Functional characterization of GPIIb- and GPIIIa-specific monoclonal antibodies. Further evidence for the existence of agonist-specific activated states of the platelet fibrinogen receptor

In this work human platelet aggregation induced in vitro by ADP, collagen, arachidonic acid and U-46619 (a thromboxane A(2) analogue) was used as a functional test to characterize 19 anti-GPIIb (M series) and anti2 GPIIIa (P series) monoclonal antibodies whose epitope location is known for most of them. Additionally, flow cytofluorimetry was applied to study the epitope expression of these antibodies in resting, EDTA-treated and SFLLRN peptide (thrombin receptor agonist)-activated platelets. Antibodies M6 (epitope located at GPIIbH 657-665), P23-7 (GPIIIa 114-122) and P40 (GPIIIa 262-303) bind weakly to only 43%, 70% and 66%, respectively, of the resting platelet population. This binding was enhanced in EDTA-treated and in activated platelets. Platelet activation enhances the apparent binding of most of the other antibodies. Further evidence on the existence of agonist-specific activated states of GPIIb/IIIa was provided by the agonist-dependent immunochemical inhibition in vitro of platelet aggregation by some of the anti-subunit antibodies studied here. The most notable cases are those of P40 and M6, which at 140 nM inhibit most, the platelet aggregation induced by arachidonic acid and U-46619. On the other hand, three of the most strong and agonist-independent inhibitors, P37 (GPIIIa 101-109), P97 and P95-2 (GPIIIa N-terminal half) bind to resting platelets with high affinity (5-8 nM), compete with each other for binding to GPIIb-IIIa and their epitopes are located at the N-terminal domain of GPIIIa, where the receptor ligand binding site(s) have been found. Given that the formation of activated GPIIb-IIIa (GPIIb-IIIa*) is the first step at which the anti-subunit antibodies can intervene as inhibitors and that agonist-specific inhibitors should block only agonist-specific steps, while nonspecific inhibitors should block steps common to all the agonists, then our present work support the hypothesis that there are different agonist-specific GPIIb-IIIa*s or, alternatively, different receptor environments, that can be specifically blocked by some of the antibodies. These results add to earlier evidence on agonist-dependent ligand specificity and activated states found for this and other integrins. Finally, the correlation between the in vitro inhibition of platelet aggregation and the antithrombotic activity in vivo is discussed for these antibodies.     

Eradication of enterococci biofilms by lactic acid alone and combined with chlorhexidine and cetrimide

Objective: The antimicrobial activity of lactic acid (LA) alone or in combination with chlorhexidine (CHX) and cetrimide (CTR) against three Enterococcus faecalis strains, E. faecalis ATCC 29212, E. faecalis EF-D1 and E. faecalis U-1765, one Enterococcus durans strain and one dual-species biofilm was investigated. Study Design: The irrigating solutions tested were 20%, 15%, 10%, 5% and 2.5% LA, alone and in combination with 2% CHX and with 0.2% CTR. The biofilms were grown in the MBECTM high-throughput device for 24 hours and exposed to the solutions for 30 seconds and 1 minute. "Eradication" was defined as 100% bacterial kill. Results: Twenty percent LA eradicated all enterococci biofilms after 30 seconds contact time. The association of LA + 0.2% CTR achieved better results than LA alone, in contrast with the results obtained using LA + 2% CHX. E. durans was eradicated by all the tested solutions at 1 minute. The dual-species biofilm, E. faecalis ATCC 29212 + E. durans, gave intermediate values of the pure cultures. Conclusions: LA is capable of eradicating enterococci biofilm at a concentration of 20%. The combination of lower concentrations with 0.2% CTR achieved eradication after 1 minute.     

