Red Cell Flexibility and Platelet Aggregation in Patients with Chronic Obstructive Vascular Disease (COAD) and Study of Therapeutic Approaches

The red blood cell flexibility was studied in the blood of twenty patients with severe peripheral vascular disease and twenty matched controls. Patients exhibited significantly less red cell flexibility than controls. In both groups there was an inverse relationship between age and red cell flexibility. No correlation was found between red cell flexibility and sex or smoking history. Pentoxifylline, a xanthine derivative which inhibits phosphodiesterases and platelet aggregation, was found to increase red cell flexibility. This effect of the drug was greater on red cells with impaired flexibility than on normal cells. Various prostaglandins by contrast were found to decrease red cell flexibility, this could be compensated for by pentoxifylline. Forty patients with COAD were treated intravenously with PgE1. Significant inhibition of platelet aggregation and clinical improvement was noticed. It is suggested that combinations of PgE1 and pentoxifylline should be explored in clinical studies.

Multiple medical problems following agent orange exposure

A patient exposed to agent orange and a gunshot wound during the Vietnam War has developed multiple medical problems including nocardiosis, onychomycosis (Trichophyton rubrum), multiple thromboembolic episodes, hemochromatosis, diabetes mellitus type 2, diabetic neuropathy, activated protein C resistance (without Leyden V 1st mutation), degree A-V block, lung cancer (metastatic adenocarcinoma), carpal tunnel syndrome and arthritis.

Treatment of lead poisoning with an immobilized chelator comparison with conventional therapy

Lead poisoning is a global public health problem. In pregnant women it may result in developmental delays of the fetus, in children it my produce learning disability. Available chelators are nephrotoxic when eliminated as lead-chelator complexes. For safe removal of lead from the body we developed a "Lead-Hemopurifier" (L-HP), a device with an immobilized chelator. In vitro, applied to lead solutions, this device reduced the lead concentration. Applied to dogs with lead intoxication, Lead-HP-s removed lead from the blood; this was continuously replaced by lead from the bones until the skeleton was cleared from lead deposit. Treatment of lead poisoning in dogs with Lead-HP-s compared favorably with Versenate treatment of children with lead toxicity. This report demonstrates the in vivo efficiency and safety of this new detoxfication method. Methods to induce lead poisoning in dogs and procedures to identify lead released from skeletal deposits are described.

Thromboembolic disease susceptibility related to red cell membrane fluidity in patients with polycythemia vera and effect of phlebotomies

Thromboembolic disorders are frequent complications in polycythemia vera. In addition to thrombocytosis with hyperaggregability, leukocytosis, and high hematocrit, hyperviscosity syndrome, a new component, is described in the pathophysiology of this phenomenon. There is decreased red cell membrane fluidity with decreased deformability which increases the susceptibility to microvascular occlusion and also increases the chance of disseminated intravascular coagulation (DIC). Periodic phlebotomies improved the hematologic picture in these patients and results in the removal of the "stiff" red cells with an increased production of young red cells, greater membrane fluidity, deformability and less chance of microvascular occlusion.

Removal of non-transferrin-bound iron from blood with iron overload using a device with immobilized desferrioxamine

An extracorporeal hollow-fiber device with immobilized desferrioxamine (DFO) was developed for the removal of nontransferrin-bound iron (NTBI) from blood, without the toxicity of parenteral chelation. When blood circulates through the fibers having pores with 30 kD cut-off, non-transferrin-bound-iron (NTBI) crosses the fiber pores and is chelated by the immobilized desferrioxamine. Removal of circulating iron stimulates iron release from larger proteins and tissue stores, establishing continuous iron flow to the immobilized chelator. During in vitro circulation through a device, iron removed from blood of hemodialysis or sickle cell patients was proportional to, but always in less than 50% of the initial iron level. We attribute the inability to remove more serum iron to irreversible iron binding by transferrin. To investigate where removable and fixed iron was bound, iron binding proteins were analyzed in sera from six patients with genetic anemias and iron overload. Sera separated by sieving chromatography contained 1-14% of the iron in the < 30 kD protein pool, 26-48% was in the combined non-transferrin pools. Sera from hemochromatosis patients without iron overload did not contain NTBI. Circulation of hemochromatosis blood through the device removed one third of the iron, this came from all molecular weight fractions. Iron removal by the device from the < 30 kD pool appears to establish a disequilibrium, that stimulates continuous iron release from ligands with low iron affinity, renewing the pool in the < 30 kD range, which includes potentially toxic NTBI. Therapy with the chelator device having immobilized desferrioxamine should be beneficial for treatment of patients with iron overload.

