POS0282 EVALUATION OF A NEW HYALURONATE FORMULATION ONE YEAR AFTER SINGLE INJECTION TO PATIENTS WITH SYMPTOMATIC KNEE OSTEOARTHRITIS (SOYA STUDY)

Background:

Osteoarthritis (OA) is a leading cause of chronic pain and disability, and its prevalence is expected to increase worldwide (1) being the knee the most affected joint, especially in older adults. Intra-articular hyaluronic acid (HA) could be of particular benefit in OA patients with co-morbidities, and in case of inadequate response to other pharmacological treatments (2). HA has been generally administered in cycles of 3-5 injections, however, due to the pressure on public health systems, the trend is to reduce the number of injections maintaining the duration of effects as longer as possible.

Objectives:

To assess the effectiveness and safety of a new formulation of HA, up to one year after one single injection to patients in the SOYA (Symptomatic Osteoarthritis one Year Assessment) study.

Methods:

Patients with Kellgren-Lawrence (KL) grade 2-3 and Visual Analogue Scale (VAS) pain >=40-<80mm were prospectively included to receive a single injection of MPS-HA2%. At 6m a second injection could be offered to selected patients. Primary outcome was reduction of VAS pain in the target knee. VAS for joint pain and WOMAC were recorded at 6 and 12m; Minimally Clinical Important Improvement MCII (>=20% relative change for VAS pain) and patient and investigator assessments (PGA, IGA) (Likert scale 0-4 points) were also estimated. Adverse events were recorded for safety assessment.

Results:

One hundred and one patients (mean age 68 years, 74% female and 78% with overweight) were included. Mean pain at baseline in the target knee was 63.57mm and 57% were grade 3 KL with a mean evolution of 7.5 years. Table 1 shows the improvement in VAS and WOMAC scores at 6 and 12 months in the mITT population. Similar results were obtained in PP population.

Table 1.

Changes in VAS and WOMAC scores, expressed as mean values

SCOREBaseline6 months12 monthsvaluevalue% variation (95% CI)value% variation (95% CI)VAS pain63.5737.59-39.74* (-49.23; -30.25)38.37-37.67* (-47.82; -27.52)WOMACtotal50.1931.88-37.96* (-46.83; -29.09)31.65-36.47* (-46.20; -26.73)pain49.3732.01-32.92* (-43.37; -22.46)31.08-32.07* (-43.19; -20.95)stiffness49.1228.35-35.24** (-53.22; -17.23)28.71-34.08* (-49.30; 18.86)function52.0735.30-33.95* (-43.49; -24.40)35.15-32.71* (-42.80; -22.62)

*p-value: 0.0001; **p-value: 0.0002. Student test

The MCII was achieved by 66.3% of patients at 6m and 62.2% at 12m. Regarding PGA mean score was 2.44 at baseline, 1.35 at 6m and 1.46 at 12m (Wilcoxon, p-value <0.05). As for the IGA mean score was 2.29 at baseline, 1.06 at 6m and 1.48 at 12m (Wilcoxon, p-value <0.05).

Fourteen patients received a second injection at 6m and 50% of them achieved at 12m a significant and clinically relevant improvement compared to baseline, above the 20% established for the MCII.

In total, 12 adverse events (8 patients) were reported, all of them local, non-serious, and of mild-moderate intensity.

Conclusion:

Viscosupplementation with a single intra-articular injection of MPS-HA2% has proven to be effective and well tolerated up to 12 months after treatment. The re-infiltration of the joint in appropriate cases has proven to be effective in a significant number of patients. The acceptability of the treatment by the patient was optimal.

References:

[1]Sebbag E, Felten R, Sagez F, et al. The world-wide burden of musculoskeletal diseases: a systematic analysis of the World Health Organization Burden of Diseases Database. Ann Rheum Dis. 2019 Jun;78(6):844-848.

[2]Bruyère O, Cooper C, Pelletier JP, et al. An algorithm recommendation for the management of knee osteoarthritis in Europe and internationally: a report from a task force of the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO). Semin Arthritis Rheum. 2014 Dec;44(3):253-63.

Disclosure of Interests:

Carlos Gavín: None declared, Francisco Moreno: None declared, Francisco J. Blanco: None declared, José Luis Pablos: None declared, Miguel A. Caracuel-Ruiz: None declared, Jose Rosas: None declared, Pablo Hernández-Esteban: None declared, Francisco Navarro: None declared, PILAR CORONEL Employee of: Meiji Pharma Spain, S.A., Mercedes Gimeno Employee of: Employee of Meiji Pharma Spain, S.A.

Beta-amyloidolysis and glutathione in Alzheimer's disease

In this review, we hypothesized the importance of the interaction between the brain glutathione (GSH) system, the proteolytic tissue plasminogen activator (t-PA)/plasminogen/ plasmin system, regulated by plasminogen activator inhibitor (PAI-1), and neuroserpin in the pathogenesis of Alzheimer’s disease. The histopathological characteristic hallmark that gives personality to the diagnosis of Alzheimer’s disease is the accumulation of neurofibroid tangles located intracellularly in the brain, such as the protein tau and extracellular senile plaques made primarily of amyloidal substance. These formations of complex etiology are intimately related to GSH, brain protective antioxidants, and the proteolytic system, in which t-PA plays a key role. There is scientific evidence that suggests a relationship between aging, a number of neurodegenerative disorders, and the excessive production of reactive oxygen species and accompanying decreased brain proteolysis. The plasminogen system in the brain is an essential proteolytic mechanism that effectively degrades amyloid peptides (“beta-amyloidolysis”) through action of the plasmin, and this physiologic process may be considered to be a means of prevention of neurodegenerative disorders. In parallel to the decrease in GSH levels seen in aging, there is also a decrease in plasmin brain activity and a progressive decrease of t-PA activity, caused by a decrease in the expression of the t-PA together with an increase of the PAI-1 levels, which rise to an increment in the production of amyloid peptides and a lesser clearance of them. Better knowledge of the GSH mechanism and cerebral proteolysis will allow us to hypothesize about therapeutic practices.

