Sistema de bajo costo y alto rendimiento para bioensayos farmacológicos in vitro de tejido vivo / Low-Cost and High-Throughput System for Pharmacological Bioassays of Living Tissue in vitro

La potencialidad terapéutica de fármacos se averigua mediante estudios bioquímicos y celulares que nos hablan de sus acciones sobre vías de señalización y receptores. Sin embargo, en algunas enfermedades -por ejemplo, enfermedades neurológicas conocidas como "desórdenes del movimiento"-, los bioensayos realizados miden las acciones farmacológicas mediante valoraciones conductuales en modelos animales de las mismas. No se han logrado bioensayos que correlacionen la acción terapéutica de fármacos sobre la actividad del tejido vivo. Se puede medir la actividad de decenas de neuronas mediante imagenología de calcio en tejido vivo. Ciertos parámetros de esta actividad neuronal registrada in vitro reflejan su estado patológico, así como la acción terapéutica de fármacos determinados. No hay un sistema integrado orientado a estos bioensayos, por lo que se combinan diferentes equipos comerciales de manera independiente con costo final de alrededor de 100,000 USD. Presentamos un prototipo de un sistema integral encaminado a realizar este tipo de bioensayos: microscopía de epifluorescencia con calidad suficiente para adquirir y medir cuantitativamente la actividad celular del tejido vivo registrada in vitro pero de costo 10 veces menor -alrededor de 10,000 USD-. Se pueden realizar satisfactoriamente bioensayos funcionales de uso potencial en la industria farmacéutica, investigación y docencia.

The therapeutic potential of drugs is determined by biochemical and cellular studies that inform us about their actions on signaling pathways and receptors. However, in some diseases -for example, neurological diseases such as "movement disorders"-, bioassays measure the pharmacological actions by evaluating behavior in animal models of the diseases. There are no bioassays that correlate drug therapeutic actions on living tissue. The neural activity of several neurons can be measured by using calcium imaging on living tissue. Certain parameters of the recorded neuronal activity in vitro reflect the pathological state and the therapeutic actions of specific drugs. There is no integrated system oriented to these bioassays, so different commercial equipment has to be integrated independently with costs about 100,000 USD. We present a prototype of an integral system aimed to perform bioassays in vitro: epifluorescence microscopy with enough quality for the acquisition and quantitative assessment of cell activity recorded in the living tissue with costs around 10 times less -about 10,000 USD-. It allows successfully functional bioassays of potential use in the pharmaceutical industry, research an education.

Symmetry breaking in linearly coupled Korteweg-de Vries systems.

We consider solitons in a system of linearly coupled Korteweg-de Vries (KdV) equations, which model two-layer settings in various physical media. We demonstrate that traveling symmetric solitons with identical components are stable at velocities lower than a certain threshold value. Above the threshold, which is found exactly, the symmetric modes are unstable against spontaneous symmetry breaking, which gives rise to stable asymmetric solitons. The shape of the asymmetric solitons is found by means of a variational approximation and in the numerical form. Simulations of the evolution of an unstable symmetric soliton sometimes produce its breakup into two different asymmetric modes. Collisions between moving stable solitons, symmetric and asymmetric ones, are studied numerically, featuring noteworthy features. In particular, collisions between asymmetric solitons with identical polarities are always elastic, while in the case of opposite polarities the collision leads to a switch of the polarities of both solitons. Three-soliton collisions are studied too, featuring quite complex interaction scenarios.

