Alteration in Plasma Proteins and Platelet Functions with Aging and Cigarette Smoking in Healthy Men

Blood samples were obtained on four different occasions from 18 cigarette smoking and 34 non-smoking healthy men (age 4Hl9) and analped to assess age- and smoking-associated changes in plasma proteins, btood coagulation and platelet functions. C-ollagen-induced platele t aggregation was signifi cantly inclreased with agng in non-smokers. Significant gfuanges in chronic smokers were increases in platelet count and fibrinogen in plasma; elevation of platelet factor-3 (PF-3) activity in plateletpoor plasma (PPP); increase in serum levels of a1-antitr,?sin, orosomucoid, haptoglobin and properdin factor B; and sfoeftsning of the lag period of collagen-induced platelet aggregation. Filtration of PPP through Mllipore fiIters removed PF-3 membranes. The differen@s in PF-3 activities in fiItered plasma were no longer significant between smokers and non-smokers. Results suggest that chronic smokers have higher levels of acute phase proteins reflecting underlyrng inflammatory processes, and higher levels of PF-3 activity in plasma due to liberation of PF-3 membranes from platelets.

Antithrombin III Profiles in Malignancy, Relationship to Primary Tumors and Metastatic Sites

Variations of antithrombin III were studied in a non-ran-domized population of consecutive cancer cases admitted to a referral hospital. Differences between functional and immunologic assay were observed.

Decreases were observed in both assays when compared to a population of hospitalized controls. Patients with cancer of the colon, ovary and prostate showed a deficiency of antithrombin III more frequently than other common tumors. When all tumor cases were subdivided into those in remission compared to those with metastases, a significant decrease in antithrombin III also could be shown.

Metastases to the liver were strikingly common in cancer patients with decreased antithrombin III. In these patients, the decrease in antithrombin III could be statistically correlated with reduction in serum albumin.

Infusible platelet membrane microvesicles: a potential transfusion substitute for platelets

BACKGROUND

Several substitutes for intact, viable platelets have been used for transfusion, both to people and in animal models, with varied success. Infusible platelet membrane (IPM) is prepared from human platelets. IPM retains the glycoprotein (GP)lb receptor and has platelet factor 3 activity (procoagulant activity). However, factor V, serotonin, a cytoplasmic marker enzyme (purine nucleotide phosphorylase), GPIIb/IIIa complex, and HLA class I and II antigens are all absent in IPM.

STUDY DESIGN AND METHODS

IPM is prepared from outdated platelets. The platelets were disrupted by freezing and thawing; they were washed and heated to inactivate possible viral contaminants, and then the sonicated membrane microvesicle fraction was separated and lyophilized. The hemostatic activity of IPM was measured by its ability to reduce the prolonged bleeding time in thrombocytopenic rabbits.

RESULTS

Administration of IPM at a dose of 2 mg per kg results in a substantial reduction in the bleeding time. In a series of 23 experiments, a median preinjection bleeding time of 15 minutes was reduced to 6 minutes within 4 hours after IPM administration. Administration of IPM did show a mild enhancement in the thrombogenicity index, as measured in the Wessler rabbit model. This enhancement is, however, not significant, as a thrombogenicity index value of up to 0.6 is clinically acceptable.

CONCLUSION

IPM may have clinical potential as a substitute for platelets in the treatment of bleeding due to thrombocytopenia.

Platelet antithrombin defect in malignancy: platelet protein alterations

Sixty-eight patients with malignant disease were divided into two groups based on the results of the platelet antithrombin test (PAT). The normal group had a PAT clotting time ranging from 21.4 to 29.8 seconds, which was equivalent to 25% to 65% inactivation of the 2 U of thrombin added to the test system. The other group showed abnormal PAT clotting time, less than 21.4 seconds or less than 25% thrombin inactivation. The polypeptide composition of platelets from the two patient groups was analyzed by sodium dodecyl sulfate (SDS)-electrophoresis on 7.5% polyacrylamide gels. A polypeptide of 180,000 apparent mol wt was decreased or absent in both Coomassie blue- and Alcian blue-stained gels of the platelets from patients whose PAT was abnormal; this polypeptide comigrated with purified platelet thrombospondin. Tritium labeling of platelet surface glycoproteins by the periodate-borohydride method followed by two-dimensional electrophoresis was performed on platelets of seven patients with abnormal PAT. When they were compared with ten patients with normal PAT, a glycoprotein of 140,000 apparent mol wt with a pl of 4.5 to 5.2 was decreased in platelets of all seven patients with abnormal PAT. Nitrocellulose replicas of one-dimensional gels of platelets from 13 of 14 patients with abnormal PAT showed decreased reaction with an anti-human platelet glycocalicin antiserum. Platelets of these same patients also showed a decreased or absent platelet agglutination induced by ristocetin. Patients with normal PAT had a mean agglutination slope of 1.25 +/- 0.6 (n = 26) as compared with 0.37 +/- 0.34 (n = 26) for the abnormal PAT group (P less than .001). Results indicate that platelets from a subpopulation of tumor patients characterized by decreased platelet antithrombin activity have alterations in two platelet glycoproteins, identified as GPIb and thrombospondin.