A 40-month multicentre, randomised placebo-controlled study to assess the efficacy and carry-over effect of repeated intra-articular injections of hyaluronic acid in knee osteoarthritis: the AMELIA project

Objective

AMELIA (OsteoArthritis Modifying Effects of Long-term Intra-articular Adant) was designed to compare against placebo the efficacy and safety of repeated injections of hyaluronic acid (HA) and its effect on disease progression over 40 months.

Methods

A multicentre, randomised, patient and evaluator-blinded, controlled study in 306 patients fulfilling American College of Rheumatology criteria for knee osteoarthritis, radiological grades II–III (Kellgren–Lawrence) and joint space width ≥2 mm. Patients received four cycles of five intra-articular HA or placebo injections with a follow-up of 6 months after the first and second cycles, and 1 year after the third and fourth cycles. Osteoarthritis Research Society International (OARSI) 2004 responder criteria were used to assess efficacy. The consumption of rescue medication was a secondary outcome. Adverse events were recorded for safety purposes.

Results

At the 40-month visit significantly more patients responded to HA compared with placebo (OARSI 2004, p=0.004). The number of responders to HA increased through the study, whereas those to placebo did not change. Significant differences were also found in favour of HA for each individual component of the OARSI 2004. No safety problems were recorded.

Conclusions

The results of AMELIA offer pioneer evidence that repeated cycles of intra-articular injections of HA not only improve knee osteoarthritis symptoms during the in-between cycle period but also exert a marked carry-over effect for at least 1 year after the last cycle. In this respect, it is not possible to establish if this carry-over effect reflects true osteoarthritis remission or just a modification of the disease's natural course.

ClinicalTrials.gov number, NCT00669032

Use of sulodexide in patients with peripheral vascular disease

Sulodexide is a highly purified glycosaminoglycan containing a combination of heparan sulfate with affinity for antithrombin III and dermatan sulfate with affinity for heparin cofactor II. This antithrombotic and antithrombin activity is of great pharmacologic interest and makes sulodexide a suitable drug for the prophylaxis and treatment of arterial and venous peripheral diseases. In arterial pathology, changes in the Winsor Index, improvement in peripheral blood flow, and reduction in pain-free walking distance confirm that treatment with oral sulodexide is effective. Lipid components linked to the genesis of peripheral vascular processes, including triglycerides, total cholesterol, and low-density lipoprotein fractions, as well as plasma and blood viscosity, are reduced by the administration of sulodexide, whereas the high-density lipoprotein fraction increases. Sulodexide inhibits aggregation and adhesion of platelets at the level of the vascular wall, reduces plasma fibrinogen concentrations, reduces plasminogen activator inhibitor-1, and increases tissue plasminogen activator, as well as systemic fibrinolytic and thrombolytic activity, thereby demonstrating efficacy in the treatment of thromboembolic disease. There is no interaction between sulodexide and other drugs used as long-term treatment for peripheral vascular disease. It is well tolerated, and the adverse reactions described after oral administration are related mainly to transient gastrointestinal intolerance, ie, nausea, dyspepsia, and minor bowel symptoms. Sulodexide may become the treatment of choice when dealing with vascular diseases and their complications, as well as for the prevention of venous thromboembolic disease, being particularly indicated in elderly patients, due to its good tolerability and ease of management.

Cefditoren versus ceftazidime in inducer-substrate combinations for the evaluation of AmpC production in a disc approximation test

OBJECTIVE

To evaluate cefditoren in inducer-substrate combinations to screen for AmpC induction.

METHODS

100 clinical isolates (25 P. aeruginosa, 25 E. cloacae, 14 M. morganii, 13 S. marcescens, 12 C. freundii, 7 P. rettgeri, and 4 E. aerogenes) were tested by the Kirby-Bauer disc approximation method using cefditoren and ceftazidime discs as substrates, and cefditoren and imipenem discs as inducers.

RESULTS

None of the strains showed induction of AmpC with cefditoren-ceftazidime as inducer-substrate combination. Imipenem-cefditoren as inducer-substrate combination was not useful for evaluating strains of P. aeruginosa since no inhibition zones surrounding the cefditoren disc were found. Among evaluable enterobacteria (those showing substrate inhibition zone), inducible Amp C was detected in 48 out of 63 (76.2%) with cefditoren, and in 33 out of 68 (48.5%) isolates with ceftazidime as substrate. Significantly (p=0.013) higher number of AmpC producers were detected with cefditoren versus ceftazidime (76.2% vs. 48.5%), due to the differences found for E. cloacae (72.8% vs. 21.7%; p=0.0009) and S. marcescens (100% vs. 54.5%; p=0.03). Higher mean reductions of diameters around substrate discs were found for cefditoren (4.17 mm) vs. ceftazidime (3.79 mm), reaching statistical significance (p<0.05) for indol-positive proteae: M. morganii (5.32 mm vs. 3.92 mm) and P. rettgeri (3.47 mm vs. 2.64 mm).

CONCLUSION

Cefditoren showed no induction capability, and when used as substrate (with imipenem as inducer) it offered detection rates of AmpC inducible enterobacteria higher than the imipenem-ceftazidime combination, mainly for Enterobacter spp. and Serratia spp., with higher diameter reductions for indol-positive proteae.

In vitro interference of beta-lactams with biofilm development by prevalent community respiratory tract isolates

Interference of cefditoren (CDN) and amoxicillin/clavulanic acid (AMC) with biofilm production was studied using 11 Streptococcus pneumoniae isolates with minimum inhibitory concentrations (MICs) ranging from 0.015microg/mL to 0.5microg/mL for CDN and from 0.06microg/mL to 2microg/mL for AMC (except for one isolate with an AMC MIC of 8microg/mL) and 5 Haemophilus influenzae isolates with MICs of 0.03-0.06microg/mL for CDN and 0.5-16microg/mL for AMC. Slime production was assessed in antibiotic-free medium and with 0.03microg/mL CDN or 1/0.5microg/mL AMC by measuring the optical density at 450nm (OD(450)). Significantly lower mean OD(450) values were obtained for S. pneumoniae with antibiotics compared with controls (CDN, 0.088 vs. 0.118, P=0.003; and AMC, 0.095 vs. 0.112, P=0.003), with significant correlation between both antibiotics (r=0.752; P=0.008). Percent reduction in OD(450) values was higher for CDN compared with AMC (24.02% vs. 15.92%; P=0.008). For H. influenzae, significantly lower mean OD(450) values were obtained with CDN compared with controls (0.083 vs. 0.096; P=0.043) but not with AMC (0.086 vs. 0.095; P=0.08). Comparing percent reductions in S. pneumoniae versus H. influenzae for each antibiotic, no differences were found for AMC (15.92% vs. 9.40%; P=0.36), with a tendency for CDN (24.02% vs. 13.79%; P=0.069). Different beta-lactams may have different capabilities of interfering with S. pneumoniae biofilm development when tested under the same experimental conditions.

