Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.21.6 (thromboplastin)
13,278 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thromboembolic complications associated with prothrombin complex concentrate treatment may be related to the high levels of factors II and X in these products. We report here results from preclinical safety studies with a human coagulation factor IX product (AlphaNine; Alpha Therapeutic Corp., Los Angeles, Calif.) that contains no detectable factor II or VII and less than 10 units of factor X/100 units of factor IX. This product was manufactured from virally inactivated factor IX complex with a barium citrate adsorption step followed by affinity chromatography yielding factor IX concentrate with a specific activity of about 86 factor IX units/mg protein. Electrophoresis and immunoblot analysis indicated that the factor IX represents about 65% of the protein in this product. The virus inactivation step incorporated into the manufacturing process (incubation with n-heptane at 60 degrees C for 20 hours) was shown to inactivate at least 8.6 logs of type 1 human immunodeficiency virus. The barium citrate adsorption and affinity chromatography steps were found to remove 2.0 logs of the marker virus, vaccinia, and the DEAE ion-exchange chromatography used to produce factor IX complex was found to remove 1.4 logs of the marker virus, Sindbis. Analysis of three separate manufacturing lots with the polymerase chain reaction revealed no evidence of hepatitis C virus. The purified factor IX was nonthrombogenic when tested at doses of 450 units/kilogram in a rabbit stasis (Wessler) model, whereas the prothrombin complex concentrates were found to be thrombogenic at doses of less than 50 units/kg. There was no evidence of DIC in a porcine model after infusion of 200 units/kg of coagulation factor IX, as manifested by negative fibrin monomer tests, the absence of fibrin in blood vessels at autopsy, little or no change in prothrombin times and partial thromboplastin times, and only moderate decreases in platelet levels after infusion.
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PMID:Human coagulation factor IX: assessment of thrombogenicity in animal models and viral safety. 844 88

We identified 100 patients (51 males and 49 females) as having the lupus anticoagulant. The following diagnoses were found in the patient population: human immunodeficiency virus positivity, 20%; systemic lupus erythematosus, 10%; prolonged preoperative activated partial thromboplastin time (APTT), 10%; procainamide hydrochloride-induced inhibitor, 9%; deep vein thrombosis, 6%; seizure disorders/epilepsy, 5%; and miscellaneous conditions, 40%. Identification was based on a prolonged APTT (> 40 seconds) that normalized with increased phospholipid concentrations and/or a prolonged Russell viper venom clotting time patient-control ratio of 1.20 or greater. In 68 cases (group 1), patient plasma prolonged the APTT of normal plasma in a 1:1 mixing study. However, in 32 cases (group 2), no such prolongation was observed. There was a significant difference between presenting APTTs in patients from group 1 (mean +/- SD, 58.29 +/- 13.30 seconds) compared with that in group 2 (mean +/- SD, 47.93 +/- 5.09 seconds). Furthermore, 66% of group 1 patients had elevated anticardiolipin antibody titers compared with only 41% in group 2. Of the 32 patients in group 2, 16 (50%) were positive for human immunodeficiency virus. We concluded that the investigation of a lupus anticoagulant should not be abandoned because patient plasma does not prolong the APTT of normal plasma in a mixing study, especially in a human immunodeficiency virus-positive population.
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PMID:The lupus anticoagulant. High incidence of 'negative' mixing studies in a human immunodeficiency virus-positive population. 850 27

