Experiencia de transferencia tecnológica de la Consejería Telefónica para Cuidados Crónicos de Salud, a equipos de Atención Primaria / Experience of technology transfer from telephone Counseling for Chronic Conditions to Primary Care Teams

El proceso de transferencia tecnológica exige capacitar en conocimientos y habilidades específicas a los futuros usuarios, así como también la realización de adecuaciones administrativas para la incorporación efectiva de la innovación en la estructura del sistema y en la atención profesional. La Escuela de Enfermería a la que pertenecen los autores, desarrolló un modelo de Apoyo Tecnológico para el Autocuidado en Salud que incluye el uso de consejerías telefónicas para apoyar a personas con enfermedades crónicas en el automanejo y autocuidado de su condición. Se presenta a continuación la experiencia llevada a cabo para transferir esta tecnología a profesionales del Programa de Salud Cardiovascular en Centros de Atención Primaria públicos de una comuna de bajos recursos en Chile, para su incorporación en la atención de pacientes con diabetes tipo 2 adscritos a dicho programa. Este proceso se realizó en dos etapas: 1. Realización de un taller teórico práctico en apoyo a la toma de decisiones en salud y estrategias motivacionales para el cambio de conducta en salud (talleres y demostraciones) y 2. Demostración en terreno, y seguimiento con supervisión y reuniones a nivel local. Los profesionales que participaron del programa de transferencia tecnológica, lograron desarrollar las destrezas esperadas en la herramienta de Consejería Telefónica de Apoyo al Auto-Manejo de Personas con DM2. Finalmente, para incorporar las consejerías telefónicas en la práctica clínica, los centros de salud reestructuraron el sistema de prestación de servicios, integrando así dichas consejerías a su quehacer profesional (AU)

The technology transfer process requires training future users in specific knowledge and skills, as well as performing administrative adjustments for an effective incorporation of innovation into the structure of the system and into the professional care. Pontificia Universidad Católica de Chile's School of Nursing developed a model of Technological Support for Health Self-Care, which includes the use of telephone counseling to help people who suffer from chronic diseases manage their condition and look after themselves by teaching them techniques which alleviate their disease. Here, we present an experience that was carried out to transfer this technology to professionals related to the Cardiovascular Health Program in Chilean Public Primary Healthcare Centers located in a low-income district of Chile's capital city, Santiago, so that the technology could be applied to patients with type 2 diabetes who had joined such program. This process was conducted in two stages: 1. Making of a theoretical-practical workshop to support health decision-making and motivational strategies for health behavior change (workshops and demonstrations); and 2. Field demonstration, and monitoring with supervision and meetings at local level. The professionals who participated in the technology transfer program succeeded in developing the skills expected in the Telephone Counseling Tool to Support Self-Management of People suffering from DM2. Finally, to enable telephone counseling in clinical practice, healthcare centers restructured their system of service provisions, incorporating such counseling into their professional duties (AU)

Conformational changes induced by cloxacillin in class a beta-lactamase from Bacillus cereus.

Class A beta-lactamases are enzymes that hydrolyse beta-lactam antibiotics such as penicillins and cephalosporins. They also hydrolyse substrate analogues such as oxacillin and cloxacillin, with a biphasic kinetic as it has been reported for Bacillus cereus beta-lactamase. A molecular model of Bacillus cereus beta-lactamase was built and the conformational changes that the substrates benzylpenicillin and cloxacilline produced in the conformation of selected regions of the protein were analyzed. This study was performed using the docking of the substrates, their tetrahedral intermediates and the corresponding acids on the active site, followed by molecular dynamic and subsequent optimisation procedures. The most important changes were produced on Tyr105 and Tyr273, when the tetrahedral intermediate of cloxacillin was docked at the active site, these amino acids are partially responsible for the stabilisation of the substrates at the active site. These changes may explain the kinetic differences observed during the hydrolysis of substrates type S and type A by beta-lactamases class A.

Poly-beta-hydroxyalkanoates consumption during degradation of 2,4,6-trichlorophenol by Sphingopyxis chilensis S37.

