Protroca: A Noninterventional Study on Prophylactic Lipegfilgrastim against Chemotherapy-Induced Neutropenia in Nonselected Breast Cancer Patients

BackgroundProtroca evaluated the efficacy and safety of primary and secondary prophylaxis of neutropenia with lipegfilgrastim (Lonquex®) in breast cancer patients receiving neoadjuvant or adjuvant chemotherapy (CT).Patients and MethodsOf the 255 patients enrolled, 248 patients were evaluable for the intent-to-treat (ITT) and 194 patients for the per-protocol set. Primary and secondary end points after lipegfilgrastim treatment were assessed.ResultsNine patients of the ITT set receiving lipegfilgrastim as primary prophylaxis (n = 222) had febrile neutropenia of grade 3–4 (5 patients) or infection of grade 3–4 (4 patients); 1/26 of those receiving secondary prophylaxis had an event. Dose reductions were performed in 9.5% of the patients. Postponement of cancer CT cycles for >3 days occurred in <15% of patients; 10.8% (92/851 AEs) and 8% (2/25 SAEs) of documented adverse events and serious adverse events, respectively, were related to lipegfilgrastim.ConclusionsApplication of lipegfilgrastim was effective as primary and secondary prophylaxis in the prevention of CT-induced neutropenia in breast cancer.     

The pyridoindole antioxidant stobadine inhibited glycation-induced absorbance and fluorescence changes in albumin

We studied the effect of the pyridoindole antioxidant stobadine on glycation-induced absorbance and fluorescence changes in bovine serum albumin (BSA), used as a model protein. Incubation of BSA (4 mg/ml) with glucose (100–400 mM) in 0.12 M phosphate buffer, pH 7.4, in the presence of 100 M Cu²⁺ at 37°C resulted in a time-dependent increase of absorbance (320 nm) and fluorescence (excitation 350 nm, emission 415 nm). The process was found to be dependent on the presence of oxygen and transition metal ions, but equimolar iron could not fully substitute for the activity of copper. The glucose-induced chromo- and fluorophore formation was reduced significantly by stobadine. For 200 mM glucose, in 7- and 14-day incubations, 51%–60% inhibition was obtained at a stobadine concentration of 0.1 mM, and the effect leveled off at higher concentrations of the drug. No inhibition was observed withN-acetyl stobadine, a derivative with restricted antioxidant activity. Since stobadine did not affect the Amadori product formation determined by the thiobarbituric acid (TBA) method as 5-hydroxymethyl furfural (5-HMF) released in boiling oxalic acid, the inhibitory action of stobadine may be explained by its interference with metal-catalyzed oxidation reactions following after the glycation step. The results obtained suggest that antioxidant therapy could be used to limit the damage from adverse glycation-induced processes in diabetes mellitus.     

Heterogeneity in Rhesus Macaque Complement Factor H Binding to Meningococcal Factor H Binding Protein (FHbp) Informs Selection of Primates To Assess Immunogenicity of FHbp-Based Vaccines

Neisseria meningitidis causes disease only in humans. An important mechanism underlying this host specificity is the ability of the organism to resist complement by recruiting the complement downregulator factor H (FH) to the bacterial surface. In previous studies, binding of FH to one of the major meningococcal FH ligands, factor H binding protein (FHbp), was reported to be specific for human FH. Here we report that sera from 23 of 73 rhesus macaques (32%) tested had high FH binding to FHbp. Similar to human FH, binding of macaque FH to the meningococcal cell surface inhibited the complement alternative pathway by decreasing deposition of C3b. FH contains 20 domains (or short consensus repeats), with domains 6 and 7 being responsible for binding of human FH to FHbp. DNA sequence analyses of FH domains 6 and 7 from macaques with high or low FH binding showed a polymorphism at residue 352 in domain 6, with Tyr being associated with high binding and His with low binding. A recombinant macaque FH 6,7/Fc fragment with Tyr352 showed higher binding to FHbp than the corresponding fragment with His352. In previous studies in human FH transgenic mice, binding of FH to FHbp vaccines decreased protective antibody responses, and mutant FHbp vaccines with decreased FH binding elicited serum antibodies with greater protective activity. Thus, macaques with high FH binding to FHbp represent an attractive nonhuman primate model to investigate further the effects of FH binding on the immunogenicity of FHbp vaccines.     

