Active polymers containing Lactobacillus curvatus CRL705 bacteriocins: effectiveness assessment in Wieners.

Bacteriocins from lactic acid bacteria have potential as natural food preservatives. In this study two active (synthetic and gluten) films were obtained by the incorporation of lactocin 705 and lactocin AL705, bacteriocins produced by Lactobacillus curvatus CRL705 with antimicrobial activity against spoilage lactic acid bacteria and Listeria. Antimicrobial film effectiveness was determined in Wieners inoculated with Lactobacillus plantarum CRL691 and Listeria innocua 7 (10(4)CFU/g) stored at 5°C during 45days. Active and control (absence of bacteriocins) packages were prepared and bacterial counts in selective media were carried out. Visual inspection and pH measurement of Wieners were also performed. Typical growth of both inoculated microorganisms was observed in control packages which reached 10(6)-10(7)CFU/g at the end of storage period. In the active packages, L. innocua 7 was effectively inhibited (2.5 log cycles reduction at day 45), while L. plantarum CRL691 was only slightly inhibited (0.5 log cycles) up to the second week of storage, then counts around 10(6)-10(7)CFU/g were reached. Changes in pH values from 6.3 to 5.8 were produced and gas formation was observed in active and control packages. The low inhibitory effectiveness against lactic acid bacteria is in correlation with the low activity observed for lactocin 705 in the presence of fat; Wieners fat content (20-30%) may adversely affect antimicrobial activity. This study supports the feasibility of using polymers activated with L. curvatus CRL705 bacteriocins to control Listeria on the surface of Wieners and highlights the importance of evaluating antimicrobial packaging systems for each particular food application.

Development and characterization of an active polyethylene film containing Lactobacillus curvatus CRL705 bacteriocins.

The development and characterization of a bacteriocin-containing polyethylene-based film is described, incorporating lactocin 705 and lactocin AL705, produced by Lactobacillus curvatus CRL705, and nisin. Three different procedures to obtain lactocin 705 and AL705 solution were evaluated, with the partially purified aqueous bacteriocin solution showing the highest inhibitory activity against indicator strains (Lactobacillus plantarum CRL691 and Listeria innocua 7). Pouch contact, soaking and a contact method were compared for incorporating bacteriocins onto PE-based films. Contact between the PE film and bacteriocin solution was the most effective, resulting in a more uniform distribution of bacteriocins on the film surface and using less active solution. The minimal inhibitory concentration of bacteriocin solution was 267 AU cm(-3) (lactocin 705) and 2133 AU cm(-3) (lactocin AL705), while the minimal contact time was 1 h. When relative inhibition area for antilisterial activity of the active films was compared, those treated with L. curvatus CRL705 bacteriocins displayed higher inhibitory activity than nisin-treated films. Functional properties of active PE-films containing lactocin 705 and AL705 showed no differences compared with non-active control films. Bacteriocin-active PE-based films are shown to be highly effective in inhibiting growth of Listeria. The potential use of commercially available packaging films as bacteriocins carriers may benefit active-packaging systems.

Reversible changes in adrenocorticotropin (ACTH)-induced adrenocortical steroidogenesis and expression of the peripheral-type benzodiazepine receptor during the ACTH-insensitive period in young rats.

We previously demonstrated decreased adrenal content of a mitochondrial cholesterol transporter [peripheral-type benzodiazepine receptor (PBR)] during the first postnatal week in rats, when ACTH-inducible steroidogenesis is low. Here we report that the expression of PBR protein and mRNA increases throughout the neonatal/juvenile period in rats in parallel with ACTH-inducible steroidogenesis in vitro. We also previously reported that chronic stimulation of rat pups with daily ACTH injections augmented the steroidogenic response of the developing adrenal cortex. We therefore tested the hypotheses that the change in phenotype induced by ACTH was permanent, and that the effects of ACTH were mediated by increased PBR expression. Pups were injected with ACTH or saline from postnatal d (pd) 2-8 or 2-14. Another group of pups received ACTH from pd 2-7, followed by saline from pd 8-14. On the final day, all pups were challenged with a test injection of ACTH or saline. Exposure to ACTH, but not saline, for 1 wk significantly increased adrenal mass, the corticosterone response to ACTH, and the expression of PBR protein and mRNA. Continued ACTH treatment for a second week maintained adrenal mass, steroidogenesis, and PBR mRNA expression. When ACTH was withdrawn after 1 wk and replaced with daily saline injections, however, adrenal mass, ACTH-inducible steroidogenesis, and PBR expression returned to levels comparable to those in age-matched saline controls (i.e. animals that had not received ACTH injections during the first 2 wk). Thus, although ACTH was capable of inducing increased steroidogenic capacity of the juvenile rat adrenal, its effects were only manifest when pups were exposed regularly to high plasma ACTH levels. ACTH, therefore, has significant, but reversible, effects on the development of adrenocortical function, possibly mediated in part by increased expression of PBR.

