Ultrasonido Perioperatorio: El reto de aplicar una vieja tecnología en nuevos escenarios clínicos / Perioperative Ultrasound: The challenge of applying an old technology in new clinical settings

In anaesthesia, anticipating problems and responding quickly and effectively to peri-operative risks to the patient is crucial. As a result of recent technological advances over the last few decades, ultrasound has emerged as a tool to guide a huge number of procedures in the practice of various specialties. In particular in anaesthesia, it has become critical in establishing vascular accesses, providing regional anaesthesia, performing interventional procedures for acute and chronic pain relief, and for gathering relevant qualitative information for the diagnosis or treatment of low output syndromes, hypovolemia, acute pulmonary events, and for the assessment of gastric content as a risk for aspiration, and assessment of the airway, among other things.

Randomized trial of benznidazole for chronic Chagas' cardiomyopathy

BACKGROUND:The role of trypanocidal therapy in patients with established Chagas' cardiomyopathy is unproven.METHODS:We conducted a prospective, multicenter, randomized study involving 2854 patients with Chagas' cardiomyopathy who received benznidazole or placebo for up to 80 days and were followed for a mean of 5.4 years. The primary outcome in the time-to-event analysis was the first event of any of the components of the composite outcome of death, resuscitated cardiac arrest, sustained ventricular tachycardia, insertion of a pacemaker or implantable cardioverter-defibrillator, cardiac transplantation, new heart failure, stroke, or other thromboembolic event.RESULTS:The primary outcome occurred in 394 patients (27.5%) in the benznidazole group and in 414 (29.1%) in the placebo group (hazard ratio, 0.93; 95% confidence interval [CI], 0.81 to 1.07; P=0.31). At baseline, a polymerase-chain-reaction (PCR) assay was performed on blood samples obtained from 1896 patients; 60.5% had positive results for Trypanosoma cruzi on PCR. The rates of conversion to negative PCR results (PCR conversion) were 66.2% in the benznidazole group and 33.5% in the placebo group at the end of treatment, 55.4% and 35.3%, respectively, at 2 years, and 46.7% and 33.1%, respectively, at 5 years or more (P<0.001 for all comparisons)...

Direct observation of the spatial distribution of charges on a polypropylene fiber via Electrostatic Force Microscopy.

The spatial distribution of electrical charges along the longitudinal axes of a polypropylene electret fiber was determined using Electrostatic Force Microscopy (EFM). EFM mapping on highly curved surfaces, such as those of polymeric fibers, is a challenging endeavour and most work reported in the scientific literature has been limited to single line-scan analysis or flat specimens. Charged polymeric fibers, electrets, are extensively used in high performance filtration applications and methods to determine the amount and magnitude of the charges on these fibers remain elusive. Electrical charge maps of individual fibers were obtained by biasing the tip to -10 V and maintaining a constant tip-sample distance of 100 nm. Spatially dependant EFM phase and magnitude gradients were determined and the developed technique may provide a unique understanding into the heterogeneous charge distribution on electrets fibers. Direct mapping of the charge distribution in electrets fibers can offer new insights in the development of antistatic additives, new means to facilitate electrostatic self-assembly of nano-moieties on the surface of fibrous materials and a quantitative metrics capable of determining discharge dynamics and predicting the shelf-life of filtration media.

General biochemical and immunological characteristics of the venom from Peruvian scorpion Hadruroides lunatus.

This communication describes the general biochemical properties and some immunological characteristics of the venom from the Peruvian scorpion Hadruroides lunatus, which is the most medically relevant species in Peru. The soluble venom of this scorpion is toxic to mice, the LD50 determined was 0.1 mg/kg and 21.55 mg/kg when the venom was injected intracranial or intraperitoneally, respectively. The soluble venom displayed proteolytic, hyaluronidasic, phospholipasic and cardiotoxic activities. High performance liquid chromatography of the soluble venom resulted in the separation of 20 fractions. Two peptides with phospholipasic activity were isolated to homogeneity and their molecular masses determined by mass spectrometry (MALDI TOF). Anti-H. lunatus venom sera were produced in rabbits. Western blotting analysis showed that most of the protein content of this venom is immunogenic. H. lunatus anti-venom displayed consistent cross-reactivity with venom antigens from the new World-scorpions Tityus serrulatus and Centruroides sculpturatus venoms; however, a weaker reactivity was observed against the venom antigens from the old World-scorpion Androctonus australis Hector.

