Maturation of mononuclear phagocytes in the lungs of young calves--in vitro study.

The influences of age in calves' immune system are described in their first phase of life. We hypothesized that variations that occur in the main mechanisms of lung innate response can help to identify periods of greater susceptibility to the respiratory diseases that affect calves in the first stage of their life. This study aimed to evaluate the innate immune system. Nine healthy calves were monitored for 3 mo and 8 immunologic evaluations were performed. Bronchoalveolar lavage samples were recovered by bronchoscopy. The alveolar macrophages in samples were identified by protein expression of cluster of differentiation 14 (CD14) and underwent functional evaluation of phagocytosis (Staphylococcus aureus stained with propidium iodide and Escherichia coli). Data was assessed by one-way ANOVA (unstacked and parametric) and the Mann-Whitney test (nonparametric). Functional alterations in CD14-positive phagocytes were observed, with punctual higher intensity of phagocytosis in the third week and its decrease starting at 45 d of life. A gradual increase in phagocytosis rate was observed starting at this date. It is concluded that from 45 d of life on, alveolar macrophages have less phagocytic capacity but more cells perform this function. We suggest that this occurs because lung macrophages of calves start to maintain their immune response without passive immunity influence. Until 90 d of life, calves did not achieve the stability to conclude the maturation of local innate immune response.

Antibody dynamics in Holstein Friesian heifers vaccinated with Brucella abortus strain 19, using seven serological tests.

The serological response induced by Brucella abortus strain 19 was evaluated in 52 Holstein females from a brucellosis-free herd using seven serological tests. Each calf was vaccinated at an age of 4 and 8 months old with 3 x 10(10) CFU B. abortus S19 and the antibody response was determined as the proportion of positive results to each test. The antibody dynamics, measured with the buffered plate antigen (BPA) test and the rapid automated presumptive (RAP) test, were similar. The proportion of positive reactions in these tests reached 100% one week after vaccination and remained at this level for seven weeks, after which the proportion of positive samples slowly declined to 8% (BPA) and 2% (RAP) at week 50. The response in the indirect enzyme immunoassay (i-ELISA) was similar, but shorter than that observed with the BPA/RAP. The antibody dynamic, measured using the seroagglutination test (SAT) in parallel with the 2-mercaptoethanol (2-Me) test and the complement fixation test (CFT) were similar to the RAP/BPA, but of slightly shorter duration. The competitive ELISA (c-ELISA) was positive in all animals for 3 weeks, followed by a rapid decline. The fluorescence polarization assay (FPA) reached a maximum of 68.5% positive animals at week 4 and then declined. Based on these data, the c-ELISA and FPA discriminated residual antibody activity due to vaccination more efficiently than the other tests.

Does a diol cyclic urea inhibitor of HIV-1 protease bind tighter than its corresponding alcohol form? A study by free energy perturbation and continuum electrostatics calculations.

The cyclic urea inhibitors of HIV-1 protease generally have two hydroxyl groups on the seven-membered ring. In this study, free energy perturbation and continuum electrostatic calculations were used to study the contributions of the two hydroxyl groups to the binding affinity and solubility of a cyclic urea inhibitor DMP323. The results indicated that the inhibitor with one hydroxyl group has better binding affinity and solubility than the inhibitor with two hydroxyl groups. Therefore, removal of one hydroxyl group from DMP323 may help to improve the properties of DMP323. This is also likely to be true for other cyclic urea inhibitors. The study also illustrated the difficulty in accurate modeling of the binding affinities of HIV-1 protease inhibitors, which involves many possible protonation states of the two catalytic aspartic acids in the active site of the enzyme.

Stereospecific synthesis, structure-activity relationship, and oral bioavailability of tetrahydropyrimidin-2-one HIV protease inhibitors.

The use of tetrahydropyrimidinones as an alternate scaffold for designing HIVPR inhibitors has advantages, over the previously disclosed hexahydro-1,3-diazepin-2-ones, of being more unsymmetrical (different P1/P1'), less crystalline, more soluble, and more lipophilic (mono-ol vs diol). They show a better translation of Ki to IC90 for the more polar P2 groups that in general give the more potent enzyme inhibitors. Structure-activity relationship (SAR) studies of the tetrahydropyrimidinones showed that the phenylethyl P1' substituent, the hydroxyl group, and the urea carbonyl are all critical for good activity. However, there was significant flexibility in the possible P2/P2' substituents that could be used. Many analogues that contained identical or different P2/P2' substituents, or only one P2 substituent, were found to have excellent enzyme potency and several had excellent antiviral potency. Several of these compounds were examined for oral bioavailability in the rat or the dog at 10 mg/kg. However, the oral bioavailability of the tetrahydropyrimidinones was, in general, less than the corresponding hexahydro-1,3-diazepin-2-ones. Unfortunately, when all factors are considered, including potency, protein binding, solubility, bioavailability, and resistance profile, the tetrahydropyrimidinones did not offer any advantage over the previously disclosed hexahydro-1,3-diazepin-2-ones series.