Efficacy, safety and pharmacokinetics of palonosetron in patients receiving highly emetogenic cisplatin-based chemotherapy: a dose-ranging clinical study.

BACKGROUND: Although currently available 5-hydroxytryptamine type 3 receptor (5-HT3) antagonists are effective, not all patients receiving these agents achieve adequate control of chemotherapy-induced nausea and vomiting (CINV). Palonosetron, a potent and highly selective 5-HT3 antagonist with a strong affinity for 5-HT3 and a prolonged plasma elimination half-life, may provide a longer duration of action than other approved agents. PATIENTS AND METHODS: One hundred and sixty-one patients were randomly assigned to receive a single intravenous bolus dose of palonosetron (0.3, 1, 3, 10, 30 or 90 microg/kg) before administration of highly emetogenic chemotherapy, with no pretreatment with corticosteroids. RESULTS: The four highest doses of palonosetron were similarly effective during the first 24 h, producing clearly higher complete response (CR) (no emesis, no rescue medication) rates in the 3, 10, 30 and 90 microg/kg groups (46%, 40%, 50% and 46%, respectively) than in the 0.3-1 microg/kg group (24%) of evaluable patients (n = 148). The 3 microg/kg dose was identified as the lowest effective dose. A single dose of palonosetron showed prolonged efficacy in preventing delayed emesis, with approximately one-third of patients who received palonosetron 10 or 30 microg/kg maintaining a CR throughout the 7-day period following chemotherapy administration. Dose-proportional increases in pharmacokinetic parameters and a long plasma half-life (43.7-128 h) were observed. Palonosetron was well-tolerated, with no dose-response effect evident for the incidence or intensity of adverse events. CONCLUSIONS: Palonosetron is an effective and well-tolerated agent for the prevention of CINV following highly emetogenic chemotherapy, with 3 and 10 microg/kg identified as the lowest effective palonosetron doses.

Factor XII-dependent increases in thrombin activity induce carboxypeptidase-mediated attenuation of pharmacological fibrinolysis.

Activation of the contact system in patients treated with fibrinolytic agents may be an important source of thrombin that activates thrombin-activated fibrinolysis inhibitor (TAFI) and attenuates fibrinolysis. Factor (F)XIIa in plasma increased 2-fold over 60 min in patients given either tissue plasminogen activator (t-PA) or streptokinase (SK). To determine whether FXIIa-mediated generation of thrombin and activated TAFI (TAFIa) attenuates fibrinolysis in vitro, plasma clots were incubated with SK (250 U mL-1) or t-PA (2.5 g mL-1) and the rate of lysis was measured. Plasma FXIIa impaired lysis judging from marked acceleration when 2.5 micro m corn trypsin inhibitor were added (lysis increased by 172 +/- 144% for SK and 40 +/- 31% for t-PA vs. no inhibitor, n = 16, P < 0.01). Moreover, inhibition of thrombin with hirudin and TAFIa with carboxypeptidase inhibitor accelerated lysis. We conclude that activation of FXII increases thrombin generation, which promotes TAFIa-mediated attenuation of fibrinolysis.

Comparison of gemcitabine versus the matrix metalloproteinase inhibitor BAY 12-9566 in patients with advanced or metastatic adenocarcinoma of the pancreas: a phase III trial of the National Cancer Institute of Canada Clinical Trials Group.