Colominic acid is a homopolymer of N-acetylneuraminic acid (NANA), which has an alpha-2,8 ketosidic linkage between its polymer units. In this study, colominic acids were sulfated under different conditions and their antiviral activities against human immunodeficiency virus type 1 (HIV-1) were examined. Sulfated colominic acids, containing 6-12% sulfur, blocked the expression of HIV-1 antigen in MT-4 cells or C8166 cells following exposure to MOLT-4/HTLV-IIIB or HIV-1[GUN-1]. The compounds inhibited syncytium formation upon co-cultivation of MOLT-4 cells (clone 8) with MOLT-4/HTLV-IIIB cells and abolished the production of HIV-1 p24 antigen in culture medium of peripheral blood lymphocytes (PBLs). HIV-1 reverse transcriptase (RT) activity was not directly affected by the drugs. The compounds did not prolong activated partial thromboplastin time (APTT) at 10 and 1.0 microgram/ml, suggesting that they may not have appreciable side effects in vivo. These agents were still able to block the expression of HIV-1 antigen even when the cells were infected with HIV-1 in RPMI-1640 medium containing high percentages of fetal calf serum (FCS). These properties may be therapeutically advantageous if these compounds were considered for possible clinical use.
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PMID:Sulfated colominic acid: an antiviral agent that inhibits the human immunodeficiency virus type 1 in vitro. 879 13

5' GTGGTGGGTGGGTGGGT-3' (AR177) is a 17-mer oligonucleotide with anti-human immunodeficiency virus (HIV) activity that is composed of a phosphodiester backbone and single phosphorothioate linkages at the 3' and 5' ends. A hemodynamic toxicity study was conducted in which cynomolgus monkeys were infused i.v. over a 10-minute period with single doses of 5, 20 or 50 mg AR177/kg or saline. Blood pressure, ECG, clinical chemistry, hematology, complement factors, coagulation parameters and the AR177 plasma concentration were determined. AR177 did not cause any mortality in this study, nor did it cause changes in blood pressure, ECG, clinical chemistry or hematology parameters at any dose. There was a minimal, dose-dependent increase in the levels of complement split product Bb and total hemolytic complement. There was a significant dose-dependent and reversible inhibition of coagulation with the 20- and 50-mg/kg doses that lasted up to several hours after infusion. The time course of the inhibition of coagulation closely matched the plasma levels of AR177. There was a no-effect plasma AR177 concentration vs. activated partial thromboplastin time of approximately 60 to 100 micrograms AR177/ml, above which there was prolongation of activated partial thromboplastin time. These data demonstrate that AR177 does not cause significant hemodynamic toxicity at the doses studied and that this drug could be administered as a rapid infusion without any acute, life-threatening effects at doses that produce plasma concentrations that have shown anti-HIV activity in vitro.
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PMID:Single-dose hemodynamic toxicity and pharmacokinetics of a partial phosphorothioate anti-HIV oligonucleotide (AR177) after intravenous infusion to cynomolgus monkeys. 881 16

5'GTGGTGGGTGGGTGGGT-3' (AR177) is a partial phosphorothioate, 17-mer oligonucleotide that has been shown to have anti-human immunodeficiency virus (HIV) activity in vitro and to be a potent inhibitor of HIV-1 integrase. A repeat-dose toxicity and pharmacokinetic study was conducted in which cynomolgus monkeys were given bolus i.v. injections of 2.5, 10 or 40 mg AR177/kg/day every other day for a total of 12 doses. Control monkeys received saline. ECG, clinical chemistry, hematology, coagulation parameters, histopathology and the AR177 plasma concentration were evaluated. AR177 did not cause any mortality in this study, nor did it cause changes in ECG, clinical chemistry, hematology values or histology. However, there was a dose-dependent inhibition of coagulation measured by a prolongation of activated partial thromboplastin time; this inhibition was reversible with drug washout. Analysis of plasma samples by HPLC demonstrated that there was no difference between the AR177 plasma concentrations that were achieved after the 1st and 12th (last) doses of 2.5, 10 or 40 mg/kg. There was a direct relationship between the AR177 plasma concentration and activated partial thromboplastin time. These results indicate that repeated bolus i.v. administration of AR177 to cynomolgus monkeys at doses as high as 40 mg/kg was well tolerated and was not associated with the serious cardiovascular responses previously observed with other oligonucleotides administered i.v.
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PMID:Repeat-dose toxicity and pharmacokinetics of a partial phosphorothioate anti-HIV oligonucleotide (AR177) after bolus intravenous administration to cynomolgus monkeys. 881 17

