance and partial hepatobiliary clearance of carrier Gd-EIDA; and 3) prolonged reticuloendothelial retention of all IDA complexes, similar to GdCl3. Whole body and tissue distribution data paralleled the scintigraphic findings. Gd-153 scintigraphy provides a simple method to assess balance, distribution, kinetics, and stability of new paramagnetic contrast agents, and bis-iminodiacetate gadolinium complexes, unlike technetium analogues, lack effective stability to prevent gadolinium hydrolysis or translocation.

  17. Evaluation of hypertensive patients by means of captopril enhanced renal scintigraphy with technetium-99m DTPA

    SciTech Connect

    Dondi, M.; Franchi, R.; Levorato, M.; Zuccala, A.; Gaggi, R.; Mirelli, M.; Stella, A.; Marchetta, F.; Losinno, F.; Monetti, N.

    1989-05-01

    One-hundred five hypertensive patients underwent conventional renal scintigraphy followed 2 or 3 days later by Captopril-enhanced renal scintigraphy, performed 1 hr after premedication with 50 mg of Captopril per os. All patients were then submitted to renal arteriography, performed within 15-30 days. Fifty-five patients had no renal artery stenosis, 29 had unilateral disease, and 21 bilateral. Overall, 34/37 patients were diagnosed by the provocative test as having at least one renal artery affected by a stenosis greater than 50%. Of those with no stenosis (n = 55) or stenosis less than 50% (n = 13) only two cases were falsely positive. Thus sensitivity was 92% and specificity 97%. For single kidney identification with stenosis greater than 50%, sensitivity of renal scintigraphy after Captopril administration was 94% and specificity 98%. Captopril enhanced renal scintigraphy is thus suggested as the first test to be performed in hypertensive patients referred for renal scintigraphic studies. Only those cases with equivocal results require a baseline study for better assessment.

  18. Bone scintigraphy for neonatal osteomyelitis: simulation by extravasation of intravenous calcium

    SciTech Connect

    Balsam, D.; Goldfarb, C.R.; Stringer, B.; Farruggia, S.

    1980-04-01

    Intravenously administered calcium gluconate has become increasingly popular in the treatment of neonatal tetany. Occasionally, extravasation results in cellulitis, leading to a clinical diagnosis of superimposed osteomyelitis. Osseous scintigraphy, as the accepted modality in the early detection of osteomyelitis, would tend to be used in this circumstance. This case illustrates a false-positive result, probably due to soft-tissue calcification.

  19. Exercise thallium-201 scintigraphy in the diagnosis and prognosis of coronary artery disease

    SciTech Connect

    Kotler, T.S.; Diamond, G.A. )

    1990-11-01

    The objective of this study is to determine the discriminant accuracy of exercise thallium-201 myocardial perfusion scintigraphy for the diagnosis and prognosis of patients with known or suspected coronary artery disease. This is a survey of the National Library of Medicine MEDLINE database. The key medical subject headings used were coronary disease, myocardial infarction, radionuclide imaging, and thallium. A total of 122 retrieved studies were considered relevant and were reviewed in depth. Only studies reporting both the sensitivity and specificity of thallium scintigraphy were analyzed. Discriminant accuracy for diagnosis and prognosis was summarized in terms of pooled sensitivity and specificity. Exercise thallium scintigraphy is useful in the noninvasive diagnosis of coronary artery disease, especially in patients with abnormal resting electrocardiograms, restricted exercise tolerance, and intermediate probability of having disease at the time of testing as well as of defining the prognosis of patients with known or suspected coronary artery disease, especially in those with previous myocardial infarction. Because of various shortcomings in the published record, however, the marginal discriminant accuracy and cost effectiveness of thallium scintigraphy compared with conventional clinical assessment and exercise electrocardiography remain controversial. 193 references.

  20. Evaluation of Feline Renal Perfusion with Contrast-Enhanced Ultrasonography and Scintigraphy

    PubMed Central

    Vanderperren, Katrien; Bosmans, Tim; Dobbeleir, André; Duchateau, Luc; Hesta, Myriam; Lybaert, Lien; Peremans, Kathelijne; Vandermeulen, Eva; Saunders, Jimmy

    2016-01-01

    Contrast-enhanced ultrasound (CEUS) is an emerging technique to evaluate tissue perfusion. Promising results have been obtained in the evaluation of renal perfusion in health and disease, both in human and veterinary medicine. Renal scintigraphy using 99mTc-Mercaptoacetyltriglycine (MAG3) is another non-invasive technique that can be used to evaluate renal perfusion. However, no data are available on the ability of CEUS or 99mTc- MAG3 scintigraphy to detect small changes in renal perfusion in cats. Therefore, both techniques were applied in a normal feline population to evaluate detection possibilities of perfusion changes by angiotensin II (AT II). Contrast-enhanced ultrasound using a bolus injection of commercially available contrast agent and renal scintigraphy using 99mTc-MAG3 were performed in 11 healthy cats after infusion of 0,9% NaCl (control) and AT II. Angiotensin II induced changes were noticed on several CEUS parameters. Mean peak enhancement, wash-in perfusion index and wash-out rate for the entire kidney decreased significantly after AT II infusion. Moreover, a tendency towards a lower wash-in area-under-the curve was present. Renal scintigraphy could not detect perfusion changes induced by AT II. This study shows that CEUS is able to detect changes in feline renal perfusion induced by AT II infusion. PMID:27736928

  1. Early detection of restenosis after successful percutaneous transluminal coronary angioplasty by exercise-redistribution thallium scintigraphy

    SciTech Connect

    Wijns, W.; Serruys, P.W.; Reiber, J.H.; de Feyter, P.J.; van den Brand, M.; Simoons, M.L.; Hugenholtz, P.G.

    1985-02-01

    The value of exercise testing and thallium scintigraphy in predicting recurrence of angina pectoris and restenosis after a primary successful transluminal coronary angioplasty (PTCA) was prospectively evaluated. In 89 patients, a symptom-limited exercise electrocardiogram (ECG) and thallium scintigraphy were performed 4 weeks after they had undergone successful PTCA. Thereafter, the patients were followed for 6.4 +/- 2.5 months (mean +/- standard deviation) or until recurrence of angina. They all underwent a repeat coronary angiography at 6 months or earlier if symptoms recurred. PTCA was considered successful if the patients had no symptoms and if the stenosis was reduced to less than 50% of the luminal diameter. Restenosis was defined as an increase of the stenosis to more than 50% luminal diameter. The ability of the thallium scintigram (presence of a reversible defect) to predict recurrence of angina was 66%, vs 38% for the exercise ECG (ST-segment depression or angina at peak workload). Restenosis was predicted in 74% of patients by thallium scintigraphy, but only in 50% of patients by the exercise ECG. Thus, thallium scintigraphy was highly predictive but the exercise ECG was not (p less than 0.005). These results suggest that restenosis had occurred to some extent already at 4 weeks after the PTCA in most patients in whom it was going to occur.

  2. Transdiaphragmatic peritoneal hernia complicating peritoneal dialysis: demonstration with spiral computed tomography peritoneography and peritoneal scintigraphy.

    PubMed

    Coche, Emmanuel; Lonneux, Max; Goffin, Eric

    2005-08-01

    The authors describe a rare case of peritoneal transdiaphragmatic hernia discovered immediately after a car accident in a young male patient on peritoneal dialysis. The potential role of CT peritoneography and peritoneal scintigraphy to demonstrate and understand thoracic complications of ambulatory peritoneal dialysis is discussed.

  3. Evaluation of soft tissue injury by Tc-99m bone agent scintigraphy

    SciTech Connect

    Delpassand, E.S.; Dhekne, R.D.; Barron, B.J.; Moore, W.H. )

    1991-05-01

    Six patients with soft tissue injury secondary to different etiologic factors are presented. The degree and extent of tissue necrosis was precisely identified by scintigraphy. In two of these, radionuclide imaging helped to establish accurately the level of amputation that resulted in appropriate wound healing.

  4. The effect of scatter and attenuation on aerosol deposition as determined by gamma scintigraphy.

    PubMed

    Lee, Z; Berridge, M S; Nelson, A D; Heald, D L

    2001-01-01

    Gamma scintigraphy is often used to quantify deposition patterns from aerosol inhalers. The errors caused by scatter and tissue attenuation in planar Tc-99m gamma scintigraphy were investigated based on the data collected from four subjects in this study. Several error correction methods were tested. The results from two scatter correction methods, Jaszczak's method and factor analysis of dynamic sequences (FADS), were similar. Scatter accounted for 20% of raw data in the whole lung, 20% in the oropharynx, and 43% in the central airways and esophagus. Three attenuation correction methods were investigated and compared. These were: uniform attenuation correction (UAC), a known method used for inhalation drug imaging work; the broad-beam attenuation correction used for organ imaging in nuclear medicine; and a narrow-beam inhomogeneous tissue attenuation correction proposed in this study. The three methods differed significantly (p < 0.05), but all indicated that attenuation is a severe quantification problem. The narrow beam attenuation correction with scatter correction, showed that raw data underestimated tracer deposition by 44% in the lung, 137% in the oropharynx, and 153% in the trachea/esophageal region. To quantify aerosol lung deposition using planar scintigraphy even in relative terms, corrections are necessary. Much of the literature concerning quantified aerosol dose distributions measured by gamma scintigraphy needs to be interpreted carefully.

  5. Continuing impact of thyroid scintigraphy on the diagnosis of thyroid enlargement

    SciTech Connect

    Maxon, H.R.; Hertzberg, V.; Vasavada, P.; Pu, M.Y.; Volarich, D.

    1986-05-01

    The impact of thyroid scintigraphy on the working diagnosis was evaluated in 204 consecutive patients referred for thyroid testing. The a priori and a posteriori diagnoses were discordant about one third of the time. The differences were highly significant (P less than 0.001) in the cases of uninodular and multinodular goiter.

  6. Platelet Lysates Produced from Expired Platelet Concentrates Support Growth and Osteogenic Differentiation of Mesenchymal Stem Cells

    PubMed Central

    Jonsdottir-Buch, Sandra Mjoll; Lieder, Ramona; Sigurjonsson, Olafur Eysteinn

    2013-01-01

    Background Mesenchymal stem cells are promising candidates in regenerative cell therapy. Conventional culture methods involve the use of animal substances, specifically fetal bovine serum as growth supplement. Since the use of animal-derived products is undesirable for human applications, platelet lysates produced from human platelets are an attractive alternative. This is especially true if platelet lysates from already approved transfusion units at blood banks can be utilized. The purpose of this study was to produce human platelet lysates from expired, blood bank-approved platelet concentrates and evaluate their use as growth supplement in the culture of mesenchymal stem cells. Methodology/Principal Findings In this study, bone marrow-derived mesenchymal stem cells were cultured with one of three culture supplements; fetal bovine serum, lysates from freshly prepared human platelet concentrates, or lysates from expired human platelet concentrates. The effects of these platelet-derived culture supplements on basic mesenchymal stem cell characteristics were evaluated. All cultures maintained the typical mesenchymal stem cell surface marker expression, trilineage differentiation potential, and the ability to suppress in vitro immune responses. However, mesenchymal stem cells supplemented with platelet lysates proliferated faster than traditionally cultured cells and increased the expression of the osteogenic marker gene RUNX-2; yet no difference between the use of fresh and expired platelet concentrates was observed. Conclusion/Significance Our findings suggest that human platelet lysates produced from expired platelet concentrates can be used as an alternative to fetal bovine serum for mesenchymal stem cell culture to the same extent as lysates from fresh platelets. PMID:23874839

  7. Platelets

    MedlinePlus

    ... an inherited gene mutation that limits the normal regulation and control, the complement system can damage our ... email: Evaren-Page@ouhsc.edu ), Department of Biostatistics & Epidemiology, College of Public Health, OUHSC Dee Terrell, PhD, ...