Myocardial release of non-transferrin-bound iron during cardio-pulmonary bypass surgery

Myocardium reperfusion following coronary artery bypass grafting (CABG) may result in "reperfusion injury" by free radical generations. Since desferrioxamine administration attenuates this syndrome, non-transferrin-bound-iron (NTBI) released into the perfusing medium during CABG was implicated as a catalyst for oxygen radical formation. From 13 patients with "redo" CABG, specimens were collected from the coronary sinus (influx) and the aortic vent (efflux) after each distal coronary anastomosis. Specimens were subjected to sieving chromatography, and fractions were analyzed for total iron and NTBI using atomic absorption spectrometry (AAS). A statistically significant increase in NTBI was measured in influx (p = 0.002) and efflux samples (p = 0.023) collected after each graft. The combined amount of NTBI measured in these specimen was proportional to the CK-MB increase measured in the patients' sera on the day of surgery and the subsequent day. NTBI which accumulated in the circulatory bypass fluid during CABG may catalyze the generation of free radicals in the myocardium when body temperature is restored. This may aggravate myocardial damage as reflected by a post-surgical increase in CK-MB concentrations. Studies are in progress to develop new methods for the removal of NTBI during cardiac surgery. Tissue injury occurs with reperfusion during ischemia. This has been attributed to oxygen-derived free radicals that are generated by substances released from hypoxic areas (Kloner, Przyklenk et al., 1989; McCord, 1998). Reperfusion injury, i.e. the "reperfusion syndrome," occurs after coronary artery bypass grafting (CABG) when the ischemic myocardium is again provided with a supply of blood. Its most serious manifestations are arrhythmia and myocardial stunning (Ar"Rajab, Dawidson et al., 1996; Ferrari, Ceconi et al, 1996). The role of iron in reperfusion injury has been implicated by indirect evidence: during the reperfusion syndrome, the binding of iron with the chelator desferrioxamine (Ambrosio, Zweier et al., 1987; Bel, Martinod et al., 1996), or the administration of exogenous apo-transferrin, improved cardiac contractility and delayed manifestations of cardiac injury (Tiede, Sareen et al., 1990). Iron, as a transition metal, is able to catalyze free radical formation when released into the circulation from endogenous stores as non-transferrin-bound-iron (NTBI). This iron may be bound to small proteins or inorganic ligands (Halliwell and Gutteridge, 1984; Pollock and Campana, 1980; Zweier, 1992). A method for the measurement of NTBI was recently developed (Ambrus, Stadler et al., 1999). The purpose of this study was to explore whether a correlation exists among (a) the amount of NTBI released during CABG surgery, (b) the length of time of myocardial ischemia, and (c) the myocardial damage that occurs during cardiopulmonary bypass.

Treatment of aluminum overload using a cartridge with immobilized desferrioxamine

Intravenous desferrioxamine (DFO) is the method commonly used to treat aluminum toxicity. This laboratory has developed a hollow fiber device with immobilized DFO, an "Aluminum DFO-HP" (DFO-HP), for the purpose of removing aluminum without the chelator (DFO) entering the blood. With Food and Drug Administration approval, a polysulfone DFO-HP, placed in the extracorporeal circuit in series with the patient's customary dialyzer, was tested for its safety and ability to remove aluminum in patients with ESRD who had aluminum overload. During treatment with this device, no toxic reactions, side effects, or hematologic or clinical laboratory changes were seen other than those associated with dialysis. Average aluminum clearance with the DFO-HP device was 25.3 mL/min with a range of 7.2 to 52.4 mL/min, whereas aluminum clearance with the F-60 polysulfone high-flux dialyzer was 8.4 mL/min. Aluminum clearance of the cuprophane dialyzers in series with the DFO-HP was negligible. The amount of aluminum removed over a 2-h treatment with DFO-HP ranged from 94 to 628 micrograms, which corresponded to 32 to 199% of the initial aluminum in the circulation before that particular treatment. The excess 99% was provided from aluminum released from tissue sites into the circulation throughout the duration of the treatment. It is expected that, because of the efficiency and safety of the DFO-HP device, the time presently needed for aluminum depletion using intravenous DFO will be greatly shortened and the potential toxicity of intravenous DFO will be eliminated.