Safety profile of cefditoren. A pooled analysis of data from clinical trials in community-acquired respiratory tract infections

INTRODUCTION

A high number of individuals in the population are exposed to antibiotics for the treatment of respiratory tract infections. It is important to review the adverse events profile related to antibiotic exposure during the clinical development of drugs that are or have been recently included in the therapeutic armamentarium.

MATERIAL AND METHODS

Safety data from all 13 clinical trials of cefditoren on community acquired respiratory infections were reviewed. Safety population was defined as all randomized patients with at least one dose intake. Adverse events considered by investigators as related during antibiotic exposure were considered.

RESULTS

The overall safety population consisted in 4,592 patients for cefditoren and 2,784 for comparators. Overall reported diarrhoea related to cefditoren administration was significantly higher (p < or = 0.001) than comparators (9.9% vs 6.9%) due to the significant difference in the pooled pharyngotonsillitis studies (8.3% vs 3.2%), while no significant differences in others pathologies were found, with 9.4% (with cefditoren) vs 10.3% (with comparators) in the case of community-acquired pneumonia (CAP). Dyspepsia and abdominal pain were reported as adverse events in < 2.7% patients regardless the treated disease. In females population lower related vaginosis rate was found in cefditoren vs comparators, mainly due to differences among patients treated for sinusitis (4.5% vs 8.1%) and CAP (2.3% vs 5.5%) although differences were not significant (p = 0.017 and p = 0.008, respectively).

CONCLUSION

This study analysing reported adverse events from clinical trials showed an adverse events profile of cefditoren similar to those of standard antibiotics used in the treatment of respiratory tract infections.

beta-lactam susceptibility of Escherichia coli isolates from urinary tract infections exhibiting different resistance phenotypes

Susceptibility to beta-lactams was determined in 203 recent Spanish E. coli isolates from urinary tract infections exhibiting different resistance phenotypes: a) susceptible (n = 60); b) quinolone-resistant (n = 45); c) penicillinase (n=64); d) hyperproduction of penicillinase (n=8); e) inhibitor resistant TEM (IRT) (n=18), and f) extended spectrum betalactamase (ESBL) (n=8).Minimum inhibitory concentration (MIC) determination by agar dilution and susceptibility tests for ESBL detection by macrodilution were performed following CLSI recommendations. All the beta-lactams tested showed high activity against susceptible and penicillinase phenotypes, with close to 100 % susceptibility. Hyperproduction of penicillinase increased MIC90 values for all antibiotics except for meropenem, with 100% resistance to cefuroxime and amoxicillin/clavulanic acid, and 100% susceptibility to cefotaxime, piperacillin/tazobactam and meropenem. All the antibiotics, except for amoxicillin/clavulanic acid, exhibited high activity against IRT. Meropenem, cefminox and piperacillin/tazobactam exhibited the highest activity against ESBL, followed by amoxicillin/clavulanic acid. The most active compound among the parenteral antibiotics was meropenem, regardless of the resistance phenotype. Among the oral antibiotics, the most active compound was cefditoren with the exception of ESBL where amoxicillin/clavulanic acid where the MIC90 value was one dilution lower.

In vitro activity of oral cephalosporins against pediatric isolates of Streptococcus pneumoniae non-susceptible to penicillin, amoxicillin or erythromycin

The aim of this study was to evaluate the effects of penicillin, amoxicillin or erythromycin resistance on the in vitro activity of oral cephalosporins against Streptococcus pneumoniae pediatric isolates. A total of 282 pediatric isolates received during 2005 in the Spanish Reference Pneumococcal Laboratory were tested by agar dilution: 104 strains were penicillin-susceptible, 72 intermediate, and 106 resistant. Serotypes 9 and 14 were the most troublesome with <10% susceptibility to oral cephalosporins. Cefditoren exhibited the highest intrinsic activity against penicillin/amoxicillin-resistant pneumococci, with MIC(90s )of 0.5 microg/ml, followed by cefotaxime (2 microg/ml), cefpodoxime (4 microg/ml), cefuroxime (16 microg/ml), and cefaclor/cefixime (>or= 32 microg/ml), with 0% susceptibility to cefaclor, cefuroxime and cefpodoxime. Cefditoren 0.5 microg/ml inhibited 95.3%, 95.5%, and 98.6% of penicillin-, amoxicillin-, and erythromycin-resistant isolates, respectively. Susceptibility to oral cephalosporins shifted from >90% in penicillin-susceptible isolates to approximately 38% for cefuroxime/cefpodoxime and approximately 7% for cefaclor in penicillin-intermediate, and to 0% in resistant isolates. Despite the different in vitro activity of oral cephalosporins, full resistance to penicillin or amoxicillin implied lack of susceptibility to all oral cephalosporins with defined CLSI breakpoints, rendering them inadequate as empirical treatment in countries with a high prevalence of penicillin resistance.