Current plasmapheresis practice in the United States

The principal differences of the USA plasmapheresis collection system from most other countries are: it is conducted by the pharmaceutical industry rather than government, it uses remunerated donors, and it draws a larger volume of plasma than is permitted elsewhere. The implications of these features are reviewed in terms of the effects on donors and the effects on the plasma supply. Protein metabolism is reviewed, and the effects of plasmapheresis on overall nitrogen balance are presented.

Alteration in plasma proteins and platelet functions with aging and cigarette smoking in healthy men

Blood samples were obtained on four different occasions from 18 cigarette smoking and 34 non-smoking healthy men (age 40-69) and analyzed to assess age- and smoking-associated changes in plasma proteins, blood coagulation and platelet functions. Collagen-induced platelet aggregation was significantly increased with aging in non-smokers. Significant changes in chronic smokers were increases in platelet count and fibrinogen in plasma; elevation of platelet factor-3 (PF-3) activity in platelet-poor plasma (PPP); increase in serum levels of alpha 1-antitrypsin, orosomucoid, haptoglobin and properdin factor B; and shortening of the lag period of collagen-induced platelet aggregation. Filtration of PPP through Millipore filters removed PF-3 membranes. The differences in PF-3 activities in filtered plasma were no longer significant between smokers and non-smokers. Results suggest that chronic smokers have higher levels of acute phase proteins reflecting underlying inflammatory processes, and higher levels of PF-3 activity in plasma due to liberation of PF-3 membranes from platelets.

Thrombin inhibition by malignant and normal cells: a cell-bound antithrombin effect

Analysis of fresh surgical specimens of normal tissue and tumor tissue show a cellular antithrombin activity to be present in certain organs. In normal tissues it was noted chiefly in normal colon, testes, breast, and uterus. In malignant tissues it was prominent in adenocarcinomas of the colon, breast, and lung. No epidermoid tumors showed evidence of thrombin binding. The thrombin- binding activity required the presence of intact cells and was distinct from the soluble antithrombins normally present in plasma and serum. There is growing evidence to suggest an interrelationship between clotting and the growth and dissemination of cancer. The implications of cellular antithrombins are reviewed in this context.

Antithrombin III profiles in malignancy, relationship primary tumors and metastatic sites

Variations of antithrombin III were studied in a non-randomized population of consecutive cancer cases admitted to a referral hospital. Differences between functional and immunologic assay were observed. Decreases were observed in both assays when compared to a population of hospitalized controls. Patients with cancer of the colon, ovary and prostate showed a deficiency of antithrombin III more frequently than other common tumors. When all tumor cases were subdivided into those in remission compared to those with metastases, a significant decrease in antithrombin III also could be shown. Metastases to the liver were strikingly common in cancer patients with decreased antithrombin III. In these patients, the decrease in antithrombin III could be statistically correlated with reduction in serum albumin.

L-asparaginase effect on antithrombin-III levels

The effect of L-asparaginase (L-asp) therapy on circulating antithrombin-III (AT-III) was monitored in three patients with acute lymphoblastic leukemia. Serial determination for AT-III by both a functional assay and an immunologic assay demonstrated a rapid decrease in serum AT-III levels, followed by a protracted recovery beyond the period of L-asp exposure. One of the three patients developed a reversible venous thrombosis of the arm. The mechanism of the L-asparaginase effect may be related to peripheral degradation of AT-III or to inhibition of production.

Ristocetin precipitation test: a new simple test for detection of fibrin monomer and fibrin degradation products

The ristocetin precipitation test was designed as a simplified test to detect fibrin monomers and fibrinogen/fibrin degradation products (FPD/fdp). The ristocetin precipitation test is positive in plasma samples containing either fibrin monomer (greater than 5--10 microgram/ml) or early fdp (greater than 50--100 microgram/ml). The ristocetin precipitation test is negative in plasma with fibrinogen concentrations to 1,000 mg/dl or fibrinogen degradation products FDP) and late fdp to 400 microgram/ml. The ristocetin precipitation test is positive in plasmas collected from rabbits after the infusion of thrombin (2.7 u/kg) or thrombin and streptokinase (10,000 u/kg); the test is negative in plasmas from animals treated with streptokinase or saline solution alone. The ristocetin precipitation test is negative in normal human plasmas and plasmas from patients who have primary firbinogenolysis, but positive in plasmas from patients with disseminated intravascular coagulation. These results suggest that the restocetin precipitation test can be a useful test for the detection of plasma fibrin monomers and early fdp.