Potentiation of thrombolytic therapy by enzyme combinations and with aspirin or pentoxifylline

Radioactively labeled human fibrin clots were placed into veins of Macaca arctoides monkeys. Thrombolysis was recorded by the disappearance of radioactivity and by angiography. Streptokinase (SK) and urokinase (UK) induced thrombolysis was potentiated by low dose aspirin (ASA) and pentoxifylline (PE). Studies on the mechanisms of action revealed that PE inhibits platelet aggregation, releases tissue plasminogen activator (t-PA) from the endothelium, increases red cell deformability and inhibits white cell adhesion. Thrombolysis by pro-urokinase (pro-UK) was potentiated by low dose SK probably because of streptokinase-plasmin activation of pro-UK to UK. Platelet aggregation inhibitory effects, disaggregation of platelet aggregate inducing effects, and the t-PA releasing activity of PE was demonstrated in patients with obstructive cardiovascular disease. Pharmacodynamic studies suggested that PE metabolites one and five are most effective from this point of view. These metabolites are currently studied in combination with thrombolytic enzymes.

Studies on tumor induced angiogenesis

Methods were developed to test angiogenic response to human tumor implants and various biologic agents in the cornea of rabbits and non-human primates (Macaca arctoides). Crude PDGF preparations were found to have significant angiogenic effect. Purified, recombinant PDGF preparations were also effective inhibitors (e.g. pentoxifylline (Px) (which also were found to release PgI2 and t-PA) inhibited human tumor implant induced angiogenesis and reduced spontaneous metastases in 3 transplantable murine tumors (Furth-Columbia Wilms' tumor in Furth-Wistar rats, C-1300 neuroblastoma in A/J mice and HM-Kim mammary carcinoma in Wistar rats) but not in the NIH adenocarcinoma in Balb/c mice. Sodium diethyldithiocarbamate (DDTC), a metal complexing agent with special affinity to copper and anti-thyroid as well as, immune stimulating activity was shown to be anti-angiogenic and to potentiate the effect of Px. The anti-fibrinolytic agents epsilon amino caproic acid (EACA) and tranaxamic acid (t-AMCHA) were anti-angiogenic. DDTC and Px were synergistic from this point of view.

Erythrocyte filterability in normal and high-risk pregnancy

Erythrocyte filterability was studied longitudinally in normal pregnancy and in certain categories of high-risk pregnancy. Study subjects included ten normal controls, 12 insulin-dependent diabetics, eight gestational diabetics, and five essential hypertensives. Our results indicate that erythrocyte filterability remains relatively stable over the course of normal gestation. We noted no differences between controls and essential hypertensives or gestational diabetics, although a favorable effect of insulin therapy was suggested in gestational diabetics. Erythrocyte filterability and mean arterial blood pressure were not related. Insulin-dependent diabetics demonstrated a significantly elevated and widely varying erythrocyte filterability, and individual patient trends correlated well with outcome. Fibrinogen levels in diabetics rose precipitously and were significantly higher than normal throughout gestation. Fibrinogen levels paralleled changes in erythrocyte filterability, with the two parameters positively correlated. Mean glucose control had no influence on filterability. We conclude that in the diabetic pregnancy, varying erythrocyte filterability is related to altered fibrinogen metabolism and may contribute to perinatal morbidity.

