Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Recombination”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 613 records · Page 34Linked to original sources

Enhanced synthesis of poly(3-hydroxybutyrate) in recombinant Escherichia coli by means of error-prone PCR mutagenesis, saturation mutagenesis, and in vitro recombination of the type II polyhydroxyalkanoate synthase gene.

Type II synthase (PhaC1(Ps)) for polyhydroxyalkanoate (PHA) from Pseudomonas sp. 61-3 was subjected to an in vitro evolution system including PCR-mediated mutagenesis in order to improve the function of PhaC1(Ps) in terms of its ability to produce poly(3-hydroxybutyrate) [P(3HB)] in recombinant Escherichia coli. Based on our established in vivo assay system, two positions (Ser325 and Gln481) where mutations provided remarkable increases in P(3HB) synthesis were identified. Saturation mutagenesis at these positions was carried out to explore whether there might be more beneficial sequences for P(3HB) synthesis than those identified in the point mutation library. As a result, five single mutants [S325C (T) and Q481M (K, R)] gave rise to highly enhanced P(3HB) synthesis. Drastically enhanced P(3HB) synthesis (up to 340- to 400-fold the amount of that of the wild type) was further achieved by generation of all five variants of the double mutants combining the codons for residues 325/481. It is feasible that the replacement of Ser (specific for type II synthase) by Thr (specific for type I synthase) at position 325 resulted in acquiring greater P(3HB) synthesis ability as exhibited by type I synthases. The other hot spot, 481, that positively contributes to enhanced P(3HB) synthesis is located adjacent to a His479, a residue that forms a putative catalytic diad that can be inferred by sequence alignment.

Acyltransferases↗

Epoetin alfa: patient management issues and development through recombinant DNA technology. Part 1: Focus on Epoetin alfa patient management and recombinant DNA technology.

The emergence of the Epoetin alfa as an effective therapy in the treatment of the anemia of chronic renal failure has reemphasized the importance of nursing monitoring and intervention in the treatment of these patients. This article examines the role of nurses in monitoring and managing patients receiving Epoetin alfa and the development of medications, such as Epoetin alfa, with recombinant DNA technology.

Anemia, Hypochromic↗

Acute arterial thrombosis after escalated-dose methotrexate, vinblastine, doxorubicin, and cisplatin chemotherapy with recombinant granulocyte colony-stimulating factor. A possible new recombinant granulocyte colony-stimulating factor toxicity.

Combination chemotherapy with a regimen of methotrexate, vinblastine, doxorubicin, and cisplatin (M-VAC) has produced long-term survival times in a significant proportion of patients with advanced nodal and metastatic urothelial tumors. The availability of the colony-stimulating factors has spurred interest in studies evaluating escalated dosing schedules of M-VAC in an attempt to improve major response rates and overall survival. More frequent use of the colony-stimulating factors, however, in this and other settings may be associated with unrecognized side effects. The authors report a case of arterial thrombosis in a 69-year-old man receiving recombinant granulocyte colony-stimulating factor (rhG-CSF) and escalated-dose M-VAC for treatment of a transitional cell carcinoma of the bladder. Incidents of venous thrombosis have been reported previously with the use of colony-stimulating factors, but, to the knowledge of the authors, this case represents the first report of an arterial thrombosis occurring in a patient receiving rhG-CSF.

Aged↗

Randomized trial of intra-arterial recombinant tissue plasminogen activator, intravenous recombinant tissue plasminogen activator and intra-arterial streptokinase in peripheral arterial thrombolysis.

Sixty patients were recruited into a randomized parallel group comparison of three thrombolytic regimens for acute or subacute peripheral arterial thrombosis. There were no significant differences in age, duration of history, length of occlusion or presence of neurosensory deficit between the groups. Initially successful lysis was significantly greater with intra-arterial (IA) recombinant tissue plasminogen activator (rt-PA) than with either streptokinase (Sk) (P less than 0.04) or intravenous (IV) rt-PA (P less than 0.01). The duration of therapy varied from a median of 35 h with IA rt-PA to 40 h with Sk (P greater than 0.5). The median (confidence interval) increase in ankle:brachial pressure index following IA rt-PA of 0.57 (0.33-0.82) was significantly higher than for either Sk of 0.24 (0-0.57) or for IV rt-PA of 0.18 (0-0.41). Limb salvage at 30 days was achieved in 80, 60 and 45 per cent respectively for IA rt-PA, Sk and IV rt-PA. Haemorrhagic complications occurred in six patients following Sk and in 13 following IV rt-PA; only one minor haemorrhage occurred following a catheter perforation in a patient who received IA rt-PA (P less than 0.05). IA rt-PA provides a more effective, safer fibrinolytic regimen than conventional therapy with Sk. IV rt-PA has not been as successful and carries a significantly higher risk of haemorrhagic complications.

