The genus Pseudohemiodon (Siluriformes, Loricariidae) in Ecuador, with the description of a new species.

At the Fish Collection of the Museo de la Escuela Politecnica Nacional (MEPN), Quito, the specimens of the genus Pseudohemiodon were revised and three species were identified. The three species inhabit the Amazon versant of Ecuador. Chronologically the species are: P. lamina (Gnther 1868) originally described from Xeberos (Jeberos), Peru; P. apithanos Isbrcker Nijssen 1978, originally described from the Conejo River, Putumayo River system, Ecuador, and a new species described herein. The new species was caught in the Aguarico River, Napo River system, and is represented by two small sized specimens. It is distinguished from all congeners by the combination of the following characters: abdomen totally covered with small to medium-sized, irregularly shaped plates; absence of small plates, anterior to gill openings; eyes relatively small, and six to seven dark transverse bands, posterior to the dorsal-fin. Isbrcker Nijssen (1978) indicate the presence of P. laticeps (Regan 1904) in Ecuador; however we didnt find any specimen of this species. The specimens that could potentially be identified as P. laticeps are large sized specimens of P. apithanos. Some external morphological characters, morphometric and meristic data of analyzed specimens of P. apithanos and P. lamina are provided.

New finding of Rhadinoloricaria macromystax (Siluriformes: Loricariidae): redescription of the genus and description of a new species from Ecuador.

The fish collection from the Museum of Escuela Politécnica Nacional, Quito, Ecuador, has nine lots with 12 specimens assigned to genus Rhadinoloricaria. Specimens come from the Napo and Pastaza rivers, Amazon River basin, eastern Ecuador. One specimen matches accurately with figures and original description of Loricaria macromystax Günther, 1869, type species of Rhadinoloricaria. After 150 years, this is the first secure identification of the species, which allowed an accurate description of the genus Rhadinoloricaria, and the discovery of a new species from Ecuador, described herein. In addition, using available specimens, figures and literature, a comparative analysis on external morphology was performed among the eight species included in Rhadinoloricaria. The analysis documented significant differences between them, in some morphological external characters and in buccal ornamentation. The results suggest that the eight species can be grouped into three or four genera. Rhadinoloricaria, in strict sense, has two species. Apistoloricaria is considered a valid genus, and include the four species previously assigned to it. Rhadinoloricaria bahuaja and R. rhami do not belong to the known genera in the Pseudohemiodon group. At this time, available data suggests that both species could continue included in 'Rhadinoloricaria', waiting further analyses to solve their generic status. Results support the use of buccal ornamentation patterns alone or combined with some morphological characters as valuable tool for generic identification within Loricariini.

Species of Ancistrus (Siluriformes, Loricariidae) from Ecuador, with the description of a new species from the Amazon River Basin.

To elucidate the species of the genus Ancistrus that inhabit freshwater systems of Ecuador, cataloged lots of the Fish Collection, Museo de la Escuela Politécnica Nacional (MEPN), in Quito, were analyzed. Four species were identified: Ancistrus alga (Cope, 1872), A. malacops (Cope, 1872), A. clementinae Rendahl, 1937, and a new species that herein is described. Ancistrus clementinae inhabits aquatic systems of the Pacific slope, mostly in the Guayas River drainage. The other three species live in freshwater systems that drain to the Amazon River Basin. Ancistrus alga inhabit the northern and central portions of eastern Ecuador. Ancistrus malacops has a broad distribution from north to south, but is absent from the Santiago River. Both species occasionally live in sympatry. The new species is restricted to the Santiago River, in Morona-Santiago province. Each species has unique external morphological features and/or a coloration pattern that allow unambiguous identification, at least of males. This paper provides a description of the new species, and a re-description and images of the other three.

Cytotoxicity induced by carbon nanotubes in experimental malignant glioma.