  8. Blood platelets in the progression of Alzheimer's disease.

    PubMed

    Gowert, Nina S; Donner, Lili; Chatterjee, Madhumita; Eisele, Yvonne S; Towhid, Seyda T; Münzer, Patrick; Walker, Britta; Ogorek, Isabella; Borst, Oliver; Grandoch, Maria; Schaller, Martin; Fischer, Jens W; Gawaz, Meinrad; Weggen, Sascha; Lang, Florian; Jucker, Mathias; Elvers, Margitta

    2014-01-01

    Alzheimer's disease (AD) is characterized by neurotoxic amyloid-ß plaque formation in brain parenchyma and cerebral blood vessels known as cerebral amyloid angiopathy (CAA). Besides CAA, AD is strongly related to vascular diseases such as stroke and atherosclerosis. Cerebrovascular dysfunction occurs in AD patients leading to alterations in blood flow that might play an important role in AD pathology with neuronal loss and memory deficits. Platelets are the major players in hemostasis and thrombosis, but are also involved in neuroinflammatory diseases like AD. For many years, platelets were accepted as peripheral model to study the pathophysiology of AD because platelets display the enzymatic activities to generate amyloid-ß (Aß) peptides. In addition, platelets are considered to be a biomarker for early diagnosis of AD. Effects of Aß peptides on platelets and the impact of platelets in the progression of AD remained, however, ill-defined. The present study explored the cellular mechanisms triggered by Aß in platelets. Treatment of platelets with Aß led to platelet activation and enhanced generation of reactive oxygen species (ROS) and membrane scrambling, suggesting enhanced platelet apoptosis. More important, platelets modulate soluble Aß into fibrillar structures that were absorbed by apoptotic but not vital platelets. This together with enhanced platelet adhesion under flow ex vivo and in vivo and platelet accumulation at amyloid deposits of cerebral vessels of AD transgenic mice suggested that platelets are major contributors of CAA inducing platelet thrombus formation at vascular amyloid plaques leading to vessel occlusion critical for cerebrovascular events like stroke.

  9. 21 CFR 864.5700 - Automated platelet aggregation system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... addition of an aggregating reagent to a platelet-rich plasma. (b) Classification. Class II (performance... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Automated platelet aggregation system. 864.5700... § 864.5700 Automated platelet aggregation system. (a) Identification. An automated platelet...

  10. Brief Report: Platelet-Poor Plasma Serotonin in Autism

    ERIC Educational Resources Information Center

    Anderson, George M.; Hertzig, Margaret E.; McBride, P. A.

    2012-01-01

    Possible explanations for the well-replicated platelet hyperserotonemia of autism include an alteration in the platelet's handling of serotonin (5-hydroxyserotonin, 5-HT) or an increased exposure of the platelet to 5-HT. Measurement of platelet-poor plasma (PPP) levels of 5-HT appears to provide the best available index of in vivo exposure of the…

  11. 21 CFR 864.5700 - Automated platelet aggregation system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... addition of an aggregating reagent to a platelet-rich plasma. (b) Classification. Class II (performance... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Automated platelet aggregation system. 864.5700... § 864.5700 Automated platelet aggregation system. (a) Identification. An automated platelet...

  12. Aspirin treatment reduces platelet resistance to deformation.

    PubMed

    Burris, S M; Smith, C M; Rao, G H; White, J G

    1987-01-01

    The present investigation has evaluated the influence of aspirin, its constituents, and other nonsteroidal anti-inflammatory agents on the resistance of human platelets to aspiration into micropipettes. Aspirin increased the length of platelet extensions into the micropipette over the entire negative tension range of 0.04 to 0.40 dynes/cm after exposure to the drug in vitro or after ingestion of the agent. Other cyclooxygenase inhibitors, ibuprofen and indomethacin, did not increase platelet deformability. The influence of aspirin was mimicked to some degree by high concentrations of salicylic acid, but acetylation of platelets with acetic anhydride had little influence on platelet deformability. Incubation of platelets with both salicylic acid and acetic anhydride had no more effect than salicylic acid alone. Benzoic acid, chemically similar to salicylic acid, had a minimal effect. The studies demonstrate that aspirin makes platelets more deformable, while components of the drug or other nonsteroidal antiinflammatory agents and cyclooxygenase inhibitors do not have the same influence on resistance to deformation.

  13. The York Platelet Syndrome: a third case.

    PubMed

    White, James G; Gunay-Aygun, Meral

    2011-01-01

    Our present study has described a third patient with the York Platelet Syndrome (YPS). The condition consists of a mitochondrial myopathy associated with unique platelet pathology. Their mitochondrial myopathy has not been completely delineated and will be the subject of further study. Platelet pathology in the new patient is essentially identical to that described in the first two patients. Thin sections of her thrombocytes reveal a normal complement of α and δ granules (dense bodies) in some, a decreased number in others and complete absence in a few. The unique pathological feature is the presence of giant organelles, including an intensely electron dense, huge body, the opaque organelle (OO) and a multilayered large body, the target organelle. In addition platelets from the new patient contain large masses and coils of smooth endoplasmic reticulum present infrequently in platelets of the first two patients. The giant opaque and target organelles appear to develop in rough and smooth endoplasmic reticulum of the parent megakaryocyte and mature in the dense tubular system of circulating platelets. The relationship of the unique platelet pathology and mitochondrial myopathy has not been defined.

  14. Platelet ITAM Signaling and Vascular Integrity

    PubMed Central

    Boulaftali, Yacine; Hess, Paul R.; Kahn, Mark L.; Bergmeier, Wolfgang

    2014-01-01

    Platelets are well-known for their critical role in hemostasis, i.e. the prevention of blood loss at sites of mechanical vessel injury. Inappropriate platelet activation and adhesion, however, can lead to thrombotic complications, such as myocardial infarction and stroke. To fulfill its role in hemostasis, the platelet is equipped with various G protein-coupled receptors (GPCRs) that mediate the response to soluble agonists such as thrombin, ADP, and thromboxane A2. In addition to GPCRs, platelets express three glycoproteins (GP) that belong to the family of immunoreceptor tyrosine-based activation motif (ITAM) receptors: Fc receptor (FcR) γ chain, which is non-covalently associated with the GPVI collagen receptor, C-type lectin 2 (CLEC2), the receptor for podoplanin, and FcγRIIA, a low-affinity receptor for immune complexes. While both genetic and chemical approaches have documented a critical role for platelet GPCRs in hemostasis, the contribution of ITAM receptors to this process is less defined. Studies performed over the last decade, however, have identified new roles for platelet ITAM signaling in vascular integrity in utero and at sites of inflammation. The purpose of this review is to summarize recent findings on how platelet ITAM signaling controls vascular integrity, both in the presence and absence of mechanical injury. PMID:24677237

  15. Platelet antibody: review of detection methods

    SciTech Connect

    Schwartz, K.A.

    1988-10-01

    The driving force behind development of in vitro methods for platelet antibodies is identification of plasma factors causing platelet destruction. Early methods relied on measurement of platelet activation. Current methods are more specific and use a purified antibody against immunoglobulin or complement, which is usually labeled with /sup 125/I or tagged with an enzyme or fluorescein. Comparisons of quantitation of platelet-associated IgG show wide variability between different methods. The disparate results can be related both to differences in binding of secondary antibodies to immunoglobulin in solution compared to immunoglobulins attached to platelets and to the improper assumption that the binding ratio between the secondary detecting and primary antiplatelet antibody is one. Most assays can 1) identify neonatal isoimmune thrombocytopenia and posttransfusion purpura, 2) help to differentiate between immune and nonimmune thrombocytopenias, 3) help to sort out the offending drug when drug-induced thrombocytopenia is suspected, and 4) identify platelet alloantibodies and potential platelet donors via a cross match assay for refractory patients. However, the advantages of quantitative assays over qualitative methods with respect to predictions of patients clinical course and response to different treatments remain to be investigated. 61 references.

  16. Splenic microenvironment and self recognition as factors in allograft rejection in rats. A study using indium-111-labeled cells

    SciTech Connect

    Pollak, R.; Blanchard, J.M.; Lazda, V.A.

    1986-11-01

    Splenectomy facilitates organ allograft survival in some rat strains, and in weak donor-recipient histoincompatible pairs. We have found using a heart spleen twin graft model, using ACI rats as recipients and Lewis rats as donors, that the transplanted heart will survive in most recipients after delayed host splenectomy. The presence of a viable mass of splenic tissue will allow rejection to proceed only when the transplanted spleen is of host origin, and not when it comes from the donor (i.e., when it is allogeneic). The use of 111In-labeled cells has allowed us to show that lymphocyte traffic and trapping is markedly altered in the transplanted allogeneic spleens, when compared with control transplanted syngeneic spleens. Thus, despite the presence of the splenic ''microenvironment,'' cardiac allograft rejection does not occur in the absence of syngeneic splenic tissue. We conclude that the role of the spleen in the immune response is to facilitate the recognition of self and the acquisition of alloreactivity in weak responder rat strains and donor-recipient pairs.

  17. Indium-111-labeled autologous leukocyte imaging and fecal excretion. Comparison with conventional methods of assessment of inflammatory bowel disease

    SciTech Connect

    Leddin, D.J.; Paterson, W.G.; DaCosta, L.R.; Dinda, P.K.; Depew, W.T.; Markotich, J.; McKaigney, J.P.; Groll, A.; Beck, I.T.

    1987-04-01

    This study was designed to evaluate the role of /sup 111/In-labeled leukocyte imaging and fecal excretion in the assessment of inflammatory bowel disease. We compared these tests to various indices of disease activity in Crohn's disease, to Truelove's grading in ulcerative colitis, and to endoscopy, x-ray, and pathology in both diseases. Eleven controls, 16 patients with Crohn's disease, 13 with ulcerative colitis, and 3 with other types of acute bowel inflammation were studied (positive controls). Indium scanning was performed at 1, 4, and 24 hr. Fourteen of 16 patients with active Crohn's disease had positive scans but in only five was localization accurate. One patient had inactive ulcerative colitis, and the scan was negative. Of 12 patients with active ulcerative colitis, 10 had positive scans but disease localization was accurate in only four. Disease extent was correctly defined in 1 of the 3 Positive Controls. There was no significant difference in the accuracy of scanning at 1, 4, or 24 hr. /sup 111/In fecal excretion was significantly higher in patients with inflammatory bowel disease than in controls, and there was correlation between /sup 111/In fecal excretion and most of the indices of disease activity in Crohn's disease. In ulcerative colitis, /sup 111/In fecal excretion did not correlate with Truelove's grading but reflected colonoscopic assessment of severity. In conclusion, /sup 111/In-labeled leukocyte scanning lacks sensitivity with respect to disease extent, but fecal excretion of /sup 111/In correlates well with disease severity as determined by other methods.

  18. In vivo tracing of indium-111 oxine-labeled human peripheral blood mononuclear cells in patients with lymphatic malignancies

    SciTech Connect

    Mueller, C.Z.; Zielinski, C.C.; Linkesch, W.; Ludwig, H.; Sinzinger, H.

    1989-06-01

    The in vivo migration of (/sup 111/In)oxine-labeled peripheral mononuclear cells (PMNC) was studied in 20 patients with various lymphatic malignancies and palpable enlarged lymph nodes. The maximal labeling dose of 10 microCi (0.37 MBq) (/sup 111/In)oxine/10(8) PMNC was found not to adversely influence either cell viability or lymphocyte proliferation in vitro. For in vivo studies, 1.5 X 10(9) PMNC were gained by lymphapheresis and reinjected intravenously after radioactive labeling, 150 microCi (5.55 MBq). The labeling of enlarged palpable lymph nodes was achieved in three out of three patients with Hodgkin's disease and in five out of five with high-malignant lymphoma, whereas three out of seven patients with low malignant lymphoma and no patient with chronic lymphatic leukemia had positive lymph node imaging. We thus conclude that PMNC retain their ability to migrate after (/sup 111/In)oxine labeling and that these cells traffic to involved lymph nodes of some, but not all hematologic malignancies.

  19. Detection of acute osteomyelitis with indium-111 labeled white blood cells in a patient with sickle cell disease

    SciTech Connect

    Fernandez-Ulloa, M.; Vasavada, P.J.; Black, R.R.

    1989-02-01

    A young patient with sickle cell disease (SCD) and multiple hospitalizations for crisis was admitted because of suspected osteomyelitis. Initial laboratory work, radiographs, and bone images were not contributory. An In-111 white blood cell (WBC) study demonstrated two areas of increased radionuclide uptake consistent with osteomyelitis. One of these had associated soft tissue infection. No other areas of active osteomyelitis were visualized, in spite of the presence of several additional infection sites. Imaging with In-111 WBC is probably not justified for routine diagnosis of acute osteomyelitis in areas free of previous disease, where conventional bone images are highly efficient. In-111 WBC imaging, however, may be helpful in detecting osteomyelitis in selected patients with SCD in whom Tc-99m bone images and radiographs are usually abnormal and difficult to interpret due to previous bone infarcts. Localization of the infection focus is very important in choosing the aspiration site for bacteriologic studies. A negative study, however, should be interpreted cautiously.