Clinical pharmacokinetics of ferric natural protein in iron-deficient females

Although iron therapy is very common, few studies have assessed iron absorption or iron kinetics in general, particularly with Fe(3+). This was the primary objective of this study, with assessment of tolerance as a secondary objective. Eight nonsmoking iron-deficient females without other associated pathologies, with an average age of 21.62 +/- 1.69 years, were studied. The diagnosis of iron deficiency was established by determination of sideraemia (28.7 +/- 13.5 microg/dl), iron binding capacity (380.5 +/- 70.2 microg/dl) and ferritin (5 +/- 1.4 microg/L) on the prestudy visit. The women remained in the Phase I Unit during days 0, 1, 2 and 3 of the study. A serum iron concentration curve was obtained daily from blood samples drawn at 0, 1, 2, 4, 6, 8 and 12 hours postdose. Therapy with ferric natural protein (ferrimannitol ovoalbumin) 40mg twice daily was started on day 1 of the study and continued for 30 days. The following parameters were evaluated: area under the curve (AUC(0-12h)), peak iron concentration (C(max)) and time to reach peak concentration (t(max)). Serum iron concentration-time curves were practically flat on day 0, but showed an increase following ferric therapy (Friedman, p < 0.05), confirming the usefulness of the postabsorption test and good absorption of ferric iron (Fe(3+)). The increase in AUC (314.65 +/- 67.9 to 1174.44 +/- 1071.8 microg/dl.h) and C(max) (49 +/- 24.4 to 146 +/- 101.9 microg/dl) from day 1 and the correlation between both parameters (r(2) > 0.85, p </= 0.008) supported the use of either parameter. The t(max) ranged from 4 to 6 hours. Ferric therapy was well tolerated by all patients. This study shows that ferric iron contained in this preparation is well absorbed and provides a satisfactory method for evaluation of iron absorption.

Efficacy of cefditoren in the treatment of upper respiratory tract infections: a pooled analysis of six clinical trials

OBJECTIVE

A pooled analysis of all upper respiratory tract infection studies performed with cefditoren (CDN) was performed.

METHODS

Studies were prospective, comparative, multicentre and randomised. Comparators were penicillin V (pharyngitis) and cefuroxime or amoxicillin/clavulanate (sinusitis). A total of 1,322 patients were randomized, 1,241 included in intention-to-treat (ITT) and 1,010 in per-protocol populations (PP) in pharyngotonsillitis studies, and 1,819 randomized, 1,726 included in ITT and 1,589 in PP in acute sinusitis studies.

RESULTS

No significant differences in pharyngitis clinical response were found (success rates: 89.4 % to 95.3 %). S. pyogenes eradication was higher with cefditoren at end of therapy (EOT) (90.4% vs. 82.7%; p=0.002) and follow-up (84.7% vs. 76.7%; p=0.008), although no statistically significant (p<0.001). In both groups, clinical failures were significantly higher (p<0.001) in patients showing S. pyogenes persistence than in those showing eradication (> or =98.5% vs. 51.4 %). No differences in sinusitis clinical response were found between CDN and comparators both at EOT (80.2% vs. 84.8%) and at end of follow-up (71.2% vs. 77.4%).

CONCLUSION

Cefditoren had similar point estimates of clinical efficacy to comparators in pharyngotonsillitis and sinusitis, and a tendency to higher S. pyogenes eradication in pharyngotonsillitis.

Beta-lactam activity against penicillin-resistant Streptococcus pneumoniae strains exhibiting higher amoxicillin versus penicillin minimum inhibitory concentration values: an in vitro pharmacodynamic simulation

BACKGROUND

Activity of simulated serum concentrations after oral therapy with 400 mg cefditoren pivoxil b.i.d., 500 mg cefuroxime axetil b.i.d. and 875/125 mg amoxicillin/clavulanic acid b.i.d. and t.i.d. regimens was explored over 24 h against Streptococcus pneumoniae.

METHODS

Computerized pharmacodynamic simulations were performed against strains with penicillin/amoxicillin/cefuroxime/cefditoren minimum inhibitory concentrations (MICs, microg/ml) and serotypes: strain 1 (0.25/0.12/1/0.12; serotype 6A), strain 2 (2/4/ 2/0.25; serotype 6B), strain 3 (4/16/4/0.5; serotype 14), and strain 4 (4/16/8/1; serotype 14).

RESULTS

Bactericidal activity (> or =3 log(10) reduction) at 12 and 24 h was obtained against all strains with cefditoren, against strains 1 and 2 with cefuroxime and amoxicillin/clavulanic acid t.i.d., but only against strain 1 with amoxicillin/clavulanic acid b.i.d.. Bactericidal activity at 24 h was related to T > MIC of >30% dosing interval, 1.7-2.0 log(10) reductions with T > MIC of 20-30%, and <1 log(10) reduction or regrowth with T > MIC of 0%.

CONCLUSIONS

It is difficult to achieve pharmacodynamic coverage and bactericidal activity by physiological concentrations of oral beta-lactams against penicillin-resistant pneumococcal strains exhibiting higher amoxicillin versus penicillin MICs. Cefditoren may offer alternatives.

Antimicrobial susceptibilities of amoxycillin-non-susceptible and susceptible isolates among penicillin-non-susceptible Streptococcus pneumoniae

Antimicrobial susceptibilities of 244 amoxycillin-non-susceptible and 81 amoxycillin-susceptible pneumococcal isolates from 15 Spanish hospitals were determined and clonal relationships were investigated by pulsed-field gel electrophoresis after SmaI restriction. Amoxycillin-non-susceptible isolates exhibited higher rates of resistance to cefuroxime, cefixime, cefpodoxime and clarithromycin, but not to levofloxacin and cefotaxime. Cefditoren exhibited MIC(90) values one dilution lower than those of cefotaxime. Higher numbers of the Spain(14)-5 and Spain(6B)-2 clones, but not the Spain(9V)-3 and Spain(23F)-1 clones, were found among amoxycillin-non-susceptible isolates. Spain(14)-5 was the most problematic clone in terms of antibiotic resistance.

influence of TEM-1 beta-lactamase on the pharmacodynamic activity of simulated total versus free-drug serum concentrations of cefditoren (400 milligrams) versus amoxicillin-clavulanic acid (2,000/125 milligrams) against Haemophilus influenzae strains exhibiting an N526K mutation in the ftsI gene