Aged↗

Comparison of the effects of recombinant interleukin 6 and recombinant interleukin 1 on nonspecific resistance to infection.

Interleukin 1 (IL 1) is a potent enhancer of nonspecific resistance to infection in mice. Since IL 1 also induces interleukin 6 (IL 6), we tested the hypothesis that IL 6 mediates the effect of IL 1 on nonspecific resistance. In a lethal Pseudomonas aeruginosa infection in granulocytopenic mice, in which 80 ng of recombinant human IL 1 alpha protects against death, IL 6 appeared to be much less effective. Dosages of 8 ng, 80 ng and 320 ng IL 6 did not differ from the control, whereas 800 ng had a marginal protective effect (0.05 less than p less than 0.1). IL 1 and IL 6 did not potentiate each other in animals treated with suboptimal dosages of both cytokines. Numbers of bacteria cultured from the blood, thigh muscle, liver, spleen, and kidney were similar in animals treated with 800 ng IL 6 and in control animals, arguing against activation of microbicidal mechanisms. The serum concentration profile of IL 6 after an i.p. injection of 80 ng IL 1 was similar to that after 80 ng IL 6 i.p. Only minute amounts of IL 1 were detected in serum after an i.p. injection of IL 6. Taken these data together, it appears that increased resistance to infection induced by IL 1 is not mediated by IL 6.

Animals↗

A functional analysis of recombinant soluble CD46 in vivo and a comparison with recombinant soluble forms of CD55 and CD35 in vitro.

The human cell surface complement regulatory proteins CD46 (MCP), CD55 (DAF) and CD35 (CR1) protect autologous cells from complement-mediated damage by inhibiting C3 and C5 convertases. This regulatory potential has previously been exploited in the treatment of some models of inflammatory injury by the generation of recombinant soluble (rs) proteins, such as rsCD55 and rsCD35 . More recently, we have shown that rsCD46 inhibits complement activation in the fluid phase. In this report, the ability of rsCD46, rsD55 and rsCD35 to regulate human complement activation mediated by the classical pathway in vitro was clearly demonstrated by all three soluble proteins; however, rsCD35 was a more effective inhibitor than either rsCD46 or rsCD55. A combination of rsCD46+ rsCD55 was more potent than either of these proteins alone. Cell lysis via alternative pathway activation in vitro was efficiently regulated by rsCD46 and rsCD35 to a similar extent, whereas rsCD55 was not effective. Assays of rsCD46 in vivo have previously not been possible due to difficulties in expressing sufficient quantities of protein. This limitation has been overcome and now we report the ability of rsCD46 to inhibit immune complex-mediated inflammation in a rat using the reverse passive Arthus reaction model. Administration of rsCD46 significantly reduced the size of lesion, and histological examination showed a reduction in inflammatory infiltrate and edema. These data suggest that rsCD46, in addition to rsCd55 and rsCD35, may be useful a therapeutic agent.

Animals↗

Anti-tumor activity of recombinant mouse tumor necrosis factor (TNF) on colon cancer in rats is promoted by recombinant rat interferon gamma; toxicity is reduced by indomethacin.

