Change in the magnetic configurations of tubular nanostructures by tuning dipolar interactions.

We have investigated the equilibrium states of ferromagnetic single wall nanotubes by means of atomistic Monte Carlo simulations of a zig-zag lattice of Heisenberg spins on the surface of a cylinder. The main focus of our study is to determine how the competition between short-range exchange (J) and long-range dipolar (D) interactions influences the low temperature magnetic order of the nanotubes as well as the thermal-driven transitions involved. Apart from the uniform and vortex states occurring for dominant J or D, we find that helical states become stable for a range of intermediate values of γ = D/J that depends on the radius and length of the nanotube. Introducing a vorticity order parameter to better characterize helical and vortex states, we find the pseudo-critical temperatures for the transitions between these states and we establish the magnetic phase diagrams of their stability regions as a function of the nanotube aspect ratio. Comparison of the energy of the states obtained by simulation with those of simpler theoretical structures that interpolate continuously between them, reveals a high degree of metastability of the helical structures that might be relevant for their reversal modes.

Assessment of the rs4340 ACE gene polymorphism in acute coronary syndrome in a Western Mexican population.

Acute coronary syndrome (ACS) is considered one of the main causes of death worldwide. Contradictory findings concerning the impact of the angiotensin-converting enzyme (ACE) gene on cardiovascular diseases have been reported. Previous conclusions point out that the variability in results depends on ethnicity and genetic polymorphisms to determine the association of rs4340 polymorphisms of the ACE gene and ACE circulating levels in ACS. Genotyping of rs4340 polymorphisms was performed in a total of 600 individuals from Western Mexico divided into two groups: the ACS and the control group (CG). The polymorphisms were identified by polymerase chain reaction. Serum ACE concentration was determined by enzyme-linked immunosorbent assay. D/D carriers had higher ACE levels than I/I carriers (3.6 vs 2.8 ng/mL, P < 0.0021) in the CG. The D/D genotype of the rs4340 polymorphism is associated with higher ACE concentration levels; however, the polymorphism was not associated with ACS.

Influence of haplotypes, gene expression and soluble levels of L-selectin on the risk of acute coronary syndrome.

BACKGROUND: L-selectin gene (SELL) is a candidate gene for the development of acute coronary syndrome (ACS) that contributes to endothelial dysfunction. The -642C>T (rs2205849) and 725C>T (rs2229569) polymorphisms have been associated with changes in gene expression, ligand affinity and increased risk of cardiovascular disease. The aim of this study was to investigate the association between the haplotypes constructed with the -642C>T and 725C>T polymorphisms of the SELL gene, the expression levels of its mRNA and the serum levels of soluble L-selectin with ACS. METHODS: We recruited 615 individuals of Mexican origin matched by age, including 342 patients with ACS and 273 individuals without personal history of ischemic cardiopathy as control group (CG). Genotyping was performed by PCR-RFLP. The qPCR technique was used to analyze the expression of mRNA using TaqMan® UPL probes. The levels of soluble L-selectin were measured with ELISA. RESULTS: The allele variants in both polymorphisms were over-represented in the CG compared to the ACS (OR range: 0.371-0.716, p<0.006). The CT and TT haplotypes had a protective effect against the development of ACS (OR=0.401, p<0.0001; OR=0.628, p<0.0001, respectively). SELL expression was 3.076 times higher in the ACS group compared to CG (p<0.001). The levels of soluble L-selectin were similar between ACS and CG. CONCLUSIONS: Both polymorphisms had no effect on mRNA expression and soluble protein levels. The polymorphisms -642C>T and 725C>T of the SELL gene are protective factors against the development of ACS. There is an increased gene expression of L-selectin in ACS compared to CG in the population of Western Mexico.

Salmonella enterica serovar Typhimurium BaeSR two-component system positively regulates sodA in response to ciprofloxacin.