  20. Specificity of indium-111 granulocyte scanning and fecal excretion measurement in inflammatory bowel disease--an autoradiographic study

    SciTech Connect

    Keshavarzian, A.; Price, Y.E.; Peters, A.M.; Lavender, J.P.; Wright, N.A.; Hodgson, H.J.

    1985-12-01

    The validity of /sup 111/In granulocyte scanning and fecal excretion measurement, as a reflection of loss of cells into the gastrointestinal tract, was studied using an autoradiographic technique in 11 patients in whom /sup 111/In granulocyte scan and colonoscopy were carried out simultaneously. /sup 111/In granulocytes were injected 1.5-4 hr prior to colonoscopy, and intraluminal fluid, mucosal brushings, and colonic biopsies were collected during the colonoscopy. In two patients with no histological evidence of inflammatory bowel disease, and four patients with clinically and histologically inactive inflammatory bowel disease, no /sup 111/Indium was detected in fluid, brushing, or biopsies. In five patients with active disease, 85% of the /sup 111/In activity in colonic fluid was precipitated by low-speed centrifugation. Autoradiography confirmed that the label remained attached to whole granulocytes in colonic fluid and mucosal brushings. Studies on biopsies, at intervals up to 4 1/2 hr following labeled granulocyte injection, demonstrated labeled polymorphonuclear neutrophils (PMNs) on the inflamed epithelial surface, with occasional cells in crypt abscesses by 110 min. We conclude that the techniques of /sup 111/In granulocyte scanning and fecal counting in patients with IBD are specifically measuring cell loss; labeled PMNs are capable of migrating through the gastrointestinal mucosa, in active disease, within 2 hr of administration.

  1. Indium-111-antimyosin antibody imaging for detecting different stages of myocardial infarction: Comparison with technetium-99m-pyrophosphate imaging

    SciTech Connect

    Tamaki, N.; Yamada, T.; Matsumori, A.; Yoshida, A.; Fujita, T.; Ohtani, H.; Watanabe, Y.; Yonekura, Y.; Endo, K.; Konishi, J. )

    1990-02-01

    The diagnostic value of {sup 111}In-antimyosin (AM) imaging for identifying myocardial infarction was evaluated in comparison with {sup 99m}Tc-pyrophosphate (PPi) imaging. Twenty-four patients with various stages of myocardial infarction, ranging from three days to nine months after the onset of infarction, underwent both AM and PPi scans. Of 26 infarct lesions AM scan identified 22 (85%), while PPi scans detected 10 (38%) (p less than 0.01). When less than a week had passed since the onset both scans demonstrated all infarct lesions. For seven subacute lesions studied within one to two weeks of onset, AM scans detected (100%), while PPi scans identified only 2 (29%). Furthermore, AM scans showed discrete myocardial uptake in 7 (64%) of those studied more than two weeks after onset. The intensity of AM uptake in the infarcts studied more than seven days after onset was less than that in acute infarcts studied within seven days of onset (p less than 0.05). These preliminary data indicate that the abnormal myocardial uptake of AM persists beyond the first two weeks when PPi no longer accumulates. Thus, AM scans can be considered to provide a sensitive diagnosis of subacute as well as acute myocardial necrosis.

  2. Indium-111-labeled white blood cells in the detection of osteomyelitis complicated by a pre-existing condition.

    PubMed

    McCarthy, K; Velchik, M G; Alavi, A; Mandell, G A; Esterhai, J L; Goll, S

    1988-06-01

    Forty-six patients (23M, 23F) ranging in age from 19 to 79 yr with a clinical history of a nonunion fracture, surgery, diabetes or a soft-tissue infection were studied with [111In]oxine WBCs to detect osteomyelitis. There were 27 true-positive, nine true-negative, two false-positive and one false-negative. The false-positives and the false-negative occurred in patients with soft-tissue infections overlying the area of interest. All diagnoses were confirmed by intraoperative bone biopsies and cultures. Bone biopsy and scan were performed within 2 days of each other in 39 patients. The overall sensitivity was 97% (27/28), specificity, 82% (9/11) and the diagnostic accuracy, 92% (36/39). The remaining seven patients had negative [111In]WBC scans several months after positive bone biopsies and definite antibiotic treatment. This suggests that [In]WBC scans become negative after appropriate therapy is undertaken. Interobserver data was obtained from four nuclear physicians of varying experience blinded to clinical information. A high degree of agreement was found in over 90% of the cases. This study demonstrates the utility of [111In]WBC scans in the diagnosis and follow-up of complicated osteomyelitis and a high level of interobserver agreement in scan interpretation.

  3. Transcellular activation of platelets and endothelial cells by bioactive lipids in platelet microparticles.

    PubMed Central

    Barry, O. P.; Pratico, D.; Lawson, J. A.; FitzGerald, G. A.

    1997-01-01

    Microparticles are released during platelet activation in vitro and have been detected in vivo in syndromes of platelet activation. They have been reported to express both pro- and anticoagulant activities. Nevertheless, their functional significance has remained unresolved. To address the mechanism(s) of cellular activation by platelet microparticles, we examined their effects on platelets and endothelial cells. Activation of human platelets by diverse stimuli (thrombin, 0.1 U/ml; collagen, 4 microg/ml; and the calcium ionophore A23187, 1 microM) results in shedding of microparticles. Pretreatment of these particles, but not membrane fractions from resting platelets, with (s)PLA2 evokes a dose-dependent increase in platelet aggregation, intracellular [Ca2+] movement, and inositol phosphate formation. These effects localize to the arachidonic acid fraction of the microparticles and are mimicked by arachidonic acid isolated from them. However, platelet activation requires prior metabolism of microparticle arachidonic acid to thromboxane A2. Thus, pretreatment of platelets with the cyclooxygenase (COX) inhibitor, indomethacin (20 microM), the thromboxane antagonist SQ29,548 (1 microM), or the protein kinase C inhibitor GF109203X (5 microM) prevents platelet activation by microparticles. However, platelet microparticles fail to evoke an inositol phosphate response directly, via either of the cloned thromboxane receptor isoforms stably expressed in human embryonic kidney (HEK) 293 cells. Prelabeling platelets with [2H(8)] arachidonate was used to demonstrate platelet metabolism of the microparticle-derived substrate to thromboxane. Platelet microparticles can also induce expression of COX-2 and prostacyclin (PGI2) production, but not expression of COX-1, in human endothelial cells. These effects are prevented by pretreatment with actinomycin D (12 microM) or cycloheximide (5 microg/ml). Expression of COX-2 is again induced by the microparticle arachidonate fraction

  4. Myocardial perfusion scintigraphy and coronary disease risk factors in systemic lupus erythematosus

    PubMed Central

    Sella, E; Sato, E; Leite, W; Filho, J; Barbieri, A

    2003-01-01

    Objective: To evaluate the prevalence of myocardial perfusion abnormalities and the possible association between myocardial perfusion defects and traditional coronary artery disease (CAD) risk factors as well as systemic lupus erythematosus (SLE) related risk factors. Patients and methods: Female patients with SLE, disease duration >5 years, age 18–55 years, who had used steroids for at least one year were enrolled. Traditional CAD risk factors evaluated were arterial hypertension, diabetes mellitus, dyslipidaemia, postmenopausal status, smoking, obesity, and premature family CAD profile. Myocardial perfusion scintigraphy was evaluated by single photon emission computed tomography with technetium 99m-sestamibi at rest and after dipyridamole induced stress. Results: Eight two female patients with SLE without angina pectoris with mean (SD) age 37 (10) years, disease duration 127 (57) months, SLE Disease Activity Index (SLEDAI) score 6 (5), and SLICC/ACR-DI score 2 (2) were evaluated. Myocardial perfusion abnormalities were found in 23 patients (28%). The mean (SD) number of CAD risk factors was 2.2 (1.6). There was a significant positive correlation between age and number of CAD risk factors. Lower high density lipoprotein (HDL) cholesterol level showed a significant association with abnormal scintigraphy. Logistic regression analysis showed that lower HDL cholesterol level and diabetes mellitus were associated with myocardial perfusion abnormalities. Current vasculitis was also associated with abnormal scintigraphy. Conclusions: Lower HDL cholesterol level and diabetes mellitus have a significant influence on abnormal myocardial perfusion results found in asymptomatic patients with SLE. Current vasculitis was associated with abnormal myocardial scintigraphy. These data suggest that abnormal myocardial scintigraphy may be related to subclinical atherosclerosis. PMID:14583569

  5. Regulating billions of blood platelets: glycans and beyond

    PubMed Central

    Grozovsky, Renata; Giannini, Silvia; Falet, Hervé

    2015-01-01

    The human body produces and removes 1011 platelets daily to maintain a normal steady state platelet count. Platelet production must be regulated to avoid spontaneous bleeding or arterial occlusion and organ damage. Multifaceted and complex mechanisms control platelet production and removal in physiological and pathological conditions. This review will focus on different mechanisms of platelet senescence and clearance with specific emphasis on the role of posttranslational modifications. It will also briefly address platelet transfusion and the role of glycans in the clearance of stored platelets. PMID:26330242

  6. Regulating billions of blood platelets: glycans and beyond.

    PubMed

    Grozovsky, Renata; Giannini, Silvia; Falet, Hervé; Hoffmeister, Karin M

    2015-10-15

    The human body produces and removes 10(11) platelets daily to maintain a normal steady state platelet count. Platelet production must be regulated to avoid spontaneous bleeding or arterial occlusion and organ damage. Multifaceted and complex mechanisms control platelet production and removal in physiological and pathological conditions. This review will focus on different mechanisms of platelet senescence and clearance with specific emphasis on the role of posttranslational modifications. It will also briefly address platelet transfusion and the role of glycans in the clearance of stored platelets.

  7. Imipramine binding in subpopulations of normal human blood platelets

    SciTech Connect

    Arora, R.C.; Meltzer, H.Y.

    1984-02-01

    Imipramine binding was studied in platelet membranes isolated with different proportions of heavy (young) and light (old) platelets. The B/sub max/, a measure of the number of binding sites, was greater in the heavier platelets than in the light platelets. However, the dissociation constant K/sub d/ (a reflection of the affinity of imipramine binding) was greater in the lighter platelets compared to the heavy platelets. These results indicate that differences in K/sub d/ and B/sub max/ in particular membrane preparation, could be due to the differences in the relative proportion of heavy and light platelets.

  8. Analysis of aggregation of platelets in thrombosis

    NASA Astrophysics Data System (ADS)

    Ahuja, Suresh

    Platelets are key players in thrombus formation by first rolling over collagen bound von Willebrand factor followed by formation of a stable interaction with collagen. The first adhered platelets bind additional platelets until the whole injury is sealed off by a platelet aggregate. The coagulation system stabilizes the formed platelet plug by creating a tight fibrin network, and then wound contraction takes place because of morphological changes in platelets. Coagulation takes place by platelet activation and aggregation mainly through fibrinogen polymerization into fibrin fibers. The process includes multiple factors, such as thrombin, plasmin, and local shear-rate which regulate and control the process. Coagulation can be divided into two pathways: the intrinsic pathway and the extrinsic pathway. The intrinsic pathway is initiated by the exposure of a negatively charged. It is able to activate factor XII, using a complex reaction that includes prekallikrein and high-molecular-weight kininogen as cofactors.. Thrombin is the final enzyme that is needed to convert fibrinogen into fibrin. The extrinsic pathway starts with the exposure of tissue factor to the circulating blood, which is the major initiator of coagulation. There are several feedback loops that reinforce the coagulation cascade, resulting in large amounts of thrombin. It is dependent on the presence of pro-coagulant surfaces of cells expressing negatively charged phospholipids--which include phosphatidylserine (PS)--on their outer membrane. PS-bearing surfaces are able to increase the efficiency of the reactions by concentrating and co-localizing coagulation factors.. Aggregation of platelets are analyzed and compared to adhesion of platelet to erythrocyte and to endothelial cells. This abstract is replacing MAR16-2015-020003.

