Solvent-Tuned Supramolecular Assembly of Fluorescent Catechol/Pyrene Amphiphilic Molecules.

The synthesis and structuration of a novel low-molecular-weight amphiphilic catechol compound is reported. The combination of a hydrophilic tail containing a catechol unit and a pyrene-based hydrophobic head favors solvent-tuned supramolecular assembly. Formation of hollow nanocapsules/vesicles occurs in concentrated solutions of polar protic and nonprotic organic solvents, whereas a fibril-like aggregation process is favored in water, even at low concentrations. The emission properties of the pyrene moiety allow monitoring of the self-assembly process, which could be confirmed by optical and electronic microscopy. In organic solvents and at low concentrations, this compound remains in its nonassembled monomeric form. As the concentration increases, the aggregation containing preassociated pyrene moieties becomes more evident up to a critical micellar concentration, at which vesicle-like structures are formed. In contrast, nanosized twist beltlike fibers are observed in water, even at low concentrations, whereas microplate structures appear at high concentrations. The interactions between molecules in different solvents were studied by using molecular dynamics simulations, which have confirmed different solvent-driven supramolecular interactions.

Limitación del tratamiento de soporte vital en el traumatismo grave en edades avanzadas tras el ingreso en una unidad de cuidados intensivos / Limitation of life-sustaining treatment in severe trauma in the elderly after admission to an intensive care unit

Objetivo: Analizar los factores asociados al proceso de limitación del tratamiento de soporte vital (LTSV) en los pacientes de edad avanzada que ingresan en una unidad de cuidados intensivos (UCI) tras un traumatismo. Diseño: Estudio observacional, descriptivo, retrospectivo. Ámbito: UCI. Pacientes: Ciento cuarenta y nueve pacientes con una edad igual o mayor de 65 años ingresados en UCI tras un traumatismo. Se analizó la mortalidad intrahospitalaria, la decisión de LTSV y los factores asociados a dicho proceso. Intervenciones: Ninguna. Resultados: La edad media fue de 76,3±6,36 años. La puntuación media en la escala APACHE II fue de 15,9±7,4 puntos, y en la escala ISS, de 19,6±11,4 puntos. Se decidió LTSV en 37 pacientes (24,8%). Los factores asociados a este proceso fueron la edad (OR 1,16; IC 95% 1,08-1,25), la puntuación en el APACHE II (OR 1,11; IC 95%1,05-1,67), la puntuación en el ISS (OR 1,03; IC 95% 1,01-1,06), el ingreso como consecuencia de un deterioro neurológico (OR 19,17; IC 95% 2,33-157,83) y el traumatismo craneoencefálico (OR 2,89; IC 95% 1,05-7,96). Conclusiones: La LTSV se establece con frecuencia en los pacientes de edad avanzada que ingresan en la UCI tras un traumatismo, y se asocia con la mortalidad intrahospitalaria. Los factores asociados al proceso de LTSV son una mayor edad, una mayor puntuación en las escalas APACHE II e ISS, el ingreso como consecuencia de un deterioro neurológico y la presencia de traumatismo craneoencefálico (AU)

Objective: To analyze the factors associated to limitation of life-sustaining treatment (LLST) measures in elderly patients admitted to an intensive care unit (ICU) due to trauma. Design: A retrospective, descriptive, observational study was carried out. Setting: ICU. Patients: A total of 149 patients aged 65 years or older admitted to the ICU due to trauma. Hospital mortality, the decision to limit life-sustaining treatment and the factors associated to these measures were analyzed. Interventions: None. Results: The mean patient age was 76.3±6.36 years. The average APACHE II and ISS scores were 15.9±7.4 and 19.6±11.4 points, respectively. LLST were used in 37 patients (24.8%). Factors associated to the use of these measures were patient age (OR 1.16; 95% CI 1.08 to 1.25], APACHE II score (OR 1.11; 95% CI 1.05-1.67), ISS score (OR 1.03; 95% CI 1.01 to 1.06), admission due to neurological impairment (OR 19.17; 95% CI 2.33 to 157.83) and traumatic brain injury (OR 2.89; 95% CI 1.05 to 7.96). Conclusions: LLST is frequently established in elderly patients admitted to the ICU due to trauma, and is associated to hospital mortality. Factors associated with the use of these measures are patient age, higher APACHE II and ISS scores, admission due to neurological impairment, and the presence of head injuries (AU)

