Effect of Divalent Cations on the Interaction of Carboxylate Self-Assembled Monolayers.

Interactions between organic molecules in aqueous environments, whether in the fluid phase or adsorbed on solids, are often affected by the cations present in the solution. We investigated, at nanometer scale, how surface carboxylate interactions are influenced by dissolved divalent cations: Mg2+, Ca2+, Sr2+, and Ba2+. Self-assembled monolayer (SAM) surfaces with exposed terminations of alkyl, -CH3, carboxylate, -COO- , or dicarboxylate, -DiCOO-, were deposited on gold-coated tips and substrates. We used atomic force microscopy (AFM), in chemical force mapping (CFM) mode, to measure adhesion forces between various combinations of SAMs on the tip and substrate, in solutions of 0.5 M NaCl, that contained 0.012 M of one of the divalent cations. The type of cation, the number of carboxyl groups that interact, and their structure on the SAM influenced adhesion between the surfaces. The effect of the reference solution, which only contains Na+ cations, on adhesion force was mainly attributed to van der Waals and hydrophobic forces, explaining the lower force in systems that are more hydrophilic, i.e., -COO--COO-, and higher force for more hydrophobic systems. For charged surfaces, i.e., -COO- and -DiCOO-, in divalent cation solutions results were consistent with ion bridging. The inclusion of a hydrophobic surface, i.e., the -CH3-COO- or -CH3-DiCOO- system, decreased the possibility for strong cation bridging with the charged surface, resulting in lower adhesion. For systems including -COO-, the adhesion force series followed the inverse cation hydrated radius trend (Na+ ≈ Mg2+ < Sr2+ < Ca2+ < Ba2+) whereas -DiCOO- was responsible for lower adhesion force and modified trends, depending on the corresponding surface in the system. Differences in force magnitude between the monolayers were correlated with lower charge availability on the -DiCOO- surface as a result of fewer active sites, probably because of the tendency of exposed malonate surface groups to interact between them, as well as high rigidity, resulting from the molecule structure. The characteristic response of the -DiCOO- surface in solutions of Sr2+ and Ca2+ was correlated with possible malonate complexation modes. Comparison with previous studies suggested that the strong response of a -DiCOO- surface to Sr2+ resulted from bidentate chelation, whereas Ca2+ response was attributed to alpha-mode association to malonate.

Specific Ion Effects on the Interaction of Hydrophobic and Hydrophilic Self-Assembled Monolayers.

Interactions between mineral surfaces and organic molecules are fundamental to life processes. The presence of cations in natural environments can change the behavior of organic compounds and thus alter the mineral-organic interfaces. We investigated the influence of Na+, Mg2+, Ca2+, Sr2+, and Ba2+ on the interaction between two models, self-assembled monolayers, that were tailored to have hydrophobic -CH3 or hydrophilic -COO(H) terminations. Atomic force microscopy in chemical force mapping mode, where the tips were functionalized with the same terminations, was used to measure adhesion forces between the tip and substrate surfaces, to gather fundamental information about the role of these cations in the behavior of organic compounds and the surfaces where they adsorb. Adhesion force between hydrophobic surfaces in 0.5 M NaCl solutions that contained 0.012 M divalent cations did not change, regardless of the ionic potential, that is, the charge per unit radius, of the cation. For systems where one or the other surface was functionalized with carboxylate, -COO(H), mostly in its deprotonated form, -COO-, a reproducible change in the adhesion force was observed for each of the ions. The trend of increasing adhesion force followed the pattern: Na+ ≈ Mg2+ < Sr2+ < Ca2+ < Ba2+, suggesting that ionic potential, thus hydrated radius, controls the interaction. The presence of a -CH3 surface in the asymmetric system leads to lower adhesion forces than in the hydrophilic system, whereas the ionic trend remains the same. Although specific ion effects are felt in both systems, the lower adhesion force in the asymmetric system, compared with the hydrophilic system, implies that the -CH3 surface plays an important role.

Ofatumumab and high-dose methylprednisolone for the treatment of patients with relapsed or refractory chronic lymphocytic leukemia.