The activity and toxicity of rMuTNF, alone or combined with rat recombinant interferon gamma (rRIFN gamma), was tested in inbred WAG rats bearing a weakly immunogenic colon adenocarcinoma (CC531). The tumor was implanted s.c. or under the renal capsule. A single i.v. injection of 10 micrograms of rMuTNF in non-tumor bearers was lethal in 3 to 5 hr, whereas 2 micrograms was not. Doses of 1 microgram rMuTNF were well tolerated when given daily for one week. The most prominent toxic feature was hemorrhagic colitis which could be alleviated when rMuTNF was preceded by i.p. administration of 10 mg/kg indomethacin. Three intralesional injections of 10 micrograms rMuTNF on days 0, 10 and 15 into s.c. tumors (diameter 1-1.5 cm) led to a moderate retardation of growth in 20% of the cases. Combined with 10(5) units of rRIFN gamma, which on its own had no effect, the overall response rate (arrest of tumor growth or regression) was 50%. Two out of 20 tumors treated intralesionally with rMuTNF and rRIFN gamma regressed. The subrenal capsule assay was used to study the possible interference of indomethacin with the anti-tumor activity of rMuTNF. Tumor cubes of 6-8 mg were implanted under the renal capsule; the test was evaluated by weighing. Treatment with 10 mg indomethacin alone on days 0, 2 and 4 had no effect (40 +/- 8 mg vs. 48 +/- 13 mg in controls) whereas 2 micrograms of rMuTNF on the same days resulted in significant tumor inhibition (24 +/- 7 mg, p less than 0.001). The combined administration of 2 micrograms of rMuTNF and indomethacin had an effect similar to that of rMuTNF alone (25 +/- 9 mg). Under protection of indomethacin the rMuTNF dose was increased from 2 micrograms to 10 micrograms. However, this did not lead to further improvement of the results.

Adenocarcinoma↗

Recombinant human granulocyte-colony stimulating factor and recombinant human macrophage-colony stimulating factor synergize in vivo to enhance proliferation of granulocyte-macrophage, erythroid, and multipotential progenitor cells in mice.

Combinations of low dosages of purified recombinant human (rh) macrophage-colony stimulating factor (M-CSF; also termed CSF-1) and rh granulocyte-colony stimulating factor (G-CSF) were compared alone and in combination for their influence on the cycling rates and numbers of bone marrow and splenic granulocyte-macrophage, erythroid, and multipotential progenitor cells in vivo in mice pretreated with iron-saturated human lactoferrin (LF). LF was used to enhance detection of the stimulating effects of exogenously added CSFs. Concentrations of each CSF that were not active in vivo when given alone were active when given together, with the other CSF. The concentrations of rhM-CSF and rhG-CSF needed to increase progenitor cell cycling in the marrow and spleen were reduced by factors of 40-200 when these CSFs were administered in combination with low dosages of the other CSF. At the concentrations of rhM-CSF and rhG-CSF tested, synergism was not noted on absolute numbers of progenitor cells or total nucleated cell counts per organ or circulating in the blood. These findings may have potential relevance when considered in a clinical setting where the CSFs might be used in combination with other biotherapy and/or chemotherapy.

Animals↗

Biological oxidations and P450 reactions. Recombinant mouse CYP1B1 expressed in Escherichia coli exhibits selective binding by polycyclic hydrocarbons and metabolism which parallels C3H10T1/2 cell microsomes, but differs from human recombinant CYP1B1.

Orthologs of a previously identified CYP1B subfamily designated CYP1B1, which are constitutively expressed in mammary, uterine, and embryonic cells, have previously been functionally linked to 7,12-dimethylbenz-a-anthracene (DMBA) metabolism. A chimeric construct of mouse CYP1B1 in which the 20 NH2-terminal amino acids have been replaced by eight residues from human CYP17 has been expressed in Escherichia coli. This recombinant mouse CYP1B1 (recCYP1B1m) exhibited DMBA metabolism accurately reproducing the characteristic product distribution and specific activity of 3.4 nmol/nmol P450/min seen in C3H10T1/2 cells from which this cDNA has been cloned. The high proportion of 10,11- and 3,4-dihydrodiols and near absence of 5,6-dihyrodiol- and 7-hydroxy-DMBA metabolites are seen only in rodent microsomes where CYP1B1 is highly expressed. This distribution of products from recCYP1B1m was highly dependent on addition of epoxide hydrolase, particularly the ratio of 3,4-dihydrodiol to 4-phenol metabolites. These characteristics in addition to inhibition by antibodies raised to recCYP1B1m establish that the CYP1B1 cDNA indeed encodes the P450 responsible for polycyclic aromatic hydrocarbon (PAH) metabolism from C3H10T1/2 cells. DMBA metabolites from cDNA-expressed human CYP1B1 (recCYP1B1h) however, exhibited a different regioselectivity toward DMBA resembling human CYP1A1 catalyzed DMBA metabolism. Reconstitution of recCYP1B1m with different concentrations of NADPH-P450 reductase indicated a high affinity interaction with an apparent Km of 3 nM. Large PAH such as benz[a]pyrene, benz[e]pyrene, benz[a]anthracene, DMBA, 3-methylcholanthrene, and 1-ethynylpyrene bound to recCYP1B1m with high affinity (Kd 0.08 to 0.22 microM) concomitant with substantial spectral shifts (40% low to high spin state change). Smaller PAHs like pyrene, phenanthrene, and naphthalene neither produced spectral changes nor inhibited the spectral change caused by benz[a]pyrene. Among tested steroids, progesterone bound weakly to recCYP1B1m (Kd > 20 microM) with a comparable spectral shift and was a weak inhibitor of DMBA metabolism, but was not metabolized. While 17beta-estradiol is a substrate for human CYP1B1 we have found no evidence for binding to mouse CYP1B1. This data establishes CYP1B1 as an important contributor to activation of PAHs, particularly in extra hepatic tissues that are susceptible to cancer where CYP1B1 in contrast to CYP1A1 is constitutively expressed.