  9. Safety of platelet transfusion: past, present and future.

    PubMed

    Katus, M C; Szczepiorkowski, Z M; Dumont, L J; Dunbar, N M

    2014-08-01

    Platelet components became routinely available to many institutions in the late 1960s and since then utilization has steadily increased. Platelets are produced by three principal methods and their manufacturing process is regulated by multiple agencies. As the field of platelet transfusion has evolved, a broad array of strategies to improve platelet safety has developed. This review will explore the evolution of modern platelet component therapy, highlight the various risks associated with platelet transfusion and describe risk reduction strategies that have been implemented to improve platelet transfusion safety. In closing, the reader will be briefly introduced to select investigational platelet and platelet-mimetic products that have the potential to enhance platelet transfusion safety in the near future.

  10. Platelet-cytokine Complex Suppresses Tumour Growth by Exploiting Intratumoural Thrombin-dependent Platelet Aggregation

    PubMed Central

    Li, Yu-Tung; Nishikawa, Tomoyuki; Kaneda, Yasufumi

    2016-01-01

    Tumours constitute unique microenvironments where various blood cells and factors are exposed as a result of leaky vasculature. In the present study, we report that thrombin enrichment in B16F10 melanoma led to platelet aggregation, and this property was exploited to administer an anticancer cytokine, interferon-gamma induced protein 10 (IP10), through the formation of a platelet-IP10 complex. When intravenously infused, the complex reached platelet microaggregates in the tumour. The responses induced by the complex were solely immune-mediated, and tumour cytotoxicity was not observed. The complex suppressed the growth of mouse melanoma in vivo, while both platelets and the complex suppressed the accumulation of FoxP3+ regulatory T cells in the tumour. These results demonstrated that thrombin-dependent platelet aggregation in B16F10 tumours defines platelets as a vector to deliver anticancer cytokines and provide specific treatment benefits. PMID:27117228

  11. Secrets of platelet exocytosis – what do we really know about platelet secretion mechanisms?

    PubMed Central

    Golebiewska, Ewelina M; Poole, Alastair W

    2014-01-01

    Upon activation by extracellular matrix components or soluble agonists, platelets release in excess of 300 active molecules from intracellular granules. Those factors can both activate further platelets and mediate a range of responses in other cells. The complex microenvironment of a growing thrombus, as well as platelets' roles in both physiological and pathological processes, require platelet secretion to be highly spatially and temporally regulated to ensure appropriate responses to a range of stimuli. However, how this regulation is achieved remains incompletely understood. In this review we outline the importance of regulated secretion in thrombosis as well as in ‘novel’ scenarios beyond haemostasis and give a detailed summary of what is known about the molecular mechanisms of platelet exocytosis. We also discuss a number of theories of how different cargoes could be released in a tightly orchestrated manner, allowing complex interactions between platelets and their environment. PMID:24588354

  12. Decrease in platelet activating factor stimulated phosphoinositide turnover during storage of human platelets in plasma

    SciTech Connect

    Carter, M.G.; Shukla, S.D. )

    1987-05-01

    Human platelet concentrate from the American Red Cross Blood Center was stored at 24{degree}C in a shaker and aliquots were taken out at time intervals aseptically. Platelet activating factor (PAF) stimulated turnover of phosphoinositide (PPI) was monitored by assaying {sup 32}P incorporation into phosphoinositides using platelet rich plasma (PRP). Platelets in PRP were incubated with 1 {times} 10{sup {minus}7} M PAF at 37{degree}C with gentle shaking and after 5 min their lipids were extracted and analysed by TLC for {sup 32}P-phosphoinositides. The percent stimulation of {sup 32}P incorporation by PAF (over control) into PPI was approximately 250, 100, 60, 25 and 20 on days 1, 2, 3, 5 and 6, respectively. This indicated a dramatic decrease in PAF responsive turnover of platelet PPI during storage. These findings have important implications in relation to PAF receptor activity and viability of platelets at different periods of storage.

  13. [Glycoproteins, inherited diseases of platelets, and the role of platelets in wound healing].

    PubMed

    Nurden, Alan T; Nurden, Paquita

    2013-02-01

    Recognition that platelets have a glycocalyx rich in membrane glycoproteins prompted the discovery in France that inherited bleeding syndromes due to defects of platelet adhesion and aggregation were caused by deficiencies in major receptors at the platelet surface. Identification of the alpha IIb beta3 integrin prompted the development of powerful anti-thrombotic drugs that have gained worldwide use. Since these discoveries, the genetic causes of many other defects of platelet function and production have been elucidated, with the identification of an ADP receptor, P2 Y12, another widespread target for anti-thrombotic drugs. Discovery of the molecular basis of a rare disease of storage of biologically active proteins in platelet alpha-granules has been accompanied by the recognition of the roles of platelets in inflammation, the innate immune system and tissue repair, opening new avenues for therapeutic advances.

  14. Transcellular lipoxygenase metabolism between monocytes and platelets

    SciTech Connect

    Bigby, T.D.; Meslier, N. )

    1989-09-15

    We have examined the effects of co-culture and in vitro co-stimulation on lipoxygenase metabolism in monocytes and platelets. Monocytes were obtained from the peripheral blood of normal volunteers by discontinuous gradient centrifugation and adherence to tissue culture plastic. Platelets were obtained from the platelet-rich plasma of the same donor. When 10(9) platelets and 2.5 x 10(6) monocytes were co-stimulated with 1 microM A23187, these preparations released greater quantities of 12(S)-hydroxy-10-trans-5,8,14-cis-eicosatetraenoic acid, 5(S),12-(S)dihydroxy-6,10-trans-8,14-cis-eicosatetraenoic acid, and leukotriene C4, 5(S)-hydroxy-6(R)-S-glutathionyl-7,9-trans-11,14-cis-eicosatetraenoic (LTC4) when compared with monocytes alone. Release of arachidonic acid, 5-HETE, delta 6-trans-LTB4, and delta 6-trans-12-epi-LTB4 from monocytes was decreased in the presence of platelets. A dose-response curve was constructed and revealed that the above changes became evident when the platelet number exceeded 10(7). Dual radiolabeling experiments with 3H- and 14C-arachidonic acid revealed that monocytes provided arachidonic acid, 5-HETE, and LTA4 for further metabolism by the platelet. Monocytes did not metabolize platelet intermediates detectably. In addition, as much as 1.2 microM 12(S)-hydroxy-10-trans-5,8,14-cis-eicosatetraenoic acid and 12(S)-hydroperoxy-10-trans-5,8,14-cis-eicosatetraenoic acid had no effect on monocyte lipoxygenase metabolism. Platelets were capable of converting LTA4 to LTC4, but conversion of LTA4 to LTB4 was not detected. We conclude that the monocyte and platelet lipoxygenase pathways undergo a transcellular lipoxygenase interaction that differs from the interaction of the neutrophil and platelet lipoxygenase pathways. In this interaction monocytes provide intermediate substrates for further metabolic conversion by platelets in an unidirectional manner.

  15. Flow cytometric assessment of activation of peripheral blood platelets in dogs with normal platelet count and asymptomatic thrombocytopenia.

    PubMed

    Żmigrodzka, M; Guzera, M; Winnicka, A

    2016-01-01

    Platelets play a crucial role in hemostasis. Their activation has not yet been evaluated in healthy dogs with a normal and low platelet count. The aim of this study was to determine the influence of activators on platelet activation in dogs with a normal platelet count and asymptomatic thrombocytopenia. 72 clinically healthy dogs were enrolled. Patients were allocated into three groups. Group 1 consisted of 30 dogs with a normal platelet count, group 2 included 22 dogs with a platelet count between 100 and 200×109/l and group 3 consisted of 20 dogs with a platelet count lower than 100×109/l. Platelet rich-plasma (PRP) was obtained from peripheral blood samples using tripotassium ethylenediaminetetraacetic acid (K3-EDTA) as anticoagulant. Next, platelets were stimulated using phorbol-12-myristate-13-acetate or thrombin, stabilized using procaine or left unstimulated. The expression of CD51 and CD41/CD61 was evaluated. Co-expression of CD41/CD61 and Annexin V served as a marker of platelet activation. The expression of CD41/CD61 and CD51 did not differ between the 3 groups. Thrombin-stimulated platelets had a significantly higher activity in dogs with a normal platelet count than in dogs with asymptomatic thrombocytopenia. Procaine inhibited platelet activity in all groups. In conclusion, activation of platelets of healthy dogs in vitro varied depending on the platelet count and platelet activator.

  16. Activated platelets inhibit hepatocellular carcinoma cell differentiation and promote tumor progression via platelet-tumor cell binding

    PubMed Central

    Xu, Jingchao; Li, Bing; Liu, Yue-Jian; Cheng, Cheng; Zhou, Chunyan; Zhao, Yongfu; Liu, Yang

    2016-01-01

    Lack of differentiation in hepatocellular carcinoma (HCC) is associated with increased circulating platelet size. We measured platelet activation and plasma adenosine diphosphate (ADP) levels in HCC patients based on differentiation status. Local platelet accumulation and platelet-hepatoma cell binding were measured using immunohistochemistry (IHC) or flow cytometry. Using a xenograft assay in NON/SCID mice, we tested the effects of the anti-platelet drug clopidogrel on platelet activation, platelet infiltration, platelet-tumor cell binding and tumor cell differentiation. HCC patients with poor differentiation status displayed elevated platelet activation and higher ADP levels. Platelets accumulated within poorly differentiated tissues and localized at hepatoma cell membranes. Platelet-tumor cell binding was existed in carcinoma tissues, largely mediated by P-selectin on platelets. NOD/SCID mice with xenograft tumors also exhibited increased platelet activation and platelet-tumor cell binding. Clopidogrel therapy triggered hepatoma cell differentiation by attenuating platelet activation and platelet-tumor cell binding. TCF4 knockdown promoted HepG-2 cell differentiation and inhibited tumor formation, and TCF4 could be the potential downstream target for clopidogrel therapy. PMID:27542264

  17. The growth of charged platelets.

    PubMed

    Labbez, C; Jönsson, Bo; Woodward, Cliff; Nonat, A; Delhorme, M

    2014-11-21

    Growth models of charged nanoplatelets are investigated with Monte Carlo simulations and simple theory. In a first model, 2-dimensional simulations in the canonical ensemble are used to demonstrate that the growth of a single weakly charged platelet could be limited by its own internal repulsion. The short range attractive interaction in the crystal is modeled with a square well potential while the electrostatic interactions are described with a screened Coulomb potential. The qualitative behavior of this case can also be described by simply balancing the attractive crystal energy with the screened Coulomb repulsion between the crystal sites. This repulsion is a free energy term dominated by counterion entropy and of course reduced by added salt. For a strongly coupled system, that is with high charge density and divalent counterions as in calcium silicate hydrate, the main product of cement hydration, the screened Coulomb approximation becomes inadequate and the growth behavior has to be described with the full primitive model. In this case, the energetic interactions become relatively more important and the entropy of the system plays a minor role. As a consequence, the electrostatic interactions gradually become less of a hindrance for aggregation and in extreme cases electrostatics actually promote the growth. This is manifested as an increased aggregation with, for example, increasing surface charge density. In the presence of divalent calcium ions and at the high negative surface charge density typical for calcium silicate hydrate, electrostatic interactions are not a hindrance for an infinite growth of the particles. By combining experimental and simulated data we can show that the limited sized platelets found in cement paste is due to a very fast nucleation rate compared to the growth rate.

  18. Geometric design of microfluidic chambers: platelet adhesion versus accumulation.

    PubMed

    Casa, Lauren D C; Ku, David N

    2014-02-01

    Arterial, platelet-rich thrombosis depends on shear rates and integrin binding to either a collagen surface or to the growing thrombus, which are mechanistically different. In general, small microfluidic test sections may favor platelet-surface adhesion without testing for the primary mode of intra-arterial thrombosis, i.e. platelet-platelet bonding and accumulation. In the present report, the ratio of platelet-platelet to platelet-surface interactions, R, and the percentage of platelet-platelet interactions, P, are estimated using an analytical approach for circular and rectangular test sections. Results show that the test section geometry strongly affects both R and P, with test section height in low-aspect ratio channels or diameter greater than 90 μm dominated by platelet-platelet interactions (R >10). Increasing rectangular test section aspect ratio decreases the required height. R increases linearly while P approaches 100 % asymptotically with increasing channel dimension. Analysis of platelet shape shows that the assumption of spherical platelets has a small effect on R compared to discoid platelets adhering flat against test section wall. However, an increase in average platelet volume resulted in a large decrease in R. Nonetheless, Monte Carlo simulations of a typical distribution of human platelet sizes show intrasubject variation in platelet size has only a 10 % net effect on R. Finally, experiments of thrombus formation show that platelet-surface lag times and platelet-platelet accumulation are similar for rectangular microfluidic test sections and round test sections when R >10. The findings show that the size of a microfluidic test section should be carefully considered in studies of cell-cell accumulation versus cell-surface adhesion.