Platelet antithrombin deficiency: a new clinical entity

A kindred with a history of multiple thromboses was studied for coagulant abnormalities. A deficiency of serum antithrombin III was found in approximately half of the 13 family members by either coagulant or immunologic assay. No clear relationship between antithrombin III deficiency and a history of thrombosis was present. Platelet antithrombin assays were also studied in the same subjects. Ten of the 13 members were deficient. None of the remaining three had a history of thrombosis. On the basis of these findings, the hypothesis is proposed that in some cases familial hypercoagulability may be due to a platelet antithrombin deficiency and that the serum antithrombin III deficiency in some cases is a secondary rather than a primary effect.

Intraaterial hepatic infusion and intravenous adriamycin for treatment of hepatocellular carcinoma: a clinical and pharmacology report

Four patients received intraarterial (ia) hepatic infusion and 10 received intravenous (iv) adriamycin for hepatocellular carcinoma. Four of each group are evaluable. The remaining 6 patients died within 14 days of intravenous therapy and are, therefore, considered nonevaluable. Patients received 2 to 9 courses of adriamycin every 3 weeks. One half of each group of evaluable patients had partial responses (pr). The group had pr for 22.5 weeks (range 8 to 37). The iv group had pr 27.2 weeks (range: 16 to 38.5). Mean survival was 21 weeks for nonresponders, and 43 weeks for responders. Intraarterial infusion did not protect patients from adriamycin toxicity. Cardiac and liver toxicity were not seen, but marrow and gastrointestinal toxicity developed at 1.2 X 10(-7)M adriamycin serum level. Adriamycin disappearance curves after ia and iv therapy were similar for similar bilirubin levels, and prolonged with hyperbilirubinemia. Ascites fluid did not accumulate detectable adriamycin. Pharmacokinetics are described in this report.

Plateletpheresis by discontinuous centrifugation: effect of collecting methods on the in vitro function of platelets

The in vitro function of platelets collected by two different methods during centrifugal plateletpheresis was compared. The RBC method involves collecting platelets with red cells followed by a supplementary spin to remove them, whereas the no-RBC method requires collecting platelets only from the buffy coat without red cells. Platelet response to adenosine diphosphate (ADP), epinephrine and collagen was slightly reduced in platelet-rich plasma (PRP) prepared by no-RBC technique and was markedly decreased in samples obtained by the RBC technique when compared to prepheresis controls. The decrease in platelet response to ADP, epinephrine and collagen was apparent in three testing systems: aggregation, release of serotonin and reptilase clot retraction. Both plasma and platelets appeared to be affected by the pheresis procedure. Platelet preparations obtained by both RBC and no-RBC techniques showed an increase of platelet factor 3 activity and an enhancement of aggregation, release of serotonin and clot retraction induced by thrombin as compared to prepheresis controls. Postpheresis platelet-poor plasma contains platelet membrane fragments which exhibit a high platelet factor 3 activity. The results showed that the RBC method, although providing a higher platelet yield, caused more qualitative alterations in platelets than in those obtained by no-RBC method, and that both methods of collecting platelets activated the procoagulant activity of platelets.

Precipitation of fibrin monomers and fibrin degradation products by ristocetin

Ristocetin, at relatively low concentrations (1.0 mg/ml-1.5 mg/ml), can selectively precipitate fibrin monomers and fibrin degradation products (fdp) from plasma without effect on fibrinogen or fibrinogen degradation products (FDP). 125I-labeled fibrin monomers and fibrin degradation products were precipitated by ristocetin when their plasma concentrations were greater than 0.25 microgram/ml and 50 microgram/ml, respectively. In order to obtain a visible precipitated, 2 microgram/ml of fibrin monomers of 50 to 100 microgram/ml of fibrin degradation products were necessary. These effects were optimally observed under the following conditions: (1) temperature, 20 C to 37 C; (2) pH, 7.0 to 7.5; and (3) incubation time, 15 to 60 minutes. Late-fibrin degradation products are approximately eight times less sensitive to ristocetin-induced precipitation than early-fibrin degradation products. Plasma medium is essential for the differentiation of fibrin monomers and fibrin degradation products from fibrinogen and fibrinogen degradation products by ristocetin. These results suggest that the specific detection of fibrin monomers and fibrin degradation products in plasma may be easily performed by ristocetin.

