Disposition of mitomycin C after local intraarterial application.
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Antibiotics, Antineoplastic↗
Biomedical subjects
G Joseph
Publications and source records attributed to G Joseph.
Triglyceride expression.
Current epidemiologic reports claim an important role for triglycerides in coronary artery disease (CAD). By cross-sectional data analysis, the role of triglycerides was assessed in 1726 consecutive patients investigated for chest pain, 1119 with CAD and 607 with normal coronaries. Besides study of male and female patients as separate groups, the males were divided into age groups of below 40 years, 41 to 50 years, 51 to 60 years and over 61 years. The female patients were divided into those below 50 years and over 51 years because of smaller numbers. Using the mean value for cholesterol, triglyceride, HDL cholesterol, LDL cholesterol and body mass index for normals as the demarcation line, logistic regression analysis was carried out to study their association in the patients with CAD and normals. Results showed that while the odds ratio for total cholesterol were higher for the younger age groups, the odds ratio for triglycerides were consistently higher for the groups over 51 years both male and female. It is speculated that there may be a difference in the relative importance of lipid fractions with reference to age in the development of atherosclerotic plaque with cholesterol playing a more important role in younger people and triglycerides being equally or more important in older people, on the basis of metabolic handling of lipid fractions.
Adult↗
Nucleolin is a sequence-specific RNA-binding protein: characterization of targets on pre-ribosomal RNA.
Nucleolin is an abundant nucleolar protein, which plays an essential, but largely unknown role in ribosome biogenesis. Nucleolin contains four consensus RNA-binding domains (CS-RBD), the presence of which suggests that the molecular function of this protein is likely reflected by its RNA-binding properties. Indeed, by immunocytological analysis performed on ribosomal transcription units, we have found several nucleolin molecules associated with nascent pre-rRNA. In mouse, two high-affinity binding sites with an apparent dissociation constant (Kd) of 50 to 100 nM have been mapped in the 5' ETS upstream from the early pre-rRNA processing site. Interestingly, nucleolin of mouse origin has recognized analogous sequences in the 5' ETS of human pre-rRNA. In parallel, selection-amplification (SELEX) experiments have identified an 18-nucleotide long RNA sequence that binds nucleolin with high affinity (Kd 5 to 20 nM) and shares a common UCCCGA motif with the characterized pre-rRNA binding sites. By mutagenesis and a structural analysis, we have characterized the nucleolin RNA binding site and found that it is constituted by a minimal 18-nucleotide long stem-loop structure. The sequence UCCCGA that is found within the hairpin loop is necessary for the specific interaction. Mutation of any of the C or G residues within this motif abolishes nucleolin interaction. Furthermore, point mutation in the stem that completely disrupt the hairpin structure also prevents nucleolin binding. By determining the minimal 5' and 3' ends of the RNA that is bound to the protein we concluded that nucleolin binding site is constituted by a short four to five-base-pair stem and an eight-nucleotide loop. This structural motif is very similar to hairpins recognized by two other CS-RBD-containing proteins (U1 snRNP A and U2 snRNP B"). Possible functional implications of our findings are discussed.
Animals↗
Safety and efficacy of purified factor IX concentrate and antifibrinolytic agents for dental extractions in hemophilia B.
This study evaluated the safety and efficacy of combined treatment with epsilon-aminocaproic acid or tranexamic acid and monoclonal antibody purified factor IX (MAb factor IX) for prophylaxis against bleeding in eight hemophilia B patients undergoing nine dental extraction procedures. All patients achieved excellent hemostasis without clinical evidence of thrombosis. There were no significant changes in hemoglobin or hematocrit or in markers of hemostatic system activation (prothrombin fragment F1+2, fibrinopeptide A, and fragment B beta 15-42) after surgery. Thus, a highly purified factor IX concentrate and antifibrinolytic therapy can be effectively and safely combined in hemophilia B patients undergoing dental extractions.
Adult↗
Localization of nucleolin binding sites on human and mouse pre-ribosomal RNA.