In response to antibiotics, bacteria activate regulatory systems that control the expression of genes that participate in detoxifying these compounds, like multidrug efflux systems. We previously demonstrated that the BaeSR two-component system from Salmonella enterica serovar Typhimurium (S. Typhimurium) participates in the detection of ciprofloxacin, a bactericidal antibiotic, and in the positive regulation of mdtA, an efflux pump implicated in antibiotic resistance. In the present work, we provide further evidence for a role of the S. Typhimurium BaeSR two-component system in response to ciprofloxacin treatment and show that it regulates sodA expression. We demonstrate that, in the absence of BaeSR, the transcript levels of sodA and the activity of its gene product are lower. Using electrophoretic mobility shift assays and transcriptional fusions, we demonstrate that BaeR regulates sodA by a direct interaction with the promoter region.

Nifedipine versus fenoterol in the management of preterm labor: a randomized, multicenter clinical study.

PURPOSE: To compare the efficacy of nifedipine and fenoterol in the management of threatened preterm labor (TPL). METHODS: A randomized and multicenter study assessing the tocolytic effect of nifedipine versus fenoterol in patients admitted to the participating maternity units with a diagnosis of TPL and a cost-savings study for economic assessment. For a power of 80% and an α error equal to 0.05, 132 consecutive patients were recruited during the study period; 66 patients were assigned to each group. A χ(2) analysis and a mean differences test were performed according to variable types and survival curves per intention-to-treat. RESULTS: Demographics were similar in both groups. The latency period was similar in both groups (26.7 vs. 25.6; p = 0.3). There were no differences in the results obtained. Nifedipine failed more frequently to obtain tocolysis when used as a first-line agent (80 vs. 90%, p = 0.0001). The group treated with fenoterol showed more drug adverse events (57.8 vs. 19.0%, p = 0.0001). The economic assessment did not evidence a significant difference in terms of cost savings between groups treated with either drug. CONCLUSION: The present study failed to demonstrate either clinical or economic superiority of any of the two drugs used in TPL management. The highest failure percentage of nifedipine when used as a first-line agent should encourage further research.

Resultados obstétricos asociados al incremento del índice de masa corporal durante el embarazo en el Hospital Clínico de la Universidad de Chile / No disponible

Introducción: Estudios previos muestran que el incremento en la categoría del índice de masa corporal (IMC) se asocia a un mayor riesgo de complicaciones obstétricas. Objetivo: Investigar el impacto que tiene el incremento del IMC durante el embarazo en los resultados obstétricos en el Hospital Clínico de la Universidad de Chile. Material y métodos: Estudio retrospectivo que incluye a embarazadas atendidas en el hospital entre el año 2001 y 2006. Las mujeres con embarazos únicos fueron clasificadas en las distintas categorías de IMC. El incremento del IMC se calculó como la diferencia entre el IMC del inicio y el del final de la gestación. Para comparar las variables categóricas se usó el test exacto de Fisher y para las variables continuas el test de la t para comparación de 2 medias. Resultados: El estudio incluyó a 5.478 mujeres: 568(10,48%) no incrementaron su categoría de IMC y4.910 (89,51%) aumentaron su IMC en 1 o más categorías. El incremento del IMC se asoció a mayor riesgo de preeclampsia (p = 0,004) y operación cesárea (p =0,009) en las pacientes con sobrepeso, no así en las pacientes con normopeso al inicio del embarazo. Las pacientes obesas presentan mayor riesgo de preeclampsia(p = 0,008), diabetes gestacional (p < 0,001), operación cesárea (p < 0,001) e infección posparto (p = 0,009).Conclusión: El incremento en la categoría de IMC se asocia a un aumento del riesgo de complicaciones obstétricas (AU)

Background: Previous studies have shown that an increase in body mass index (BMI) is associated with a greater risk of obstetric complications. Aim: To investigate the effect of an increase in BMI category on obstetric outcomes in Hospital Clínic of the University of Chile. Material and methods: A retrospective study was conducted of women followed-up in the hospital from2001 to 2006. Women with singleton pregnancies were placed in standard BMI categories. Increases in BMI were calculated as the difference between initial BMI and that at delivery. Fisher’s exact test was used to compare categorical variables and the t test between two means was used for continuous variables. Results: This study included 5,478 women: 568(10.48%) had no change in BMI category and 4.910(89.51%) increased their BMI by >= 1 category. An increase in BMI category was associated with higher rates of preeclampsia (p = 0.004) and cesarean delivery(p = 0.009) in overweight women but not in women with a healthy weight at the beginning of pregnancy. Obese women had a higher risk of preeclampsia (p =0.008), gestational diabetes (p < 0.001), cesarean delivery(p < 0.001), and postpartum infection (p = 0.009).Conclusions: An increase in BMI category is associated with a greater risk of obstetric complications (AU)

Body condition and protein supplementation positively affect periovulatory ovarian activity by non LH-mediated pathways in goats.