Dietary total antioxidant capacity and current asthma in Spanish schoolchildren: a case control–control study

The aim of this work was to study the relationship between dietary total antioxidant capacity (TAC) and current asthma in a group of Spanish schoolchildren. A total of 78 Spanish schoolchildren (26 asthmatic and 52 healthy controls) were randomly selected from a cohort of 564 children (9–12 years of age). The weight and height of all subjects were recorded. A questionnaire, completed by the subjects' parents, was used to obtain personal and health information. Current asthma was established when children had ever had asthma, they had been diagnosed with asthma by a physician, and they had been treated with medications at some time in the previous 12 months. Food intake was monitored using a 3-day food record. All consumed foods were converted into energy and nutrients. Dietary TAC was evaluated using the ferric reducing antioxidant power (FRAP), radical-trapping antioxidant parameter (TRAP), and Trolox equivalent antioxidant capacity (TEAC) assays. The TAC measured using all the assays was significantly lower in children with asthma than in children without this condition (2.95 (2.10–3.75)?mmol Fe(II)/day vs. 3.70 (3.08–4.49)?mmol Fe(II)/day, p?<?0.01; 1.50 (1.06–2.05)?mmol Trolox equivalents/day vs. 2.10 (1.40–2.65)?mmol Trolox equivalents/day, p?<?0.05; and 1.60 (1.08–2.00)?mmol Trolox equivalents/day vs. 1.85 (1.50–2.68)?mmol Trolox equivalents/day, p?<?0.05 for FRAP, TEAC, and TRAP, respectively). After adjusting for energy intake, children with FRAP values higher than 3.5 mmol Fe(II)/day (p50) and TEAC values higher than 1.9 mmol Trolox equivalents/day (p50) had 22.6 and 35.0 %, respectively, lower likelihood of suffering asthma episodes than children with lower values. When logistic regression analysis was performed separately for children with nonsmoker and smoker (at least one) parents, the association between dietary TAC and asthma was only observed in the nonsmoker group (OR?=?0.257, 95 % CI?=?0.107–0.618, p?=?0.002 for FRAP; OR?=?0.212, 95 % CI?=?0.069–0.639, p?=?0.006 for TEAC; and OR?=?0.264, 95 % CI?=?0.091–0.769, p?=?0.015 for TRAP assay). Conclusion: Dietary TAC may have a favorable role in asthma in children and, specially, in those with nonsmoker parents.     

Isolation of Actinobacillus seminis from the genital tract of rams in spain

Actinobacillus seminis isolates were cultured from the semen (two isolates) and the left testis (one isolate) of two one-year-old rams in León, Spain. One animal showed lesions of chronic unilateral orchitis and epididymitis while the other appeared to suffer a subclinical infection and only a moderate number of pleomorphic rods and inflammatory cells were present in its semen. The isolates were biochemically similar to the A. seminis type strain NCTC 10851 and two other European A. seminis isolates, except that they produced acid from sorbitol; their identity was confirmed by arbitrarily primed polymerase chain reaction. The isolates were also tested against 30 antimicrobial agents, and only marbofloxacin was found active against all of them. As far as is known, this is the first report of A. seminis isolation from rams in southern Europe.     

Alginate/chitosan particulate systems for sodium diclofenac release.

Alginate/chitosan particles were prepared by ionic gelation (Ca2+ and Al3+) for the sodium diclofenac release. The systems were characterized by electron microscopy and differential scanning calorimetry. The ability to release the active substance was examined as a function of some technological parameters and pH of dissolution medium. The release of sodium diclofenac is prevented at acidic pH, while is complete in a few minutes when pH is raised up to 6.4 and 7.2. The alginate/chitosan ratio and the nature of the gelifying cation allow a control of the release rate of the drug. The release mechanism was briefly discussed.     

Profilaxis antibiótica «dirigida» por cultivos rectales antes de la biopsia prostática transrectal: reducción de complicaciones infecciosas y costes de atención sanitaria

Background

Transrectal ultrasound-guided prostate biopsy (TUPB) is associated with infectious complications (ICs), which are related to a greater prevalence of ciprofloxacin-resistant bacteria (CRB) in rectal flora. We examined the ICs that occurred in 2 groups: A guided antibiotic prophylaxis (GP) group and an empiric prophylaxis (EP) group. We assessed the financial impact of GP.