AIMS: To analyse the possible effect of poly-beta-hydroxyalkanoate (PHA) consumption on 2,4,6-trichlorophenol (2,4,6-TCP) degradation during starvation by Sphingopyxis chilensis S37 strain, which stores PHAs and degrades 2,4,6-TCP. METHODS AND RESULTS: The strain was inoculated in saline solution supplemented with 2,4,6-TCP (25-400 microm). Chlorophenol degradation was followed both spectrophotometrically and by chlorine released; viable bacterial counts were also determined. Cells starved for 24, 48 or 72 h were incubated with 25 microm of 2,4,6-TCP and PHA in cells investigated by spectrofluorimetric and flow cytometry. Results demonstrated that starvation decreased the ability to degrade 2,4,6-TCP. After 72 h of starvation, degradation of 2,4,6-TCP decreased to less than 10% and the relative PHA content diminished to ca 50% during the first 24 h. CONCLUSION: Utilization of PHA may be an important factor for the degradation of toxic compounds, such as 2,4,6-TCP, in bacterial strains unable to use this toxic compound as carbon and energy source. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study describing a relationship between intracellular PHA consumption and 2,4,6-TCP degradation. Therefore, PHAs provides an endogenous carbon and energy source under starvation and can play a significant role in the degradation of toxic compounds.

Crystallization and 2.2 A resolution structure of R-phycoerythrin from Gracilaria chilensis: a case of perfect hemihedral twinning.

R-phycoerythrin, a light-harvesting component from the red algae Gracilaria chilensis, was crystallized by vapour diffusion using ammonium sulfate as precipitant agent. Red crystals grew after one week at 293 K and diffracted to 2.70 A resolution. Three serial macroseeding assays were necessary to grow a second larger crystal to dimensions of 0.68 x 0.16 x 0.16 mm. This crystal diffracted to 2.24 A resolution using synchrotron radiation at beamline BM14 of the European Synchrotron Radiation Facility (ESRF) at Grenoble, France and was used for structure determination. Data were collected at 100 K to a completeness of 98.6%. The crystal was trigonal, space group R3, with unit-cell parameters a = b = 187.3, c = 59.1 A, alpha = beta = 90, gamma = 120 degrees. Data treatment using the CCP4 suite of programs indicated that the crystal was twinned ((I(2))/(I)(2) = 1.41). Molecular replacement was performed with AMoRe using the R-phycoerythrin from Polysiphonia urceolata [Chang et al. (1996), J. Mol. Biol. 249, 424-440] as a search model. In order to overcome the twinning problem, SHELX97 was used for the crystallographic refinement. The twin fraction was 0.48, indicating a nearly perfect hemihedrally twinned crystal. The final R(work) and R(free) factors are 0.16 and 0.25, respectively. All the residues and chromophores of the alpha- and beta-chains are well defined in the electron-density maps. Some residues belonging to the gamma-linker are also recognizable.

Active-site studies of enzymes by secondary structure prediction and by molecular modeling.

Since the determination of the tertiary structure by X-ray crystallography has been achieved only for a limited number of proteins, alternative approaches are being sought. In this article, the use of secondary structure prediction and of molecular modeling is discussed. Several examples are analyzed in detail.

Interactions that regulate the helical fold in proteins.

Several factors that may contribute to the stabilization of the helical structure in proteins, detected in studies made on short synthetic peptides, have been reported. Some of them are: presence of alanine or leucine, ionic-pair bonding, stabilization of the helical dipole moment by appropriate charges at the helix N- and C-caps, and aromatic interactions of amino acids located at positions i, i + 4. An analysis of 54 helical structures from 12 proteins showed that all these stabilizing factors were also present in proteins, but the influence of any of them had a different weight, according to the distribution of the hydrophobic and hydrophilic amino acid residues in the helical sequence. The role of non-sequence depending interactions in helical stability, such as presence of disulfide bridges, or bonding of helical residues to substrate and/or cofactors, was also analysed.