Effects of rumen undegradable intake protein (UIP) supplementation on ovarian activity and serum insulin, GH, and LH were evaluated in goats having low or high body condition (BC). Goats with either low BC (n=16, 28.7+/-0.8 kg BW, BC=2.1+/-0.3) or high BC (n=16, 38.4+/-0.8 kg, BC=3.2+/-0.3) received, during 40-days, one of the two protein supplementation levels: without UIP or with UIP (120 g goat(-1)d(-1)). Oestrus was synchronized with two i.m. doses of PGF(2alpha), and jugular blood samples were collected from 36 to 42 h after the second prostaglandin injection at 15 min intervals. Serum concentrations of insulin, LH, and GH were measured The number of preovulatory follicles and the number of corpora lutea (CL) were evaluated by transrectal ultrasonography at 1 and 4 days after the second prostaglandin dose, respectively. Does with higher BC had more CL than those in the lower condition group (2.8+/-0.2 versus 1.8+/-0.2, P<0.05). Similarly, goats receiving UIP supplementation had more follicles (2.6+/-0.2 versus 1.9+/-0.2, P<0.05) and tended to have more CL (2.6+/-0.2 versus 2.0+/-0.2, P=0.05) than does not receiving UIP. Neither BCS nor UIP supplementation affected serum GH or LH concentrations, pulsatility, or area under the curve. High BC does produced more insulin (1.92+/-0.17 versus 0.81+/-0.17 ng/mL, P<0.01 ng/mL) than lower BC goats; the same for UIP-supplemented (1.69+/-0.18 versus 1.04+/-0.18, P<0.05). Results suggest that the increased ovarian activity observed in both UIP-supplemented and higher BC goats was not the result of changes in LH or GH, suggesting effects at a local level, through changes in insulin in a non-GnRH-gonadotrophin dependent manner.

Pautas de prescripción de nutrición parenteral / Prescription of parenteral nutrition

En 1968 se describió la seguridad y la eficacia de la administración de nutrientes por vía intravenosa a seres humanos. Desde entonces hemos asistido a numerosos avances tanto de las técnicas de administración como de la composición y elaboración de las mezclas de nutrientes, que han conducido a una mayor seguridad en la administración de la nutrición parenteral (NP). Sin embargo, sigue siendo una técnica de alimentación artificial que puede dar lugar a numerosas complicaciones de distinta gravedad. Por ello, es necesaria una selección adecuada de los pacientes que realmente se van a beneficiar de la NP. Esta revisión analiza las indicaciones y los tipos de NP, así como las características principales de los macronutrientes y micronutrientes, el aporte de energía y de agua, las formas de elaboración y administración y la posibilidad de combinarlos con fármacos intravenosos. La prescripción individualizada de la NP, de acuerdo con las recomendaciones vigentes de sociedades científicas, contribuye a mejorar la seguridad y la eficacia de esta forma de tratamiento nutricional (AU)

The safety and efficacy of parenteral administration of nutrients to humans was first described in 1968. Since then, there have been numerous advances in administration techniques, as well as in the composition and preparation of intravenous nutrient mixtures; these advances have increased the safety of the administration of parenteral nutrition (PN). Nevertheless, this treatment modality remains an artificial feeding technique that can give rise to numerous complications of varying severity. Therefore, appropriate selection of those patients who will derive a true benefit from PN is essential. This review analyzes the indications and types of PN, along with the main characteristics of macro- and micronutrients, the quantity of energy and water, preparation and administration methods, and the possibility of associating other intravenous drugs. The individualized prescription of PN, according to current recommendations established by scientific societies, helps to improve the safety and effectiveness of this nutritional therapy (AU)

Vitamina D y trasplante hepático, ¿Sólo efectos óseos? / Is the role ot Vitamin D in liver transplantation limited to bone health?