Nucleolin, a major RNA binding protein of the nucleolus is found associated mainly to the pre-ribosomal particles and is absent from the cytoplasmic mature ribosomes. The role of this protein in ribosome biogenesis remains largely unknown, and is likely to be reflected by its RNA binding properties. Nucleolin contains in its central domain four RNA recognition motifs (RRM, also called RBD for RNA binding domain) which are conserved among different species. RNA binding studies have revealed that nucleolin interacts specifically with a short stem loop structure called NRE (nucleolin recognition element). We show that nucleolin extracted from human, hamster and mouse cells interacts with the same specificity and affinity to a mouse 5'ETS (external transcribed spacer) RNA fragment which contains a NRE motif. A similar structure within the human 5'ETS is also efficiently recognized by mouse nucleolin. We identified putative NRE not only in the 5'ETS but also in the 3'ETS, ITS (internal transcribed spacer) and in the 18S and 28S RNA sequences. This is in agreement with in vivo cross-linking data and a previous immunocytological analysis of ribosomal transcription units. Interestingly, we found that all the NRE localized in the 28S region are within the variable domains. Despite considerable sequence divergence of these domains, several of the NRE have sequences perfectly conserved between these two species. This suggests that these nucleolin binding sites might be functionally important, in particular for ribosome biogenesis.
Animals↗
Influence of ECG measurement accuracy on ECG diagnostic statements.
Computer analysis of electrocardiograms (ECGs) provides a large amount of ECG measurement data, which may be used for diagnostic classification and storage in ECG databases. Until now, neither error limits for ECG measurements have been specified nor has their influence on diagnostic statements been systematically investigated. An analytical method is presented to estimate the influence of measurement errors on the accuracy of diagnostic ECG statements. Systematic (offset) errors will usually result in an increase of false positive or false negative statements since they cause a shift of the working point on the receiver operating characteristics curve. Measurement error dispersion broadens the distribution function of discriminative measurement parameters and, therefore, usually increases the overlap between discriminative parameters. This results in a flattening of the receiver operating characteristics curve and an increase of false positive and false negative classifications. The method developed has been applied to ECG conduction defect diagnoses by using the proposed International Electrotechnical Commission's interval measurement tolerance limits. These limits appear too large because more than 30% of false positive atrial conduction defect statements and 10-18% of false intraventricular conduction defect statements could be expected due to tolerated measurement errors. To assure long-term usability of ECG measurement databases, it is recommended that systems provide its error tolerance limits obtained on a defined test set.
Arrhythmias, Cardiac↗
Coronary angiographic findings in patients with diabetes: an exercise in cardiovascular epidemiology.
A study of 516 patients with diabetes mellitus who presented with chest pain and an equal number of matched controls without diabetes examined by selective coronary arteriography was undertaken. Detailed analysis of the angiograms showed that prevalence of CAD in diabetics with symptoms was 86.6%. This prevalence increased with age. Multivessel disease was more common in diabetics that in controls (p < 0.01). In diabetic patients disease involvement of proximal and distal segments in the same vessel was more common (p < 0.01). The Gensini score of quantitative expression of severity of CAD was higher in diabetics (p < 0.05). The number of occluded segments in the coronary tree was higher in diabetics (p < 0.01). No correlation could be established between severity of disease and age, body mass index or duration of diabetes. It is concluded that diabetes affects the coronary arteries of Indian patients more adversely than those of non-diabetics. The prevalence of CAD among diabetics increases linearly with age.
Adult↗
"Peptide walking" is a novel method for mapping functional domains in proteins. Its application to the Rac1-dependent activation of NADPH oxidase.
Activation of the superoxide generating NADPH oxidase of phagocytes involves the assembly of a multimolecular complex and is dependent on the participation of the small molecular weight GTP-binding protein Rac (1 or 2). This model system was used for mapping functional domains in the primary sequence of Rac1, based on assessing the inhibitory effect of 90 individual overlapping pentadecapeptides, spanning the entire length of Rac1, on NADPH oxidase activation in two types of cell-free assay. Five functional domains were identified, each consisting of a cluster of contiguous residues shared by members of five groups of overlapping inhibitory peptides. Four of the five domains are exposed on the molecular surface of Rac1 and were not identified previously by mutational analysis; the fifth corresponds to a polybasic motif near the carboxyl terminus, confirming earlier reports. Screening the entire linear sequence of a protein with a battery of overlapping peptides for interference with its ability to interact with upstream or downstream molecules should be of wide applicability as a reliable, fast, and economical method for mapping of functionally relevant domains.