Interactions that regulate the helical fold in proteins

Several factors that may contribute to the stabilization of the helical structure in proteins, detected in studies made on short synthetic peptides, have been reported. Some of them are: presence of alanine or leucine, ionic-pair bonding, stabilization of the helical dipole moment by appropriate charges at the helix N- and C-caps, and aromatic interactions of amino acids located at positions i, i + 4. An analysis of 54 helical structures from 12 proteins showed that all these stabilizing factors were also present in proteins, but the influence of any of them had a different weight, according to the distribution of the hydrophobic and hydrophilic amino acid residues in the helical sequence. The role of non-sequence depending interactions in helical stability, such as presence of disulfide bridges, or bonding of helical residues to substrate and/or cofactors, was also analysed

Active-site studies of enzymes by secondary structure prediction and by molecular modeling

Since the determination of the tertiary structure by X-ray crystallography has been achieved only for a limited number of proteins, alternative approaches are being sought. In this article, the use of secondary structure prediction and of molecular modeling is discussed. Several examples are analyzed in detail

Characterization of a plasmid codifying the synthesis of a beta-lactamase produced by Shigella flexneri.

The resistance to beta-lactam antibiotics shown by a strain of Shigella flexneri was plasmid-coded. This plasmid, pMAM-1, when transferred to Escherichia coli K-12 by conjugation, presented the same molecular weight (100 kbp) and conferred the same high level of resistance to ampicillin in the transconjugant as in the wild type strains (MIC, 2048-4096). Restriction analysis of the plasmid in transconjugants revealed various restrictive sites to some endonucleases (i.e. Bam HI, Eco RI, Pst I, Nco I, Cla I, Sf I and Sau 3AI, Nhe and Hin dIII), and no restrictive sites at all for other endonucleases (such as Xho I, Dra I, Kpn I, and Sal I). Some restricted DNA fragments were appropriate for cloning and isolation of the beta-lactamase gene present in Shigella flexneri UCSF 129. This work provides the first step in this direction.

Hydrophobicity and structural classes in proteins.

The bulk hydrophobic character for the 20 natural amino acid residues, has been obtained from a database of 60 protein structures, grouped in the four structural classes alpha alpha, beta beta, alpha + beta and alpha/beta. The hydrophobicity coefficients thus obtained are compared with Ponnuswamy's original values using scales normalized to average = 0.0 and standard deviation = 1.0. Even though most of the amino acid residues do not change their hydropathic character in the different structural classes, their behaviour suggests the convenience that averaging methods should only consider proteins of the same structural class and that this information should be included in the secondary structure methods.

The relationship between the structures of four beta-lactamases obtained from Bacillus cereus.

Bacillus cereus has proved to be one of the most interesting microorganisms in the study of beta-lactamases. It secrets these enzymes very efficiently and, frequently, in multiple forms. Three different forms are produced by strain 569/H; mutant 5/B of the same microorganism is constitutive for the secretion of beta-lactamases I and II. The present study, based on secondary structure prediction by two independent methods, states the relationship among the structures of beta-lactamases I, II and III produced by B. cereus 569/H and beta-lactamase I from the strain 5/B of this microorganism. A strong similarity is also established for the enzyme type III of B. cereus and the enzyme type I produced by B. licheniformis which could have an evolutionary explanation. A structural analysis of the leader peptide regions of these enzymes by the method of Mohana and Argos is also reported.

Secondary structure prediction of human salivary proline-rich proteins.

Conformations associated with secondary structure in human salivary proline-rich proteins A (PRPA), C (PRPC), P-D and P-E were predicted by analysis of their respective hydrophobicity profiles by computer programming. Structurally, PRPA and PRPC would present a globular head and a tail that consists of type 3(10) polyproline helices. P-D and P-E would be fibrilar molecules with helical zones of the polyproline 3(10) type. Alternatively for PRPA and PRPC, the head and tail would form one globular domain with the tail folding upon itself at places where random coils occur.

A model for the secondary structure of beta-lactamases.

A 3-dimensional model, common for the secondary structures of four beta-lactamases obtained from Escherichia coli, Bacillus licheniformis, Bacillus cereus and Staphylococcus aureus, is proposed. The predictions of the structures were made by the hydrophobicity profiles method complemented by the modified Chou and Fasman's method. The model proposed presents 56% constancy and can be described as a 2-domain structure, in agreement with low resolution X-ray data reported for the E. coli enzyme. The model would explain how a common function can be performed by enzymes of very different sizes, composition and sequence.