Limitation of life-sustaining treatment in severe trauma in the elderly after admission to an intensive care unit. / Limitación del tratamiento de soporte vital en el traumatismo grave en edades avanzadas tras el ingreso en una unidad de cuidados intensivos.

OBJECTIVE: To analyze the factors associated to limitation of life-sustaining treatment (LLST) measures in elderly patients admitted to an intensive care unit (ICU) due to trauma. DESIGN: A retrospective, descriptive, observational study was carried out. SETTING: ICU. PATIENTS: A total of 149 patients aged 65 years or older admitted to the ICU due to trauma. Hospital mortality, the decision to limit life-sustaining treatment and the factors associated to these measures were analyzed. INTERVENTIONS: None. RESULTS: The mean patient age was 76.3±6.36 years. The average APACHE II and ISS scores were 15.9±7.4 and 19.6±11.4 points, respectively. LLST were used in 37 patients (24.8%). Factors associated to the use of these measures were patient age (OR 1.16; 95% CI 1.08 to 1.25], APACHE II score (OR 1.11; 95% CI 1.05-1.67), ISS score (OR 1.03; 95% CI 1.01 to 1.06), admission due to neurological impairment (OR 19.17; 95% CI 2.33 to 157.83) and traumatic brain injury (OR 2.89; 95% CI 1.05 to 7.96). CONCLUSIONS: LLST is frequently established in elderly patients admitted to the ICU due to trauma, and is associated to hospital mortality. Factors associated with the use of these measures are patient age, higher APACHE II and ISS scores, admission due to neurological impairment, and the presence of head injuries.

[Outbreak of multiresistant and extended spectrum ß-lactamase producing Klebsiella pneumoniae in a high risk neonatal unit]. / Brote por Klebsiella pneumoniae multiresistente y productora de ß-lactamasa de espectro extendido en una unidad de alto riesgo neonatal.

Klebsiella pneumoniae as a producer of extended spectrum beta-lactamase (ESBL) has played an important role as a cause of infection in the neonatal high risk unit (NHRU) of the Autonomous Hospital Institute of the Universidad de Los Andes (AHIULA). In this paper an outbreak caused by this bacterial specie that affected neonates hospitalized in this unit during February 2007 is described. Besides, the environment and the personnel were studied as possible sources of this organism. The strains of K. pneumonia isolated from the outbreak had the same resistance phenotype, produced ESBL type TEM and SHV and belonged to the same genotype as the isolated strains from the hands and the soapy solutions, possible sources of infection. This indicates that it was the same clone. The outbreak was resolved using two important measurements: reinforcing hand washing and with the opportune treatment of neonates with imipenem.

Brote por Klebsiella pneumoniae multiresistente y productora de β-lactamasa de espectro extendido en una unidad de alto riesgo neonatal / Outbreak of multiresistant and extended spectrum β-lactamase producing Klebsiella pneumoniae in a high risk neonatal unit

Klebsiella pneumoniae productora de β-lactamasa de espectro expandido (BLEE) ha jugado un papel importante como causa de infecciones en la unidad de alto riesgo neonatal (UARN) del Instituto Autónomo Hospital Universitario de Los Andes (IAHULA). En el presente trabajo se describe un brote ocasionado por esta bacteria en los neonatos hospitalizados en dicha unidad durante el mes de febrero 2007, así como también, cepas aisladas en los meses siguientes al brote y además, se estudia el ambiente y el personal, como posible fuente de esta bacteria. Las cepas de K. pneumoniae aisladas del brote eran del mismo fenotipo de resistencia, productoras de (3LEE tipo TEM y SHV y pertenecían al mismo genotipo que las cepas aisladas de las manos y de las soluciones jabonosas, posible fuente de infección, lo cual indica que se trataba del mismo clon. El brote se resolvió usando dos importantes medidas: reforzando el lavado de manos y con la indicación oportuna de imipenem a los neonatos afectados.