Extracorporeal enzyme reactors for depletion of phenylalanine in phenylketonuria

Multitubular enzyme reactors with immobilized enzymes were developed to achieve depletion of circulating substrate by extracorporeal means. To act as prototypes, reactors were prepared with immobilized L-phenylalanine ammonia-lyase, an enzyme that metabolizes phenylalanine to trans-cinnamic acid and ammonia without the need for a coenzyme. We report the first application of phenylalanine ammonia-lyase reactors in an extracorporeal circulation system in a patient with phenylketonuria. A phenylalanine level of 1.82 mmol/L (for the last 6 years) decreased to 1.24 mmol/L after 5.5. hours of treatment, without the enzyme entering the circulation. Total phenylalanine depletion from blood and tissue stores was estimated at 1800 mg. The hemodialysis-like procedure proved to be without side effects, specific for phenylalanine, and suitable in the management of pregnant women with phenylketonuria and late-onset hyperphenylalaninemia. The extracorporeal use of enzyme reactors for temporary enzyme replacement represents a new, safe, and effective therapeutic modality.

Determination of aromatic amino acids by ion-pair reversed-phase liquid chromatography in human sera from healthy and phenylketonuric individuals

A simple chromatographic procedure is described for simultaneous analysis of aromatic amino acids in serum samples obtained from normal individuals and from phenylketonuric patients. Quantitative measurement of phenylalanine, tyrosine, histidine and tryptophan is made in samples as small as 10 microliter after deproteinization with trichloroacetic acid. With phenoxyacetic acid as the internal standard, samples are analyzed by reversed-phase chromatography isocratically by an ion-pairing agent in the eluent, and the amino acids are detected with the UV detector at 210nm. Total analysis time was about 30 minutes. Using this method in serum samples from phenylketonuric patients phenylalanine was increased (as expected), and histidine was decreased, at a statistically significant level.

The role of fibrinolysis in the therapy of peripheral vascular disease

In vivo thrombolytic studies in stumptailed monkeys indicated that pentoxifylline potentiates thrombolysis induced by urokinase activated human plasmin. Pentoxifylline as well as prostaglandin E1 released plasminogen activators and activated the fibrinolysin system. From this point of view pentoxifylline and prostaglandin E1 synergized with each other. Pentoxifylline potentiated the thrombolytic effect of prostaglandin E1 in vivo.

Prostaglandin E2 production by human tumors. Defense mechanism against the host? A preliminary report

Immunoreactive PGE2 was determined in 11 surgically removed malignant tumors. When compared to adjacent non-malignant tissues PGE2 content was significantly higher in the neoplastic tissues. These findings support the view that PG may play a role in cell proliferation and/or vascular supply to tumor tissues. The hypothesis was also discussed that PGE2 may represent a tumor against host defense since it can decrease spontaneous and antibody dependent cytotoxicity. PGE2 may also play a role in tumor induced osteoporosis and hypercalcemia. If this hypothesis is correct PGE2 synthesis inhibitors may be employed as auxiliary antitumor agents.

Legionella and the enterobacterial common antigen

Legionella pneumophilia Philadelphia 1 and Knoxville 1 were examined by in vitro hemagglutination and dermal hypersensitivity reactions in guinea pigs for the presence of the enterobacterial common antigen. No ECA was found and no cross reactivity was demonstrated between ECA and the proteinaceous cross reacting antigen.

Antineoplastic effect of the xanthine derivative Trental

The xanthine derivative, Trental (pentoxifylline) was found to inhibit several human leukemic and lymphoma cell lines in tissue cultures. Optimal concentrations were less inhibitory for a normal B-lymphocyte cell line then for the neoplastic cell lines. In fact, small concentrations stimulated DNA synthesis in the normal cell line. Trental and beta-interferon appeared to be additive synergists at certain dosages. Possible mechanisms are discussed.

Studies on osteoporosis X. Effect of estrogen-progestin combination on heparin-induced osteoporosis

Neutron activation analysis was employed to determine total body calcium in C3H/St(Ha) female mice. As 99% of body calcium is in bone, loss of calcium was used as an index of bone loss (osteoporosis). Heparin (500 U/kg b.i.d. caused bone loss in 3 months. Premarin (2 mg/kg q.d.) or norethindrone (40 mg/kg q.d.) alone prevented this osteoporosis. A Premarin-norethindrone combination (2 mg - 10 mg q.d. respectively) appeared to be somewhat more effective than either agent alone, but this difference was not significant at the 5% level. Combinations of estrogen and progestins may prevent metabolic bone disease at the same time reducing the danger of estrogen induced neoplasia.