[Use of intravitreal bevacizumab for the treatment of choroidal neovascularization secondary to choroidal rupture]. / Bevacizumab intravítreo en el tratamiento de la neovascularización subretiniana secundaria a rotura coroidea.

CASE REPORT: A 28 year-old male attended our Emergency Department with a traumatic choroidal rupture and macular haemorrhage. After pneumatic displacement of the haemorrhage with C(3)F(8) and tissue plasminogen activator, the haemorrhage was reabsorbed and visual acuity (VA) improved. Three months later the patient presented with decreased VA and a juxtafoveal choroidal neovascularisation (CNV) that was treated with intravitreal bevacizumab. One year after a single bevacizumab injection the CNV remained inactive, with a final VA of 0.5. DISCUSSION: Intravitreal bevacizumab injection is a new and effective treatment for traumatic CNV. In our patient, in contrast to other aetiologies, the CNV needed no more than one Avastin(®) injection to be inactivated, after one year of follow-up.

Bevacizumab intravítreo en el tratamiento de la neovascularización subretiniana secundaria a rotura coroidea / Use of intravitreal bevacizumab for the treatment of choroidal neovascularization secondary to choroidal rupture

Caso clínico: Paciente varón de 28 años que presenta rotura coroidea y hemorragia macular postraumáticas de 24 horas de evolución acude al servicio de urgencias. Se realizó desplazamiento neumático de la hemorragia mediante inyección intravítrea de C3F8 y activador tisular del plasminógeno (rTPA), consiguiéndose la reabsorción de la hemorragia y mejora de la agudeza visual (AV). Al cabo de 3 meses, el paciente acude por empeoramiento de la visión con metamorfopsia, diagnosticándose de neovascularización (NVC) yuxtafoveal en la zona de la rotura, que se trata con una inyección de bevacizumab intravítreo. Un año después, la NVC permanece inactiva y la AV se mantiene en 0,5. Discusión: La inyección intravítrea de bevacizumab representa una nueva forma efectiva de tratamiento de la NVC postraumática. A diferencia de lo descrito en otras etiologías, la NVC secundaria a rotura coroidea en nuestro paciente requirió solamente una dosis de Avastin® para su inactivación, en un periodo de seguimiento de un año(AU)

Case report: A 28 year-old male attended our Emergency Department with a traumatic choroidal rupture and macular haemorrhage. After pneumatic displacement of the haemorrhage with C3F8 and tissue plasminogen activator, the haemorrhage was reabsorbed and visual acuity (VA) improved. Three months later the patient presented with decreased VA and a juxtafoveal choroidal neovascularisation (CNV) that was treated with intravitreal bevacizumab. One year after a single bevacizumab injection the CNV remained inactive, with a final VA of 0.5. Discussion: Intravitreal bevacizumab injection is a new and effective treatment for traumatic CNV. In our patient, in contrast to other aetiologies, the CNV needed no more than one Avastin® injection to be inactivated, after one year of follow-up(AU)

Descripción de técnica anestésica con dexmedetomidina más anestesia controlada por el paciente de alfentanilo para litotripsia extracorpórea en tratamiento de urolitiasis / Description of anesthetic technique with dexmedetomidine plus anesthesia controlled by the alfentanil patient for extracorporeal lithotripsy in treatment of urolithiasis

La litotripsia extracorpórea es un procedimiento frecuente en el ejercicio de la urología para el manejo no invasivo de la enfermedad litiásica renal. Desde el punto de vista anestésico, para la litotripsia extracorpórea se han utilizado la anestesia general, la regional y técnicas analgésicas. En una serie de casos se describe la técnica de dexmedetomidina más anestesia controlada por el paciente (PCA), con alfentanilo como analgesia intravenosa para dicho procedimiento; se observó una adecuada analgesia y aceptación por parte del paciente y el urólogo, con excelente seguridad. Este reporte de casos es la base para estudios aleatorios posteriores para comparar las técnicas utilizadas actualmente y esta nueva técnica.

The shock wave lithotripsy is a frequent procedure in the exercise of urology. From the anesthetic point of view, the following procedures have been used for the shock wave lithotripsy: general, regional anesthesia, regional anesthesia and analgesic techniques. We describe, in a case series, the technique of dexmedetomidina and Patient Controlled Analgesia (PCA) with alfentanil intravenous analgesia for this procedure, being observed a suitable analgesia and acceptance on the part of the patient and the practitioner with excellent security. This case report is the base to randomized study to compare the actual technical used and this new technique.