Neurosífilis en pacientes portadores y no portadores de VIH: descripción y comparación de dos cohortes históricas / Neurosyphilis in the patients with and without HIV infection: description and comparison of two historical cohorts

Neurosyphilis follows a more aggressive and different clinical course in HIV-infected patients compared to patients with normal immunity. Two historical series of patients with a diagnosis of neurosyphilis between 1995 and 2008 were compared: they included a group of 15 patients with y and 28 patients without HIV infection. Probability of neurosyphilis in patients with positive serum VDRL was increased in patients infected with HIV comparedto HIV negative patients (OR: 62.37 IC:95 percent (32.1-119.1) p value:< 0,001). Predominant clinical manifestations in neurosyphilis in the HIV negative group were ocular abnormality, vascular encephalic and spinal cord lesions. In the HIV positive group, they were fever, ocular abnormalities and headache. There were no differences in cerebrospinal fluid characteristics between both groups. Neurosyphilis was diagnosed even in patients with blood VDRL of < 1:32, that happened in 17.8 percent of the HIV positive patients with blood and in 60 percent of t he HIV negative patients. Penicillin sodium given at dose ¡Ý than 18.000.000 IU/day IV during 14 days was the most common treatment. In patients with clinical neurosyphilis, 93 percent of HIV negative group, and 54.2 percent of HIV positive group had persistent neurological after-effects. Three HIV positive patients died due to causes not related to neurosyphilis.

[Hepatitis B, C, Treponema pallidum and Toxoplasma gondii co-infections in HIV infected patients]. / Coinfecciones por virus hepatitis B, virus hepatitis C, Treponema pallidum y Toxoplasma gondii en la cohorte de pacientes VIH positivos en control en la Pontificia Universidad Católica de Chile.

BACKGROUND: Some infections share common modes of transmission with HIV and have the potential to change the course of the latter. AIM: To assess the prevalence of hepatitis B virus (HBV) hepatitis C virus (HCV), Treponema palladium and Toxoplasmosis gondii co-infections in HIV-1 infected patients followed at a university hospital. MATERIAL AND METHODS: Clinical records of HIV-positive individuals were reviewed. The analysis included: demographical data, hepatitis B surface antigen (HBsAg), IgM and IgG anti-HBc, antibodies, anti-HCV antibodies, RPR or VDRL test and IgG anti Tgondii antibodies. RESULTS: Three hundred ninety five patients (aged 16 to 89 years, 359 males) were included in the review. Seventy nine percent had been tested for HBV status with HBsAg, and the global HIV-HBV co-infection prevalence was 6.1%. A subgroup of 190 individuals were tested for HBV infection with HBsAg and IgM/IgG anti-HBc markers. Of these, 46% fulfilled co-infection criteria: eight with acute hepatitis B, 11 with chronic hepatitis B and 69 with inactive HBV infection. The frequency of HIV-HBV co-infection was 48% and 22% among men and women respectively (NS). HCV-HN co-infection was detected in 3%, syphilis-HIV co-infection in 21% and T gondii-HIV co-infection in 26%. CONCLUSIONS: In this cohort, HIV infection is accompanied by a high prevalence of other co-infections, particularly HBV among men.

La enfermería en salud pública: el caso de la Influenza / The public health nursing: the case of influenza

Ante un brote de una enfermedad infecto-contagiosa, el estudio de contactos limita la transmisión de esta. El objetivo de este trabajo fue identificar a los contactos de los posibles casos de influenza en trabajadores de la UNAM para establecer una comunicación y proporcionar educación para la salud sobre medidas higiénicas. Material y métodos: Se elaboró un cuestionario, se estableció contacto con los casos por vía telefónica y se llevó a cabo una visita domiciliaria. Se llevó a cabo un análisis descriptivo de los datos y una descripción de las experiencias y percepciones durante las visitas. Resultados: Se identificó que la mayoría de los contactos eran familiares directos de los casos, que no contaban con un esquema de vacunación completo, ni contra la influenza y la frecuencia de síntomas varió de 1 hasta 4. Comentarios finales: Ante una situación de este tipo (la Pandemia del Virus de la Influenza Humana A (H1N1)) el papel de la enfermera en salud pública es de suma importancia no solo en la búsqueda de los casos y sus contactos, sino también en la orientación y educación de la población en relación a las medidas preventivas.