Klebsiella pneumoniae as a producer of extended spectrum beta-lactamase (ESBL) has played an important role as a cause of infection in the neonatal high risk unit (NHRU) of the Autonomous Hospital Institute of the Universidad de Los Andes (AHIULA). In this paper an outbreak caused by this bacterial specie that affected neonates hospitalized in this unit during February 2007 is described. Besides, the environment and the personnel were studied as possible sources of this organism. The strains of K. pneumonia isolated from the outbreak had the same resistance phenotype, produced ESBL type TEM and SHV and belonged to the same genotype as the isolated strains from the hands and the soapy solutions, possible sources of infection. This indicates that it was the same clone. The outbreak was resolved using two important measurements: reinforcing hand washing and with the opportune treatment of neonates with imipenem.

A cDNA for nuclear-encoded chloroplast translational initiation factor 2 from a higher plant is able to complement an infB Escherichia coli null mutant.

Formation of the initiation translation complex containing the three initiation factors, IF1, IF2, and IF3, tRNA(fMet), and GTP constitutes the earliest event in the protein synthesis. IF2, a GTP-binding protein, is the principal factor involved in selecting and binding fMet-tRNA(fMet) to the 30 S ribosomal subunit. Although some chloroplast initiation translational factors have been identified and purified from algae, none of these factors have been characterized from plants. In this work, we report the molecular characterization of a nuclear-encoded chloroplastic IF2 gene from common bean (PvIF2cp). We show that the PvIF2cp gene encodes a protein containing a chloroplast translocation signal peptide, able to target a green fluorescent protein fusion protein to chloroplasts. A high accumulation of PvIF2cp transcript was found in photosynthetic tissues, whereas low mRNA levels were detected in etiolated plants and in nonphotosynthetic organs. Additional data indicate that the PvIF2cp transcript accumulation is modulated by light. The PvIF2cp gene encodes a functional factor, since the PvIF2cp conserved region, containing the G-domain and the C-terminal end, complements an Escherichia coli infB null mutation. Phylogenetic analysis using the PvIF2cp conserved region suggests that the PvIF2cp gene originated via endosymbiotic gene transfer to the nucleus and that it may be a useful marker for phylogeny reconstruction.

Challenges and strategies for conducting intervention research with culturally diverse populations.

Conducting intervention research with culturally diverse, underserved, and often hard to reach populations in naturalistic or field settings presents investigators with a number of practical challenges. This article describes four special challenges and strategies for dealing with them that clients, service providers, and researchers experienced in conducting a prevention intervention to reduce substance use and sexual risky behaviors with low-income Latina young women. The challenges are (a) building community partnerships; (b) developing interventions that are acceptable and relevant; (c) promoting successful recruitment, participation, and retention of participants; and (d) developing a diverse, cohesive, and committed research team and effective managerial information support systems.

Correlates of alcohol and drug use among low-income Hispanic immigrant childbearing women living in the USA.