Amino Acid Sequence↗
Human DNA helicase IV is nucleolin, an RNA helicase modulated by phosphorylation.
The cDNA encoding human DNA helicase IV (HDH IV), a 100-kDa protein which unwinds DNA in the 5' to 3' direction with respect to the bound strand, was cloned and sequenced. It was found to be identical to the human cDNA encoding nucleolin, a ubiquitous eukaryotic protein essential for pre-ribosome assembly. HDH IV/nucleolin can unwind RNA-RNA duplexes, as well as DNA-DNA and DNA-RNA duplexes. Phosphorylation of HDH IV/nucleolin by cdc2 kinase and casein kinase II enhanced its unwinding activity in an additive way. The Gly-rich C-terminal domain possesses a limited ATP-dependent duplex-unwinding activity which contributes to the helicase activity of HDH IV/nucleolin.
Adenosine Triphosphatases↗
Effect of annealing temperature on the degradation of reinforcing fibers for absorbable implants.
Calcium phosphate fibers designed for reinforcement of bioabsorbable fracture fixation devices were evaluated for their properties upon annealing. The composition of these fibers were 54% PO4, 27% Ca, 12% ZnO, 2.5% NaPO3, and 4.5% Fe2O3, and they were either not annealed, annealed at 250 degrees C, or annealed at 420 degrees C. Chemical degradation, mass loss, and morphology upon degradation were studied. Chemical degradation was performed in Tris-buffered HCl, while mass loss and morphologic studies were performed in both physiologic and nonphysiologic solutions. The results showed that degradation rates for fibers were inversely proportional to the annealing temperature. Mass loss analysis of fibers immersed in the two physiologic solutions (calf serum and simulated body fluid) revealed little change in fiber diameter up to 60 days. Morphologic examination revealed little change in fibers immersed in the two physiologic solutions until 60 days, after which thin shells were found to be peeling off the outer coating of the fiber. Samples in tris-buffered HCl revealed a dramatic difference in mode of degradation among the three fibers. Fibers not annealed and those annealed at lower temperatures underwent a delaminating type of degradation that appeared to destroy the overall integrity of the fiber, whereas fibers annealed at 420 degrees C underwent crater-like deterioration in which the overall alignment of the fiber remained intact. It is therefore concluded that annealing fibers at higher temperatures also undergo a mode of degradation that allows them to maintain their structural integrity. Although annealing fibers close to glass transition temperature may produce an initially weaker fiber, chemical and physical degradation occur much slower, making these fibers most suitable for reinforcement of biodegradable implants.
Absorption↗
Phase II trial of 5-fluorouracil, folinic acid, and N,N1,N11-triethylenethiophosphoramide (thiotepa) in patients with advanced breast cancer.
A total of 35 women with advanced, metastatic breast cancer were treated with combination chemotherapy consisting of folinic acid 500 mg/m2 over 2 hours administered with 600 mg/m2 of 5FU at the midpoint of the folinic acid infusion weekly for 6 weeks, plus 60 mg/m2 of thiotepa on day 1 and day 28. The cycle was repeated every 8 weeks. Patients were evaluated for toxicity weekly. Response was evaluated at the end of each 8-week cycle. The median age was 55 years (range: 34-67). Prior to this study 30 patients had received chemotherapy; 13 had 1 regimen; 17 had 2 or more regimens; 8 had 5FU treatment. The overall response rate was 40% (1 complete and 13 partial); median duration of response was 4 months. Four of 8 patients with prior 5FU responded. Hematologic toxicity was significant; nadir WBC count: < 1,000/mm3 (10 patients); 1,000-1,999/mm (13 patients); nadir platelet count: < 20,000/mm3 (8 patients): 20,000-49,000/mm3 (8 patients); 50,000-99,000/mm3 (10 patients). We conclude that the combination of thiotepa, 5FU, and leucovorin had significant myelotoxicity and do not recommend its routine use in the treatment of metastatic breast cancer.
Adult↗
Electrocardiographic changes during isoflurane anesthesia suggesting asymptomatic coronary artery disease in three patients.
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Aged↗
Closure of a popliteal arteriovenous fistula using an autologous vein-covered Palmaz stent.