Protection of normal tissues with 2-aminoethylisothiouronium during local pelvic radiation in monkeys

Intestinal and bladder injury are the main limiting factors to radiation therapy in patients with pelvic neoplasms. 2-Amino-ethylisothiouronium (AET) is a radiation-protective agent when given systemically but absorbs poorly from the intestines. Accordingly, it was explored for the local protection of the bowel and bladder during radiation to the pelvis. Radiation localized to the pelvis in various high fractionated doses and various schedules was applied to pairs of stumptailed monkeys (Macaca arctoides): one was always a control; and the other was treated with AET. AET was applied to the bladder through a catheter and to the rectum with a cotton tampon during the time of radiation. After radiation, AET was removed by repeated washings. Control animals developed hemorrhage, diarrhea, and emaciation and died at various times after completion of the radiation course; biopsy of rectal mucosa showed severe radiation damage. AET-treated animals had only occult blood in the stools and suffered slight weight loss; rectal biopsies showed normal tissues 2 weeks after radiation.

In vivo safety of hollow fiber enzyme-reactors with immobilized phenylalanine ammonia-lyase in a large animal model for phenylketonuria

Hollow fiber enzyme-reactors with immobilized phenylalanine ammonia-lyase (PAL) were developed for the in vivo depletion of phenylalanine (Phe) in circulating blood. A series of experiments was conducted with a large animal model in order to explore its safety for clinical use. The level of red blood cells, white blood cells and platelets did not change during a 2-hr application of the reactors in anesthetized, heparinized dogs and monkeys with experimental hyperphenylalaninemia. No increase in blood urea nitrogen was observed due to generation of ammonia from PAL-catalyzed Phe breakdown. The other metabolic product, trans-cinnamic acid, was reported to be nontoxic. Repeated application of the PAL-reactors to the same animals did not produce untoward physiological or immunological reactions. These data suggest that PAL-reactors may be safe for in vivo use to control excess Phe brought about by fever, infection or pregnancy in phenylketonuric individuals otherwise balanced by a Phe-poor diet. Application of PAL-reactors may serve as a model for extracorporeal enzyme replacement in enzyme-deficiency diseases.

Depletion of phenylalanine in the blood of phenylketonuric patients using a PAL-enzyme reactor. An in vitro study

Blood samples obtained from eight adult phenylketonuric individuals had a mean phenylalanine level of 25 mg/dl. When these samples were circulated through multitubular enzyme-reactors prepared with immobilized phenylalanine ammonia lyase an average of 77% of phenylalanine was metabolized within 30 minutes. We conclude that phenylalanine in human phenylketonuric blood is just as susceptible to metabolism by PAL-enzyme reactors as phenylalanine that is added to normal blood, or that is circulating in dogs and monkeys made hyperphenylalaninemic by experimental means.

Development of a refractory stage in a dog model for phenylketonuria

Dogs were fed a continuous diet of phenylalanine (Phe) daily and para-chloro-phenylalanine (p-CPhe), an inhibitor of phenylalanine hydroxylase (PH-ase) every second day. It was reported that such a diet produces a sustained hyperphenylalanemia in rats. We have found, however, that in dogs an initial rise in circulating Phe is followed, after a period of time, by a return to normal levels in spite of diet maintenance. PH-ase ws measured in liver samples obtained from dogs before the start of the above diet and at the time when Phe levels returned to normal. It was found that the post-feeding liver sample had 57%-100% less activity than the normal sample. Accordingly, decline in Phe levels cannot be attributed to an increase in PH-ase activity. Experiments are being initiated using labelled Phe, to investigate whether chronic feeding of Phe and p-CPhe resulted in an intestinal block to Phe absorption, which may explain our experimental findings.