Annual discourse--don't eat the quails

Physicians were the first individuals recorded by name in history. Their attempts to define disease influenced fundamentally the cultures and religions of the world. Surgical skills, although highly developed in ancient times, appear to have been less well documented historically than medical disorders. Because of the greater threat to survival that diseases posed, they became incorporated into religious customs. Contagious diseases also influenced greatly the laws, traditions and historical events of the Bible. Leprosy provided a physical example that presumably represented an image of sin, but it probably was no more prevalent as a disease during Biblical times than at present. Many of the Biblical stories assumed to be allegorical may have been founded on medical fact. For example, it appears likely that the quails that poisoned the wandering Jews were contaminated with cyanide.

Platelet antithrombins: role of thrombin binding and the release of platelet fibrinogen

The nature of platelet antithrombin was elucidated by comparison of thrombin binding and antithrombin activities of intact platelets and by purification of antithrombin from platelet lysates using glycerol osmotic lysis, ethanol precipitation and Sephadex gel filtration techniques. The major portion of the antithrombin and thrombin binding activity of intact platelets is lost after brief sonication. The antithrombin activity in destroyed platelets is found to be due to platelet fibrinogen. Treatment of platelets with PGE1 (100 microng/ml) markedly inhibits (greater than 80%) the release of platelet fibrinogen induced by thrombin. However, the PGE1 treatment produced slight (less than 30%) but significant decrease of antithrombin activity of intact platelets, whereas the binding of thrombin to platelets was not affected by PGE1 treatment. The amounts of thrombin bound to and inactivated by PGE1-treated platelets at the same cell concentration are identical. The above results suggest that platelets contain at least two antithrombin activities. One, which accounts for the major portion of platelet antithrombin is mediated by thrombin binding to platelets. The other, which attributes to a lesser extent to platelet antithrombin activity, is due to the release of platelet fibrinogen. Also, antithrombin is readily demonstrated in a plasma medium indicating physiological significance of platelet antithrombin.

Aggregation of platelets and inert particles induced by thrombin

Thrombin-induced platelet aggregation and release were investigated in washed platelet suspensions and in suspensions of inert particles in order to evaluate the role of fibrinogen-fibrin transformation in aggregometer tracings. Thrombin (0.25-2.0 U/ml) produced two waves of light transmission increase (LTI) in both platelet and inert particle suspensions containing fibrinogen, and concomittantly aggregates were observed under phase microscopy. Without fibrinogen, thrombin induced rapid release of platelet ADP but failed to cause second wave of LTI. The kinetics of LTI in platelet and inert particle systems were related to both thrombin and fibrinogen concentrations. A rapid second wave of LTI could be produced by direct interaction of thrombin-treated platelets or inert particles with polymerizing fibrin, and was inhibited by sodium sulfite and low pH of 5.1 which prevent fibrin monomer polymerization. No fibrin strands were noted in platelet aggregates fixed at the completion of the second wave of LTI. Apyrase and PGE1 inhibited the rate of first but not that of second wave LTI. The results suggest that the release of platelet ADP induced by thrombin primarily affects the first phase aggregation, and the second phase may result from interaction of thrombin-exposed platelets and polymerizing fibrin. Thus, the blood coagulation mechanism may be directly involved in platelet aggregation.

Similarities between platelet contraction and cellular motility during mitosis: role of platelet microtubules in clot retraction

The effects of inhibitors of mitosis, energy metabolism and protein synthesis on clot retraction were investigated. The results show that (1) Incubation of colchicine (0-01-0-1 mM) with platelet-rich plasma (PRP) inhibits the subsequent retraction of clots derived from diluted PRP. (2) Inhibition of clot retraction by high concentrations of colchicine (up to 40 mM) can be overcome by increasing the platelet concentration in the system. (3) Incubation of clots in colchicine or 80% D2O solutions inhibits their retraction. Exposure of partially retracted clots to these agents is without effect. (4) Hydrostatic pressure retards clot retraction. (5) Incubation of PRP with either 2-deoxy-D-glucose or antimycin alone does not affect clot retraction, but a combination of these agents is inhibitory. (6) Clot retraction is not inhibited by puromycin or cycloheximide. (7) Platelets in retracting clots have constricted regions containing microfilaments and pseudopods containing microtubules. Fibrin strands are progressively condensed around the constricted regions as retraction advances. (8) The development of platelet constriction, platelet pseudopods and the intracellular microfilaments are delayed in colchicinized clots, corresponding to the retardation of retraction. Following the initial delay of retraction colchicinized clots, like controls, show condensation of fibrin strands adjacent to these constricted areas of platelets containing microfilaments. The formation of pseudopods is impaired and no microtubules are found in platelets in the presence of colchicine. The above results suggest that the thrombin-induced platelet contraction during clot retraction is a coordinated movement, which, under optimal conditions involves both microtubules and microfilaments. The contraction of microfilaments produces the constriction of platelets and brings about clot retraction by reducing the angle between fibrin strands. Platelet microtubules are related to the development of pseudopods and play a supplementary role in facilitating microfilament-mediated cellular constriction. The similarities between platelet contraction and cellular motility in mitosis is discussed.