  19. Expression and function of purinergic receptors in platelets from apheresis-derived platelet concentrates

    PubMed Central

    Koessler, Juergen; Weber, Katja; Koessler, Angela; Yilmaz, Pinar; Boeck, Markus; Kobsar, Anna

    2016-01-01

    Background The storage of platelets affects platelet integrity and functionality, a process named platelet storage lesion (PSL). Reduced adenosine diphosphate (ADP)-induced platelet aggregation is a typical manifestation of PSL. However, the role of ADP receptors in this context has not been evaluated yet. The aim of this study was, therefore, to investigate surface expression and function of the purinergic receptors P2Y1, P2Y12 and P2X1 in stored platelet concentrates. Material and methods Platelets were obtained from venous whole blood and from apheresis-derived platelet concentrates stored for 0, 2 and 5 days. Purinergic receptor expression was measured by flow cytometry and western blot analysis. Receptor function was determined by calcium-induced fluorescence (P2Y1 and P2X1) or by flow cytometric measurement of the platelet reactivity index (P2Y12). Results The basal surface expression and total content of purinergic receptors remained unchanged throughout storage. After an initial reduction during apheresis, P2X1-mediated calcium flux was maintained, whereas the P2Y1-mediated increase of calcium flux gradually decreased during the course of storage. In contrast, the platelet reactivity index was comparable in freshly obtained and stored platelets. Discussion The function of the P2Y12 receptor is maintained during storage of apheresis-derived platelet concentrates. However, the impairment of P2X1 and especially of P2Y1 receptor function indicated by decreased receptor-mediated calcium flux is an important mechanism contributing to reduced ADP responsiveness of stored platelets. PMID:26674810

  20. Platelet Integrin αIIbβ3 Inhibitor Rescues Progression of Apoptosis in Human Platelets

    PubMed Central

    Zhu, Jie; Wang, Qinghang; Nie, Yumei; Yan, Rong; Dai, Kesheng; Zhou, Birong

    2016-01-01

    Background Apoptosis plays an important role in the physiology of platelet function. We aimed to detect the effect of the platelet integrin αIIbβ3 inhibitor, tirofiban, on apoptotic events, including mitochondrial inner-membrane potential (ΔΨm), phosphatidylserine (PS) exposure on platelet surface, and the generation of reactive oxygen species (ROS), when washed platelets were stimulated with thrombin. Material/Methods The study included washed platelets from healthy humans, divided into 4 groups: vehicle, and tirofiban (0.05 μg/ml, 0.25 μg/ml, and 0.5 μg/ml). Platelets were pretreated with vehicle or tirofiban and incubated at 37°C with agitation for 6 h and 24 h. Before thrombin addition, the vehicle group divided into 2 equal groups. Except one vehicle group, the other 4 groups were all stimulated with thrombin (1 U/ml) for 30 min at 37°C. Using flow cytometry, we studied the ΔΨm and PS exposure on platelet surfaces, and the generation of ROS in platelets. Results We observed that at the time of 6 h and 24 h, thrombin-stimulated vehicle platelets induced significant depolarization of ΔΨm, higher PS exposure, and increased ROS production compared with the vehicle group (P<0.01). However, the tirofiban group had significantly more recovery of ΔΨm, PS exposure, and ROS production compared with the thrombin group (P<0.01). Conclusions The platelet integrin αIIbβ3 inhibitor, tirofiban, inhibits the depolarization of ΔΨm, PS exposure on platelet surface, and ROS production when stimulated with thrombin. These results suggest that αIIbβ3 inhibitor inhibits the initiation of apoptosis in platelets, showing a potential clinical application of tirofiban as an apoptosis inhibitor. PMID:27827357

  1. Single-step separation of platelets from whole blood coupled with digital quantification by interfacial platelet cytometry (iPC).

    PubMed

    Basabe-Desmonts, L; Ramstrom, S; Meade, G; O'Neill, S; Riaz, A; Lee, L P; Ricco, A J; Kenny, D

    2010-09-21

    We report the efficient single-step separation of individual platelets from unprocessed whole blood, enabling digital quantification of platelet function using interfacial platelet cytometry (iPC) on a chip. iPC is accomplished by the precision micropatterning of platelet-specific protein surfaces on solid substrates. By separating platelets from whole blood using specific binding to protein spots of a defined size, iPC implements a simple incubate-and-rinse approach, without sample preparation, that enables (1) the study of platelets in the physiological situation of interaction with a protein surface, (2) the choice of the number of platelets bound on each protein spot, from one to many, (3) control of the platelet-platelet distance, including the possibility to study noninteracting single platelets, (4) digital quantification (counting) of platelet adhesion to selected protein matrices, enabling statistical characterization of platelet subpopulations from meaningfully large numbers of single platelets, (5) the study of platelet receptor expression and spatial distribution, and (6) a detailed study of the morphology of isolated single platelets at activation levels that can be manipulated. To date, we have demonstrated 1-4 of the above list. Platelets were separated from whole blood using iPC with fibrinogen, von Willebrand factor (VWF), and anti-CD42b antibody printed "spots" ranging from a fraction of one to several platelet diameters (2-24 μm). The number of platelets captured per spot depends strongly on the protein matrix and the surface area of the spot, together with the platelet volume, morphology, and activation state. Blood samples from healthy donors, a May-Hegglin-anomaly patient, and a Glanzmann's Thrombasthenia patient were analyzed via iPC to confirm the specificity of the interaction between protein matrices and platelets. For example, the results indicate that platelets interact with fibrinogen spots only through the fibrinogen receptor (

  2. Evaluation of platelet thromboxane radioimmunoassay method to measure platelet life-span: Comparison with /sup 111/indium-platelet method

    SciTech Connect

    Vallabhajosula, S.; Machac, J.; Badimon, L.; Lipszyc, H.; Goldsmith, S.J.; Fuster, V.

    1985-05-01

    The platelet activation during radiolabeling in vitro with Cr-51 and In-111 may affect the platelet life-span (PLS) in vivo. A new RIA method to measure PLS is being evaluated. Aspirin inhibits platelet thromboxane (TxA/sub 2/) by acetylating cyclooxygenase. The time required for the TxA/sub 2/ levels to return towards control values depends on the rate of new platelets entering circulation and is a measure of PLS. A single dose of aspirin (150mg) was given to 5 normal human subjects. Blood samples were collected for 2 days before aspirin and daily for 10 days. TxA/sub 2/ production in response to endogenous thrombin was studied by allowing 1 ml blood sample to clot at 37/sup 0/C for 90 min. Serum TxB/sub 2/ (stable breakdown product of Tx-A/sub 2/) levels determined by RIA technique. The plot of TxB/sub 2/ levels (% control) against time showed a gradual increase. The PLS calculated by linear regression analysis assuming a 2-day lag period before cyclooxygenase recovery is 9.7 +- 2.37. In the same 5 subjects, platelets from a 50ml blood sample were labeled with /sup 111/In-tropolone in 2 ml autologous plasma. Starting at 1 hr after injection of labeled platelets, 10 blood samples were obtained over a 8 day period. The PLS calculated based on a linear regression analysis is 10.2 +. 1.4. The PLS measured from the rate of platelet disappearance from circulation and the rate of platelet regeneration into circulation are quite comparable in normal subjects. TxA/sub 2/ regeneration RIA may provide a method to measure PLS without administering radioactivity to patient.

  3. Understanding platelet generation from megakaryocytes: implications for in vitro–derived platelets

    PubMed Central

    Sim, Xiuli; Poncz, Mortimer; Gadue, Paul

    2016-01-01

    Platelets are anucleate cytoplasmic discs derived from megakaryocytes that circulate in the blood and have major roles in hemostasis, thrombosis, inflammation, and vascular biology. Platelet transfusions are required to prevent the potentially life-threatening complications of severe thrombocytopenia seen in a variety of medical settings including cancer therapy, trauma, and sepsis. Platelets used in the clinic are currently donor-derived which is associated with concerns over sufficient availability, quality, and complications due to immunologic and/or infectious issues. To overcome our dependence on donor-derived platelets for transfusion, efforts have been made to generate in vitro–based platelets. Work in this area has advanced our understanding of the complex processes that megakaryocytes must undergo to generate platelets both in vivo and in vitro. This knowledge has also defined the challenges that must be overcome to bring in vitro–based platelet manufacturing to a clinical reality. This review will focus on our understanding of committed megakaryocytes and platelet release in vivo and in vitro, and how this knowledge can guide the development of in vitro–derived platelets for clinical application. PMID:26787738

  4. Anticoagulation inhibits tumor cell-mediated release of platelet angiogenic proteins and diminishes platelet angiogenic response.

    PubMed

    Battinelli, Elisabeth M; Markens, Beth A; Kulenthirarajan, Rajesh A; Machlus, Kellie R; Flaumenhaft, Robert; Italiano, Joseph E

    2014-01-02

    Platelets are a reservoir for angiogenic proteins that are secreted in a differentially regulated process. Because of the propensity for clotting, patients with malignancy are often anticoagulated with heparin products, which paradoxically offer a survival benefit by an unknown mechanism. We hypothesized that antithrombotic agents alter the release of angiogenesis regulatory proteins from platelets. Our data revealed that platelets exposed to heparins released significantly decreased vascular endothelial growth factor (VEGF) in response to adenosine 5'-diphosphate or tumor cells (MCF-7 cells) and exhibited a decreased angiogenic potential. The releasate from these platelets contained decreased proangiogenic proteins. The novel anticoagulant fondaparinux (Xa inhibitor) demonstrated a similar impact on the platelet angiogenic potential. Because these anticoagulants decrease thrombin generation, we hypothesized that they disrupt signaling through the platelet protease-activated receptor 1 (PAR1) receptor. Addition of PAR1 antagonists to platelets decreased VEGF release and angiogenic potential. Exposure to a PAR1 agonist in the presence of anticoagulants rescued the angiogenic potential. In vivo studies demonstrated that platelets from anticoagulated patients had decreased VEGF release and angiogenic potential. Our data suggest that the mechanism by which antithrombotic agents increase survival and decrease metastasis in cancer patients is through attenuation of platelet angiogenic potential.

  5. Platelets and erythrocyte-bound platelets bind infectious HIV-1 in plasma of chronically infected patients.

    PubMed

    Beck, Zoltan; Jagodzinski, Linda L; Eller, Michael A; Thelian, Doris; Matyas, Gary R; Kunz, Anjali N; Alving, Carl R

    2013-01-01

    Chronic HIV-1 infection is associated with persistent viremia in most patients, but it remains unclear how free virus may survive the potential hostile effects of plasma. We investigated whether sites might exist on the surfaces of circulating blood cells for protection of infectious HIV-1 particles. Red blood cells (RBC) either from blood of uninfected normal individuals, or from blood obtained without EDTA from chronically infected HIV-1 patients, invariably contained a small number of RBC having attached platelets as determined by flow cytometry, light microscopy, and immunofluorescence microscopy. After mixing normal RBC with platelet-rich plasma, discrete populations of RBC, platelets, and complexes of platelets attached to RBC were purified by fluorescence-activated cell sorting. Upon incubation of purified cells or platelets with HIV-1 followed by washing and co-incubation with CD4-positive peripheral blood mononuclear cells (PBMC), platelets, and platelet-RBC complexes, but not platelet-free RBC, caused infection of PBMC. Infection was prevented by pre-treating the platelet-RBC complexes with EDTA. Plasma and RBC (comprising a RBC/platelet-RBC mixture) from chronically infected patients with low viral loads were also co-incubated with PBMC ex vivo to determine the presence of infectious HIV-1. All freshly isolated plasmas from the HIV-1-infected donors, obtained in the absence of anticoagulant, were noninfectious. Interestingly, the RBC from most of the patients caused cell-cell infection of PBMC that was prevented by stripping the RBC with EDTA. A monoclonal antibody to DC-SIGN partially inhibited cell-cell HIV-1 infection of PBMC by normal RBC pre-incubated with platelets and HIV-1. We conclude: (a) platelet-free EDTA-free plasma from chronically infected HIV-1 patients, although containing viral RNA, is an environment that lacks detectable infectious HIV-1; (b) platelets and platelet-RBC complexes, but not purified RBC, bind infectious HIV-1; (c) DC

  6. Genotyping for human platelet alloantigen polymorphisms: applications in the diagnosis of alloimmune platelet disorders.