The aim of this study was to explore bactericidal activity of total and free serum simulated concentrations after the oral administration of cefditoren (400 mg, twice daily [bid]) versus the oral administration of amoxicillin-clavulanic acid extended release formulation (2,000/125 mg bid) against Haemophilus influenzae. A computerized pharmacodynamic simulation was performed, and colony counts and beta-lactamase activity were determined over 48 h. Three strains were used: ampicillin-susceptible, beta-lactamase-negative ampicillin-resistant (BLNAR) (also resistant to amoxicillin-clavulanic acid) and beta-lactamase-positive amoxicillin-clavulanic acid-resistant (BLPACR) strains, with cefditoren MICs of < or =0.12 microg/ml and amoxicillin-clavulanic acid MICs of 2, 8, and 8 microg/ml, respectively. Against the ampicillin-susceptible and BLNAR strains, bactericidal activity (> or =3 log(10) reduction) was obtained from 6 h on with either total and free cefditoren or amoxicillin-clavulanic acid. Against the BLPACR strain, free cefditoren showed bactericidal activity from 8 h on. In amoxicillin-clavulanic acid simulations the increase in colony counts from 4 h on occurred in parallel with the increase in beta-lactamase activity for the BLPACR strain. Since both BLNAR and BLPACR strains exhibited the same MIC, this was due to the significantly lower (P < or = 0.012) amoxicillin concentrations from 4 h on in simulations with beta-lactamase positive versus negative strains, thus decreasing the time above MIC (T>MIC). From a pharmacodynamic point of view, the theoretical amoxicillin T>MIC against strains with elevated ampicillin/amoxicillin-clavulanic acid MICs should be considered with caution since the presence of beta-lactamase inactivates the antibiotic, thus rendering inaccurate theoretical calculations. The experimental bactericidal activity of cefditoren is maintained over the dosing interval regardless of the presence of a mutation in the ftsI gene or beta-lactamase production.

Effects of human albumin and serum on the in vitro bactericidal activity of cefditoren against penicillin-resistant Streptococcus pneumoniae

OBJECTIVES

Attempts to interpret antibiotic pharmacodynamics using reported protein binding may underestimate true activity. To elucidate this issue we examined bacterial killing kinetics at cefditoren concentrations equal to C(max) in the presence of 90% human serum or albumin at physiological concentrations.

METHODS

Killing curves (final inocula of approximately 10(7) cfu/mL, cefditoren concentration of 4.2 mg/L) were performed against Streptococcus pneumoniae strains exhibiting cefditoren MICs (mg/L) of 0.12 (strain 1), 0.25 (strain 2) and 0.5 (strain 3) in different media: (i) C(max)-MH, Mueller-Hinton broth plus 5% lysed horse blood (MH), (ii) C(max)-HS, MH broth with a final human serum concentration of 90%; and (iii) C(max)-HAlb, MH broth with 4 g/dL human albumin. Killing curves were also performed with a final cefditoren concentration of 0.5 mg/L (similar to free-drug C(max) considering 88% protein binding) in MH broth (12% C(max)).

RESULTS

No significant differences were found between the different media or concentrations with strain 1 (log(10) reductions >or=4 at 24 h). Against strains 2 and 3, we observed significantly higher initial inocula decreases at 24 h for C(max)-HS as compared with C(max)-HAlb or 12% C(max). Bactericidal activity (>or=3 log(10) reduction) was obtained at 24 h against the three strains only with C(max)-HS and C(max)-MH.

CONCLUSIONS

The presence of physiological concentrations of human albumin, but not 90% human serum, limited bactericidal activity as did the use of concentrations similar to free-drug C(max), suggesting that extrapolation of active drug from total drug by using the protein binding rate is not an accurate method to study antibacterial activity.

Measurement of dielectric properties of pumpable food materials under static and continuous flow conditions

Continuous flow microwave sterilization is an emerging technology that has the potential to replace the conventional heating processes for viscous and pumpable food products. Dielectric properties of pumpable food products were measured by a new approach (under continuous flow conditions) at a temperature range of 20 to 130 degrees C and compared with those measured by the conventional approach (under static conditions). The food products chosen for this study were skim milk, green pea puree, carrot puree, and salsa con queso. Second-order polynomial correlations for the dependence of dielectric properties at 915 MHz of the food products on temperature were developed. Dielectric properties measured under static and continuous flow conditions were similar for homogeneous food products such as skim milk and vegetable puree, but they were significantly different for salsa con queso, which is a multiphase food product. The results from this study suggest that, for a multiphase product, dielectric properties measured under continuous flow conditions should be used for designing a continuous flow microwave heating system.

Are β-lactam breakpoints adequate to define non-susceptibility for all Haemophilus influenzae resistance phenotypes from a pharmacodynamic point of view?

OBJECTIVES

To investigate the bactericidal activity, against Haemophilus influenzae strains exhibiting different resistance phenotypes, of simulated serum concentrations obtained in humans after administration of 400 mg of cefditoren twice daily, 500 mg of cefuroxime twice daily, 875/125 mg of co-amoxiclav twice daily or 875/125 mg of co-amoxiclav three times daily.

METHODS

An in vitro computerized pharmacodynamic simulation was carried out and colony counts determined over 24 h. Four H. influenzae strains were used, one ampicillin-susceptible strain (Strain 1) and three ampicillin-resistant strains following CLSI and BSAC breakpoints: one beta-lactamase-positive strain with an MIC of co-amoxiclav of 0.5 mg/L (Strain 2), one beta-lactamase-negative ampicillin-resistant strain (BLNAR; ampicillin MIC = 16 mg/L) (Strain 3) and one beta-lactamase-positive strain with an MIC of co-amoxiclav of 4 mg/L (Strain 4). All strains were susceptible to cefuroxime and co-amoxiclav according to current CLSI breakpoints, but Strains 3 and 4 were resistant according to BSAC breakpoints. All strains exhibited cefditoren MIC <or= 0.12 mg/L.

RESULTS

Bacterial counts of Strains 1 and 2 were >or= 6 log(10) reduced with all antibiotics tested at 12 and 24 h. Against Strains 3 and 4, log(10) reductions at 12 and 24 h were significantly higher for cefditoren versus cefuroxime (P < 0.01) (although both exhibited bactericidal activity, i.e. >or= 3 log(10) reduction) and versus the two co-amoxiclav regimens (P < 0.001) (that exhibited negligible initial inocula reductions).