In the view of an infectious and contagious disease epidemic, the identification of the contacts limits its transmission. The objective of this work was to identify the contacts of the possible cases of UNAM workers in order to establish communication and provide health education about hygiene measures. Material and methods: A questionnaire was prepared, telephone contact was established with the cases, and a home visit was arranged. A descriptive analysis of the data was carried out, as well as, a description of the experiences and perception during the home visit. Results: Most identified contacts were relatives of the cases, which did not have a complete vaccine scheme, no even against influenza, and the frequency of symptoms varied between 1 a 4. Final comments: In a situation like this (A(H1N1) human influenza virus pandemic) the public health nurse roll is of great importance, not just in the identification of the cases and its contacts, but also in the orientation and education of the population in relation to preventive measures.

Coinfecciones por virus hepatitis B, virus hepatitis C, Treponema pallidum y Toxoplasma gondii en la cohorte de pacientes VIH positivos en control en la Pontificia Universidad Católica de Chile / Hepatitis B, C, Treponema pallidum and Toxoplasma gondii co-infections in HIV infected patients

Background: Some infections share common modes of transmission with HIV and have the potential to change the course of the latter. Aim: To assess the prevalence of hepatitis B virus (HBV) hepatitis C virus (HCV), Treponema palladium and Toxoplasmosis gondii co-infections in HIV-1 infected patients followed at a university hospital. Material and methods: Clinical records of HIV-positive individuals were reviewed. The analysis included: demographical data, hepatitis B surface antigen (HBsAg), IgM and IgG anti-HBc, antibodies, anti-HCV antibodies, RPR or VDRL test and IgG anti Tgondii antibodies. Results: Three hundred ninety five patients (aged 16 to 89years, 359 males) were included in the review. Seventy nine percent had been tested for HBV status with HBsAg, and the global HIV-HBV co-infection prevalence was 6.1 percent. A subgroup of190 individuals were tested for HBV infection with HBsAg and IgM/IgG anti-HBc markers. Of these, 46 percent fulfilled co-infection criteria: eight with acute hepatitis B, 11 with chronic hepatitis B and 69 with inactive HBV infection. The frequency of HIV-HBV co-infection was 48 percent and 22 percent among men and women respectively (NS). HCV-HN co-infection was detected in 3 percent, syphilis-HIV co-infection in 21 percent and T gondii-HIV co-infection in 26 percent. Conclusions: In this cohort, HIV infection is accompanied by a high prevalence of other co-infections, particularly HBV among men.

Moving embedded lattice solitons.

It was recently proved that solitons embedded in the spectrum of linear waves may exist in discrete systems, and explicit solutions for isolated unstable embedded lattice solitons (ELS) of a differential-difference version of a higher-order nonlinear Schrodinger equation were found [Gonzalez-Perez-Sandi, Fujioka, and Malomed, Physica D 197, 86 (2004)]. The discovery of these ELS gives rise to relevant questions such as the following: (1) Are there continuous families of ELS? (2) Can ELS be stable? (3) Is it possible for ELS to move along the lattice? (4) How do ELS interact? The present work addresses these questions by showing that a novel equation (a discrete version of a complex modified Korteweg-de Vries equation that includes next-nearest-neighbor couplings) has a two-parameter continuous family of exact ELS. These solitons can move with arbitrary velocities across the lattice, and the numerical simulations demonstrate that these ELS are completely stable. Moreover, the numerical tests show that these ELS are robust enough to withstand collisions, and the result of a collision is only a shift in the positions of the solitons. The model may apply to the description of a Bose-Einstein condensate with dipole-dipole interactions between the atoms, trapped in a deep optical-lattice potential.

Standard and embedded solitons in nematic optical fibers.