Multitubular reactors with immobilized L-phenylalanine ammonia-lyase for use in extracorporeal shunts

Hollow fiber cartridges of improved design have been loaded with L-phenylalanine ammonia-lyase [EC 4.3.1.5.] from Rhodotorula glutinis in order to prepare multitubular enzyme reactors for removal of L-phenylalanine from blood. The kinetics of the enzyme in free solution was investigated and the results showed a behavior similar to that reported for L-phenylalanine ammonia-lyase from other sources. On the other hand kinetic data with the reactors were obtained in a recirculating system by measuring the increase in trans-cinnamate concentration in the perfusate. The effect of changing the enzyme load in the hollow fiber cartridge, the length of the cartridge, the substrate concentration, pH as well as the flow rate and the temperature have been investigated. The results showed that the overall kinetics of the enzymic reaction in the multitubular reactor is not the same as that in free solution and the difference can be attributed to diffusion resistances in the hollow fiber system.

Inhibitors of fibrinolysis in diabetic children, mothers, and their newborn

Late diabetic complications are often related to vascular changes and formation of thrombi in the altered vasculature. Contributing factors to thrombosis susceptibility of diabetic patients include changes in clotting factors, platelets, and inhibition of fibrinolysis. We have measured various fibrinolytic inhibitors in the blood of diabetic children, diabetic pregnant women and their offspring, and healthy controls. Inhibitors studied included 1) fast (immediate) antiplasmin, 2) slow (progressive) antiplasmin, 3) alpha-2-macroglobulin, and 4) alpha-1-antitrypsin. It appears from our study that high fast-antiplasmin levels, and low or missing slow-antiplasmin levels are characteristic of diabetic patients and of newborn of diabetic mothers. The reason for high fast-antiplasmin levels is not clear: Levels are not connected with the age of the patient or duration of diabetes, and are not elevated in response to a fibrinolytic process (fibrin decomposition products could not be shown to be present in the serum of diabetic children). Alpha-2-macroglobulin was significantly higher and alpha-1-antitrypsin significantly lower in diabetic women than in controls. In the other groups of patients studied differences in these inhibitors from the appropriate control groups were not statistically significant.

The biphasic nature and temperature dependence of the activation of human plasminogen by urokinase. A simple urokinase assay based on this phenomenon

Activation of plasminogen is a biphasic process, the first phase is temperature independent, the second phase is not. The first phase of activation is completed immediately when urokinase (UK) is combined with plasminogen. At 4 degrees C the fibrinolytic activity generated in the first phase is directly proportional to the concentration of UK used for activation. This linear relationship permits the construction of a standard curve for the quantitative measurement of UK in samples with unknown concentrations of UK. The second, slower phase of activation follows the first only at higher temperatures (e.g. 28 degrees C), is limited by the plasminogen concentration, and is completed within 30 minutes of incubations. Activation of plasminogen by streptokinase under the same conditions follows a different pattern.

The fibrinolysin system and its relationship to disease in the newborn

The fibrinolysin system is incomplete in newborn infants. Lack of serum plasminogen in premature newborn has an important role in the pathophysiology of the respiratory distress syndrome since alveolar fibrin deposits cannot be eliminated. Urokinase activated human plasmin has increased the survival rate of infants with respiratory distress syndrome. Plasminogen given I.V. at birth has reduced the incidence and the severity of respiratory distress syndrome, in a randomized double-blind study of 500 premature infants. Death in the plasminogen recipient group occurred only among infants born to mothers with bleeding complications of pregnancy. Plasmin inhibitors measured with a functional assay were the highest in this group of infants, serum plasminogen was the lowest; when activator and purified human plasminogen were added to the serum, fibrinolytic activity was elicited in excess of the plasminogen added. It is suggested that plasminogen and/or plasmin inhibitors may be abnormal fetal variants in infants born to mothers with bleeding complications.

Phenylalanine depletion for the management of phenylketonuria: use of enzyme reactors with immobilized enzymes

Multitubular enzyme reactors with immobilized phenylalanine ammonia lyase were tested in vitro and in vivo for depletion of phenylalanine in circulating blood. Sustained reduction of phenylalanine was achieved in less than 30 minutes. A 50% decrease of phenylalanine was obtained with a 2-hour application of enzyme reactors and was maintained for more than 2 days. Similar enzyme reactors have therapeutic potential for temporary management of phenylketonuric patients when their circulating phenylalanine becomes exceedingly high because of infection, fever, or pregnancy.