Evaluación de la vía aérea en el paciente crítico / Evaluation of the airway in the critical patient

El manejo de la vía aérea (MVA) debe ser prioridad en el cuidado de pacientes críticos, las intervenciones en vía aérea tienen como finalidad asegurarla o controlar la ventilación ademas de evitar complicaciones.1,2,3 La evaluación de vía aérea (EVA) previa es un prerrequisito, con el fin de determinar la dificultad de la maniobra, los posibles riesgos y complicaciones a las que se ve enfrentado el médico y el paciente.4,5,6,7 Surgen interrogantes con respecto a la EVA como parte del MVA en las unidades de cuidado intensivo, como los siguientes: ¿Con qué frecuencia realizamos esta evaluación?, ¿es nuestra evaluación completa y adecuada?, si es así, ¿con qué certeza podemos afirmar que la evaluación nos puede dar información cierta? y ¿qué tan confiados podemos sentirnos a la hora de intubar nuestro paciente? El siguiente texto tiene como finalidad discutir la importancia de las actitudes adecuadas y los procesos a seguir previos al MVA en el paciente crítico.

Airway management (MVA) must be priority in the care of critical patients. Airway intervention is needed to assure or control the ventilation.1,2 The Airway evaluation (EVA) is a requirement, with the purpose of determining the difficulty of the orotraqueal intubation maneuver, the possible risks and complications for the physician and the patient.4,5,6,7 There is some questions with respect to EVA like part of the MVA in the intensive care units; ¿how frequently we made this evaluation?, ¿Is it a complete and suitable evaluation?, if it is thus, ¿how certain could we affirm that the evaluation can give true information to us? and ¿how trusted can we feel at the time of patient intubation? The following text has the purpose of discuss the importance of suitable attitudes and the processes to follow previously to the MVA in the critical patient.

Adaptation of Cryptosporidium oocysts to different excystation conditions.

Within the genus Cryptosporidium 2 lineages have evolved, one adapted to the acid environment of the stomach and abomasum, the other comprising parasites that multiply in the small intestine. We tested whether the release of sporozoites from oocysts, a process known as excystation, is triggered by conditions which mimic the site of infection. Specifically, we exposed oocysts from gastric and intestinal Cryptosporidium species to acid conditions or to a neutral solution of taurocholic acid, at 37 degrees C. We found that oocysts from the gastric species C. muris and C. andersoni excysted in both conditions, whereas the intestinal species C. parvum and C. hominis did not respond to acid. When the effect of temperature alone was tested on C. muris and C. parvum, only oocysts from the former species excysted in significant numbers. Oocysts from intestinal species did not respond to temperature alone, nor to acidity. These observations are consistent with the need of gastric species to rapidly excyst and release the sporozoites upon ingestion, and indicate that Cryptosporidium oocysts have evolved to maximize delivery of sporozoites to the region of the gastro-intestinal tract where the parasite multiplies.

Aspectos Perioperatorios del Trasplante Renal / Aspects Perioperatorios of the Transplant

El Trasplante de órganos es una opción terapéutica para algunas patologías de carácter irreversible. En el mundo durante los últimos años se han ampliado las indicaciones para trasplante renal. Pacientes con enfermedades de mal pronostico como Diabetes Mellitus (DM), Nefroesclerosis Hipertensiva, Glomerulonefritis y Enfermedad Quística renal, causantes de enfermedad renal Terminal, y pacientes con patologías asociadas como disfunción ventricular enfermedades autoinmunes, enfermedad de células falciformes, obesidad y hepatitis B según el antígeno que expresen, ven en el trasplante renal una opción para aumentar tiempo y calidad de vida. Todo mediante un procedimiento seguro, hoy en día la mortalidad del receptor es cercana al 0.03 por cien.1 El éxito del trasplante es indirectamente proporcional al tiempo de dependencia de diálisis pretrasplante y el entendimiento de la fisiopatología de la falla renal Terminal redunda en el pronóstico de estos pacientes.2 El paciente nefrópata en estadio terminal plantea al anestesiólogo un reto en la visualización del panorama clínico y sus implicaciones anestésicas. La siguiente revisión pretende abarcar aspectos del ámbito perioperatorio del trasplante renal en forma clara y concisa, enfatizando en aspectos importantes y nombrando someramente algunos otros. Es un tema extenso, parcialmente inexplorado y donde la medicina basada en evidencia tiene aun un largo camino por recorrer.