Nonsymmetric P2/P2' cyclic urea HIV protease inhibitors. Structure-activity relationship, bioavailability, and resistance profile of monoindazole-substituted P2 analogues.

Using the structural information gathered from the X-ray structures of various cyclic urea/HIVPR complexes, we designed and synthesized many nonsymmetrical P2/P2'-substituted cyclic urea analogues. Our efforts concentrated on using an indazole as one of the P2 substituents since this group imparted enzyme (Ki) potency as well as translation into excellent antiviral (IC90) potency. The second P2 substituent was used to adjust the physical and chemical properties in order to maximize oral bioavailability. Using this approach several very potent (IC90 11 nM) and orally bioavailable (F% 93-100%) compounds were discovered (21, 22). However, the resistance profiles of these compounds were inadequate, especially against the double (I84V/V82F) and ritonavir-selected mutant viruses. Further modification of the second P2 substituent in order to increase H-bonding interactions with the backbone atoms of residues Asp 29, Asp 30, and Gly 48 led to analogues with much better resistance profiles. However, these larger analogues were incompatible with the apparent molecular weight requirements for good oral bioavailability of the cyclic urea class of HIVPR inhibitors (MW < 610).

Design, synthesis, and evaluation of tetrahydropyrimidinones as an example of a general approach to nonpeptide HIV protease inhibitors.

Re-examination of the design of the cyclic urea class of HIV protease (HIVPR) inhibitors suggests a general approach to designing novel nonpeptide cyclic HIVPR inhibitors. This process involves the inversion of the stereochemical centers of the core transition-state isostere of the linear HIVPR inhibitors and cyclization of the resulting core using an appropriate cyclizing reagent. As an example, this process is applied to the diamino alcohol class of HIVPR inhibitors to give tetrahydropyrimidinones. Conformational analysis of the tetrahydropyrimidinones and modeling of its interaction with the active site of HIVPR suggested modifications which led to very potent inhibitors of HIVPR (24 with a Ki = 0.018 nM). The X-ray crystallographic structure of the complex of 24 with HIVPR confirms the analysis and modeling predictions. The example reported in this study and other examples that are cited indicate that this process may be generally applicable to other linear inhibitors.

Estudio clínico de eficacia y tolerancia con sultamicilina fipexiam en procesos infecciosos de tratamiento ambulatorio / Clinic study of efficacy and toleration with sultamicilina fipeham in infectious process of ambulatory treatment

Se realizó un estudio abierto, multicéntrico, no comparativo donde se avaluó la eficacia y tolerancia de la combinación Ampicilina/Sulbatam por vía oral-Sultamicilina-(Fipexiam), en adultos y niños con infecciones del tracto respiratorio superior e inferior y con infeciones de piel y partes blandas, y adultos con Enfermedad Inflamatoria Pélvica (EIP). El estudio reunió los investigadores de 73 Centros. Se trataron un total de 195 pacientes obteniéndose una efectividad global de 93.3 por ciento. De estos pacientes 84 presentaron Otitis media aguda, resultando curas clínicas en el 89.2 por ciento, 67 presentaron procesos orofaríngeos con curación en el 94 por ciento; en los casos con infecciones de piel y partes blandas, así como en las mujeres tratadas con (EIP) la curación clínica fue de 100 por ciento. Se reportaron efectos adversos en 10.9 por ciento, siendo las molestias gastrointestinales más resaltantes con 8.7 por ciento de los casos reportados, siendo menores a lo reportado por la literatura médica

Preparation and structure-activity relationship of novel P1/P1'-substituted cyclic urea-based human immunodeficiency virus type-1 protease inhibitors.

A series of novel P1/P1'-substituted cyclic urea-based HIV-1 protease inhibitors was prepared. Three different synthetic schemes were used to assemble these compounds. The first approach uses amino acid-based starting materials and was originally used to prepare DMP 323. The other two approaches use L-tartaric acid or L-mannitol as the starting material. The required four contiguous R,S,S,R centers of the cyclic urea scaffold are introduced using substrate control methodology. Each approach has specific advantages based on the desired P1/P1' substituent. Designing analogs based on the enzyme's natural substrates provided compounds with reduced activity. Attempts at exploiting hydrogen bond sites in the S1/S1' pocket, suggested by molecular modeling studies, were not fruitful. Several analogs had better binding affinity compared to our initial leads. Modulating the compound's physical properties led to a 10-fold improvement in translation resulting in better overall antiviral activity.