CONCLUSIONS

Cefditoren exhibited the highest bactericidal activity maintained over time against ampicillin-resistant H. influenzae, regardless of beta-lactamase production and/or BLNAR phenotype. From the pharmacodynamic perspective, BSAC breakpoints seem more adequate to define or detect BLNAR strains.

Pharmacokinetic/pharmacodynamic serum and urine profile of cefditoren following single-dose and multiple twice- and thrice-daily regimens in healthy volunteers: a phase I study

The objectives of this randomized, double-blind study were to evaluate the pharmacokinetics, and the pharmacodynamic and gastrointestinal (GI) tolerance of cefditoren pivoxil in healthy adult male volunteers when it is administered three times a day. Twenty healthy volunteers were included in the study. On day 1, 10 subjects received a 200-mg single dose of cefditoren pivoxil and 10 received a 400-mg dose. After a washout period of 8 days, eight subjects received cefditoren pivoxil 400 mg b.i.d., eight received 400 mg t.i.d., and four received placebo for 10 days. Medication was taken 30 min after meals. Blood and urine collections were carried out on days 1, 9, 14 and 19. Volunteers were asked about any GI change, especially about bowel habits, nausea, vomiting and abdominal pain. The maximum cefditoren concentration (C(max)) had a mean value of 3.77+/-0.66 mg/l, and was reached between 1.5 and 3 h in the thrice-daily administration. In the twice-daily regimen, the C(max) was 3.27+/-0.64 mg/l. The mean time above breakpoint minumum inhibitory concentration (MIC), calculated with data from each pharmacokinetic profile, was always above 40%, in both the twice- and thrice-daily regimens. The half-life of cefditoren was 1.19+/-0.2 h and 1.36+/-0.2 h in the twice-daily and thrice-daily regimens, respectively. The C(max) of cefditoren in urine was reached between 2 and 4 h postadministration, with a mean value of 154.53 mg/l in the twice-daily regimen, and 186.59 mg/l in the thrice-daily administration. There were no differences between the groups in the incidence of GI adverse events. The present data show that the administration of cefditoren pivoxil 400 mg t.i.d. is possible because it is well tolerated, and it increases the probability of success when the MIC of the causative bacteria is close to the susceptibility breakpoint. The high concentrations of active drug in the urine enable cefditoren to be considered as a useful candidate for the treatment of uncomplicated urinary tract infections (UTIs).

Comparison of Sensory, Microbiological, and Biochemical Parameters of Microwave Versus Indirect UHT Fluid Skim Milk During Storage

Shelf-stable milk could benefit from sensory quality improvement. Current methods of heating cause flavor and nutrient degradation through exposure to overheated thermal exchange surfaces. Rapid heating with microwaves followed by sudden cooling could reduce or eliminate this problem. The objectives for this study were focused on designing and implementing continuous microwave thermal processing of skim fluid milks (white and chocolate) to compare sensory, microbiological, and biochemical parameters with conventionally prepared, indirect UHT milks. All test products were aseptically packaged and stored at ambient temperature for 12 mo. Every 3 mo, samples were taken for microbiological testing, reactive sulfhydryl determinations, active enzyme analysis, instrumental viscosity readings, color measurements, and descriptive sensory evaluation. Microbiological plate counts were negative on all milks at each time point. Enzymatic assays showed that plasmin was inactivated by both heat treatments. 5,5'-dithio-bis(2-nitrobenzoic acid) analysis, a measure of reactive sulfhydryl (-SH-) groups, showed that the initial thiol content was not significantly different between the microwave-processed and UHT-treated milks. However, both heating methods resulted in an increased thiol level compared with conventionally pasteurized milk samples due to the higher temperatures attained. Sulfhydryl oxidase, a milk enzyme that catalyzes disulfide bond formation using a variety of protein substrates, retained activity following microwave processing, and decreased during storage. Viscosity values were essentially equivalent in microwave- and UHT-heated white skim milks. Sensory analyses established that UHT-treated milks were visibly darker, and exhibited higher caramelized and stale/fatty flavors with increased astringency compared with the microwave samples. Sweet aromatic flavor and sweet taste decreased during storage in both UHT and microwave milk products, whereas stale/fatty flavors increased over time. Sensory effects were more apparent in white milks than in chocolate varieties. These studies suggest that microwave technology may provide a useful alternative processing method for delivery of aseptic milk products that retain a long shelf life.

Geographical patterns of onchocerciasis in southern Venezuela: relationships between environment and infection prevalence

Onchocerciasis is a chronic filarial infection transmitted by Simulium flies that has a focal geographical distribution in Latin America. The southern Venezuelan focus has a gradient of endemicity that includes the largest number of hyperendemic communities in the continent, many of them in remote forest and mountainous areas, where it is an important public health problem among the Yanomami indigenous population. The recent introduction of Geographical Information Systems (GIS) tools and a landscape epidemiology approach for study of vector borne diseases is helping to understand relationships between environment and transmission dynamics of onchocerciasis. Striking differences in the transmission dynamics of onchocerciasis between different river courses were detected. A significant relationship between onchocerciasis and temperature was also demonstrated. The geologic substrate, kind of landscape and vegetation seemed also to influence the transmission of onchocerciasis. In the Venezuelan Amazon, different kinds of landscapes associated with distinctive vector species, show different intensities of transmission of onchocerciasis. In this sense, landscape analysis aided by GIS, may prove to be a useful tool for better identification of the spatial distribution of onchocerciasis risk in the Orinoco basin.

Comparative study of hyaluronic derivatives: rheological behaviour, mechanical and chemical degradation

Depolymerisation by oxytetracycline (OTC) as well as the progressive cleavage of hyaluronic acid induced by ultrasound was investigated in nine commercially available hyaluronic polymers. Sample solutions differed in molecular weight, from 500 to 7000 kDa, and in their source. The hyaluronic acid concentration in each sample was analysed by HPLC. The concentration range was over 8.39-10.18 mg ml(-1) in samples with a nominal concentration of 1%, and 14.05 mg ml(-1) in one sample with a nominal concentration of 1.5%. It was found that stability was dependent on both molecular weight and the concentration of the samples. The rheological parameters n (power law index) and K (consistency coefficient) were good predictors regarding the degradation behaviour. Although many factors are involved in obtaining a therapeutic response, the results obtained in this work support the notion that both mechanical and chemical degradation are reduced in hyaluronate solutions with low molecular weight, the final concentration of the product being a critical factor.