The function of human immunodeficiency virus nef gene product has been much debated but the precise activity of this protein in the HIV replication cycle remains unknown. HIV-1 Nef was obtained as a fusion protein with maltose binding protein (MBF), purified by amylose column chromatography and separated from MBP by cleavage with factor Xa. Purified HIV-1 Nef protein, but not the fusion protein MBP-Nef, binds to RNA in vitro as tested by three different assays, radioactive or non-radioactive. North-western analysis, UV cross-linking or band-shift analysis. This activity was lost in a deletion mutant lacking 22 amino acids from the amino terminus of HIV-1 Nef, while a deletion of 44 residues from the carboxy terminus of the protein does not impair the RNA binding activity. Moreover, a single amino acid replacement, Arg to Gly at position 22 produces a Nef variant deficient in its ability to interact with RNA. Different Nef proteins from HIV-1, HIV-2 or SIV were fused to MBP and cleaved with factor Xa. The different Nef proteins were all endowed with RNA-binding capacity. Sequence similarities between several RNA binding proteins, including picornavirus 2C and different Nef proteins are observed. The function of Nef during the HIV replication cycle is discussed on the basis of the present findings.
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PMID:Human immunodeficiency virus (HIV) Nef is an RNA binding protein in cell-free systems. 887 44

The human immunodeficiency virus (HIV) infection is becoming more complex. Hemostatic abnormalities occur frequently in the patient with HIV. HIV-related thrombocytopenia (Tr-HIV) is the most common hemostatic disorder with a high morbidity and affects patients from every risk group independently of age, sex, or stage of infection. Two mechanisms are responsible for the Tr-HIV: bone marrow failure and immunological disorders, namely, circulating immune complex deposited on the platelet membrane and the production of autoantibodies directed against platelets. The treatment of choice is zidovudine; other available options are not as effective as zidovudine. In addition, there are some abnormalities in the fluid phase of the coagulation cascade which can produce bleeding or thrombosis in the HIV patient. The most common are a prolonged partially activated thromboplastin time test, the production of a lupic anticoagulant and anticardiolipin antibodies, and several abnormalities in the natural-occurring anticoagulants. The thrombotic thrombocytopenic purpura recently associated with HIV has a clinical presentation and treatment alternatives that closely resemble those for the classical disease. The knowledge of these hemostatic abnormalities in the HIV seropositive patient allows a more rational care of these patients.
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PMID:[Changes in blood coagulation in HIV infection]. 922 57

A polysaccharide extracted from the leaf of Rhizophora apiculata (RAP) was assessed in cell culture systems, for its activity against human and simian immunodeficiency viruses. RAP inhibited HIV-1 or HIV-2 or SIV strains in various cell cultures and assay systems. It blocked the expression of HIV-1 antigen in MT-4 cells and abolished the production of HIV-1 p24 antigen in peripheral blood mononuclear cells (PBMC); the 50% effective concentration (EC50) of RAP in HIV-1 infected MT-4 cells and in PBMC was 10.7 and 25.9 microg/ml, respectively. RAP (100 microg/ml) completely blocked the binding of HIV-1 virions to MT-4 cells. RAP also reduced the production of viral mRNA when added before virus adsorption. RAP inhibited syncytium formation in cocultures of MOLT-4 cells and MOLT-4/HIV-1(IIIB) cells. RAP did not prolong activated partial thromboplastin time (APTT) up to 500 microg/ml. These properties may be advantageous should RAP be considered for further development.
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PMID:Antiviral properties of a mangrove plant, Rhizophora apiculata Blume, against human immunodeficiency virus. 1066 61