Ofatumumab is a humanized anti-CD20 monoclonal antibody that has been approved by the FDA for the treatment of patients with chronic lymphocytic leukemia. We conducted a phase II single-arm study at a single center. Patients received ofatumumab (300 mg then 1000 mg weekly for 12 weeks) and methylprednisolone (1000 mg/m(2) for 3 days of each 28-day cycle). Twenty-one patients enrolled, including 29% with unfavorable cytogenetics (del17p or del11q). Ninety percent of patients received the full course without dose reductions or delays. The overall response rate was 81% (17/21) with 5% complete response, 10% nodular partial response, 67% partial response, 14% stable disease and 5% progressive disease. After a median follow-up of 31 months, the median progression-free survival was 9.9 months and the median time to next treatment was 12.1 months. The median overall survival has not yet been reached. The combination of high-dose methylprednisolone and ofatumumab is an effective and tolerable treatment regimen. This regimen may be useful for patients who are unable to tolerate more aggressive therapies, or have not responded to other treatments.

A new jasmonic acid stereoisomeric derivative induces apoptosis via reactive oxygen species in human prostate cancer cells.

With the aim of identifying novel agents with antigrowth and pro-apoptotic activity on prostate cancer cells, in the present study, we evaluated the effect of a (-)-jasmonic acid derivative, the 3-hydroxy-2(S)-(2Z-butenyl)-cyclopentane-1(S)-acetic acid, obtained by biotransformation, on cell growth in androgen-sensitive (LNCaP) and androgen-insensitive (DU-145) human prostate cancer cells. The results obtained show that the new compound was able to inhibit the growth of both prostate cancer cells. In addition, our data seem to indicate that the apoptosis evocated by this new molecule, at least in part, appears to be associated with an increase of reactive oxygen species (ROS) production.

Arterioesclerosis subclinica, factores de riesgo cardiovascular clásicos y emergentes en niños obesos chilenos / Subclinical atherosclerosis, traditional cardiovascular risk factors in obese children and emerging Chilean

La arteriosclerosis puede comenzar en la niñez y desarrollarse crónicamente dependiendo de la carga de factores de riesgo (FR) cardiovascular. Comparar niños obesos con eutrófilos en cuanto a FR clásicos, emergentes (proteina C Reactiva ultrasensible: PCRus) y arteriosclerosis subclínica, mediante dos nuevas técnicas no invasivas.

Arterioesclerosis subclínica, factores de riesgo cardiovascular clásicos y emergentes en niños obesos chilenos / Subclinical atherosclerosis: classic and emerging cardiovascular risk factors in Chilean obese children

La arteriosclerosis puede comenzar en la niñez y desarrollarse crónicamente dependiendo de la carga de factores de riesgo (FR) cardiovascular. Objetivo: Comparar niños obesos con eutróficos en cuanto a FR clásicos, emergentes (Proteína C Reactiva ultrasensible: PCRus) y arteriosclerosis subclínica, mediante dos nuevas técnicas no invasivas: dilatación mediada por flujo de la arteria braquial (DMF) y grosor de la íntima-media carotídea (IMT). Método: Se estudiaron 26 niños obesos (IMC ³ Pc95) y 57 eutróficos (IMC: Pc10 - Pc85). Se evaluó antropometría, presión arterial (PA), DMF, IMT, y se determinó de PCRus, perfil lipídico y glicemia de ayunas. Resultados: El 50 por ciento fueron mujeres y 41 por ciento prepúberes. Con edad de 9,9 + - 1,6 y 9,8 + - 1,8 años (ns), zIMC: 2,0 + - 0 2 y 1,7 + - 0,6, perímetro de cintura (por ciento Media): 133,5 + - 16 y 100,5 + -1 0 por ciento en obesos y eutróficos respectivamente. Los obesos tuvieron mayor Colesterol Total, CLDL, Triglicéridos, PCRus y menor CHDL (p < 0,005). No hubo diferencia significativa en DMF: 9,03 + - 5,2 por ciento vs 9,3 + - 4,2 por ciento, IMT: 0,49 + - 0,03 vs 0,50 + - 0,03 mm, glicemia ni PA. Conclusión: Este grupo de niños obesos chilenos presenta mayor carga de FR clásicos y nivel de PCRus que los eutróficos, pero no se encontró diferencia significativa en marcadores sustitutos de arteriosclerosis subclínica.