Despite multiple advances in the diagnosis of brain tumors, there is no effective treatment for glioblastoma. Multiwalled carbon nanotubes (MWCNTs), which were previously used as a diagnostic and drug delivery tool, have now been explored as a possible therapy against neoplasms. However, although the toxicity profile of nanotubes is dependent on the physicochemical characteristics of specific particles, there are no studies exploring how the effectivity of the carbon nanotubes (CNTs) is affected by different methods of production. In this study, we characterize the structure and biocompatibility of four different types of MWCNTs in rat astrocytes and in RG2 glioma cells as well as the induction of cell lysis and possible additive effect of the combination of MWCNTs with temozolomide. We used undoped MWCNTs (labeled simply as MWCNTs) and nitrogen-doped MWCNTs (labeled as N-MWCNTs). The average diameter of both pristine MWCNTs and pristine N-MWCNTs was ~22 and ~35 nm, respectively. In vitro and in vivo results suggested that these CNTs can be used as adjuvant therapy along with the standard treatment to increase the survival of rats implanted with malignant glioma.

Role of Redox Status in Development of Glioblastoma.

Glioblastoma multiforme (GBM) is a highly aggressive neoplasia, prognosis remains dismal, and current therapy is mostly palliative. There are no known risk factors associated with gliomagenesis; however, it is well established that chronic inflammation in brain tissue induces oxidative stress in astrocytes and microglia. High quantities of reactive species of oxygen into the cells can react with several macromolecules, including chromosomal and mitochondrial DNA, leading to damage and malfunction of DNA repair enzymes. These changes bring genetic instability and abnormal metabolic processes, favoring oxidative environment and increase rate of cell proliferation. In GBM, a high metabolic rate and increased basal levels of reactive oxygen species play an important role as chemical mediators in the regulation of signal transduction, protecting malignant cells from apoptosis, thus creating an immunosuppressive environment. New redox therapeutics could reduce oxidative stress preventing cellular damage and high mutation rate accompanied by chromosomal instability, reducing the immunosuppressive environment. In addition, therapies directed to modulate redox rate reduce resistance and moderate the high rate of cell proliferation, favoring apoptosis of tumoral cells. This review describes the redox status in GBM, and how this imbalance could promote gliomagenesis through genomic and mitochondrial DNA damage, inducing the pro-oxidant and proinflammatory environment involved in tumor cell proliferation, resistance, and immune escape. In addition, some therapeutic agents that modulate redox status and might be advantageous in therapy against GBM are described.

Vitamin A increases nerve growth factor and retinoic acid receptor beta and improves diabetic neuropathy in rats.

All-trans retinoic acid (ATRA) promotes the endogenous expression of both nerve growth factor (NGF) and retinoic acid receptor beta (RAR-ß). We have previously shown that the administration of ATRA partly reverts the damage induced by diabetic neuropathy (DN). In this investigation, we evaluated the effects of vitamin A, a commercial, inexpensive compound of retinoic acid, on the therapy of DN. A total of 70 rats were randomized into 4 groups. Group A was the control, and groups B, C, and D received a total dose of 60 mg/kg streptozotocin intraperitoneally. When signs of DN developed, groups C and D were treated either with vitamin A (20,000 IU) or with ATRA 25 mg/kg for 60 days. Plasma glucose, contents of NGF, thermal and nociceptive tests, and RAR-ß expression were evaluated. All diabetic rats developed neuropathy. The treatment with vitamin A and ATRA reverted similarly the sensorial disturbances, which was associated with increased contents of NGF and RAR-ß expression. Our results indicate that the administration of vitamin A has the same therapeutic effect as ATRA on peripheral neuropathy and suggest its potential therapeutic use in patients with diabetes.

Staphylococcus aureus outbreak in the intensive care unit of the largest public hospital in Quito, Ecuador

Staphylococcus aureus is a frequent cause of nosocomial pneumonia and bacteremia worldwide. Classical and molecular epidemiology approaches were used to study a S. aureus outbreak in the intensive care unit (ICU) of one of the largest public hospitals in Quito. Staphylococcus aureus isolates from 17 patients and 19 potential carriers from the staff were collected from March 2007 to February 2008 and analyzed by pulsed-field gel electrophoresis (PFGE) to determine their clonal relationships. During this period the hospital reported 16 cases of hospital-acquired staphylococcal pneumonia and an apparent outbreak occurred from June to September 2007. DNA from these isolates formed six different PFGE patterns: four clonal groups, and two groups of clonally related isolates. Molecular typing failed to identify any staphylococcal reservoir among staff members. The current study suggested that a staphylococcal outbreak that occurred in the summer of 2007 was caused by different bacterial clones, although some clones were shared by two patients. Historical analysis of the staphylococcal infections in the ICU showed a higher incidence during the summer months, which coincided with the programmed personnel shift. This observation suggests that outbreaks might be produced by the introduction of improperly trained personnel (AU)

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Staphylococcus aureus outbreak in the intensive care unit of the largest public hospital in Quito, Ecuador.