La osteoporosis postrasplante causa una importante morbilidad en la creciente población de supervivientes del trasplante hepático. Los fármacos inmunosupresores habitualmente empleados son uno de los principales responsables de la osteoporosis postrasplante. La vitamina D y sus análogos sintéticos podrían ser útiles en el período postrasplante, ya que a sus efectos protectores a nivel óseo se añade su papel inmunomodulador, en particular de la inmunidad mediada por células T, lo que podría permitir no sólo disminuir la dosis de inmunosupresores, sino también colaborar en la prevención de la aparición de rechazo crónico

Liver transplantation has become a fairly common and successful procedure, and post-transplantation osteoporosis is now a usual complication in these patients. Immuno-suppressive therapy has been involved in this setting. Vitamin D and their related analogs may have a role in the post-transplantation therapy, adding the role of immuno-modulator (mainly in T cells) to their already protective one in bone metabolism. This might not only allow for the possibility of reducing immuno-suppressive doses, but also of reducing instances of transplant rejections

Osteoporosis en mujer postmenopáusica con hiperostosis idiopática difusa / Osteoporosis in post-menopausal woman with diffuse idiopathic hyperostosis

Presentamos el caso de una mujer de 74 años, diagnosticada de hiperostosis idiopática difusa que presentaba, además, osteporosis a nivel de la cabeza femoral (según los criterios de la Organización Mundial de la Salud [OMS]) sin disminución densitométrica de masa ósea en columna lumbar. Realizamos una pequeña revisión de una patología tan prevalente como la hiperostosis idiopática difusa y planteamos la necesidad de determinar la densidad mineral ósea (DMO) en cadera, para lograr una adecuada estimación de masa ósea en estos pacientes

The case discussed is that of a 74 years old woman, diagnosed with diffuse skeletal hyperostosis, who also presented osteoporosis in the femur head (according to WHO criteria) with no reduction of bone mass in the DXA at the lumbar spine. We present a small review of such a widespread pathology and discuss the necessity to determine the bone mineral density, not only in the lumbar spine but also in the hip, to obtain an adequate estimation of bone mass in these patients

Esteroides sexuales y hueso: ¿tiene sexo el hueso? / Sexual steroids and bone: does the bone have a gender?

Es conocido que los esteroides sexuales ejercen un papel regulador en el metabolismoóseo. En los últimos años se han efectuado importantes avances paraesclarecer en qué consiste y cómo se realiza esta regulación, definiendo, apartedel ya conocido mecanismo genómico a través del receptor esteroideo, una acciónautocrina y paracrina mediada por citocinas y un mecanismo no genómicoy no dependiente del sexo que abre una nueva línea de investigación con importantesimplicaciones terapéuticas.Los avances en las técnicas de laboratorio y en la investigación transgénica hanpermitido establecer la localización y función de los receptores esteroideos en losdistintos componentes del compartimento óseo, con hallazgos sumamente interesantesen el campo de los andrógenos y de su receptor.El objetivo de este artículo es revisar los datos derivados de las investigacionesin vitro e in vivo en animales y humanos sobre el mecanismo de acción de los esteroidessexuales en el hueso y su papel en la homeostasis ósea y en la protecciónfrente a la osteoporosis. Prestaremos especial atención a la importancia delsexo en la modulación de su efecto

It is known that sexual steroids have a regulating role in bone metabolism. Inrecent years, important advances have been made to clarify what this regulationconsists in and how it occurs, defining, in addition to the already knowngenomic mechanism through the steroid receptor, an autocrine and paracrineaction mediated by cytokines and a non-genomic mechanism, not gender dependent,that opens a new line of investigation with important therapeutic implications.The advances in laboratory techniques and transgenic investigation have madeit possible to establish the site and function of the steroid receptors in the differentbone compartment components, with extremely interesting findings inthe field of androgens and their receptor.This article aims to review the data derived from in vitro and in vivo researchin animals and humans on the action mechanism of sexual steroids on the boneand their role in bone homeostasis and on protection against osteoporosis. Wegive special attention to the importance of gender in the modulation of theireffect

A tissue phantom for investigating volume quantification on retinal images obtained with the Stratus OCT system.