PURPOSE: To report the use of autologous vein to cover a stainless steel stent designated for repair of a traumatic popliteal arteriovenous (AV) fistula. METHODS AND RESULTS: Autologous cephalic vein was harvested to cover a Palmaz biliary stent selected to close a traumatic popliteal AV fistula that persisted despite reparative attempts with balloon occlusion and coil embolization. The vein-covered stent was delivered percutaneously and deployed, successfully obliterating the vascular communication. Patency of the popliteal artery was documented arteriographically at 5 months, and symptomatic improvement continues at 10 months. CONCLUSION: The simplicity of this percutaneous approach and the use of autologous vein to cover endovascular prostheses create the possibility for evaluating this technique in myriad anatomical situations.
Aged↗
Characterization of the metabolites of the peptidomimetic human immunodeficiency virus type 1 protease inhibitor SK&F 107461 in rats using liquid chromatography/mass spectrometry.
The metabolic fate of SK&F 107461 [Cbz-Ala-Ala-Phe psi [CHOHCH2] Gly-Val-Val-OMe], a potent and specific inhibitor of the protease encoded by human immunodeficiency virus type 1, in male Sprague-Dawley rats is described. SK&F 107461 is a hexapeptide analog containing a hydroxyethylene linkage in place of one of the peptide bonds, and in which the amino terminus is blocked with a carbobenzyloxy group and the carboxy terminus is modified to a methyl ester. The major metabolites of SK&F 107461 found in bile and urine after intravenous administration of 3H-labeled compound were characterized by LC/MS using either thermospray or continuous flow/FAB models of ionization. Approximately 80% of the administered radioactivity was recovered in the bile of bile duct-exteriorized rats following an intravenous dose. Radiochromatographic profiling indicated that SK&F 107461 was subject to extensive biotransformation. Structures were determined for three major biliary and five major urinary metabolites. Two of the major circulating plasma metabolites observed after intravenous bolus administration had similar retention times to metabolites that were observed in both bile and urine. A pathway for the biotransformation of SK&F 107461 in the rat is proposed. The parent molecule underwent two primary modes of metabolism. Hydrolysis of the carboxy-terminal ester or hydrolysis of the Ala-Ala peptide bond near the amino terminus were the primary metabolic events. All of the other metabolites characterized can be accounted for by exopeptidase activity subsequent to one or both of these primary events. There were no major metabolites observed resulting from anything other than hydrolysis of the ester or peptide bonds in the parent molecule.
Amino Acid Sequence↗
[Pharmacologic action profile of crataegus extract in comparison to epinephrine, amirinone, milrinone and digoxin in the isolated perfused guinea pig heart].
Using isolated perfused guinea pig hearts experiments were performed to investigate the influence of crataegus extract LI 132 (Faros 300, CRA) in comparison to other inotropic drugs--epinephrine (adrenaline, ADR), amrinone (AM), milrinone (MIL) and digoxin (DIG)--on different functional parameters, with special emphasis on the effective refractory period of the myocardium. The simultaneous registration of appropriate parameters allowed to relate the effect on the refractory period to the inotropic, chronotropic, dromotropic and coronary actions of these compounds at each concentration level. All substances--with the exception of CRA--shortened the effective refractory period concentration-dependently besides their known other functional effects (max.: 1 x 10(-5) mol/l ADR by 38%, 7 x 10(-7) mol/l DIG by 26%, 1 x 10(-4) mol/l MIL by 13% and 5 x 10(-4) mol/l AM by 1.6%). Related to the positive inotropy the shortening was most effective under MIL (1.32 ms/mN), followed by AM (0.65 ms/mN), DIG (0.40 ms/mN) and ADR (0.28 ms/mN). On the contrary, CRA produced a prolongation of the effective refractory period by maximally 10% resp. by 2.54 ms/mN. Thus, the pharmacologic profile of CRA differs from that of other inotropic compounds mainly in this parameter (with potentially reduced arrhythmogenic risk).
Amrinone↗
Inhibition of NADPH oxidase activation by synthetic peptides mapping within the carboxyl-terminal domain of small GTP-binding proteins. Lack of amino acid sequence specificity and importance of polybasic motif.