    PubMed

    Curtis, Brian R

    2008-09-01

    Molecular typing for platelet allelic polymorphisms was first made possible by discovery of the HPA-1a/1b single nucleotide polymorphism in 1989. Since then, six other biallelic human platelet antigen (HPA) systems have been determined and can be typed using genomic DNA. The introduction of polymerase chain reaction enabled development of several different assays including polymerase chain reaction-sequence-specific primer, melting curve analysis by LightCycler, and 5'-nuclease assays. More recently, multiplex polymerase chain reaction has allowed for the development of high-throughput assays for genotyping large numbers of patients and blood donors for not only platelet gene polymorphisms but also for those of other blood cell genes. Platelet genotyping is a valuable tool in confirming platelet antigen specificities of alloantibodies detected in patient sera to complement the clinical history in the diagnosis of alloimmune platelet disorders such as fetal and neonatal alloimmune thrombocytopenia (FNAIT), posttransfusion purpura, and multiplatelet transfusion refractoriness. In addition, it has made possible prenatal platelet typing of the fetus in suspected cases of FNAIT and large-scale blood donor typing for provision of antigen-negative platelets to transfuse highly alloimmunized patients. Platelet genotyping may also someday prove important as an aid in determining the relative risk of patients for various thrombotic disorders.

  7. Geldanamycin disrupts platelet-membrane structure, leading to membrane permeabilization and inhibition of platelet aggregation.

    PubMed Central

    Suttitanamongkol, S; Gear, A R; Polanowska-Grabowska, R

    2000-01-01

    Geldanamycin (GA), a benzoquinoid ansamycin antibiotic, has been used as a tyrosine kinase inhibitor and an anti-tumour agent and is known to bind to heat-shock protein 90. In the present study on human platelets we have found that GA inhibited platelet aggregation induced by ADP, thrombin and the thrombin-receptor-activating peptide and caused platelet plasma-membrane damage, detected by leakage of adenine nucleotides as well as serotonin. Scanning electron microscopy (SEM) revealed that platelet exposure to GA led to the formation of holes or fenestrations in the platelet plasma membrane, confirming GA's ability to initiate membrane damage. In addition, GA itself caused both the dephosphorylation and phosphorylation of proteins in resting platelets and prevented agonist-induced phosphorylation of pleckstrin, the 20-kDa myosin light chain and other proteins. Another ansamycin, herbimycin A, also inhibited platelet aggregation, but caused minimal membrane permeabilization, as detected by (3)H release from platelets labelled previously with [(3)H]adenine, and much less membrane damage, revealed by SEM. Overall, GA is able to disrupt membrane structure and inhibit platelet aggregation, an ability which may be linked to alterations in the activity of protein kinases and phosphatases. PMID:10620508

  8. Platelet lipidomics: a modern day perspective on lipid discovery and characterization in platelets

    PubMed Central

    O’Donnell, Valerie B; Murphy, Robert C.; Watson, Steve P

    2014-01-01

    Lipids are diverse families of biomolecules that perform essential structural and signaling roles in platelets. Their formation and metabolism is tightly controlled by enzymes and signal transduction pathways, and their dysregulation leads to significant defects in platelet function and disease. Platelet activation is associated with significant changes to membrane lipids, and formation of diverse bioactive lipids that play essential roles in hemostasis. In recent years, new generation mass spectrometry analysis of lipids (termed “lipidomics”) has begun to alter our understanding of how these molecules participate in key cellular processes. While, the application of lipidomics to platelet biology is still in its infancy, seminal earlier studies have shaped our knowledge of how lipids regulate key aspects of platelet biology, including aggregation, shape change, coagulation and degranulation, as well as how lipids generated by platelets influence other cells, such as leukocytes and the vascular wall, and thus how they regulate hemostasis, vascular integrity and inflammation, as well as contribute to pathologies including arterial/deep vein thrombosis and atherosclerosis. This review will provide a brief historical perspective on the characterization of lipids in platelets, then an overview of the new generation lipidomic approaches, their recent application to platelet biology, and future perspectives for research in this area. The major platelet-regulatory lipid families, their formation, metabolism, and their role in health and disease, will be summarized. PMID:24677238

  9. Platelet utilization: a Canadian Blood Services research and development symposium.

    PubMed

    Webert, Kathryn E; Alam, Asim Q; Chargé, Sophie B; Sheffield, William P

    2014-04-01

    Considerable progress has been made in recent years in understanding platelet biology and in strengthening the clinical evidence base around platelet transfusion thresholds and appropriate platelet dosing. Platelet alloimmunization rates have also declined. Nevertheless, controversies and uncertainties remain that are relevant to how these products can best be used for the benefit of platelet transfusion recipients. Platelets are unique among the blood products directly derived from whole blood or apheresis donations in requiring storage, with shaking, at ambient temperature. Storage is accordingly constrained between the need to limit the growth of any microbes in the product and the need to minimize losses in platelet function associated with storage. Proteomic and genomic approaches are being applied to the platelet storage lesion. Platelet inventory management is made challenging by these constraints. Although bacterial screening has enhanced the safety of platelet transfusions, pathogen reduction technology may offer further benefits. Continuing clinical investigations are warranted to understand the value of transfusing platelets prophylactically or only in response to bleeding in different patient groups and how best to manage the most grievously injured trauma patients. Patients refractory to platelet transfusions also require expert clinical management. The engineering of platelet substitute products is an active area of research, but considerable hurdles remain before any clinical uses may be contemplated. Roles for platelets in biological areas distinct from hemostasis are also emerging. Platelet utilization is variably affected by all of the above factors, by demographic changes, by new medications, and by new patient care approaches.

  10. Desmopressin (DDAVP) improves recruitment of activated platelets to collagen but simultaneously increases platelet endothelial interactions in vitro.

    PubMed

    Calmer, Simone; Ferkau, Annika; Larmann, Jan; Johanning, Kai; Czaja, Eliana; Hagl, Christian; Echtermeyer, Frank; Goudeva, Lilia; Heuft, Hans-Gert; Theilmeier, Gregor

    2014-01-01

    Platelet dysfunction can cause clinically relevant bleeding. Treatment with DDAVP is advocated for this condition. DDAVP increases von Willebrand factor (VWF) on endothelial cells (ECs) and in plasma. VWF could facilitate platelet deposition on subendothelial collagen. VWF also facilitates platelet/EC interactions. Therefore DDAVP could precipitate thromboembolic events. We used a flow chamber model to study in vitro and ex vivo if DDAVP alters recruitment of platelets to EC and collagen. Resting or TRAP-activated platelets and EC were treated individually or simultaneously with 0.4 ng/ml DDAVP. Fluorophor-labeled platelets (10(6)/ml) were resuspended in reconstituted blood and superfused across EC and collagen in an in vitro flow chamber model at arterial shear (320 s(-1)). Adhesion of platelets to the respective surface was recorded fluorescence microscopically and platelet covered area was assessed. TRAP significantly induced adhesiveness of platelets for collagen and EC. DDAVP pretreatment of platelets did not affect adhesiveness of resting or TRAP-activated platelets for collagen or EC. Adhesiveness of resting but not TRAP-activated platelets was induced on DDAVP-treated EC. DDAVP-conditioned EC supernatant contained vWF and significantly increased platelet deposition on collagen. Platelets from patients with clinically suspected platelet dysfunction undergoing aortic valve replacement exhibited decreased platelet deposition on collagen surfaces. In summary, our data confirm that DDAVP can induce release of platelet adhesion promoting factors from EC, which is most likely vWF. DDAVP has no direct effect on platelets. Blood samples from DDAVP-treated patients do not exhibit significantly augmented platelet deposition on collagen ex vivo. This influence of released promoting factors might cause an increase of undesirable interactions of platelets with EC.

  11. Genetics Home Reference: gray platelet syndrome

    MedlinePlus

    ... platelets, which are blood cell fragments involved in blood clotting. People with this condition tend to bruise easily ... factors and other proteins that are important for blood clotting and wound healing . In response to an injury ...

  12. 21 CFR 640.20 - Platelets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... one unit of blood and resuspended in an appropriate volume of original plasma, as prescribed in § 640.24(d). (b) Source. The source material for Platelets is plasma which may be obtained by whole...

  13. 21 CFR 640.20 - Platelets.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... one unit of blood and resuspended in an appropriate volume of original plasma, as prescribed in § 640.24(d). (b) Source. The source material for Platelets is plasma which may be obtained by whole...

  14. 21 CFR 640.20 - Platelets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... one unit of blood and resuspended in an appropriate volume of original plasma, as prescribed in § 640.24(d). (b) Source. The source material for Platelets is plasma which may be obtained by whole...

  15. 21 CFR 640.20 - Platelets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... one unit of blood and resuspended in an appropriate volume of original plasma, as prescribed in § 640.24(d). (b) Source. The source material for Platelets is plasma which may be obtained by whole...

  16. 21 CFR 640.20 - Platelets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... one unit of blood and resuspended in an appropriate volume of original plasma, as prescribed in § 640.24(d). (b) Source. The source material for Platelets is plasma which may be obtained by whole...

  17. Platelet factor 4: a chemokine enigma.

    PubMed

    Slungaard, Arne

    2005-06-01

    Platelet factor 4 (PF4) is a platelet alpha-granule protein sequenced over 25 years ago that is a founding member of the C-X-C chemokine family, yet its physiologic function has yet to be definitively established. Initial investigations focused on possible procoagulant roles for PF4 in platelet function and plasmatic coagulation. Subsequent in vitro studies have, however, described a puzzling array of other apparently unrelated biologic functions, including inhibition of angiogenesis and hematopoiesis, promotion of neutrophil adhesion, and activation, enhancement of oxy-LDL binding to the LDL receptor and stimulation of anti-coagulant activated protein C generation by the thrombomodulin/protein C system. Preliminary studies with a just-described PF4 knockout mouse line support a role for PF4 in platelet-dependent thrombosis in vivo.

  18. [Platelet transfusion role in neonatal immune thrombocytopenia].

    PubMed

    Petermann, R

    2016-11-01

    Neonatal immune thrombocytopenia represent less than 5% of cases of early thrombocytopenia (early-onset<72hours post-delivery). As in adults, thrombocytopenia in neonates is defined as a platelet count less than 150G/L. They are either auto- or allo-immune. Thrombocytopenia resulting from transplacental passage of maternal antibodies directed to platelet membrane glycoproteins can be severe. The major complication of severe thrombocytopenia is bleeding and particularly intra-cranial haemorrhage and neurologic sequelea following. However, auto- and allo-immune thrombocytopenia have very different characteristics including the treatment management. In fact, this treatment is based on platelet transfusion associated or not to intravenous immunoglobulin administration. The purpose of this article is to remind platelet transfusion's place in neonatal immune thrombocytopenia in terms of recently published French guidelines and international practices.

  19. Propranolol modifies platelet serotonergic mechanisms in rats.

    PubMed

    Zółtowski, R; Pawlak, R; Matys, T; Pietraszek, M; Buczko, W

    2002-06-01

    Though the mechanisms for the vascular actions of vasodilatory beta-blockers are mostly determined, some of their interactions with monoaminergic systems are not elucidated. Because there are evidences supporting a possible involvement of serotonin (5-HT) in the actions of beta-blockers, we studied the effect of propranolol on peripheral serotonergic mechanisms in normotensive and Goldblatt two-kidney - one clip (2K1C) hypertensive rats. In both groups of animals propranolol decreased systolic blood pressure, significantly increased whole blood serotonin concentration and at the same time it decreased platelet serotonin level. The uptake of the amine by platelets from hypertensive animals was lower than that of normotensive animals and it was decreased by propranolol only in the latter. In both groups propranolol inhibited potentiation of ADP-induced platelet aggregation by serotonin. In conclusion, this study provides evidence that propranolol modifies platelet serotonergic mechanisms in normotensive and renal hypertensive rats.