9,10-Dimethyl-1,2-benzanthracene↗

Recombinant thyrotropin stimulates cAMP formation in CHO-K1 cells expressing recombinant chorionic gonadotropin receptor.

Using CHO-K1 cells expressing rat thyrotropin-receptor (CHO-rTSH-R cells) or rat chorionic gonadotropin-receptor (CHO-rCG-R cells), we have examined their reactivity or cross-reactivity to recombinant human thyrotropin (TSH) or human chorionic gonadotropin (hCG). TSH stimulated cAMP formation in CHO-rTSH-R cells dose-dependently, and the maximum response was obtained at 1 mIU/ml. hCG also increased cAMP in the cells from 10(4) mIU/ml, and the maximum stimulation was observed at 10(6) mIU/ml. 10(7) mIU of hCG had the same potency with 1 mIU of TSH to rTSH-R. On the other hand, 10(-1) mIU/ml of hCG increased cAMP content in CHO-rCG-R cells and reached the maximum level at 10(2) mIU/ml. TSH also showed the stimulatory activity to CHO-rCG-R cells. It increased cAMP formation in CHO-rCG-R cells dose-dependently from 10 mIU/ml to 10(3) mIU/ml. Thirty mIU of TSH was calculated to be equivalent to 1 mIU of hCG to CG-R. These results indicate that TSH and hCG cross-react each other with rTSH-R or rCG-R.

Animals↗

A phase II double-blind randomized study of the simultaneous administration of recombinant human interleukin-6 and recombinant human granulocyte colony-stimulating factor following paclitaxel and carboplatin chemotherapy in patients with advanced epithelial ovarian cancer.

PURPOSE: Recombinant human interleukin-6 (rhuIL-6) is a glycosylated cytokine with hematopoietic stimulatory effects. In particular, preclinical studies suggest the agent can stimulate thrombopoiesis, even in conjunction with chemotherapy. We attempted to determine whether higher dose chemotherapy for ovarian cancer was possible given the pharmacologic use of this important growth factor. METHODS: We conducted a randomized, double-blind phase II study of IL-6 plus granulocyte colony-stimulating factor (G-CSF) versus placebo plus G-CSF in combination with a standard chemotherapy regimen. Patients with epithelial ovarian cancer, stages Ic to IV, were eligible. All patients were previously untreated with chemotherapy and had Karnofsky performance status >/=60. rhuIL-6 (Escherichia coli, SDZ ILS 969) 1.0 micrograms/kg or placebo was given subcutaneously on days 2-8 every cycle together with G-CSF 5.0 micrograms/kg subcutaneously days 2-15, following administration of paclitaxel 175 mg/m2 as a 3-h infusion and carboplatin given to a desired AUC of 7.5 on day 1 every 21 days. RESULTS: Fifty patients were entered in this study, although the study was temporarily suspended by the FDA in midstudy over manufacturing concerns. Therefore, 37 patients were evaluable for efficacy of growth factor; 19 patients received placebo plus G-CSF and 18 rhIL-6 plus G-CSF. There was no difference in prognostic variables between these two groups. Platelet nadirs were lower in the first cycle for the placebo group (P = 0.004, Wilcoxon sum-rank test) but not in other cycles. There was no statistically significant difference in cycle treatment delays, carboplatin dose delivered, number of patients with grade 4 thrombocytopenia, or platelet transfusion. Nonetheless, the trend of the data favored IL-6 in all cases. CONCLUSIONS: This study demonstrated a minimal effect (statistically significant in the first cycle only) on thrombopoiesis in women undergoing paclitaxel and carboplatin therapy of ovarian cancer. No clinically significant effect on actual chemotherapy delivery was demonstrated, however. Future studies, if warranted, to ameliorate thrombocytopenia should be carried out with regimens producing even greater thrombocytopenia than the current regimen in the control arm.