The pyridoindole antioxidant stobadine attenuates albuminuria,enzymuria, kidney lipid peroxidation and matrix collagen cross-linking in streptozotocin-induced diabetic rats

The aim of the present study was to investigate the effect of dietary supplementation with the pyridoindole antioxidant stobadine on kidney status and function in streptozotocin-induced diabetic rats. Diabetic male Wistar rats were fed a standard diet for 32 weeks or a diet supplemented with stobadine (0.05% w/w). The diabetic state was characterized by significantly elevated plasma levels of glucose, HbA1c and urea, severe reduction of total body weight and relatively enlarged kidneys. Elevated levels of conjugated dienes were recorded in the diabetic kidney confirming the presence of oxidative stress in diabetic animals. All diabetic rats showed marked proteinuria and albuminuria along with elevated excretion of the enzyme N-acetyl-beta-D-glucosaminidase. Long-term treatment of diabetic animals with stobadine significantly reduced total proteinuria, albuminuria and enzymuria, yet left the overall physical and glycemic status unaffected. It reduced oxidative damage of kidney tissue as shown by decreased conjugated diene level, and decreased matrix collagen cross-linking, as indicated by decreased breaking time values of rat tail tendons. These beneficial effects of stobadine, supported also by histological findings, may be brought about by virtue of the combination of its antioxidant potential with other effects, e.g., the postulated cholesterol-lowering ability or its ability to alter vascular reactivity and reduce the vascular tone.     

Involvement of L-arginine-nitric oxide system in the response of isolated trachea to reactive oxygen species

The aim of this study was to investigate the effect of reactive oxygen species (ROS), generated by electrolysis of Krebs-Henseleit solution (GE-KHS), on isolated guinea pig trachea and to assess the possible involvement of nitric oxide (NO) in the observed effects. The isolated trachea was superfused in GE-KHS, generating H2O2 and hypochlorous acid (HOCl), both of which slowly increased in the organ bath and reached final stable concentrations of 42 and 63 microM, respectively, at the rate of 20 ml/min(-1), and 261 and 245 microM, respectively, at the rate of 5 ml/min(-1). ROS GE-KHS-induced relaxation of tracheal rings was preceded by a small transient contraction in 40% and 65% of experiments when tracheal rings were superfused at the rate of 20 ml/min(-1) and 5 ml/min(-1), respectively. Removal of tracheal epithelium abolished the relaxation of the trachea induced by ROS GE-KHS and unmasked or potentiated trachealis contraction. The ROS GE-KHS-induced changes in trachealis tension were accompanied by an increase in thiobarbituric acid reactive substances (TBARS) and a decrease in nonprotein (NP) thiols in the trachea. These changes were inhibited by treatment with the antioxidant N-acetylcysteine (100 microM). Pretreatment of tracheal rings with the inhibitor of NO synthase (NOS) N(omega)-nitro-L-arginine (L-NOARG; 100 microM) for 20 min prior to exposure to ROS GE-KHS decreased the ROS GE-KHS-induced relaxation. When L-NOARG (100 microM) was present in the superfusing solution, not only 20 min before but also during superfusion with ROS GE-KHS, the evoked trachealis relaxation was reduced in the first 15 min but was enhanced in the 30th min. This late enhancement of relaxation was accompanied by a 12-fold increase in nitric oxide metabolites (NO(x)). ROS GE-KHS-induced elevation of TBARS levels in the trachea was decreased to 63% by pretreatment with L-NOARG (100 microM). Elevation of TBARS levels induced by incubation of brain liposomes with a hydroxyl radical generating system was decreased to 90% by L-NOARG (10, 100 microM), while the antioxidant stobadine (100 microM) nearly completely inhibited the evoked lipid peroxidation. In comparison with Trolox, L-NOARG exerted a slight scavenging effect on the 1,1-diphenyl-2-picrylhydrazyl radical. The presence of L-arginine and D-arginine in the superfusion fluid for 15-20 min before and during exposure of the trachea to ROS GE-KHS inhibited trachealis relaxation. Results indicate that epithelium derived NO may participate in the response of guinea pig trachea to ROS GE-KHS. The presence of L-NOARG in the bathing fluid during superfusion with ROS GE-KHS gave rise to NO(x), with relaxing activity. L- and D-arginine induced an inhibition of the relaxatory response to ROS GE-KHS and partially prevented a ROS-induced decrease in NP thiols. The involvement of the small antioxidant effects of L-NOARG and L- and D-arginine in the above mentioned actions of L-NOARG and L-arginine requires additional investigation.     

Dietary supplementation of the pyridoindole antioxidant stobadine reduces vascular impairment in streptozotocin-diabetic rats

We studied the influence of hyperglycemia lasting 1, 4, 6 and 8 months on the reactivity and ultrastructure of the aorta in Wistar rats. Moreover, the effect of the pyridoindole antioxidant stobadine ((-)-cis-2,8-dimethyl-2,3,4,4a,5,9b-hexahydro-1H-pyrido[4,3-b]indole) on the changes induced by the 8-month hyperglycemia were studied. Hyperglycemia was induced by streptozotocin (STZ, 55 mg/kg i.v.). In the functional study, responses to KCl, acetylcholine (ACh), noradrenaline (NA) and hydrogen peroxide were evaluated under isometric conditions. The first changes in aortic reactivity started after 1 month of hyperglycemia and were exhibited by significantly increased NA-induced contractions. Relaxant responses to acetylcholine were decreased, although not significantly. Prolongation of hyperglycemia to 4, 6 and 8 months did not cause any additional significant changes in responsiveness to NA. Decreased ACh-induced relaxation and increased contractile responses to H2O2 were observed in month 4. The functional responses were not substantially deteriorated by prolongation of hyperglycemia to 6 and 8 months. Ultrastructural examination of the diabetic aorta showed disturbances in normal tissue organization. An 8-month supplementation of stobadine in diabetic rats resulted in the protection of aortic function as well as its ultrastructure. These results suggest that abnormalities occurring in the aorta of diabetic rats might result from the damaging effects of oxygen free radicals.     