Staphylococcus aureus is a frequent cause of nosocomial pneumonia and bacteremia worldwide. Classical and molecular epidemiology approaches were used to study a S. aureus outbreak in the intensive care unit (ICU) of one of the largest public hospitals in Quito. Staphylococcus aureus isolates from 17 patients and 19 potential carriers from the staff were collected from March 2007 to February 2008 and analyzed by pulsed-field gel electrophoresis (PFGE) to determine their clonal relationships. During this period the hospital reported 16 cases of hospital-acquired staphylococcal pneumonia and an apparent outbreak occurred from June to September 2007. DNA from these isolates formed six different PFGE patterns: four clonal groups, and two groups of clonally related isolates. Molecular typing failed to identify any staphylococcal reservoir among staff members. The current study suggested that a staphylococcal outbreak that occurred in the summer of 2007 was caused by different bacterial clones, although some clones were shared by two patients. Historical analysis of the staphylococcal infections in the ICU showed a higher incidence during the summer months, which coincided with the programmed personnel shift. This observation suggests that outbreaks might be produced by the introduction of improperly trained personnel.

Estratégias de prevención de dengue - Rosário, Argentina / Dengue prevention strategies - Rosário, Argentina

A pesar de la presencia de Aedes aegypti en el município de Rosário - República Aregentina no se han notificado casos de Dengue autóctono. Esta condición y otras características que convierten a la ciudad vulnerable para el desarollo de la enfermedad, brindan, en contrapartida la posibilidad de intervernir para prevenirla, como pocas veces ofrecen los problemas de salud comunitaria. El sistema Municipal de Epidemiologia definió em el marco de um proceso intersectorial y coparticipativo entre Estado y comunidad, acciones de promoción y prevención dirigidas a lograr la cooperación efectiva de la población en la eliminación de criaderos potenciales del vector. Se inició así en el año 2000, um proceso, com diversos grados de intervención estatal, centrando el trabajo en la acción de promotores domiciliários, que acercaron conocimientos a los ciudadanos sobre el Dengue y su vector transmissor. Se recabó, además información para evaluar el riesgo asociado a la presencia de criaderos. La actividad se extendió a establecimientos educacionales y organizaciones barrriales. Se promovieron, también, actividades intersectoraiales concretas de limpieza y ordenamiento ambiental. La evaluación de dichas intervenciones, permitió verificar el perfeccionamento de los conocimientos de la población mediante la promoción personalizada y posibilitó apreciar que se lograron mejores resultados con la incorporación de lãs escuelas y con las intervenciones realizadas con amplia participación estatal. Este trabajo puso en evidencia la necessidad del rol del Estado como incentivador y organizador de actividades para modificar actitudes e incorporar comportamientos responsables y solidarios de los ciudadanos, que aporten a las estrategias saludables.

Comparación entre colecistectomía laparoscópica y abierta, Clínica Arequipa 1995

El objetivo del presente estudio fue comparar a los pacientes operados mediante colecistectomía abierta(C.A) y colecistectomía laparoscópica(C.L) así como el costo de las intervenciones. Se sometieron a estudio 20 pacientes sometidos a C.L y 40 pacientes sometidos a C.L. Se usó la prueba estadística de Ji². La colecistectomía laparoscópica tiene evidentes ventajas y beneficios sobre la colecistetomía abierta con diferencia significativa en lo que se refiere a: complicaciones, magnitud del dolor, terápia post-operatoria, inicio de la dieta oral, tiempo de hospitalización, inicio de la deambulación, retorno al trabajo. El costo global de colecistectomía laparoscópica es más caro que el de la colecistectomía abierta, por que los equipos son más costosos y los honorarios más altos