The performance of the Stratus OCT system in extracting shape and volume of retinal lesions was investigated by scanning a tissue phantom containing specific enclosed geometric gaps of known size. Measurements were made by filling the gaps with an aqueous suspension containing a fixed tissue suspended in phosphate-buffered saline inside the gaps. OCT raw data was exported for subsequent analysis using custom software written in MATLAB software platform. An active contour model was used to outline the boundaries of the fixed tissue on OCT images of the tissue phantom. Images provided by the OCT system were analyzed with the custom software and later compared with the actual geometric parameters of the tissue phantom. An active contour model is effective in detecting the boundaries of the tested object and accurately estimating its volume. We show that a tissue phantom provides an easy and reproducible method of verifying the accuracy and precision of specific features in the images retrieved by the Stratus OCT system.

Utilización de procolinérgicos en la prevención del deliriopostoperatorio del adulto mayor sometido a cirugía de fracturade cadera. Ensayo clínico controlado / Use of citicoline in the prevention of delirium in hip fracture surgery in elderly a randomized control trial

Introducción. Hasta un 40 o 50 por ciento de las personas mayores con fractura de cadera sometidas a cirugía presentan delirio. La morbimortalidad aumentó en aquellos enfermos que presentaron delirio. Objetivo. Evaluar el uso de la citicolina (CDP-colina) en la prevención del delirio en pacientes mayores sometidos a cirugía de fractura de cadera. Pacientes y métodos. Ensayo clínico controlado y aleatorizado, en pacientes con fractura de cadera sin demencia ni ninguna otra enfermedad orgánica cerebral. Se administró la medicación 24 horas antes y 4 días después de la cirugía. La dosis administrada fue de 1,2 g/día. La medida inicial del resultado era el porcentaje de pacientes con delirio medidos con el Abbreviated Mental Test (AMT) y Confusion Assessment Method (CAM). Se utilizó el Mini-Mental State (MMS) antes de la cirugía y cuatro días después de la misma. Los resultados fueron sometidos al test de la ji alcuadrado y a la pueba de Wilcoson y considerados estadísticamente significativos, con p< 0,05. Resultados. El tamaño de la muestra incluyó 81 pacientes (46 placebo y 35 citicolina). La edad media era de 79,45 años en el grupo estudiado y 79,97 años en el grupo placebo. No se encontró diferencia estadísticamente significativa entre los grupos con respecto a la clase ASA de anestesia. La incidencia de delirio era 17,39 por ciento en el grupo placebo y 11,76 por ciento en el grupo de la citicolina (p= 0,6). CAM y AMT a los 1, 2, 3, 4, días posoperatorios no eran significativos en el grupo placebo ni en el grupo de la citicolina (p= 0,8 y p= 0,34). Conclusión. En el presente estudio la citicolina no previno ni redujo la incidencia del delirio en adultos mayores sometidos a cirugía de fractura de cadera (AU)

[Use of procholinergics in the prevention of postoperative delirium in hip fracture surgery in the elderly. A randomized controlled trial]. / Utilización de procolinérgicos en la prevención del delirio post operatorio del adulto mayor sometidos a cirugía de fractura de cadera. Ensayo clínico controlado.