PURPOSE: To compare the selective matrix metalloproteinase inhibitor BAY 12-9566 with the nucleoside analog gemcitabine in the treatment of advanced pancreatic cancer. METHODS: Patients with advanced pancreatic adenocarcinoma who had not previously received chemotherapy were randomly assigned to receive BAY 12-9566 800 mg orally bid continuously or gemcitabine 1,000 mg/m2 administered intravenously on days 1, 8, 15, 22, 29, 36, and 43 for the first 8 weeks, and then days 1, 8, and 15 of each subsequent 28-day cycle. The primary end point was overall survival; secondary end points were progression-free survival, tumor response, quality of life, and clinical benefit. The planned sample size of the study was 350 patients. Two formal interim analyses were planned. RESULTS: The study was closed to accrual after the second interim analysis on the basis of the recommendation of the National Cancer Institute of Canada Clinical Trials Group Data Safety Monitoring Committee. There were 277 patients enrolled onto the study, 138 in the BAY 12-9566 arm and 139 in the gemcitabine arm. The rates of serious toxicity were low in both arms. The median survival for the BAY 12-9566 arm and the gemcitabine arm was 3.74 months and 6.59 months, respectively (P <.001; stratified log-rank test). The median progression-free survival for the BAY 12-9566 and gemcitabine arms was 1.68 and 3.5 months, respectively (P <.001). Quality-of-life analysis also favored gemcitabine. CONCLUSION: Gemcitabine is significantly superior to BAY 12-9566 in advanced pancreatic cancer.

Efficacy of a targeted, oral penicillin-based yaws control program among children living in rural South America.

Yaws is endemic in rural Guyana. An observational study was conducted to determine the efficacy of oral penicillin V therapy in treating skin lesions of yaws in children. In 1999, inhabitants of 7 rural villages near Bartica, Guyana, were screened for skin lesions of yaws. Cases were confirmed by serological testing. A control program was implemented in 2000: children < or =14 years old were screened, and those with active lesions were treated with oral penicillin V for 7-10 days. In 2001, children were rescreened and active cases were treated. Prevalence of yaws skin lesions fell from 5.1% (52 of 1020 children screened in 2000) to 1.6% (8 of 516 in 2001), a 71% drop. Sixteen (94%) of 17 children treated in 2000 and reassessed in 2001 had complete resolution of lesions. A targeted, oral penicillin-based treatment regimen can successfully treat dermatologic yaws in individual children and can decrease the prevalence of skin yaws in a community in which it is endemic. This information may aid in the implementation of additional control efforts.

Randomised, phase II trial comparing oral capecitabine (Xeloda) with paclitaxel in patients with metastatic/advanced breast cancer pretreated with anthracyclines.

Capecitabine, an oral fluoropyrimidine carbamate, was designed to generate 5-fluorouracil preferentially at the tumour site. This randomised, phase II trial evaluated the efficacy and safety of capecitabine or paclitaxel in patients with anthracycline-pretreated metastatic breast cancer. Outpatients with locally advanced and/or metastatic breast cancer whose disease was unresponsive or resistant to anthracycline therapy were randomised to 3-week cycles of intermittent oral capecitabine (1255 mg m(-2) twice daily, days 1-14, (22 patients)) or a reference arm of i.v. paclitaxel (175 mg m(-2), (20 patients)). Two additional patients were initially randomised to continuous capecitabine 666 mg m(-2) twice daily, but this arm was closed following selection of the intermittent schedule for further development. Overall response rate was 36% (95% CI 17-59%) with capecitabine (including three complete responses) and 26% (95% CI 9-51%) with paclitaxel (no complete responses). Median time to disease progression was similar in the two treatment groups (3.0 months with capecitabine, 3.1 months with paclitaxel), as was overall survival (7.6 and 9.4 months, respectively). Paclitaxel was associated with more alopecia, peripheral neuropathy, myalgia and neutropenia, whereas typical capecitabine-related adverse events were diarrhoea, vomiting and hand-foot syndrome. Twenty-three per cent of capecitabine-treated patients and 16% of paclitaxel-treated patients achieved a > or =10% improvement in Karnofsky Performance Status. Oral capecitabine is active in anthracycline-pretreated advanced/metastatic breast cancer and has a favourable safety profile. Furthermore, capecitabine provides a convenient, patient-orientated therapy.