A model for a non-Kerr cylindrical nematic fiber is presented. We use the multiple scales method to show the possibility of constructing different kinds of wave packets of transverse magnetic modes propagating through the fiber. This procedure allows us to generate different hierarchies of nonlinear partial differential equations which describe the propagation of optical pulses along the fiber. We go beyond the usual weakly nonlinear limit of a Kerr medium and derive a complex modified Korteweg-de Vries equation (CM KdV) which governs the dynamics for the amplitude of the wave packet. In this derivation the dispersion, self-focussing, and diffraction in the nematic fiber are taken into account. It is shown that this CM KdV equation has two-parameter families of bright and dark complex solitons. We show analytically that under certain conditions, the bright solitons are actually double-embedded solitons. We explain why these solitons do not radiate at all, even though their wave numbers are contained in the linear spectrum of the system. We study (numerically and analytically) the stability of these solitons. Our results show that these embedded solitons are stable solutions, which is an interesting property since in most systems the embedded solitons are weakly unstable solutions. Finally, we close the paper by making comments on the advantages as well as the limitations of our approach, and on further generalizations of the model and method presented.

Manejo del síndrome X con electroestimulación medular. A propósito de un caso clínico / Management of the X syndrome with medullar electrostimulation. Case report

Introducción: el término de "síndrome X" incluye aquellos pacientes que presentan dolor torácico típico con prueba de esfuerzo positiva y arterias coronarias angiográficamente normales, en los que se ha descartado previamente la existencia de espasmo coronario, hipertrofia ventricular izquierda, hipertensión arterial sistémica y enfermedad cardiaca valvular. A lo largo de los años la electroestimulación medular ha mostrado su eficacia en el tratamiento de la angina refractaria. La isquemia miocárdica parece desempeñar un papel en la patogenia del síndrome X. Por esta razón, nos decidimos a aplicar la estimulación medular en uno de nuestros pacientes con esta patología. Caso clínico: mujer de 56 diagnosticada de Síndrome X hace 4 años por presentar dolor retroesternal irradiado a mandíbula, ECG basal normal, ergometría clínica y eléctricamente positiva para la isquemia, radiografía de tórax y ecocardiograma sin alteraciones, zonas de menor captación en la gammagrafía de esfuerzo con talio-201 y arterias coronarias normales en la angiografía. Referida a la unidad del dolor por persistencia de crisis anginosas a pesar del tratamiento médico e ingresos repetidos en cardiología. Se procedió implantación de electroestimulador de cordones posteriores. Se realizaron controles a los dos y seis meses tras la implantación. Desde la implantación del generador la enferma refirió en todas las revisiones una mejoría subjetiva del 100 por ciento. No existieron complicaciones. Conclusiones: en nuestro caso clínico se observó una disminución del número y la intensidad de crisis anginosas, de las necesidades de nitritos y del número de ingresos. Además la técnica fue bien tolerada y no se observaron de complicaciones. Los datos de estudios previos y los resultados obtenidos en nuestro caso clínico demuestran que la electroestimulación medular podría ser útil en el enfoque terapéutico del Síndrome X (AU)

Meningitis caused by Pseudallescheria boydii treated with voriconazole.

Meningitis caused by Pseudallescheria boydii is an uncommon infection of the CNS that usually has a poor prognosis and a difficult treatment. We describe a case of chronic meningitis caused by P. boydii in an immunocompetent host that was successfully treated with voriconazole, a new antifungal agent.

Manifestaciones cutáneas del síndrome antifosfolípido / Cutaneous manifestations of the antiphospholipid syndrome

El Síndrome antifosfolípido es un transtorno caracterizado por trombosis arterial y venosa, pérdidas fetales recurrentes y, generalmente, trombocitopenia asocidada, en presencia de anticuerpos antifosfolípidos, tales como anticoagulante lúpico y anticuerpos anticardiolipinas. Dentro de la gran variedad de manifestaciones clínicas destaca la patología cutánea, que puede ser la primera expresión de la enfermedad. Las lesiones cutáneas incluyen: livedo reticularis vasculitis livedoide y necrotizante, tromboflebitis, necrosis y ulceración cutánea, máculas eritematosas, púrpura, equimosis, nódulos de la piel dolorosos y hemorragias en astilla subungueales, entre otras. Se presenta una revisión de los principales aspectos de la enfermedad (marcadores serológicos, patogenia, clasificación, clínica y tratamiento)

[Chronic prescription of drugs for geriatric patients at an urban health center]. / Prescripción crónica de fármacos en pacientes geriátricos de un centro de salud urbano.