Adenocarcinoma↗

Production of recombinant adeno-associated type 5 (rAAV5) vectors using recombinant herpes simplex viruses containing rep and cap.

We developed a scaleable production system for adeno-associated virus type 5 (AAV5)-based vectors using a replication-defective recombinant herpes simplex type 1 virus (rHSV) containing the rep and cap genes of AAV5. Multiple rHSV isolates containing AAV5 rep and cap with normal or altered p5 promoter elements were constructed and tested in vector production. Compared with rAAV5 vector yields obtained by plasmid transfection, yields of rAAV5 using any of the rHSV isolates were low. Evidence suggests that the low vector yields are a consequence of the extensive and early cytopathology induced by the rHSV isolates. In addition, we found a correlation between the amount of Rep52 or Rep40 proteins and the amount of vector produced by each rHSV isolate, suggesting that packaging of vector DNA into virus particles is rate-limiting when using rHSV to generate rAAV5 vectors.

DNA Replication↗

Metabolic effects of recombinant human insulin-like growth factor-I in humans: comparison with recombinant human growth hormone.

Many of the metabolic actions of growth hormone (GH) are mediated through insulin-like growth factors or somatomedins. Recombinant human insulin-like growth factor-I (rhIGF-I) has a dichotomous insulin-like and GH-like action when used in different clinical situations in humans. Its effects on carbohydrate metabolism show a prominent increase in total insulin sensitivity, causing hypoglycemia in higher doses and maintaining normal glucose homeostasis in lower doses. This polypeptide selectively stimulates whole body protein synthesis with no effect on proteolysis when given in doses of 100 micrograms/ kg subcutaneously twice daily for at least 5-7 days, effects which are indistinguishable from those of GH. This contrasts with the marked suppression of proteolysis observed when higher doses are given, similar to the effects observed with insulin. When used in combination with rhGH, rhIGF-I has a synergistic effect, improving total nitrogen retention in calorically deprived subjects, yet it does not cause any greater enhancement of whole body protein anabolism in normally fed volunteers than giving rhGH and rhIGF-I individually. This suggests a common pathway for IGF-I and GH enhancing protein anabolism in the normally fed state. rhIGF-I also stimulates linear growth in children with defects in the GH receptor. Recent data show that this potent growth factor has a potential advantage over GH in the treatment of severe protein catabolic states, particularly the glucocorticosteroid-dependent model, as it ameliorates the marked increase in protein catabolism caused by the steroids, but without a diabetogenic effect. Here, a brief overview is provided of available human data on the actions of this peptide on carbohydrate, lipid, and protein metabolism, linear growth, and its anabolic effects. rhIGF-I offers promise in the treatment of selective growth disorders and in protein catabolic and insulin-resistant states.

Growth Hormone↗

Comparative biological properties of a recombinant chimeric anti-carcinoma mAb and a recombinant aglycosylated variant.