Pharmacodynamics and pharmacokinetics of eptifibatide in patients with acute coronary syndromes: prospective analysis from PURSUIT.

BACKGROUND: Platelet deposition and aggregation are central to the pathogenesis of ischemic complications of acute coronary syndromes (ACS). Pharmacodynamic effects of the platelet glycoprotein IIb/IIIa antagonist eptifibatide have been delineated in healthy subjects but not in patients with ACS. We assessed effects of eptifibatide on ex vivo platelet aggregation in patients enrolled in the Platelet glycoprotein IIb/IIIa in Unstable angina: Receptor Suppression Using Integrilin (eptifibatide) Therapy (PURSUIT) trial of ACS. METHODS AND RESULTS: Patients were randomly assigned to an intravenous bolus (180 microgram/kg) and 72-hour infusion of eptifibatide (2.0 microgram/kg per minute, n=48) or placebo (n=50). We assessed correlations of plasma eptifibatide levels with receptor occupancy and inhibition of ex vivo platelet aggregation at 5 minutes and 1, 4, 24, 48, and 72 hours during treatment and 4 and 8 hours after termination of infusion. Blood was collected in buffered citrate and D-phenylalanyl-L-prolyl-L-arginine chloromethylketone anticoagulants. Although eptifibatide produced profound, prolonged inhibition of platelet aggregation during therapy, aggregation appeared to recover partially by 4 hours after the bolus. The aggregation response was greater with thrombin receptor agonist peptide versus ADP stimulation; inhibition of platelet aggregation was greater in blood samples anticoagulated with citrate versus D-phenylalanyl-L-prolyl-L-arginine chloromethylketone (PPACK). Plasma eptifibatide levels correlated significantly with receptor occupancy but not with inhibition of platelet aggregation. CONCLUSIONS: A bolus and infusion of eptifibatide inhibits platelet aggregation profoundly in patients with ACS and is followed by brief, partial recovery. These results enhance our understanding of the relation between pharmacodynamic and clinical effects of eptifibatide in such patients and may have important implications for its use in percutaneous interventions.

N-acetyl-cysteine reduces neointimal thickening and procoagulant activity after balloon-induced injury in abdominal aortae of New Zealand white rabbits.

BACKGROUND: Procoagulant activity and oxidative stress generated by balloon injury to normal vessels promote the migration of medial smooth muscle cells and their proliferation in the intima. We hypothesised that administering levo N-acetyl-cysteine (NAC) i.v. at the time of injury, and s.c. before and after injury would reduce neointimal formation 4 weeks later and would regulate procoagulant activity in vessels with neointima undergoing ballooning a second time. METHODS AND RESULTS: at the time of injury rabbits received: NAC, unfractionated heparin (HEP) or both (NAC + HEP). Neointimal thickening at 28 days, calculated as the ratio between the intimal and medial area, was attenuated after NAC, HEP and NAC+HEP by 39%, 30% and 47% respectively when compared to untreated injured animals (CONTROLS) (p <0.05). At 28 days, bound thrombin activity and platelet adhesion 1 h after a repeated balloon injury decreased in animals receiving NAC, HEP and NAC+HEP bv 54%, 63% and 64% for thrombin activity (p <0.05 vs CONTROLS), and by 56%, 66% and 75% respectively for 111Indium-platelet deposition (p <0.05 vs CONTROLS). CONCLUSIONS: NAC in-vivo was effective in reducing neointimal thickening and procoagulant response after balloon injury.

A novel synthetic inhibitor of factor Xa decreases early reocclusion and improves 24-h patency after coronary fibrinolysis in dogs.