Antimicrobial susceptibility of Haemophilus influenzae, Haemophilus parainfluenzae and Moraxella catarrhalis isolated from adult patients with respiratory tract infections in four southern European countries. The ARISE project

Over a 7-month period in 2000-2001, 1213 Haemophilus influenzae, 112 Haemophilus parainfluenzae and 142 Moraxella catarrhalis isolates were recovered from adult patients with respiratory tract infections. Patients were from four southern European countries (Spain, Italy, Portugal and Greece). The antimicrobial susceptibility of the isolates to 11 antibiotics was determined in a central laboratory. The most active drugs on the basis of MICs were levofloxacin, cefditoren, cefotaxime, cefpodoxime and amoxicillin/clavulanate. MICs > or = 2 mg/l for amoxicillin were found in 19.5, 28.6, and 75.4% of H. influenzae, H. parainfluenzae and M. catarrhalis isolates, respectively. Isolates of H. influenzae and H. parainfluenzae with reduced susceptibility or that were fully resistant to amoxicillin/clavulanate, cefuroxime and clarithromycin were detected (0.2-1.8%) as well as M. catarrhalis resistant to clarithromycin (0.7%). Regular surveys of resistance patterns for antimicrobial agents are necessary.

Antimicrobial resistance among clinical isolates of Streptococcus pneumoniae isolated in four southern European countries (ARISE project) from adult patients: results from the cefditoren surveillance program

From four southern European countries (Spain, Italy, Portugal, and Greece) 877 Streptococcus pneumoniae isolates were recovered from adult patients with respiratory tract infections between September 2000 and March 2001. The antimicrobial susceptibility to 11 antibiotics was determined in a central laboratory. Penicillin resistance was high in Greece (47.1%) and Spain (25.1%) but much lower in Portugal (7.9%) and Italy (4.8%). On the other hand, erythromycin resistance was high in Italy (38.5%) and Spain (36.2%) with no statistical difference with Greece (29.4%) but reaching significance (p <0.01) with Portugal (15.7%). Resistance to levofloxacin was low (1.5%) but present in Spanish and Italian isolates. Cefditoren, a new cephem antibiotic tested, was the most potent compound (MIC90 = 0.5 microg/ml) followed by levofloxacin and cefotaxime (MIC90 = 1 microg/ml). Given the high rates of penicillin and macrolide resistance reported, there is an evident need for new drugs and continued antimicrobial surveillance of S. pneumoniae.

Human onchocerciasis in the Amazonian area of southern Venezuela: spatial and temporal variations in biting and parity rates of black fly (Diptera: Simuliidae) vectors

We investigated some entomological factors underlying altitudinal prevalence variation in the Venezuelan Amazonia human onchocerciasis focus. Spatial and temporal variation in relative abundance, daily biting rate, proportion of parous flies, and monthly parous biting rate were studied for the three main simuliid vectors (based on their vectorial competence: Simulium oyapockense s.l. Floch & Abonnenc approximately = S. incrustatum Lutz << S. guianense s.l. Wise). Yanomami villages were selected among sentinel communities of the ivermectin control program, representing hypo- to hyperendemicity conditions of infection. Spatial variation was explored via increasing village altitude on two river systems (A: Ocamo-Putaco and B: Orinoco-Orinoquito). Temporal variation was studied between 1995 and 1999 by sampling the biting population during dry and rainy mouths. Environmental variables included monthly rainfall and maximum river height. Simuliid species composition itself varied along the altitudinal and prevalence gradient. S. oyapockense s.l. prevailed below 150 m. Above this altitude and up to 240 m, S. incrustatum and S. guianense s.l. became more frequently and evenly collected along A but not along B, where S. incrustatum remained absent. The daily biting rate of S. oyapockense s.l. was higher during the dry season along A, whereas the converse took place along B. Daily biting rate of S. incrustatum was lowest during early rains. By contrast, the daily biting rate of S. guianense s.l. was highest during this period. There was a significant negative cross-correlation between proportion of parous of S. oyapockense s.l. and river height (2 and 3 mo lagged), whereas this variable (1 and 2 mo lagged) was positively correlated with the proportion of parous flies for S. incrustatum. Monthly parous biting rate values suggest that the months contributing most to onchocerciasis transmission in the area are likely to be the dry season and the transition periods between seasons.

Cefminox versus metronidazole plus gentamicin intra-abdominal infections: a prospective randomized controlled clinical trial

BACKGROUND

The aim of this prospective study was to compare the safety and efficacy of a new cephamycin, cefminox 2 g/12 h, to those of the usual regimen combining metronidazole 500 mg/8 h and gentamicin 80 mg/8 h (M+G).

PATIENTS AND METHODS

160 patients with clinically proven intra-abdominal infection were prospectively included in an open parallel randomized comparative multicenter trial. Antibiotics were started preoperatively and discontinued after clinical and laboratory evidence of resolution of the infection. Serum and peritoneal fluid levels and serum bactericidal activities were also studied.

RESULTS

150 patients were clinically evaluable. There was one failure in the cefminox group and three in the M+G group (not significant, RR: 1.07, 95% CI: 1-1.15). No differences were found in the number of wound infections, length of stay or duration of antibiotic therapy. Adverse effects were reported in 11 cases, all of them mild to moderate. Escherichia coli and Bacteroides fragilis were the most frequently found microorganisms.

CONCLUSION

Cefminox is as effective and as safe as M+G in the treatment of intra-abdominal infections.