Preparation of immobilized L-phenylalanine ammonia-lyase in tubular form for depletion of L-phenylalanine

The enzyme L-phenylalanine ammonia-lyase (EC 4.3.1.5), which catalyzes the conversion of L-phenylalanine into trans-cinnamic acid, was adsorbed in the walls of asymmetric hollow fibers and covalently bound to the innerwall of small bore nylon tubing. Multi-tubular enzyme reactor cartridges were constructed both from hollow fibers and nylon tubes and the capacity of the reactors to degrade phenylalanine at physiological concentrations was evaluated in perfusion studies at different flow rates ranging from 30 to 80 ml/min. Hollow fiber enzyme reactors showed significantly higher activity than nylon tube reactors of commensurable dimensions and this finding is attributed to the difficulties in immobilizing L-phenylalanine ammonia-lyase via covalent linkages. The results suggest that extracorporeal use of such multi-tubular enzyme reactors offer a promising approach to deplete serum phenylalanine levels.

Progestational agents and blood coagulation. VIII. Effect of low-dose, alternate-day, estrogen-progestin combinations on blood coagulation factors in man, with a special note on the effect of freezing of blood samples

Changes in the blood coagulation system were studied in three groups of 20 patients each. The first group received 0.5 mg. of norethindrone daily, plus 0.06 mg. of ethinyl estradiol on alternate days from cycle Day 5 through 25. The second group, all of whom had been fitted with an intrauterine contraceptive device (IUD), received no hormonal treatment and served as a control group. The third group received 0.5 mg. of norethindrone daily, combined with 0.045 mg. of ethinyl estradiol given on alternate days from cycle Day 5 through 25. Blood samples were drawn prior to the initiation of the study and after three months of treatment. Tests of the following parameters of the blood coagulation system were performed: direct platelet count; platelet adhesiveness; prothrombin time; thrombin time; fibrinogen; factor II assay; activity of factors V, VII, VIII, IX, and X; antithrombin III; and fibrin/fibrinogen degradation products. For a number of these factors, both fresh and frozen blood samples were examined. It was concluded that the two treatment regimens, with the use of alternate-day estrogen administration over a three-month period, had no clinically significant effect on the blood coagulation system.

Prevention of hyaline membrane disease with plasminogen. A cooperative study

In a double-blind, randomized study, 500 premature infants were treated with plasminogen or placebo intravenously within 60 minutes of birth. There was a substantial decrease in severe clinical respiratory distress, death caused by hyaline membrane disease, and total mortality in the plasminogen-treated infants as compared to the controls.

Prevention of hyaline membrane disease with plasminogen. Preliminary report of a cooperative study

Five hundred premature infants were treated in a double blind, randomized study with intravenous plasminogen or placebo within 60 minutes of birth. There was a significant decrease in severe clinical respiratory distress, death due to hyaline membrane disease and total mortality in the plasminogen treated infants as compared to the controls.

Progestational agents and blood coagulation. VII. Thromboembolic and other complications of oral contraceptive therapy in relationship to pretreatment levels of blood coagulation factors: summary report of a ten-year study

During a ten-year period, 348 women were studied for a total of 5,877 patient months in four separate studies relating oral contraceptives to changes in hematologic parameters. Significant increases in certain factors of the blood coagulation and fibrinolysin systems (factors I,II,VII,VIII,IX, and X and plasminogen) were observed in the treated groups. Severe complications developed in four patients. All four had an abnormal blood coagulation profile, suggesting "hypercoagulability" before initiation of therapy. Some of these findings represented the most extreme abnormalities seen in the entire group of patients; some increased further during therapy. One of these patients developed a myocardial infarction before receiving any medication, shortly after the base-line values were obtained. One patient developed retinopathy 19 months after she began therapy, and another developed thrombophlebitis after 27 months of therapy. The fourth patient developed thrombophlebitis 14 days after initiation of contraceptive therapy. All four patients were of the A or AB blood group. Previous studies suggested the possiblility of increased propensity for thromboembolic episodes in patients possessing the A antigen. It appears from these data that hematologic work-ups may be useful in women who are about to start long-term oral contraceptive therapy.