Asistencia ventricular mecánica como puente al trasplante en pacientes en shock cardiogénico: Experiencia preliminar en Chile con ABIOMED BVS 5000® / Ventricular assist device as a bridge to transplant in patients with cardiogenic shock: Report of four patients

Hospitalization and death due to heart failure and cardiogenic shock is frequent and currently is increasing among the adult population. Although cardiac transplantation is the most effective treatment in patients with end-stage heart failure, its availability is limited. While waiting for transplantation, some patients become refractory to treatment and deteriorate progressively. Secondary multi-organ damage could highly compromise the transplant success and also could contraindicate it. Mechanical ventricular assist devices allow reestablishing normal cardiac output and they have been used as a bridge to recovery and transplantation. We report four patients that underwent mechanical ventricular support using the ABIOMED BVS 5000® system as a bridge for transplantation. Two patients were connected to biventricular assistance; a third patient was connected to a left ventricular support and the fourth to a right ventricular support. Three were successfully transplanted and one died of refractory non-cardiogenic shock. There were no complications related to the support system, such as infection, hemorrhage or stroke. In our experience, the ABIOMED BVS 5000® was an effective strategy as a bridge to heart transplant in patients in cardiogenic shock.

Quimioterapia preoperatoria en cáncer de mama / Preoperatory chemotherapy in breast cancer

El uso de la quimioterapia preoperatoria (Qx preop) en cáncer de mama localmente avanzado ha disminuido la tasa de pacientes consideradas inoperables y las recidivas locaes, aumentando según algunos la sobrevida libre de enfermedad y la sobrevida total. El objetivo de este trabajo es medir la respuesta del tumos de mama primario a la Qx preop y evaluar la influencia de ésta en la elección del tipo de tratamiento quirúrgico. Entre mayo de 1990 y marzo de 1995, ingresaron al protocolo de Qx preop del IOCPC, 93 pacientes con diagnóstico de cáncer de mama localmente avanzado, siendo evaluables para este estudio 80 pacientes. La Qx preop consistió en 3 ciclos de drogas con los esquemas de (CMF) o (FEC/FAC). La respuesta fue evaluada en comité oncológico al finalizar el tercer ciclo, en que se decidió la secuencia a seguir con el tratamiento, ya sea primero radioterapia (RT) o cirugía dependiendo de la respuesta clínica. La Qx preop tuvo una respuesta clínica completa o parcial en un 39 por ciento de las pacientes, permitiendo realizar un tratamiento conservador en un 16 por ciento de ellas. Con la adición de RT preoperatoria es posible reducir significativamente el número de pacientes consideradas inoperables en el momento de la evaluación inicial

Enhancement of natural killer cell activity in septic shock patients by a mixture of the calcium ionophore A23187 and the phorbol ester TPA: in vitro studies.

Preincubation of peripheral blood lymphocytes from drug-free, healthy volunteers with a mixture of the calcium ionophore A23187 (Io) and the phorbol ester TPA (12-O-tetradecanoylphorbol-13-acetate) consistently resulted in a significant enhancement (dose-dependent; maximum immunostimulation obtained with the Io + TPA final mixture concentration of 10 uM + 250 ng/ml, respectively) of natural killer cell activity (NKCA) (n = 8; mean +/- SD of 16.8 +/- 8.9 and 52.0 +/- 18.0, paired Student's t-test p < 0.005; effector-to-target cell ratio of 30:1). Results from the same protocol, but using samples from septic shock patients followed a similar trend; however, and perhaps reflecting the significantly lower baseline NKCA in this group of individuals (n = 7), the mean value reached for this cellular immune function after incubation with Io + TPA was significantly lower than that of the treated controls' group (mean +/- SD of 19.8 +/- 11.6 and 52.0 +/- 18.0, respectively, Student's t-test p < 0.005). As expected from the role of calcium in the activation of NKCA, incubation with the Io significantly increased baseline NKCA, which was largely unchanged by TPA. Expression of the CD56+ and CD16+ phenotypes in septic shock patients did not correlate directly with NKCA, suggesting that this condition may be associated with changes in the function rather than the quantity of these cellular markers.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro studies of natural killer cell activity in septic shock patients. Response to a challenge with alpha-interferon and interleukin-2.