Colchicine uptake and binding by human platelets

The uptake and binding of antimitotic alkaloid colchicine has been demonstrated in washed preparations of human pletelets. A silicone oil technique was adapted so that both uptake and binding of 14C-colchicine were examined in the same platelet preparations. The time dependence and amount of colchicine taken up and bound by different pletelet preparations during a 90 to 120 min incubation period were highly reproducible. Both colchicine uptake and binding by intact platelets, and colchicine binding by preparations of lysed platelets were specific and temperature dependent. Colchicine uptake was slowly reversible. Magnesium and GTP enhanced colchicine binding by lysed platelet preparations but calcium decreased binding. exposure of platelets to either cold (4 degrees C) or to thrombin, which disrupt platelet microtubules, produced significant increases in colchicine uptake and binding. The thrombin effect was maximal at 37 degrees C and resulted in a greater increase in uptake and binding than that produced by either cold treatment alone or, by cold treatment followed by incubation with thrombin at 37 degrees C. The amount of increase in uptake and binding produced by thrombin was independent of both thrombin (1--5 Units/10(9) platelets) and colchicine concentrations (1--50 X 10(-6) M). It is postulated that thrombin may initiate the formation, or make available, colchicine binding sites (microtubule subunits) within platelets.

Antithrombin activity of intact human platelets

Antithrombin activity has been identified in intact washed human platelets. An apparent activity was demonstrated at platelet concentrations above 0.31 X 10(9)/ml, when platelet suspensions were incubated with 2.0 NIH units/ml of thrombin. Neither red cells nor white cells revealed antithrombin activity. No significant loss of the platelet antithrombin activity was observed after ten successive washings or after treatment of platelets with antibodies to antithrombin III or alpha2-macroglobulin. Almost the same amount of antithrombin activity as normal platelets was demonstrated in the platelets from an afibrinogenemic patient. Pre-treatment of platelets with trypsin, papain, and neuroaminidase reduced the activity significantly, whereas lipase was without effect. The platelet antithrombin reacted with thrombin in less than 3 seconds, and this rapid reaction of platelet antithrombin was different from that of plasma antithrombin III or fibrinogen. The thrombin-like clotting activity of ancrod was inhibited by fibrinogen but not platelets. Also, unlike plasma antithrombin III or fibrinogen, brief exposure to heat (56 degrees C or 60 degrees C) reduced considerable amounts of platelet antithrombin activity. These results suggest that platelets possess a specific antithrombin with different characteristics from other known antithrombins.

Concentration effects of platelets, fibrinogen and thrombin on platelet aggregation and fibrin clotting

The effects of varying concentrations of platelets, fibrinogen and thrombin on platelet aggregation and on fibrin clotting were investigated. The results indicated that a threshold thrombin to platelet concentration ratio may be required to cause platelet activation. Above the threshold ratio, platelets exhibited properties which enhanced thrombin action in causing aggregation and fibrin clotting. At T/P ratios below the threshold level, the presence of platelets reduced thrombin activity, in other words, platelets exerted an antithrombin action. Fibrinogen at low concentrations (0.02-1.5 mg/ml) enhanced platelet aggregation induced by thrombin; whereas, at high concentrations of fibrinogen (2.0-4.0 mg/ml), aggregation was markedly inhibited. Continuous mixing of samples of paltelets and fibrinogen at physiological concentrations with thrombin at low concentrations (less than 2.0 U/ml) resulted in platelet aggregation. On the other hand, fibrin clots formed in samples without mixing or with high thrombin concentrations (greater than or equal to 5.0 U/ml). These results suggested that the quantitative relationships between platelets, fibrinogen and thrombin, and the presence or absence of cell contact may be important factors in determining the overall hemostasis.