Preferential infection of dividing cells by Cryptosporidium parvum.

In spite of its limitations, the culture of Cryptosporidium parvum in monolayers of epithelial cells is a suitable model to study the interaction of this protozoan parasite with the host cell, to assay oocyst infectivity, and to screen drugs for anti-cryptosporidial activity. For unknown reasons, growth of Cryptosporidium in culture is limited in time and generally does not lead to the production of significant numbers of oocysts. In monolayers infected with high doses of oocysts, we observed that many cells remain uninfected, suggesting that some cells are less susceptible to the infection. Since C. parvum and the related species C. hominis lack many essential biosynthetic pathways, we tested whether the dependence of the parasite on host cell metabolites may favour the infection of cells in mitosis. The proportion of monolayer cells in stationary (G0/G1) phase and in mitosis (S/G2/M) was determined and the prevalence of infected cells in each subpopulation was quantified. Although C. parvum infects and develops in dividing and stationary cells, a significant preference for cells in S/G2/M phase was observed. Consistent with previous observations showing that C. parvum induces apoptosis in cell monolayers, infection was accompanied by a significant increase in the proportion of mitotic cells.

Frecuencia relativa de Boophilus microplus (Acari: Ixodidae) en bovinos (Bos taurus y B. indicus) en ocho zonas ecológicas de Costa Rica / Relative frequency of Boophilus microplus (Acari: Ixodidae) in bovines (Bos taurus and B. indicus) in 8 ecological zones of Costa Rica

The research on the relative abundancy of Boophilus microplus took place in ten farms, distributed in eight ecological zones (EZ) and two rainfall systems of Costa Rica. Monthly visits were made to pick up ticks larger than 4 mm from the right side of the animals. The total number of ticks was increased by two and divided between the total of sampled bovines per farm. Farm visits were adjusted to animals bath to allow the recovery of the tick population. B. microplus was detected in all sampled farms throughout the year. Media comparison statistic analyses were made and no differences were found among EZ, farms and seasons. On the contrary, there were important statistical differences between rainfall systems. The rainfall system 1, that included rain seasonality, showed larger tick infestations (p = 0.03). An isothermal and low variability regarding relative humidity situations were present in some of the areas included in this research. Bath intensity was lower to other past studies. Even though no differences were found between production systems, it is important to emphasize that bath intensity was higher in european cattle farms, in comparison to others of the same EZ, but of crossbred. A tick manual removable system was recommended in dual-purpose and specialized dairy farms with no more than 30-35 animals, as an alternative feasible system that significantly reduced acaricide use.

Abundancia relativa de Amblyomma spp. (Acari: Ixodidae) en bovinos (Bos taurus y B. indicus) de Costa Rica / Relative abundance of Amblyomma spp. (Acari: Ixodidae) in bovines (Bos taurus and B. indicus) from Costa Rica

The research describe the big amount of ticks of the Amblyomma genus, found on bovines through monthly samplings carried out in ten farms in eight ecological zones (EZ) of Costa Rica. Ticks larger than 4 mm were picked up from the right side of the animals during the visit. The study compiled meteorological information for some farms located in the experiment, showing that the most fluctuant variable is rainfall. The most important Amblyomma species found was A. cajennense. Amblyomma nymphs were found only from January to May, which coincides with the lower humidity season in the rain seasonality area; as for it is expected only one generation per year. In the lab work Amblyomma nymphs are kept to measure the moulting season and the surviving time under controlled conditions, but no major differences were found between both sexes. The surviving periods show that it is not possible to do a grazing land handling, in order to control this genus species. Adults of the genus Amblyomma are present through all the year, not showing any specific preference for a season. The research divided the investigation areas in rain seasonability and not-seasonality systems. The highest amount of Amblyomma is found given in the rain seasonality system or of pacific influence. A. maculatum is present only in the EZ of Tropical Humid Forest transition to pre-mountainous. Likewise, Ixodes boliviensis is found in the EZ of low mountainous Very Humid Forest.

[Relative frequency of Boophilus microplus (Acari: Ixodidae) in bovines (Bos taurus and B. indicus) in 8 ecological zones of Costa Rica]. / Frecuencia relativa de Boophilus microplus (Acari: Ixodidae) en bovinos (Bos taurus y B. indicus) en ocho zonas ecológicas de Costa Rica.