It has been demonstrated previously that the degree of glycosylation of a molecule may alter its pharmacokinetic properties and, in the case of an antibody, its metabolism and other biological properties. Transfectomas producing aglycosylated chimeric B72.3(gamma 1) pancarcinoma monoclonal antibody (mAb) were developed by introduction of the eukaryotic expression construct pECMgpB72.3 HuG1-agly, into SP2/0 murine myeloma cells producing the chimeric kappa chain of mAb B72.3. After cell cloning, one subclone with the highest binding to the TAG-72-positive human colon carcinoma was designated mAb aGcB72.3, and its biological and biochemical properties were compared with those of the chimeric B72.3(gamma 1), designated mAb cB72.3. Polyacrylamide gel electrophoresis showed that under non-reducing conditions, the molecular masses of the aGcB72.3 and cB72.3 mAbs were 162 kDa and 166 kDa respectively. The heavy chain of mAb aGcB72.3 had a slightly faster mobility than that of cB72.3, while the mobility of the light chains of the two chimeric mAbs was similar. No difference was observed in the isoelectric points of either chimeric mAb. Liquid competition radioimmunoassays demonstrated that the aGcB72.3 and cB72.3 mAbs have comparable binding properties to TAG-72. These studies demonstrate that aglycosylation of the chimeric IgG1 mAb B72.3 at the CH2 domain, as has been shown for other mAbs [Dorai H., Mueller B., Reisfeld R. A., Gillies S. D. (1991) Hybridoma 10:211; Morrison S. L., Oi V. T. (1989) Adv Immunol 44:65], eliminates antibody-dependent cell-mediated cytotoxicity activity, but does not substantially alter affinity or plasma clearance in mice. These studies also demonstrate for the first time (a) no difference in plasma clearance of an aglycosylated and a chimeric mAb in a primate after i.v. inoculation; (b) a difference (P less than or equal to 0.05) in mice in the more rapid peritoneal clearance of a chimeric mAb versus an aglycosylated chimeric mAb; (c) higher (0.05 less than or equal to P less than or equal to 0.1) tumor: liver ratios at 24, 72 and 168 h using 111In-labeled aglycosylated chimeric mAb versus chimeric mAb. Since the liver is the major site of metastatic spread for most carcinomas, slight differences in tumor to normal liver ratios may be important in diagnostic applications. These studies thus indicate that comparative analyses of a novel recombinant construct (i.e., aglycosylated) and its standard chimeric counterpart require documentation in more than one system and are necessary if one is ultimately to define optimal recombinant/chimeric constructs for diagnosis and therapy in humans.

Animals↗

Differential effects of Lys- and mini-plasminogen on clot lysis induced by recombinant urokinase and recombinant pro-urokinase in a canine thrombosis model.

These studies were conducted to examine the lytic efficacy of recombinant urokinase (r-UK) and pro-urokinase (r-proUK) in the presence and absence of truncated forms of plasminogen. Due to differences in their structures, these modified proteins are more readily activated to plasmin than the circulating form of plasminogen. Use of such modified substrates for plasminogen activators may improve the clinical outcome in patients treated for a variety of thrombotic diseases. Lys-plasminogen (46 units) or mini-plasminogen (in units of equivalent chromogenic activity), in conjunction with r-UK (7,500 units), were administered in the absence of heparin to dogs (9-11 kg) in which a radiolabelled thrombus was formed in a femoral artery. Fibrinolysis was measured as a loss of radioactivity from the clot. After intra-arterial administration of the agents, clot lysis was 48 +/- 8%, 50 +/- 9% and 75 +/- 2% in the presence of r-UK + vehicle, r-UK + lys-plasminogen, and r-UK + mini-plasminogen, respectively. When these treatment groups were examined in the presence of heparin (500 units + 350 units/hour) in a second study, r-UK (2,000 units) produced clot lysis of 54 +/- 3%; addition of lys- or mini-plasminogen to the regimen resulted in lysis of 62 +/- 9% and 46 +/- 10%, respectively. A third phase of the study examined r-proUK (1,000 units) with heparin; in this case, lysis was 51 +/- 9% in the presence of vehicle, but 55 +/- 17% and 10 +/- 5% when lys- and mini-plasminogen were administered, respectively. Flow restoration, measured in the femoral artery in each experiment, generally paralleled the lytic profile. The results indicate that supplementation with mini-plasminogen is only useful when added to a lytic regimen in the absence of heparin, and that lys-plasminogen, in conjunction with either of the lytic agents, does not improve clot lysis in this canine model.

Animals↗

Studies on the in vitro biological activities of recombinant bovine tumor necrosis factor (rBoTNF) alpha. I. Synergistic antiviral efficacy of rBoTNF alpha, recombinant bovine interferon gamma (rBoIFN gamma) and their combination.