A 70-year-old patient with a history of hypertension and hypercholesterolemia was referred for evaluation of necrotic toes. The patient had a history of several cerebrovascular accidents during the previous month. Initially, she developed sudden-onset left upper extremity weakness which, over the ensuing 4 days, progressed to complete left-sided weakness. This was followed by the development of acute dysarthria. A transesophageal echocardiogram revealed moderate left ventricular hypertrophy, several vegetations on her tri-leaflet aortic valve associated with moderate aortic regurgitation, and a large right atrial thrombus with a mobile component. Bubble studies failed to reveal any septal defects. The patient's electrocardiogram was nonspecific. As serial blood cultures were negative despite fevers of up to 39.8 degrees C, the patient was treated with a 6-week course of intravenous ceftriaxone, ampicillin, gentamicin, and ciprofloxacin for a presumed diagnosis of culture-negative endocarditis. Fungal cultures of the blood were negative. The patient, however, progressed and developed several necrotic toes. Physical examination was significant for ischemic changes of the left first, second, third, and fifth toes, as well as the right first and second toes. Diffuse subungual splinter hemorrhages in the toenails, numerous 2-4-mm palpable purpuric papules on the lower extremities, and nontender hemorrhagic lesions of the soles were also noted. Peripheral and carotid pulses were intact and no carotid bruits were heard. Cardiopulmonary and abdominal examinations were unremarkable. Neurologic examination revealed a disoriented, dysarthric patient with left central facial nerve paralysis, as well as spasticity, hyperactive reflexes, and diminished strength and sensation in the left upper and lower extremities. A left visual field defect and left hemineglect were also present. The patient's last brain computerized tomogram revealed areas of low attenuation consistent with cerebral infarctions in three distinct areas of the brain. These included the left occipitotemporal area, the right parieto-occipital area, and the right posterior frontal region. The regions affected were in the distribution of both the anterior and posterior circulation. No evidence of hemorrhage was noted. The patient subsequently complained of abdominal discomfort. A computerized tomogram of the abdomen with oral and intravenous contrast revealed a 4-cm x 3-cm irregular mass in the tail of the pancreas with several low-attenuation lesions throughout the liver which were consistent with infarctions or metastases. Several splenic infarctions were also present. A biopsy of the tumor revealed pancreatic adenocarcinoma. The patient's carcinoembryonic antigen level was 18. 4 ng/mL (0-3) and the CA 19-9 antigen level was 207,000 U/mL (0-36). The alpha-fetoprotein level was normal. Other significant laboratory findings included a prothrombin time of 16.7 (international normalized ratio, 1.4), an activated partial thromboplastin time of 32 (ratio, 1.3), and a platelet count of 85,000/mm3. The Russell viper venom time, sedimentation rate, and C3 levels were normal, and the patient was negative for antinuclear antibodies, anticardiolipin antibodies, and antibodies to extractable nuclear antigens. Of note, the patient was not receiving any anticoagulation. Blood cultures for mycobacteria and fungi, human immunodeficiency virus serology, and urinalysis and culture were negative. The patient subsequently developed an inferior wall myocardial infarction and was transferred to the coronary care unit. In line with the family's request, aggressive care was ceased and the patient expired. The patient's family refused an autopsy.
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PMID:Cutaneous manifestations of marantic endocarditis. 1080 80

Anemia, thrombocytopenia, and neutropenia are common manifestations in patients with human immunodeficiency virus infection that become more frequent and severe with progression from the asymptomatic state to acquired immunodeficiency syndrome (AIDS). Causes of anemia in AIDS include nutritional deficiencies, infection, and marrow suppression by antiretroviral drugs and by the disease itself. Autoimmune hemolysis and blood loss from gastrointestinal lymphoma or Kaposi sarcoma may also contribute. Granulocytopenia may be due to infection, autoimmunity, or bone marrow suppression by drugs or the immunodeficiency virus. Lymphopenia, the classic hallmark of the disease, typically affects T-helper cells first and worsens as the disease advances. Lymphopenia is a result of the direct cytopathic effects of the virus. Thrombocytopenia can occur from antibodies causing an idiopathic thrombocytopenic purpura-like state from bone marrow suppression or from thrombotic thrombocytopenic purpura. A prolonged partial thromboplastin time due to a coagulopathy caused by lupus anticoagulant causing has been described. A variety of malignancies occurs.
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PMID:Hematological Effects of Human Immunodeficiency Virus Infection. 1088 19


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