  20. Platelets in pulmonary vascular physiology and pathology

    PubMed Central

    Kroll, Michael H.; Afshar-Kharghan, Vahid

    2012-01-01

    Almost a trillion platelets pass through the pulmonary circulation every minute, yet little is known about how they support pulmonary physiology or contribute to the pathogenesis of lung diseases. When considering this conundrum, three questions jump out: Does platelet production in the lungs occur? Why does severe thrombocytopenia—which undercuts the principal physiological role of platelets to effect hemostasis—not lead to pulmonary hemorrhage? Why does atherothrombosis—which platelets initiate, maintain, and trigger is other critically important arterial beds—not develop in the pulmonary artery? The purpose of this review is to explore these and derivative questions by providing data within a conceptual framework that begins to organize a subject that is largely unassembled. PMID:23130099

  1. Platelet miRNAs and cardiovascular diseases.

    PubMed

    Fuentes, Eduardo; Palomo, Iván; Alarcón, Marcelo

    2015-07-15

    Activated platelets play a critical role in the acute complications of atherosclerosis that cause life-threatening ischemic events at late stages of the disease. The miRNAs are a novel class of small, non-coding RNAs that play a significant role in both inflammatory and cardiovascular diseases. The miRNAs are known to be present in platelets and exert important regulatory functions. Here we systematically examine the genes that are regulated by platelet miRNAs (miRNA-223,miRNA-126,miRNA-21, miRNA-24 and miRNA-197) and the association with cardiovascular disease risks. Platelet-secreted miRNAs could be novel biomarkers associated with cardiovascular diseases.

  2. Effects of drugs on platelet function.

    PubMed

    Morse, E E

    1977-01-01

    Numerous drugs and chemicals affect the function of human blood platelets. The mechanism of action of some medications is partly understood. Aspirin is the most frequently involved drug. It appears to interfere with the platelet release reaction by acetylation of a platelet membrane protein which may be involved in the synthesis of prostaglandins. Other anti-inflammatory drugs, including indomethacin, phenylbutazone, ibuprophen (Motrin) and clonixin, also interfere with the release reaction but have a shorter acting course than aspirin. Some drugs stimulate adenylcyclase (gliclazide) or block phosphodiesterase, (dipyridamole, caffeine) both of which actions lead to an increase in adenosine cyclic 3':5' monophosphate (cAMP) and decrease aggregation by adenosine diphosphate (ADP). These interactions should be known to clinical scientists since patients using these medicaments may manifest abnormal platelet function tests in the laboratory and mild hemorrhagic syndromes in the clinic.

  3. Acid soluble, pepsin resistant platelet aggregating material

    SciTech Connect

    Schneider, M.D.

    1982-08-31

    Disclosed is an acid soluble, pepsin resistant, platelet aggregating material isolated from equine arterial tissue by extraction with dilute aqueous acid. The method of isolation and use to control bleeding are described. 4 figs.

  4. [Blood platelets and asthma caused by aspirin].

    PubMed

    Joseph, M; Capron, A; Ameisen, J C; Martinot, J B; Tonnel, A B

    1987-10-01

    Platelets isolated from patients with aspirin-induced asthma (ASA patients) react abnormally in vitro to aspirin and to non-steroid anti-inflammatory drugs (NSAID), by generating cytocidal molecules, that can kill parasitic larvae and to oxygen-dependent free radicles, which may be detected by chemiluminescence, although these drugs do not have a similar effect on platelets from normal donors or allergic asthmatics. The abnormality appears to be associated with the inhibiting properties of NSAID and aspirin on the cyclo-oxygenase pathway, that leads to a defect of the binding of prostaglandin endoperoxide PGH2 to its receptors on the platelet membrane. In addition, another metabolite from the lipoxygenase pathway which is at present poorly defined seems to participate in the anomaly. Sodium salicylate, a naturally produced catabolite of aspirin, that is well-tolerated by ASA patients, inhibits the abnormal response of the platelets and this opens new perspectives in the management of aspirin-sensitive intolerance.

  5. Platelet-Derived Serotonin Mediates Liver Regeneration

    NASA Astrophysics Data System (ADS)

    Lesurtel, Mickael; Graf, Rolf; Aleil, Boris; Walther, Diego J.; Tian, Yinghua; Jochum, Wolfram; Gachet, Christian; Bader, Michael; Clavien, Pierre-Alain

    2006-04-01

    The liver can regenerate its volume after major tissue loss. In a mouse model of liver regeneration, thrombocytopenia, or impaired platelet activity resulted in the failure to initiate cellular proliferation in the liver. Platelets are major carriers of serotonin in the blood. In thrombocytopenic mice, a serotonin agonist reconstituted liver proliferation. The expression of 5-HT2A and 2B subtype serotonin receptors in the liver increased after hepatectomy. Antagonists of 5-HT2A and 2B receptors inhibited liver regeneration. Liver regeneration was also blunted in mice lacking tryptophan hydroxylase 1, which is the rate-limiting enzyme for the synthesis of peripheral serotonin. This failure of regeneration was rescued by reloading serotonin-free platelets with a serotonin precursor molecule. These results suggest that platelet-derived serotonin is involved in the initiation of liver regeneration.

  6. Platelet Disorders: MedlinePlus Health Topic

    MedlinePlus

    ... disorders depends on the cause. NIH: National Heart, Lung, and Blood Institute Start Here Platelets (University of Oklahoma Health ... the Signs and Symptoms of Thrombocytopenia? (National Heart, Lung, and Blood Institute) Diagnosis and Tests Heparin-Induced Thrombocytopenia Antibody ...

  7. Improving the bacteriological safety of platelet transfusions.

    PubMed

    Blajchman, Morris A; Goldman, Mindy; Baeza, Federico

    2004-01-01

    Despite the increased application of aseptic techniques for blood collection and the preparation of platelet concentrates, morbidity and mortality arising from the transfusion of bacterially contaminated allogeneic platelet products persist. This problem exists because stored platelet concentrates represent a nearly ideal growth medium for bacteria and because they are stored at temperatures (22 degrees +/- 2 degrees C) that facilitate bacterial growth. The presence of bacteria in blood components including platelets has been a problem for many decades and currently is the most common microbiological cause of transfusion-associated morbidity and mortality. A variety of strategies have been devised and/or proposed in an attempt to try to reduce the risk of transfusion-associated sepsis. These include pretransfusion bacterial detection, efforts to reduce the likelihood of bacterial contamination, the optimization of blood product processing and storage, reducing recipient exposure, and the introduction of pathogen inactivation methodology. With regard to doing bacterial detection, a number of automated detection systems have become available to test for contaminated platelet components, but their utility to some extent is restricted by the time they take to indicate the presence of bacteria and/or their lack of sensitivity to detect initially low bacterial loads. A variety of other approaches has been shown to reduce the risk of bacterial contamination and include filtration to remove leukocytes and bacteria, diversion of the initial aliquot of blood during donation, and improved donor skin disinfection. Platelet pathogen inactivation methods under investigation include the addition of L-carnitine, gamma-irradiation, riboflavin plus UVA irradiation, and amotosalen HCl plus UVA irradiation. The latter process is licensed for clinical use with platelets in some countries in Europe. All of these approaches, either collectively or individually, hold considerable promise

  8. [CD36 Antigen Deficiency and Platelet Transfusion].

    PubMed

    Li, Hai-Yan; Zhou, Yan; Shen, Wei-Dong

    2016-06-01

    CD36 is a transmembrane glycoprotein, a multi-ligand receptor, possesses various biological functions. CD36 deficiency may stimulate the body to produce anti-CD36 alloimmune antibodies through the several pathways, such as blood transfusion, pregnancy or organ transplantation and so on, leading to the refractoriness of immune platelet transfusion and other diseases. The recent research advances of CD36 deficiency and its molecular biological basis, platelet transfusion and CD36 antibody detection are summarized briefey in this review.

  9. Platelet dynamics in three-dimensional simulation of whole blood.

    PubMed

    Vahidkhah, Koohyar; Diamond, Scott L; Bagchi, Prosenjit

    2014-06-03

    A high-fidelity computational model using a 3D immersed boundary method is used to study platelet dynamics in whole blood. We focus on the 3D effects of the platelet-red blood cell (RBC) interaction on platelet margination and near-wall dynamics in a shear flow. We find that the RBC distribution in whole blood becomes naturally anisotropic and creates local clusters and cavities. A platelet can enter a cavity and use it as an express lane for a fast margination toward the wall. Once near the wall, the 3D nature of the platelet-RBC interaction results in a significant platelet movement in the transverse (vorticity) direction and leads to anisotropic platelet diffusion within the RBC-depleted zone or cell-free layer (CFL). We find that the anisotropy in platelet motion further leads to the formation of platelet clusters, even in the absence of any platelet-platelet adhesion. The transverse motion, and the size and number of the platelet clusters are observed to increase with decreasing CFL thickness. The 3D nature of the platelet-RBC collision also induces fluctuations in off-shear plane orientation and, hence, a rotational diffusion of the platelets. Although most marginated platelets are observed to tumble just outside the RBC-rich zone, platelets further inside the CFL are observed to flow with an intermittent dynamics that alters between sliding and tumbling, as a result of the off-shear plane rotational diffusion, bringing them even closer to the wall. To our knowledge, these new findings are based on the fundamentally 3D nature of the platelet-RBC interaction, and they underscore the importance of using cellular-scale 3D models of whole blood to understand platelet margination and near-wall platelet dynamics.

  10. Effects of irradiation on platelet function

    SciTech Connect

    Rock, G.; Adams, G.A.; Labow, R.S.

    1988-09-01

    Current medical practice involves the irradiation of blood components, including platelet concentrates, before their administration to patients with severe immunosuppression. The authors studied the effect of irradiation on in vitro platelet function and the leaching of plasticizers from the bag, both immediately and after 5 days of storage. The platelet count, white cell count, pH, glucose, lactate, platelet aggregation and release reaction, and serotonin uptake were not altered by the irradiation of random-donor or apheresis units with 2000 rads carried out at 0 and 24 hours and 5 days after collection. The leaching of di(2-ethylhexyl)phthalate from the plastic bags followed by the conversion to mono(2-ethylhexyl)phthalate was not increased by irradiation. Therefore, it is possible to irradiate platelet concentrates on the day of collection and subsequently store them for at least 5 days while maintaining in vitro function. This procedure could have considerable benefit for blood banks involved in the provision of many platelet products.

  11. Quasicrystalline tilings with nematic colloidal platelets

    PubMed Central

    Dontabhaktuni, Jayasri; Ravnik, Miha; Žumer, Slobodan

    2014-01-01

    Complex nematic fluids have the remarkable capability for self-assembling regular colloidal structures of various symmetries and dimensionality according to their micromolecular orientational order. Colloidal chains, clusters, and crystals were demonstrated recently, exhibiting soft-matter functionalities of robust binding, spontaneous chiral symmetry breaking, entanglement, shape-driven and topological driven assembly, and even memory imprinting. However, no quasicrystalline structures were found. Here, we show with numerical modeling that quasicrystalline colloidal lattices can be achieved in the form of original Penrose P1 tiling by using pentagonal colloidal platelets in layers of nematic liquid crystals. The tilings are energetically stabilized with binding energies up to 2500 kBT for micrometer-sized platelets and further allow for hierarchical substitution tiling, i.e., hierarchical pentagulation. Quasicrystalline structures are constructed bottom-up by assembling the boat, rhombus, and star maximum density clusters, thus avoiding other (nonquasicrystalline) stable or metastable configurations of platelets. Central to our design of the quasicrystalline tilings is the symmetry breaking imposed by the platelet shape and the surface anchoring conditions at the colloidal platelets, which are misaligning and asymmetric over two perpendicular mirror planes. Finally, the design of the quasicrystalline tilings as platelets in nematic liquid crystals is inherently capable of a continuous variety of length scales of the tiling, ranging over three orders of magnitude in the typical length (from to ), which could allow for the design of quasicrystalline photonics at multiple frequency ranges. PMID:24550269

  12. Function of platelet 47K protein phosphorylation

    SciTech Connect

    Imaoka, T.