The recent demonstration of the antiviral activity of recombinant human TNF has launched an interest in the use of TNF alpha for antiviral therapy in veterinary medicine. In the precent report, we demonstrate that pretreatment of bovine cells with rBoTNF alpha reduces the yield of bovine herpesvirus type-1 (BHV-1) from infected cells. Reduction in yield was similar to that observed in the presence of rBoIFN gamma. Similarly, rBoTNF alpha was able to protect bovine cells from virus-induced cytopathology. Enhanced antiviral activity was demonstrated when rBoTNF alpha was administered in combination with rBoIFN gamma. Studies on the induction of 2',5'-oligoadenylate synthetase (2'-5' AS) production by cytokine-treated cells showed that although rBoTNF alpha by itself did not induce 2'-5' AS activity it was capable of enhancing the production of 2'-5' AS by rBoIFN gamma-treated cells. Combination of these two cytokines was also evident in the inhibition of proliferation of treated cells. In contrast, the cytotoxic effect of rBoTNF alpha towards actinomycin D-treated cells was not affected by the combination of rBoTNF alpha with rBoIFN gamma.

2',5'-Oligoadenylate Synthetase↗

Dose finding with a novel recombinant plasminogen activator (BM 06.022) in patients with acute myocardial infarction: results of the German Recombinant Plasminogen Activator Study. A study of the Arbeitsgemeinschaft Leitender Kardiologischer Krankenhausärzte (ALKK).

OBJECTIVES: The aim of this study was to determine the appropriate dose of a novel recombinant tissue-type plasminogen activator (BM 06.022) for thrombolysis in patients with acute myocardial infarction. BACKGROUND: BM 06.022 is a mutant of tissue-type plasminogen activator expressed in Escherichia coli that can be given as a single bolus because of a prolonged half-life, which might obviate the need for complicated regimens. METHODS: BM 06.022 given as a single bolus was investigated in 142 patients in a multicenter sequential dose-finding study. Efficacy of the drug was assessed from infarct-related artery patency by coronary angiography. RESULTS: With the first dose of 10 MU of BM 06.022, the predefined minimal 90-min patency of 70% was not achieved, as indicated by the sequential probability ratio test after treatment of 42 patients (group A). The second dose of 15 MU of BM 06.022 was given subsequently in the preset maximum of 100 patients (group B). Angiography 30, 60 and 90 min after the bolus injection of BM 06.022 revealed a patent infarct-related artery (Thrombolysis in Myocardial Infarction trial [TIMI] grade 2 or 3) in 65% and 66%, 73% and 74% and 66% and 75% of patients in groups A and B, respectively. Very early reocclusion up to the 90-min angiogram occurred in 17% and 13%, late reocclusion until predischarge angiography occurred in 7% and 5%, and rescue percutaneous transluminal coronary angioplasty after the 90-min angiogram was performed in 6 and 14 patients in groups A and B, respectively. Plasma fibrinogen decreased from 2.79 g/liter (range 0.94 to 4.75) to 1.69 g/liter (range 0.0 to 3.95) in group A and from 2.54 g/liter (range 0.0 to 5.02) to 0.92 g/liter (range 0.0 to 2.68) in group B. Two bleeding complications requiring transfusion or surgical intervention and one nonfatal intracranial hemorrhage were encountered. Eight patients had a reinfarction, and five patients died, all of cardiac causes. CONCLUSIONS: With BM 06.022 given as a single bolus, a high early patency rate of the infarct-related coronary artery can be achieved. The speed of thrombolysis seems to be superior to standard thrombolytic drugs. The compound warrants further evaluation with respect to safety and efficacy by clinical end points.

Adult↗

Analysis of recombinant monoclonal antibody isoforms by electrospray ionization mass spectrometry as a strategy for streamlining characterization of recombinant monoclonal antibody charge heterogeneity.

A therapeutic recombinant monoclonal antibody analyzed by cation-exchange chromatography exhibited a heterogeneous profile composed of approximately 10 isoforms. The peaks were isolated and characterized by electrospray quadrupole time-of-flight mass spectrometry (ESI-q-TOF-MS), N-terminal Edman sequencing, peptide mapping, and other techniques. Acidic (lower pI) peaks were found to represent deamidated and sialyated species. Higher pI peaks were found to contain N- and C-terminal heavy-chain variants. Biological activities of the more abundant isoforms were found to be comparable. An approach streamlining the characterization of antibody charge heterogeneity is proposed.

Antibodies, Monoclonal↗