Bioavailability of the iron formulated as natural ferric protein (TM/FMOA) and natural ferric protein + folic acid (TM/FMOA+FOL)

Numerous oral iron preparations are available for the treatment of iron deficiency anemia but only very few studies have been designed to measure the bioavailability of iron preparations. The aim of this assay is to determine the bioavailability of iron formulated as natural ferric protein (TM/FMOA)(FMOA=Ferrimannitol ovalbumin) and natural ferric protein with folic acid (TM/FMOA+FOL) in healthy and anemic rats. Determination of the bioavailability of iron has been carried out by studying the serum level-time curves after i.v. administration of a single dose of 1 mg iron/kg in the form of ferrous sulfate, and after oral administration of 2 mg of iron/kg in the form of TM/FMOA or TM/FMOA+FOL. The Cmax values obtained after oral administration of TM/FMOA and TM/FMOA+FOL are greater in the case of anemic rats, while the tmax values are similar in both types of animals. The bioavailability (F) is greater for the anemic rats (80% approx), and the presence of folic acid does not appear to influence the bioavailability of the iron. This bioavailability data with TM/FMOA can predict good results in further experiments in human beings with iron deficiencies.

Inoculum effect and bactericidal activity of cefditoren and other antibiotics against Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis

The inoculum effect on minimum inhibitory and minimum bactericidal concentrations of cefditoren, benzylpenicillin, ampicillin, cefotaxime, ceftriaxone, and meropenem against six clinical isolates each of Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis was studied using inocula of approximately 10(4) to 10(5) and 10(7) to 10(8) cfu/ml. Vancomycin was also studied against Streptococcus pneumoniae. The inoculum effect was observed only with benzylpenicillin and ampicillin against five of six strains of Haemophilus influenzae. All antibiotics tested were bactericidal.

Reliability of the measurement of postprandial thermogenesis in men of three levels of body fatness

To determine the reliability of the measurement of postprandial thermogenesis by indirect calorimetry and to clarify further the relationship of obesity to thermogenesis in men, the thermic effect of a 720-kcal, mixed liquid meal was compared in 13 lean men (mean +/- SEM, 11.2% +/- 1.4% body fat), 10 average men (22.4% +/- 1.6% body fat), and 12 obese men (33.4% +/- 1.6% body fat) on two occasions. Resting metabolic rate (RMR) was measured for 3 hours: (1) in the fasted state, and (2) after a 720-kcal mixed liquid meal, on two occasions. The thermic effect of the meal, calculated as the postprandial energy expenditure minus the fasting RMR (kcal/3h), was greater for the lean and average men than for the obese men during both trials (P less than .001), but was only marginally different between the lean and average groups (P = .16). The mean values for the two trials were similar and the measurement of thermogenesis was highly reproducible with a reliability coefficient of r = .932 (P less than .001). Across all groups, thermogenesis correlated strongly with percent body fat (r = -.64, P less than .01), but within the average men, thermogenesis was uncorrelated with percent body fat (r = .09) but highly correlated with the glucose response to the meal (r = -.75, P less than .05). Thus, factors other than body fatness, such as insulin sensitivity, may determine thermogenesis within this heterogeneous middle group.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of exercise mode and intensity on postprandial thermogenesis in lean and obese men

To characterize further the impact of exercise before a meal on thermogenesis, the effects of exercise intensity and mode and the duration of the effect of exercise on the thermic effect (TEF) of a 720-kcal mixed meal were compared in 10 lean and 10 obese men (16 +/- 1 vs. 34 +/- 2% fat). In study A, TEF (kcal/3 h) was significantly greater for the lean than the obese men during rest and immediately after 1 h of cycling at 50 and 100 W. TEF was significantly greater after both exercise intensities than during rest for the obese men, but exercise had no effect on TEF in the lean men. In study B, TEF was significantly greater for the lean than the obese men during rest and immediately after 1 h of leg cycling at an O2 consumption of 1.09 l/min but only marginally different after 1 h of arm exercise at the same O2 consumption (P = 0.15). For the obese men, TEF was greater after arm than leg cycling and greater after leg cycling than at rest (P less than 0.01), but TEF was not different among the three conditions for the lean men. In study C, TEF was compared at rest and immediately and 24 h after 1 h of cycling at 100 W. TEF was greater for the lean than the obese men under all conditions (P less than 0.05). For the obese but not the lean men, TEF was greater both immediately after and on the day after exercise than at rest (P less than 0.01). Thus, acute exercise improves but does not normalize the blunted TEF in obesity; a minimally intense bout of exercise is needed to improve TEF; exercise mode alters thermogenesis in the obese men, even at a fixed intensity; and TEF in the obese men is enhanced for as long as 24 h after exercise.

Current prevalence of hepatitis B, A and C in a healthy Spanish population. A seroepidemiological study

A seroepidemiological study was carried out in order to determine the prevalence of markers of viral hepatitis infection in employees of five health-care companies and their cohabiting family members. Each participating family unit was required to fill out a questionnaire, in which, among other data, the employee was requested to indicate his or her job category. Markers of hepatitis B infection (anti-HBs, anti-HBc or HBsAg) were observed in 11.7% (58/497) of all subjects. When employees and family members were analysed according to the employee's job category, significant differences were found between "staff" (3%) and "administrative personnel" (13.3%; p less than 0.01) or "factory workers" (16.9%; p less than 0.01). Of 489 individuals tested for the presence of anti-HAV and anti-HCV, 59.1% and 0.6% respectively, were positive. There was a correlation between the prevalence of anti-HAV and age; a large proportion of the subjects under the age of 30 years had no evidence of prior HAV infection.

Estimation of extracellular and total body water by multiple-frequency bioelectrical-impedance measurement

This study evaluated a new technology of bioelectrical-impedance (BI) measurement that makes use of multiple frequencies (5, 50, and 100 kHz) for estimation of extracellular and total body water. In 36 healthy males, resistance and reactance at three frequencies were compared with extra-cellular water (ECW) and total body water (TBW) determined by isotope dilution. ECW was best predicted by resistance measured at 5 kHz, corrected for height and weight (R = 0.930, SEE = 1.94 L) whereas TBW was best predicted by resistance at 100 kHZ and weight (R = 0.947, SEE = 2.64 L). Cross-validation analysis on two randomly selected subsets (n = 18 each) indicated that the prediction equations were reproducible and valid. Thus, BI at dual frequencies is valid for determination of body-water compartments and may be useful in the nutritional assessment of patients in whom body water and hydration is of clinical concern.