OBJECTIVE: To find the chronic prescription of medication in older people, associated variables and its quality. DESIGN: Observation, descriptive-crossover study. SETTING: Urban health district. PATIENTS: Sample stratified in age and sex groups of 385 people of 65 and over registered at the health centre and not in institutions. MEASUREMENTS AND MAIN RESULTS: Social and demographic data, self-perception of health and functional capacity were obtained through interview; and pathology and medication records, from the clinical records and authorized medication cards. 349 people, average age 73 (SD +/- 6.5), were interviewed. There were 210 women and 139 men. 12% perceived their health as bad/very bad. Barthel's index and the Lawton scale were disturbed in 13.8% and 30.4%, respectively. 93% suffered some chronic pathology (average 2.7). 81.4% habitually took medication (average 3.1). The most commonly consumed drugs belonged to the cardiovascular (32%), nervous system (21%) and digestive apparatus and metabolism (17%) groups. For the first group, the main drugs were ACEIs and diuretics; for the second, analgesics and neuroleptics; for the third, antacid and antiulcer drugs. 86% had high intrinsic value, the most prescribed drugs of those with low intrinsic value belonged to the antivaricose, cerebral and peripheral vasotherapy, and urological drugs groups. Multiple medications was related significantly to having more than two chronic pathologies (OR = 7.89, 95% CI 4.40-14.15) and self-perception of worse health (OR = 2.51, 95% CI 1.13-5.59). CONCLUSION: The elderly persons with a greater number of pathologies and perception of worse health took more medication. We thought that our quality of prescription was acceptable, although we should review the indications for neuroleptics and reduce prescription for medication of low therapeutic value.

[Agrarian change and regional settling in Chile]. / Cambio agrario y poblamiento regional en Chile.

"This study analyzes the effect of agrarian change on regional settling dynamics in Chile during the last 35 years. The transformations of agrarian structure have produced important changes in the spatial configuration of country-city relations, particularly regarding the new features of rural-urban migration in regional contexts. Whereas until the sixties rural-urban migration was associated with an occupational shift from agriculture to urban employment, after the seventies this relation practically disappeared, leaving a virtual disassociation between the territorial mobility of the population and the occupational mobility of the labor force. This disassociation is a central trait of the current regional pattern of country-city relations." (SUMMARY IN ENG)

Arthritis in Mediterranean spotted fever. An immune complex mediated synovitis.

Arthromyalgia are frequent in Mediterranean spotted fever (MSF) (16-76%) but arthritis is rare. We report on a 54-year-old woman who, 1 day after suffering from fever, headache and malaise, developed a painful and swollen left knee. A maculopapular rash and the characteristic 'tache noire' skin lesion appeared 5 days later. Immune complexes were detected in serum and in the SF and normalized following improvement of clinic manifestations. These findings along with a low C3 complement level in the SF suggest that arthritis was mediated by immune complex deposits.

[HELLP syndrome. Discussion of a case]. / HELLP syndrome. Discussione di un caso.

The HELLP syndrome is the most severe variant of pre-eclampsia. A case is reported in a primigravida patient at 25 weeks of gestation. The lack of response to medical treatment and the deterioration of maternal indices necessitated a Cesarean section with intensive neonatal care at a very premature stage. The physiopathological grounds and the various methods of treating this syndrome are discussed and the paper concludes that rapid birth is the only solution capable of preventing severe maternal complications.