Effect of dietary supplementation with the pyridoindole antioxidant stobadine on antioxidant state and ultrastructure of diabetic rat myocardium

Consistent with the postulated role of oxidative stress in the etiology of late diabetic complications, pharmacological interventions based on biological antioxidants have been suggested. The aim of the present study was to investigate the effect of dietary supplementation with the pyridoindole antioxidant stobadine on the myocardial antioxidant status and ultrastructure of streptozotocin-diabetic rats. Diabetic male Wistar rats were fed for 32 weeks a standard diet or a diet supplemented with stobadine (0.05% w/w). Control rats received a standard diet or stobadine-supplemented diet (0.16% w/w). Plasma levels of glucose, cholesterol and triglycerides were increased significantly by diabetes. Activities of superoxide dismutase and catalase were markedly elevated in the diabetic myocardium. Myocardial levels of conjugated dienes increased after eight months of diabetes, in spite of significantly increased myocardial α-tocopherol and coenzyme Q₉ content. The long-term treatment of diabetic animals with stobadine (i) reduced plasma cholesterol and triglyceride levels yet left the severe hyperglycemia unaffected, (ii) reduced oxidative damage of myocardial tissue as measured by conjugated dienes, (iii) reversed myocardial levels of α-tocopherol and coenzyme Q₉ to near control values, (iv) reduced elevated activity of superoxide dismutase in the diabetic myocardium, and (v) attenuated angiopathic and atherogenic processes in the myocardium as assessed by electron microscopy examination. These results are in accordance with the postulated prooxidant role of chronic hyperglycemia and provide further evidence that development of pathological changes in diabetic myocardium is amenable to pharmacological intervention by biological antioxidants. Received: 7 June 2000 / Accepted in revised form: 27 November 2000     

Hydrogen peroxide-dependent liver microsomal N-demethylation and N-oxygenation of stobadine, a gamma-carboline antiarrhythmic and cardioprotective agent

1. Hydrogen peroxide was capable of supporting the N-methylation and N-oxygenation of stobadine in rat liver microsomes. NADPH and O2 were not required. 2. The metabolic conversions promoted by H2O2 were completely abolished by preheating the microsomes for 5 min at 90 degrees C prior to assay, indicating the enzymic nature of the reaction. 3. The response to phenobarbital pretreatment and to inhibitors such as SKF 525-A, metyrapone and CO indicated participation of cytochrome P-450 in its oxidized form. 4. Microsomal cytochrome P-450 could not be replaced by haemoglobin, catalase, horseradish peroxidase or by its conversion to cytochrome P-420. 5. Comparative experiments on rabbits, guinea pigs and rats showed species differences in the extent of the peroxidatic metabolism of stobadine, the order of activity not being the same for C- and N-oxidation.     

Comparison of three different methods to confirm tracheal tube placement in emergency intubation

OBJECTIVES: Verification of endotracheal tube placement is of vital importance, since unrecognized esophageal intubation can be rapidly fatal (death, brain damage).The aim of our study was to compare three different methods for immediate confirmation of tube placement: auscultation, capnometry and capnography in emergency conditions in the prehospital setting. DESIGN AND SETTING: Prospective study in the prehospital setting. PATIENTS AND INTERVENTIONS: All adult patients (>18 years) were intubated by an emergency physician in the field. Tube position was initially evaluated by auscultation. Then, capnometry was performed with infrared capnometry and capnography with infrared capnography. The examiners looked for the characteristic CO(2) waveform and value of end-tidal carbon dioxide (EtCO(2)) in millimeters of mercury. Determination of final tube placement was performed by a second direct visualization with laryngoscope. Data are mean +/- SD and percentages. MEASUREMENTS AND RESULTS: Over a 4year period, 345 patients requiring emergency intubation were included. Indications for intubation included cardiac arrest ( n=246; 71%) and non-arrest conditions ( n=99; 29%). In nine (2.7%) patients, esophageal tube placement occurred. The esophageal intubations were followed by successful endotracheal intubations without complications. The capnometry (sensitivity and specificity 100%) and capnography (sensitivity and specificity 100%) were better than auscultation (sensitivity 94% and specificity 83%) in confirming endotracheal tube placement in non-arrest patients ( p<0.05). Capnometry was highly specific (100%) but not sensitive (88%) for correct endotracheal intubation in patients with cardiopulmonary arrest (capnometry versus auscultation and capnometry versus capnography, p<0.05). CONCLUSION: Capnography is the most reliable method to confirm endotracheal tube placement in emergency conditions in the prehospital setting.