Alcohol and drug use is a widespread and serious problem with deleterious consequences for the health and well-being of childbearing-age women and their children. Little information exists regarding etiological factors for substance use among Hispanic childbearing-age women immigrating to the United States (USA). This research provides a correlational analysis of factors associated with alcohol and drug use. The Social Stress Model for Substance Use Prevention provided the conceptual framework for this cross-sectional, interview-administered survey of 60 low-income predominantly Mexican-American women. The outcome variable was alcohol and drug use (alcohol, cigarettes, marijuana, cocaine and opiates). Independent variables included the major constructs of the model: stress, social support, social influences, personal competencies and community resource utilization patterns. Findings suggested that the levels of drug use were lower among this study sample than in the general USA population regardless of pregnancy status. Bivariate correlations demonstrate that women with higher drug use indices had more lenient attitudes regarding drug use and were more likely to have family and friends that used alcohol and drugs. Although drug use was relatively low among this sample of women, both women who used alcohol themselves and women whose partners used alcohol and drugs reported significantly higher levels of stress, weaker social support and poorer levels of self esteem. Implications for practice and future research are suggested.

Competence and drug use: theoretical frameworks, empirical evidence and measurement.

Statistics show that use of harmful substances (alcohol, cigarettes, marijuana, cocaine) among women of childbearing age is widespread and serious. Numerous theoretical models and empirical studies have attempted to explain the complex factors that lead individuals to use drugs. The Social Stress Model of Substance Abuse [1] is one model developed to explain parameters that influence drug use. According to the model, the likelihood of an individual engaging in drug use is seen as a function of the stress level and the extent to which it is offset by stress modifiers such as social networks, social competencies, and resources. The variables of the denominator are viewed as interacting with each other to buffer the impact of stress [1]. This article focuses on one of the constructs in this model: that of competence. It presents a summary of theoretical and conceptual formulations for the construct of competence, a review of empirical evidence for the association of competence with drug use, and describes the preliminary development of a multi-scale instrument designed to assess drug protective competence among low-income Hispanic childbearing women. Based upon theoretical and empirical studies, eight domains of drug protective competence were identified and conceptually defined. Using subscales from existing instruments with psychometric evidence for their validity and reliability, a multi-scale instrument was developed to assess drug protective competence. Hypothesis testing was used to assess construct validity. Four drug protective competence domains (social influence, sociability, self-worth, and control/responsibility) were found to be statistically associated with drug use behaviors. Although not statistically significant, expected trends were observed between drug use and the other four domains of drug protective competence (intimacy, nurturance, goal directedness, and spiritual directedness). Study limitations and suggestions for further psychometric testing of the instrument are described.

[Does the degree of metabolic control of diabetes mellitus affect the blood concentration of endothelins?]. / Afecta el grado de control metabólico de la diabetes mellitus, a la concentración plasmática de endotelinas?

BACKGROUND: Endothelins are a family of peptides with a potent constriction action that can play a role in the etiology of vascular diabetic complications. PATIENTS AND METHODS: We studied 26 prepubertal patients diagnosed with type I diabetes mellitus and treated by both insulin and dietetic regime. They were analyzed according to their age. A morning blood sample was obtained after 12 hours of overnight fasting for endothelin determination (RIA from Nichols Institute) and HbA1c (Biorad). Patients were classified into two groups: 1) good control, with HbA1c values < 8% and 2) poor control with HbA1c levels > 8%. The control groups was comprised of endocrinologically normal children that consulted the pediatrician for suspected constitutional delay of growth. Statistical analysis was made by means of nonparametric methods and with the Spearman coefficient. RESULTS: In the control group, the plasma concentration of endothelin were 4.01 +/- 1.1 pg/ml (x +/- SD). In diabetics with good control, values were 3.15 +/- 0.62 pg/ml and 3.91 +/- 1.25 in diabetics with poor control. No statistical differences were noted among these groups. CONCLUSIONS: We deduce that plasmatic levels of endothelin does not seem to be affected by the metabolic control in patients with type I diabetes mellitus without complications.

Extracellular secretion of STa heat-stable enterotoxin by Escherichia coli after fusion to a heterologous leader peptide.