The research on the relative abundancy of Boophilus microplus took place in ten farms, distributed in eight ecological zones (EZ) and two rainfall systems of Costa Rica. Monthly visits were made to pick up ticks larger than 4 mm from the right side of the animals. The total number of ticks was increased by two and divided between the total of sampled bovines per farm. Farm visits were adjusted to animals bath to allow the recovery of the tick population. B. microplus was detected in all sampled farms throughout the year. Media comparison statistic analyses were made and no differences were found among EZ, farms and seasons. On the contrary, there were important statistical differences between rainfall systems. The rainfall system 1, that included rain seasonality, showed larger tick infestations (p = 0.03). An isothermal and low variability regarding relative humidity situations were present in some of the areas included in this research. Bath intensity was lower to other past studies. Even though no differences were found between production systems, it is important to emphasize that bath intensity was higher in european cattle farms, in comparison to others of the same EZ, but of crossbred. A tick manual removable system was recommended in dual-purpose and specialized dairy farms with no more than 30-35 animals, as an alternative feasible system that significantly reduced acaricide use.

[Relative abundance of Amblyomma spp. (Acari: Ixodidae) in bovines (Bos taurus and B. indicus) from Costa Rica]. / Abundancia relativa de Amblyomma spp. (Acari: Ixodidae) en bovinos (Bos taurus y B. indicus) de Costa Rica.

The research describe the big amount of ticks of the Amblyomma genus, found on bovines through monthly samplings carried out in ten farms in eight ecological zones (EZ) of Costa Rica. Ticks larger than 4 mm were picked up from the right side of the animals during the visit. The study compiled meteorological information for some farms located in the experiment, showing that the most fluctuant variable is rainfall. The most important Amblyomma species found was A. cajennense. Amblyomma nymphs were found only from January to May, which coincides with the lower humidity season in the rain seasonality area; as for it is expected only one generation per year. In the lab work Amblyomma nymphs are kept to measure the moulting season and the surviving time under controlled conditions, but no major differences were found between both sexes. The surviving periods show that it is not possible to do a grazing land handling, in order to control this genus species. Adults of the genus Amblyomma are present through all the year, not showing any specific preference for a season. The research divided the investigation areas in rain seasonability and not-seasonality systems. The highest amount of Amblyomma is found given in the rain seasonality system or of pacific influence. A. maculatum is present only in the EZ of Tropical Humid Forest transition to pre-mountainous. Likewise, Ixodes boliviensis is found in the EZ of low mountainous Very Humid Forest.

Gene expression microarrays: a 21st century tool for directed vaccine design.

DNA microarray technology is a new and powerful tool that allows the simultaneous analysis of a large number of nucleic acid hybridization experiments in a rapid and efficient fashion. The development of the DNA microarray chip has been driven by modern techniques of microelectronic fabrication, miniaturization and integration to produce what is referred to as "laboratory-on-chip" devices. The application of DNA chip technology includes the comprehensive analysis of multiple gene mutations and expressed sequences with regard to newer drug designs, host-pathogen interactions and the design of new vaccines. An advantage of microarray technology is that it can assist researchers to better define and understand the expression profile of a given genotype associated with disease, adverse effects from exposure to certain stimuli, or the ability to understand or predict immune responses to specific antigens. This paper briefly reviews DNA microarray technology and its implications with special reference to vaccine design. The technical aspects comprising array manufacturing and design, array hybridization, formatting, scanning and data handling are also briefly discussed.

Altered cell-mediated immunity in asymptomatic Colombian natives with positive or indeterminate serology for HTLV-I.

Although HTLV-I infection has been associated with immunosuppression in symptomatic patients, no controlled study has been done in asymptomatic carriers. We evaluated delayed-type hypersensitivity (DTH) to seven antigens by multitest cell-mediated immunity (CMI) in 40 Colombian Indians, 10 HTLV-I-seropositive asymptomatic patients, and 30 matched controls. Multitest CMI was placed in the forearm and was read 48 hours later by the same physician. A positive reaction was defined as > or =2 mm. Hypoergic response was defined as <2 of 7 positive reactions per case or control. We found that HTLV-I-seropositive people had fewer positive reactions than matched controls (50% versus 64%, respectively; p < .04) but no significant difference was found in these populations in the evaluation of hypoergic responses. This study suggests the presence in asymptomatic HTLV-I-positive Colombian Indians of a marginal alteration of cell-mediated immunity that cannot be classified as hypoergic.