    1987-05-01

    To provide insight into the biochemical pathway of platelet activation, they purified both unphosphorylated and phosphorylated P47 to homogeneity from human platelets. This study represents the first demonstration of a change of physiological action of P47 in response to phosphorylation in platelet activation. SVI labelled unphosphorylated P47 had an ability to bind with platelet membrane fraction in the presence of phosphatidylserine. Effect of diacylglycerol was inhibitory in this PS dependent P47 binding with membrane. Unphosphorylated P47 had an inhibitory activity in platelet actin polymerization. Molar ratio to inhibit actin polymerization was 1:8 (P47:actin). These activities were Ca independent. Purified TSP-labelled P47 lost the binding ability with membrane, also the inhibitory activity in actin polymerization. Therefore, they propose the hypothesis that unphosphorylated P47 may loosely bind with the inside of plasma membrane of platelet and inhibit actin polymerization as a modulator, when stimulated, protein Kinase C rapidly phosphorylate P47 and induce the activation of cytoskeletal network and subsequently release reaction.

  13. [The role of blood platelets in infections].

    PubMed

    Micota, Bartłomiej; Sadowska, Beata; Różalska, Barbara

    2015-05-17

    Platelets are primarily associated with their main function, hemostasis, although it is known that these cells also exhibit biological activity in cancer progression, inflammation and infectious processes. During infection platelets, due to the expression of specific receptors - Toll-like receptors (TLRs) - which recognize molecular patterns associated with pathogens - pathogen-associated molecular patterns (PAMPs) - are activated by the presence of microorganism components and/or substances released from damaged cells/tissue. Further antimicrobial activity of platelets is based on their capacity for phagocytosis, generation of reactive oxygen species (ROS), and the synthesis, storage and release of proteins/peptides with antimicrobial activity. Another mechanism of platelet action is their immunomodulatory activity. It is based mainly on the ability to secrete chemotactic factors allowing the accumulation of professional immunocompetent cells at the site of infection, thus enhancing the effective eradication of an infectious agent. In chronic infections, platelets, due to release of numerous growth factors and various cytokines, support mechanisms of acquired immunity. They accelerate the maturation of dendritic cells, stimulate B cells to be immunoglobulin-producing plasma cells and potentiate the activity of T cells. Unfortunately, in certain situations (the existence of specific risk factors) the interaction of microorganisms with activated platelets may also be the cause of pathology within the cardiovascular system.

  14. Assessment of quality of platelets preserved in plasma and platelet additive solution: A Malaysian experience

    PubMed Central

    Mokhtar, Munirah Binti; Hashim, Hasna Binti; Joshi, Sanmukh R

    2016-01-01

    Background: A use of platelet additives solution (PAS) improves storage conditions so as to give increased shelf life to platelets and to maintain hemostatic function. Objective: The present study was aimed to compare in vitro quality of platelet rich plasma (PRP)-derived platelet concentrate (PC) during extended period of storage in plasma and in additive solution (Composol PS and Fresenius). Study Design: Randomized 19 PCs each were used in the study for plasma and PAS as the storage medium. The measurement parameters, including pH, total white blood cell (WBC) count, total platelet count, and platelet activation rate, were studied on day 1, day 5, and day 8 of the storage period. The sterility test was carried out on the eighth day of storage. Results: pH of PC suspended in PAS was significantly lower as compared to that in plasma (P < 0.001) for all the three days of sampling. The WBC count, both in plasma and in PAS, showed an acceptable values of being <0.2 Χ 109 /unit during the storage period. Platelet count in PAS was higher as compared to that in plasma, though it was not statistically significant. While both the groups showed increased platelet activation rate during the storage, the PCs suspended in PAS showed significantly higher platelet activation rate (p0.001). Results from sterility test showed no bacterial growth in the PCs in both the groups. Conclusion: Most parameters studied on platelet storage in suspending medium of native plasma and PAS remained well within the acceptable limits. However, the pH values and platelet activation rate significantly differed in PAS as compared with plasma. PMID:27011678

  15. Lack of correlation between extended pH monitoring and scintigraphy in the evaluation of infants with gastroesophageal reflux

    SciTech Connect

    Tolia, V.; Calhoun, J.A.; Kuhns, L.R.; Kauffman, R.E. )

    1990-05-01

    Sixty-nine infants younger than 1 year of age, with symptoms of persistent vomiting, recurrent choking, apnea, persistent cough, or stridor, were evaluated for gastroesophageal reflux. All infants underwent extended intraesophageal pH monitoring for 16 to 24 hours as well as gastroesophageal scintigraphy with technetium 99m sulfur colloid to study the correlation between the two tests. Forty-eight infants exhibited reflux with extended pH monitoring whereas 46 infants showed reflux with scintigraphy. However, the diagnosis of reflux in individual patients by extended pH monitoring corresponded poorly with the diagnosis of reflux in the same patients by scintigraphy. Similarly, no correlation was observed between extended pH monitoring and scintigraphy results, whether expressed as percent gastric emptying or as gastroesophageal reflux ratio. We conclude that extended pH monitoring and scintigraphy measure different pathophysiologic phenomena and detect reflux under different conditions. The ability of these tests to detect reflux may be complementary and they may be of greatest value when used together to enhance the sensitivity and specificity of the diagnostic evaluation. Extended pH monitoring and scintigraphy should not be used interchangeably to monitor gastroesophageal reflux.

  16. Comparison of whole-body MRI and bone scintigraphy in the detection of bone metastases in renal cancer.

    PubMed

    Sohaib, S A; Cook, G; Allen, S D; Hughes, M; Eisen, T; Gore, M

    2009-08-01

    This study aims to compare the sensitivity of whole-body MRI with bone scintigraphy in the detection of bone metastases in patients with renal cancer. A prospective study was carried out in 47 patients with renal cancer (mean age 62 years, range 29-79 years). All patients had assessment of the skeleton with whole-body bone scintigraphy (with technetium-99m methylene diphosphonate) and whole-body MRI (coronal T(1) weighted and short tau inversion recovery sequences). The number and sites of bony metastases were assessed on each imaging investigation independently. Sites of extra-osseous metastasis on MRI were also noted. The imaging findings were correlated with other imaging modalities and follow-up. 15 patients (32%) had bone metastases at 34 different sites. Both scintigraphy and MRI were highly specific (94% and 97%, respectively), but the sensitivity of MRI (94%) was superior (p = 0.007) to that of scintigraphy (62%). MRI identified more metastases in the spine and appendicular skeleton, whereas scintigraphy showed more lesions in the skull/facial and thoracic bones. MRI identified extra-osseous metastases in 33 patients (70%), these were mainly lung and retroperitoneal in site. Whole-body MRI is a more sensitive method for detection of bone metastases in renal cancer than bone scintigraphy, and also allows the assessment of soft-tissue disease.

  17. Platelet--arterial synthetic graft interaction and its modification

    SciTech Connect

    Callow, A.D.; Connolly, R.; O'Donnell, T.F. Jr.; Gembarowicz, R.; Keough, E.; Ramberg-Laskaris, K.; Valeri, C.R.

    1982-11-01

    We compared the in vivo platelet reactivity of two commonly used clinical grafts, Dacron and expanded polytetrafluoroethylene (PTFE), with that of a control autogenous artery graft and assessed whether platelet reactivity was modified by the platelet-antiaggregating agent prostacyclin (PGI2) (epoprostenol). Grafts were randomly placed into the carotid arteries of 21 baboons. Platelets labeled with /sup 111/In were infused within one hour after implantation graft for gamma camera scanning of platelet uptake. The accumulation of platelets on Dacron grafts began almost immediately after injection and reached a peak after one to two hours. The PTFE and control autogenous artery grafts accumulated comparable small amounts of platelets. Prostacyclin was then infused in a second series of baboons with Dacron grafts, at a rate of 150 to 200 ng/kg/min. It prevented the usual platelet uptake when administered concomitant with graft implantation and reduced previously established platelet activity.

  18. Identification of membrane proteins mediating the interaction of human platelets

    PubMed Central

    Phillips, D; Jennings, L; Edwards, H

    1980-01-01

    Membrane glycoproteins that mediate platelet-platelet interactions were investigated by identifying those associated with the cytoskeletal structures from aggregated platelets. The cytoskeletal structures from washed platelets, thrombin-activated platelets (platelets incubated with thrombin in the presence of mM EDTA to prevent aggregation) and thrombin- aggregated platelets (platelets activated in the presence of mM Ca(++) were prepared by first treating platelet suspensions with 1 percent Triton X-100 and 5 mM EGTA and then isolating the insoluble residue by centrifugation. The readily identifiable structures in electron micrographs of the residue from washed platelets had the shape and dimensions of actin filaments. Analysis of this residue from washed platelets had the shape and dimensions of actin filaments. Analysis of this residue by SDS gel electrophoresis showed that it consisted primarily of three proteins: actin (mol wt = 43,000), myosin (mol wt = 200,000) and a high molecular weight polypeptide (mol wt = 255,000) which had properties indentical to actin-binding protein (filamin). When platelets are activated with thrombin in the presence of EDTA to prevent aggregation, there was a marked increase in the amount of insoluble precipitate in the subsequent Triton extraction. Transmission electron microscopy showed that this residue not only contained the random array of actin filaments as seen above, but also organized structures from individual platelets which appeared as balls of electron-dense filamentous material approximately 1mum in diameter. SDS polyacrylamide gel analysis of the Triton residue of activated platelets showed that this preparation contained more actin, myosin and actin-binding protein than that from washed platelets plus polypeptides with mol wt of 56,000 and 90,000 and other minor polypeptides. Thus, thrombin activation appeared to increase polymerization of actin in association with other cytoskeletal proteins into structures that

  19. Platelet activation determines the severity of thrombocytopenia in dengue infection

    PubMed Central

    Ojha, Amrita; Nandi, Dipika; Batra, Harish; Singhal, Rashi; Annarapu, Gowtham K.; Bhattacharyya, Sankar; Seth, Tulika; Dar, Lalit; Medigeshi, Guruprasad R.; Vrati, Sudhanshu; Vikram, Naval K.; Guchhait, Prasenjit

    2017-01-01

    Thrombocytopenia is common in patients with dengue virus (DENV) infections. With a focus on understanding the possible mechanism of thrombocytopenia in DENV infections we described a direct correlation between activation and depletion of platelets in patients. Our data showed a sharp decrease in platelet counts at day 4 of fever in patients. The high DENV genome copies in platelets correlated directly with the elevated platelet activation along with increased binding of complement factor C3 and IgG on their surface at day 4. Recovery in platelet count was observed on day 10 through day 6 and 8 with simultaneous decrease in platelet activation markers. Further, our in vitro data supported the above observations describing a concentration-dependent increase in platelet activation by DENV serotype-2. The high copy number of DENV2 genome in the platelet pellet correlated directly with platelet activation, microparticle generation and clot formation. Furthermore the DENV2-activated platelets were phagocytosed in large numbers by the monocytes. The DENV2-mediated lysis and clearance of platelets were abrogated in presence of platelet activation inhibitor, prostacyclin. These observations collectively suggest that platelet activation status is an important determinant of thrombocytopenia in dengue infections. A careful strategy of inactivation of platelets may rescue them from rapid destruction during DENV infections. PMID:28139770

  20. Resveratrol preserves the function of human platelets stored for transfusion.

    PubMed

    Lannan, Katie L; Refaai, Majed A; Ture, Sara K; Morrell, Craig N; Blumberg, Neil; Phipps, Richard P; Spinelli, Sherry L

    2016-03-01

    Stored platelets undergo biochemical, structural and functional changes that lead to decreased efficacy and safety of platelet transfusions. Not only do platelets acquire markers of activation during storage, but they also fail to respond normally to agonists post-storage. We hypothesized that resveratrol, a cardioprotective antioxidant, could act as a novel platelet storage additive to safely prevent unwanted platelet activation during storage, while simultaneously preserving normal haemostatic function. Human platelets treated with resveratrol and stored for 5 d released less thromboxane B2 and prostaglandin E2 compared to control platelets. Resveratrol preserved the ability of platelets to aggregate, spread and respond to thrombin, suggesting an improved ability to activate post-storage. Utilizing an in vitro model of transfusion and thromboelastography, clot strength was improved with resveratrol treatment compared to conventionally stored platelets. The mechanism of resveratrol's beneficial actions on stored platelets was partly mediated through decreased platelet apoptosis in storage, resulting in a longer half-life following transfusion. Lastly, an in vivo mouse model of transfusion demonstrated that stored platelets are prothrombotic and that resveratrol delayed vessel occlusion time to a level similar to transfusion with fresh platelets. We show resveratrol has a dual ability to reduce unwanted platelet activation during storage, while preserving critical haemostatic function.