Natural killer cell activity (NKCA) in patients with septic shock was statistically significantly lower than the value recorded for a group of drug-free, healthy volunteers [9.1 +/- 7.8 (n = 20) and 20.6 +/- 16.6 (n = 15), respectively; Student's test, p < 0.05]. As expected, preincubation of peripheral blood lymphocytes from samples taken from a group of controls with either alpha-interferon or interleukin -2 resulted in an enhancement of NKCA for each and everyone of the subjects studied; however, results from a similar protocol using patient samples showed a lack of consistency, both in the direction and magnitude, in the elicited changes in NK lytic function. Whereas samples from same patient responded with either an increase or a decrease in NKCA to preincubation with both immunostimulators, others responded with NKCA upmodulation to one and downmodulation to other of these test substances. A better knowledge of the mechanism(s) responsible for the depressed expression of NKCA in septic shock patients, and its altered response to alpha-interferon and interleukin-2, could generate new modalities in the diagnosis and therapy of this condition.

Nebulization of liposomes. III. The effects of operating conditions and local environment.

Multilamellar liposomes (MLV) of saturated phosphatidylcholine and dipalmitoyl phosphatidylglycerol (DPPG) (9:1 mole ratio) containing 5,6-carboxyfluorescein (CF) were prepared and extruded through 1.0-micron polycarbonate membranes. Diluted aqueous dispersions were aerosolized for a total of 80 min using a Collison nebulizer under a variety of conditions. The effects of air pressure, temperature, buffer osmotic strength, and pH on nebulized liposome dispersions were studied. Changes in air pressure produced large changes in the percentage release of CF and ranged from 1.3% (4 psig) to 88.2% (50 psig) after 80 min of nebulization. The temperature of the nebulizer dispersions dropped during experiments. The extent of the temperature drop varied according to the air pressure used and ranged from 5 degrees C (4 psig) to 11 degrees C (greater than or equal to 30 psig). The temperature of dispersions caused no increase in CF release until the gel-to-liquid crystalline transition temperature was exceeded (54.6 degrees C), whereupon a 20% increase in leakage was observed after 80 min of nebulization. Aerosol mass output was relatively unaffected by the starting temperature of experiments when conducted within the ambient temperature range. Leakage from the liposomes was increased in hypotonic solution but decreased in hypertonic solutions. At a buffer pH of 2.85 the percentage leakage of CF was increased approximately 18% compared to that at pH 7.2 and pH 10.75. Results show that the stability of liposomes composed of saturated phosphatidylcholine and DPPG (9:1 mole ratio) is affected by the operating and environmental conditions under which aerosolization takes place, with air pressure having the greatest effect.

La enfermería en el Hospital Clínico de la Universidad Católica de Chile / The Nursing in Hospital Clínico of Universidad Católica de Chile

La historia de Enfermería en la Universidad no se puede plantear sin referencia al desarrollo de la Escuela de Enfermería, y al desarrollo del Hospital Clínico y el Centro de Diagnóstico. El Hospital se fundó en 1937 con el nombre, de Hospital Corazón Misericordioso de Jesús, que toma por la Congregación de Religiosas que atienden y administran el Hospital hasta 1966. Las Religiosas dejan progresivamente estas actividades tomando las funciones enfermeras profesionales egresadas de la misma Universidad. El Hospital en sus inicios dispone de pocos recursos económicos y servicios de atención minimos. Actualmente cuenta con amplias y modernas instalaciones, nuevas construcciones y con todos los servicios generales y de especialidades de medicina; además dispone de un Centro de Diagnóstico (CEDIUC) desde 1980, para atención de pacientes ambulatorios, equipados con laboratorios completos y modernos

La enfermería en el Hospital Clínico de la Universidad Católica de Chile / The Nursing in Hospital Clínico of Universidad Católica de Chile

La historia de Enfermería en la Universidad no se puede plantear sin referencia al desarrollo de la Escuela de Enfermería, y al desarrollo del Hospital Clínico y el Centro de Diagnóstico. El Hospital se fundó en 1937 con el nombre, de Hospital Corazón Misericordioso de Jesús, que toma por la Congregación de Religiosas que atienden y administran el Hospital hasta 1966. Las Religiosas dejan progresivamente estas actividades tomando las funciones enfermeras profesionales egresadas de la misma Universidad. El Hospital en sus inicios dispone de pocos recursos económicos y servicios de atención minimos. Actualmente cuenta con amplias y modernas instalaciones, nuevas construcciones y con todos los servicios generales y de especialidades de medicina; además dispone de un Centro de Diagnóstico (CEDIUC) desde 1980, para atención de pacientes ambulatorios, equipados con laboratorios completos y modernos(AU)