Inhibition of factor Xa (FXa) attenuates thrombus progression. This study was designed to determine whether a novel, synthetic inhibitor of FXa (ZK-807834, molecular mass 527 Da, K(i) = 0.11 nM) administered during and briefly after pharmacologic coronary fibrinolysis increases 24-h patency. Either ZK-807834 (< or = 1.6 mg/kg, n = 10; 6.5 mg/kg, n = 8; or 13 mg/kg, n = 7); a peptide inhibitor of FXa, recombinant tick anticoagulant peptide (rTAP, 13.6 mg/kg, n = 7); heparin (150 U/kg bolus and 50 U/kg/h infusion) and aspirin (5 mg/kg) (n = 7); or saline as a control (n = 13) were administered i.v. over 135 min in conscious dogs after thrombotic occlusion induced by electrical injury to a coronary artery. Fibrinolysis was induced with recombinant human tissue-type plasminogen activator (1.0 mg/kg i.v. over 1 h), and patency was monitored continuously for 24 h with an implanted Doppler probe. Reocclusion occurred in all control and heparin/aspirin-treated dogs within 1 h after fibrinolysis. High dose ZK-807834 prevented reocclusion in five of six dogs and delayed reocclusion in the other dog (186 min after recanalization, p = 0.0005 versus heparin/aspirin). Reocclusion was delayed (406 +/- 329 min), but still occurred in three of six rTAP-treated dogs (p = 0.003 versus heparin/aspirin). Patency after 24 h was 100% in ZK-807834-treated and rTAP-treated dogs compared with 67% in control and 83% in heparin/aspirin-treated dogs. PT was increased 3.7-fold, activated partial thromboplastin time 4.9-fold, and bleeding time 2.5-fold by high dose ZK-807834 compared with 1.2-fold, 11.5-fold, and 2.3-fold, respectively, for heparin/aspirin. Inhibition of FXa with ZK-807834 decreases reocclusion and improves patency of recanalized arteries without increasing bleeding compared with heparin/aspirin.

Placebo-controlled trial of bexarotene, a retinoid x receptor agonist, as maintenance therapy for patients treated with chemotherapy for advanced non-small-cell lung cancer.

This study was designed as a multicenter, randomized, double-blind, placebo-controlled trial. Patients were randomized by center to placebo (16 patients, 31%), oral bexarotene 300 mg/m2/day (21 patients, 40%), or oral bexarotene 600 mg/m2/day (15 patients, 29%) following demonstration of stable or responsive disease after first-line chemotherapy. The study was prematurely terminated because of slow accrual after 54 patients enrolled. Median time to progression (TTP) from the beginning of study drug treatment was 56 days for placebo, 82 days for moderate-dose bexarotene (300 mg/m2/day), and 128 days for high-dose bexarotene (600 mg/m2/day) (P = 0.56, log-rank test). For prior chemotherapy responders only, median TTP from the beginning of study drug treatment was 56 days for placebo, 146 days for moderate-dose bexarotene, and 177 days for high-dose bexarotene. Of note, there were more chemotherapy responders randomized to the placebo group (63%) than the bexarotene treatment arms (48% and 47%), further supporting a bexarotene-related improvement in TTP. Bexarotene-related toxicity was manageable and consisted primarily of elevated serum triglycerides and asthenia, skin toxicity (dryness, peeling, flaking), thyroid dysfunction, and headache. Because this study was closed prematurely, it does not have the statistical power to detect differences among the treatment groups. This study shows that patients can tolerate bexarotene at initial doses up to 600 mg/m2/day after platinum-based chemotherapy and that bexarotene may have the potential to delay disease progression in patients with advanced non-small-cell lung cancer with previously stable or responsive disease following platinum-based chemotherapy.

Bedside measurement of D-dimer in the identification of bacteremia in the emergency department.

The objective of this pilot study was to determine the clinical utility of the SimpliRed D-dimer bedside assay to identify patients with bacteremia in a university hospital Emergency Department. We tested 265 patients and compared blood culture results with a novel D-dimer semiquantitative whole blood assay. Bacteremia was confirmed in 25/262 patients. Sensitivity of D-dimer assay was 66.7% for Gram-positive bacteremia and 61.5% for Gram-negative bacteremia with negative predictive value of 98% for Gram-positive and 96% for Gram-negative bacteremia patients. Measurement of D-dimer appears to be of value in identifying patients at low risk for bacteremia and can be accomplished rapidly using a whole blood semiquantitative bedside assay. Although increases in D-dimer are not detected in all patients subsequently documented to have bacteremia on a single sampling, the results of this and other earlier studies suggest assay of D-dimer is useful in rapid differentiation of patients with bacteremia from those who have no bacteremia using blood culture positivity as the standard for bacteremia.