The mature 19-amino acid STa heat-stable enterotoxin of E. coli has a preceding peptide of 53 amino acids which contains two domains called Pre (aa 1-19) and Pro (aa 20-53) sequences, proposed to be essential for extracellular toxin release by this host. The Pro sequence, however, has been proven not be indispensable for this process since Pro deletion mutants secrete STa. To find out if Pre and/or other unremoved natural STa flanking sequences are responsible for toxin secretion in those mutants we genetically fused mature STa directly to the leader peptide of the periplasmic E. coli heat-labile enterotoxin B-subunit (LTB). Expression of this gene fusion resulted in extracellular secretion of biologically active STa by E. coli independently of natural STa neighboring genetic sequences. Moreover, these results suggest that STa might be able to gain access to the extracellular milieu simply upon its entry into the E. coli periplasm once guided into this compartment by the LTB leader peptide. To test if extracellular secretion in this fashion might be extended to other disulfide bond-rich small peptides, the 13 amino acid conotoxin GI and a non-enterotoxic STa-related decapeptide were cloned. None of the two peptides was found in culture supernatants, in spite of high structural homology to the toxin. Failure to be secreted most likely leads to degradation as peptides were also not detected in bacterial sonicates. We hypothesize that cysteine-rich peptides must have an amino acid length and/or number of disulfide bridges closer to those in STa for them to follow this toxin secretory pathway in E. coli.

[Development of oral vaccines based on recombinant proteins derived from cholera toxin]. / Desarrollo de vacunas orales basadas en proteínas recombinantes derivadas de la toxina del cólera.

In this paper a new approach to create antigens through genetic engineering is discussed. In this particular case the subunits of V. cholerae toxin are used as heterologous epitope carries. In this paper the manipulation of A and B subunits is described. This manipulation allows both the insertion of epitopes to the B subunit and the use of subunit A in the construction of recombinant antigens similar to the ones derived from subunit B.

Coliform septicemia and pulmonary disease associated with canine parvoviral enteritis: 88 cases (1987-1988).

Parvovirus infection was confirmed by fluorescent antibody staining or viral culturing in 137 (22%) of 615 necropsy accessions from dogs at the Missouri Veterinary Medical Diagnostic Laboratory from Jan 1, 1987 through Sept 30, 1988. Septicemic colibacillosis was diagnosed in 88 (90%) of the 98 canine parvovirus-positive accessions in which liver or lung was cultured bacteriologically. Pulmonary edema or alveolitis similar to that seen in the human adult respiratory distress syndrome was observed in 63 (69%) of the 91 canine parvovirus-positive accessions in which the lungs were examined histologically.

Chlamydial infection in aborted and stillborn lambs.

Chlamydia psittaci is a major cause of ovine abortion in the fourth to fifth months of gestation. During the lambing seasons of 1986, 1987, and 1988, fetuses from 52 cases of ovine abortion, stillbirth, or perinatal death were submitted to the laboratory for necropsy examination. Placenta or fetal tissues from 34 cases were cultured on mouse L cells for C. psittaci. Chlamydia psittaci was identified by immunofluorescence on cultures in 20 of these cases. The major gross lesion consistently associated with chlamydial abortion was placentitis with multifocal cotyledonary necrosis and accumulation of red-brown exudate in the intercotyledonary placenta. Chlamydiae appeared as spherical organisms, less than 1 micron in diameter, in the cytoplasm of trophoblasts in impression smears of cotyledons. Histologically, placentitis was sometimes accompanied by pneumonia or encephalitis in the fetus. Chlamydia psittaci was considered the cause for fetal death when chlamydial isolation was associated with placentitis or inflammation of other fetal tissues and when other abortifacient agents were not detected.

Experimental rotavirus infection in three-week-old pigs.