The small GTP-binding protein (G protein) Rac1 is an obligatory participant in the assembly of the superoxide (O2-.)-generating NADPH oxidase complex of macrophages. We investigated the effect of synthetic peptides, mapping within the near carboxyl-terminal domains of Rac1 and of related G proteins, on the activity of NADPH oxidase in a cell-free system consisting of solubilized guinea pig macrophage membrane, a cytosolic fraction enriched in p47phox and p67phox (or total cytosol), highly purified Rac1-GDP dissociation inhibitor for Rho (Rho GDI) complex, and the activating amphiphile, lithium dodecyl sulfate. Peptides Rac1-(178-188) and Rac1-(178-191), but not Rac2-(178-188), inhibited NADPH oxidase activity in a Rac1-dependent system when added prior to or simultaneously with the initiation of activation. However, undecapeptides corresponding to the near carboxyl-terminal domains of RhoA and RhoC and, most notably, a peptide containing the same amino acids as Rac1-(178-188), but in reversed orientation, were also inhibitory. Surprisingly, O2-. production in a Rac2-dependent cell-free system was inhibited by Rac1-(178-188) but not by Rac2-(178-188). Finally, basic polyamino acids containing lysine, histidine, or arginine, also inhibited NADPH oxidase activation. We conclude that inhibition of NADPH oxidase activation by synthetic peptides mapping within the carboxyl-terminal domain of certain small G proteins is not amino acid sequence-specific but related to the presence of a polybasic motif. It has been proposed that such a motif serves as a plasma membrane targeting signal for a number of small G proteins (Hancock, J.F., Paterson, H., and Marshall, C.J. (1990) Cell 63, 133-139).
Amino Acid Sequence↗
Posttransplantation plasma cell dyscrasias.
BACKGROUND: Lymphoproliferative disorders that occur in patients receiving cyclosporine for immunosuppression after solid organ transplantation typically are B-cell neoplasms associated with Epstein-Barr virus (EBV), which may be polyclonal or monoclonal in origin. Although these tumors may have partial B-cell differentiation, (manifested as plasmacytoid features), terminal differentiation to plasma cells that secrete a monoclonal immunoglobulin is rare. The case of a patient who developed a posttransplantation lymphoproliferative disorder that was composed of multiple plasmacytomas located in the abdomen and urinary bladder after liver transplantation is presented. The patient also had high levels of an immunoglobulin-G kappa monoclonal paraprotein. METHODS: The plasmacytoma was examined for the presence of EBV by both polymerase chain reaction and in situ hybridization, and the possibility of a codon-12 mutation in the ras gene was investigated by digestion of DNA amplification products with the HpaII-restriction endonuclease. RESULTS: Epstein-Barr virus genomes were demonstrated by DNA amplification of sequences in the long, internal, direct repeat region, and in situ hybridization showed expression of EBV RNA transcripts that annealed to an EBER-1 probe. Immunohistochemistry showed clonally restricted expression of kappa light chains but failed to reveal evidence of expression of the latent membrane protein 1 encoded by EBV. Mutations of codon-12 in the H-ras gene were not detected. CONCLUSIONS: Resolution of the tumor and the paraprotein after radiation and reduction of immunosuppression indicates that terminal plasmacytic differentiation does not necessarily portend an unfavorable prognosis, even in a clonal lesion.
Abdominal Neoplasms↗
The GDP-bound form of the small G protein Rac1 p21 is a potent activator of the superoxide-forming NADPH oxidase of macrophages.
Phagocytes produce superoxide by the assembly of a multicomponent complex that utilizes NADPH for the reduction of molecular oxygen (NADPH oxidase). The components participating in the assembly are a membrane-bound flavocytochrome and three cytosolic proteins, one of which was shown to be a dimer of the small GTP-binding protein (G protein) Rac1 p21 or Rac2 p21 with GDP dissociation inhibitor for Rho (Rho GDI). We determined the identity and quantity of the nucleotide bound to Rac1 p21 by high performance anion exchange chromatography of extracts prepared from highly purified Rac1 p21-Rho GDI, isolated from guinea pig macrophage cytosol. Rac1 p21 contained only GDP at a ratio of close to 1 mol of GDP per mol of G protein. The GDP-bound form of Rac1 p21 complexed to Rho GDI functioned as a potent activator of NADPH oxidase in a cell-free system that contained no free GTP or ATP. We propose that the GDP-bound form of Rac1 p21 might be the physiological activator of NADPH oxidase in macrophages, following its dissociation from Rho GDI, and that nucleotide exchange or conversion to GTP is not necessarily involved.
Amino Acid Sequence↗