INTRODUCTION: 40 to 50% of elderly with hip fracture present delirium. The morbimortality increase in patients whose presented delirium. OBJECTIVE: To study the use of citicoline (CDP choline) in the prevention of delirium in elderly under hip fracture surgery. PATIENTS AND METHODS: A randomized control trial. The patients with hip fracture without dementia or an other organic brain illness. The medication were administered 24 hours before and during 4 days after surgery. The doses was 1.2 g/day. The primary outcome measure was percentage of patients with delirium measured with Abbreviated Mental Test (AMT) and Confusion Assessment Method (CAM). The Mini Mental State (MMS) was used before and 4 days after surgery. All treatment comparation was considered statistically significant at p< 0.05 calculating chi square and Wilcoxon test. RESULTS: The sample size was 81 patients (46 placebo and 35 citicoline). The mean age was 79.45 for tested group and 79.97 for placebo. There was no statistically significant difference between groups with respect to ASA class of anesthesia. The incidence of delirium was 17.39% in placebo and 11.76% in citicoline group (p= 0.6). CAM and AMT at 1, 2, 3, 4 days post surgery was not significant in placebo and citicoline group (p= 0.8 and p= 0.34). CONCLUSION: In the present study the citicoline did not prevent or reduce the incidence of delirium in hip fracture surgery in elderly.

[Medical application of computers in obstetrics and gynecology education]. / Aplicaciones médicas de la computación en la educación en obstetricia y ginecología.

Its related the development of two application in Computer Aided Instruction (CAI) in Medical Education with an Apple IIc and 128 K. The first using the PILOT for student; and the second a program of "Simulation of Labor Troubles" for interns and specialty training developed in BASIC. Am special point is the lower time training for the teacher with the PILOT. Its demonstrate the improvement through the qualification in relation to other evaluation in the same year and the relations with other questions during the same test.

[Gyneco-obstetrical morbidity in the population of Santiago]. / Estudio de morbilidad ginecoobstétrica en la población de Santiago.

PIP: 1607 women were interviewed about their gyneco-obstetrical health in a survey of 469 randomly selected households in the province of Santiago, Chile. The dependent variables correspond to the frequency of gynecologic or obstetrical morbidity and demand for medical attention in 2 weeks of April, 1987. Independent variables were age, educational status, and health insurance coverage. 125 of the households were headed by uninsured persons. The average woman was 34.4 years old. 43.1% had 8 years or less of education, 42.6% had 9.12 years, and 14.2% had 13 or more years. 21 new cases of acute obstetrical or gynecological disorders were reported, including 15 of vulvovaginitis, 3 abortions, 1 bartholinitis, 1 intrahepatic cholestasis of pregnancy, and 1 urinary tract infection. There were 55 cases of chronic disorders, including 12 benign ovarian lesions, 8 dysmenorrheas, 8 uterine dystropias, 10 cases of menstrual disturbances, 1 of infertility, 4 benign cervical lesions, 5 benign uterine lesions, 2 pelvic inflammations, 2 cervical cancers, 2 breast cancers, and 1 ovarian cancer. Among the 1607 women, 11 had consulted for family planning in the 2 weeks, 25 for pregnancy, 22 for gynecological conditions, and 9 for postpartum care. 58.3% of the women aged 15-49 used a contraceptive method. The proportions of users of oral contraceptives and IUDs respectively were 62.5% and 37.5% for women under 20, 60% and 40% for women 20-29, 27% and 61% for women 30-39, and 15.1% and 60.6% for women 40-49. 28.2% of women over 15 had had a Pap test in the past year. The proportions of different age groups having Pap tests ranged from 2.0% for women under 20 to 46.7% for women aged 30-39. 3 women in the sample households had died in the past year of gyneco-obstetric causes, 1 of complications of childbirth and 2 of cervical cancer.^ieng

Does cholecystectomy affect colonic tumorigenesis?

To determine if cholecystectomy predisposes to colon cancer, & study of this operation's influence on chemically induced murine colonic neoplasia was conducted. One hundred mice underwent cholecystectomy or a sham operation. Equal groups received either ten weekly injections of 1,2-dimethylhydrazine (DMH) or injections of saline. Twenty-four weeks after operation, the site, histologic findings, and number of tumors were noted. Crypt metaphase index (CMI) and proliferative zone size (PZS) determinations served as markers of preneoplasia. Tumors were found in the majority of animals receiving DMH while no tumors were found in the saline groups. Both CMI and PZS were significantly increased by DMH administration. Within the saline group, cholecystectomy increased CMI and PZS two and three times, respectively, over levels seen in the sham-operated animals. This suggests that cholecystectomy alone induces preneoplastic changes in the murine colonic crypt.