Role of tissue factor-mediated coagulation in ischemia/ reperfusion-induced injury of Langendorf-perfused rabbit hearts.

BACKGROUND: Production of oxygen free radicals, and activation of neutrophils and plasma complement contribute to myocardial reperfusion injury, but the role of coagulation has not been assessed. OBJECTIVE: To characterize tissue-factor-mediated generation of thrombin and its association with tissue injury during reperfusion from normothermic ischemia of isolated, Langendorf-perfused rabbit hearts. METHODS: Activation of coagulation was assessed by addition of 12% rabbit plasma and human fibrinogen to Krebs-Henseleit-buffer perfusate with measurement of levels of human fibrinopeptide A (hFPA) in the heart effluent as an index of thrombin-mediated formation of fibrin. RESULTS: Concentrations of hFPA in the effluent were minimal during non-ischemic perfusion (5 +/- 5 ng/ml, n=6) and during 50 min of ischemia (13 +/- 3 ng/ml, n=6), but increased markedly during the first 20 min of reperfusion (to 41 +/- 29 ng/ml, P=0.03 versus before reperfusion). Addition to the perfusate of 10 microg/ml recombinant human tissue-factor-pathway inhibitor, the physiologic inhibitor of tissue-factor-mediated coagulation, abolished increases in the level of hFPA after reperfusion. However, indexes of myocardial injury manifested during reperfusion, including decrease in recovery of left ventricular pressure developed, increase in left ventricular end-diastolic pressure, and increase in activity of creatine kinase in the heart effluent, were not improved by anticoagulation with recombinant human tissue-factor-pathway inhibitor. CONCLUSION: Our results do not support the hypothesis that coagulation plays a major role in ischemia/reperfusion injury of Langendorf-perfused rabbit hearts.

Activity of exemestane in metastatic breast cancer after failure of nonsteroidal aromatase inhibitors: a phase II trial.

PURPOSE: To evaluate the antitumor activity and toxicity of a new steroidal aromatase inactivator, exemestane, in postmenopausal women with metastatic breast cancer who had progressive disease (PD) after treatment with a nonsteroidal aromatase inhibitor. PATIENTS AND METHODS: In this phase II trial, eligible patients were treated with exemestane 25 mg daily (n = 241) followed, at the time PD was determined, by exemestane 100 mg daily (n = 58). RESULTS: On the basis of the intent-to-treat analysis by independent review, exemestane 25 mg produced objective responses in 6.6% of patients (95% confidence interval [CI], 3.8% to 10.6%) and overall success (complete response + partial response + no change for 24 weeks or longer) in 24.3% (95% CI, 19.0% to 30.2%). The median durations of objective response and overall success were 58.4 weeks (95% CI, 49.7 to 71.1 weeks) and 37.0 weeks (95% CI, 35.0 to 39.4 weeks), respectively. Increasing the dose of exemestane to 100 mg upon the development of PD produced one partial response (1.7%; 95% CI, 0.0% to 9.2%). Both dosages were well tolerated and were discontinued because of adverse events in only 1.7% of patients. CONCLUSION: Exemestane 25 mg once daily seems to be an attractive alternative to chemotherapy for the treatment of patients with metastatic breast cancer after multiple hormonal therapies have failed.

Overcoming Wallstent malposition in the treatment of rectosigmoid obstruction.

In recent years, the use of transanal stenting of malignant colonic strictures for the palliation of obstructive symptoms has increased. Due to the rectosigmoid angle, stenting sigmoid tumors is more troublesome than rectal lesions, but the difficulty may be overcome by using a two-team approach. The radiologist assists the endoscopist with the use of fluoroscopy to ensure proper positioning of both the colonoscope and the stent. The most common complication is stent migration, but stent obstruction and colonic perforation may also occur. We treated a woman suffering from metastatic gastric cancer with peritoneal metastases by creating a 12-cm stricture in the sigmoid colon. Two adjoining Wallstents were required to bridge the obstruction. Following migration of the proximal stent, a third stent was introduced to bridge the previous two stents with satisfactory outcome.