Effect of various estrogen treatment schedules on antithrombin III levels

Antithrombin III levels were determined in 18 normal indiviuals of both sexes, 24 pregnant women (at term), 20 patients treated with oral contraceptives and 21 postmenopausal patients treated with Premarin. There was no sex difference in antithrombin III levels in the untreated control group. Pregnant women at term had the lowest levels of antithrombin III. The second lowest values were exhibited by women on oral contraceptives. Both of these groups differed significantly (p less than 0.05) from the controls. Premarin treated postmenopausal women had somewhat lower levels of antithrombin III than controls but these were statistically not significant.

Clinical and experimental studies on adenine, various nucleosides and their analogs in hematology

In red blood cells as well as in platelets there appears to be a decrease in adenine nucleotides during storage under blood bank conditions. This can be decreased by use of anticoagulant preservatives with higher phosphate content than the standard ACD solution, through the addition of adenine and inosine. Maintenance of higher ATP levels appears to be related to longer circulating life span after transfusion into patients in the case of red blood cells but not platelets. Inosine and more alkaline preservative medium also contribute to the maintenance of 2,3-DPG levels in red blood cells, and with it to the maintenance of normal hemoglobin dissociation curves and thus oxygen-carrying capacity. Certain nucleoside analogs may contribute to the preservation of platelets and of whole blood by their platelet-aggregation inhibitory activity. Platelet-aggregation inhibitors may also be useful in preventing thromboembolic episodes with potentially greater safety than anticoagulants.

Studies on the prevention of respiratory distress syndrome of infants due to hyaline membrane disease with plasminogen

Hyaline membrane disease (HMD) is leading single cause of death of newborn, premature infants. The "hyaline membranes" consist chiefly of fibrin. The clinical manifestation of HMD is the respiratory distress syndrome (RDS). Infants with RDS were treated with urokinase-activated human plasmin in a previous clinical trial. Survival rate was increased in the plasmin treated group as compared to the placebo recipients. However, cost and difficulty in the preparation of the enzyme made this treatment impractical. We, as well as others, have shown the premature infants lack serum plasminogen; thus they are unable to develop effective fibrinolysis and are defenseless against pulmonary fibrin deposition. Therefore, plamsinogen was tested as a possible preventive agent in RDS due to HMD. In a double blind, randomized study, infants between 1 and 2.5 kg birth weight received plasminogen or placebo shortly after birth, and were then followed for development of RDS. After 100 infants were entered into the study, the code was broken and results were evaluated to assure safety of the procedure. Among the 100 infants, 51 received placebo, 49 received plasminogen. Among the infants who received placebo, seven developed mild, and ten developed severe respiratory distress; of these ten, five died with histopathologically documented HMD. Two infants died from causes other than HMD. Among the 49 infants treated with plasminogen, 13 developed mild and three developed severe respiratory distress. There was no death due to HMD. Two deaths were due to other causes. Factors placing the infant at risk from HMD (degree of prematurity, sex, cesarean section, bleeding episodes during pregnancy, maternal diabetes) were found to be evenly distributed between control and treated groups. Since completing the first phase of the study, data of an additional 277 infants has become available. Although the code was not broken in this series, a preliminary look at mortality data in comparison with mortality data of the first series of 100 (in which the code was broken) suggests that preventive activity of plasminogen has been maintained in the second phase of the study.

Thromboembolic complications of oral contraceptive therapy

During a ten-year period, 348 women were studied for a total of 5877 patient months for changes in hematologic parameters induced by oral contraceptives. Significant increases were observed in Factors I, II, VII, VIII, IX, X and plasminogen. Severe complications developed in four patients. All four had an abnormal blood coagulation profile, suggesting "hypercoagulability" before initiation of therapy. All four patients were of A or AB blood group. It appears from these data that hematologic workups may be useful in women who are about to embark on long-term oral contraceptive therapy.