Thirteen 3-week-old pigs that had been allowed to nurse for the first 16 to 18 hours after birth were orally inoculated with 1 x 10(6.5) TCID50 of porcine rotavirus. All developed diarrhea, anorexia, and vomiting by postinoculation (PI) hour 30. These signs had abated by PI day 6. Villus blunting in the small intestine was most severe in the jejunum and ileum of pigs euthanatized between PI days 3 and 5. Villi had returned to nearly normal length by PI day 6, although fused villi were seen in a few locations in the distal portion of the jejunum and in the ileum. Virus was detected in the feces of inoculated pigs by isolation in cell cultures and by electron microscopy during the 7-day course of the experiment. There was 1 extraintestinal virus isolation from the lung of 1 pig at PI day 2. Infection and disease developed in the presence of serum-neutralizing antibody obtained by nursing seropositive sows. There was no significant change in neutralizing antibody titers in the 3-week-old pigs over the course of the experiment. In this experimental work, a model to study rotavirus infection in 3-week-old pigs has been developed.

Rotavirus replication in colostrum-fed and colostrum-deprived pigs.

A porcine rotavirus isolate was titrated in neonatal colostrum-fed and colostrum-deprived pigs. The stock rotavirus suspension had a titer of 10(-6.5)/ml and was in its fifteenth cell culture passage in MA-104 cells. Fourteen colostrum-fed pigs were orally inoculated with dilutions of the stock virus suspension ranging from undiluted to 10(-5). These pigs did not develop notable clinical signs during the 7-day experimental trial and no pathologic changes were found in intestine, liver, lung, kidney, spleen, or brain. However, rotavirus was detected in feces of the colostrum-fed pigs, using virus isolation and electron microscopic techniques. Rotavirus was also isolated from lung, brain, or spleen of 4 of 12 of these pigs. Sixteen colostrum-deprived pigs were orally inoculated with dilutions of the stock virus suspension ranging from 10(-1) to 10(-8). Diarrhea developed in 10 of 12 pigs that were given up to the 10(-6) dilution. Seven of these 12 pigs died because of the severity of diarrhea. Pigs that died of rotavirus-induced diarrhea had severe villus loss in the jejunum and ileum. Villi of the small intestine of colostrum-deprived pigs that survived the severe diarrhea were within normal limits at the end of the 7-day trial. The colostrum-deprived pigs that were inoculated with a dilution less than 10(-6) and survived past 96 hours underwent seroconversion. Rotavirus was detected by virus isolation and electron microscopy in the feces of all colostrum-deprived pigs that survived beyond 18.5 hours after inoculation. Virus was isolated from lungs, brain, or spleen of 12 of 16 colostrum-deprived pigs.

Relationship among transmissible gastroenteritis virus antibody titers in serum, colostrum, and milk from vaccinated sows, and protection in their suckling pigs.

We studied the antibody responses to transmissible gastroenteritis (TGE) in serum, colostrum, and milk from sows vaccinated with 2 attenuated (1 IM and 1 oral-IM) and 1 nonattenuated live vaccines and the relationship of these responses with the survivability of the sow's suckling pigs after challenge exposure with virulent TGE virus. Contrary to previous studies, the anti-TGE virus-neutralizing geometric mean titers (GMT) in the milk of sows vaccinated with attenuated vaccines at 3 and 5 days of lactation were similar to that found in the colostrum. Colostral and serum antibody titers were highest in sows given 2 injections of the IM attenuated vaccine. Half of the sows given the oral-IM attenuated vaccine did not seroconvert after 2 oral doses. Only sows vaccinated with the nonattenuated live vaccine had milk GMT that remained high for 21 days after farrowing. The linear relationship between colostral GMT and percentage of survivability of suckling pigs challenge exposed at 3 days of age was significant (P less than 0.05), although the relationship between serum GMT and percentage of survivability and the relationship between milk GMT and percentage of survivability were not significant (P greater than 0.10). The linear relationship between colostral (P less than 0.10) or pre-challenge exposure milk (P less than 0.05) GMT and percentage of survivability of suckling pigs challenge exposed at 5 days of age was significant.(ABSTRACT TRUNCATED AT 250 WORDS)