Goldfish hippocampal pallium is essential to associate temporally discontiguous events.

There is general agreement that the hippocampus of vertebrates, from fish to mammals, is involved in map-like spatial memory. However, in mammals the role of the hippocampus goes beyond the spatial domain as it is also involved in binding the temporally separate events that compose episodic memories. In this regard, the hippocampus of mammals is essential for trace classical conditioning, in which a stimulus-free time gap separates the conditioned stimulus (CS) and the unconditioned stimulus (US), but not for delay conditioning, in which both stimuli coincide in time. Although the involvement of the hippocampus in encoding relational memories based on a temporal frame-work has been extensively studied in mammals, there is scarce evidence about the possible contribution of the hippocampus of non-mammalian vertebrates to the temporal, non-spatial dimension of relational memories. The present work was aimed to determine if the ventral part of the lateral division of the area dorsalis telencephali (Dlv) of goldfish, proposed as homologous to the hippocampus of mammals, is also involved in trace classical conditioning. With this purpose, goldfish with lesions in Dlv, complete telencephalon ablation and sham operation, were trained in delay and trace heart rate classical conditioning. Dlv lesions severely impaired the acquisition of the conditioned response when a stimulus-free time gap was elapsed between the CS and the US (trace conditioning), but not when both stimuli overlapped in time (delay conditioning), revealing that this region, like the hippocampus of mammals, is essential to form the temporal associative memories required by trace conditioning. Present data suggest that the presence of a hippocampal pallium involved in relational, episodic-like memory that preserves both the spatial and the temporal dimensions of past events, could be a primitive feature of the vertebrate brain that has been conserved through evolution.

Análisis retrospectivo de la ventilación mecánica no invasiva frente a la ventilación mecánica invasiva en pacientes con exacerbación de la enfermedad pulmonar obstructiva crónica, en una Unidad de Cuidados Intensivos / Retrospective analysis of the Noninvasive mechanical ventilation in front of mechanical ventilation invasive in patients with exacerbation of the disease chronic obstructive pulmonary in a Care Unit Intensive

Objetivo: Análisis comparativo de la ventilación no invasiva frente a la ventilación mecánica invasiva en la exacerbación de la enfermedad pulmonar obstructiva crónica. Diseño: Cohorte retrospectiva (enero 2006- diciembre 2012). Ámbito: Unidad de Cuidados Intensivos médico-quirúrgica. Pacientes: Se analizaron 142 pacientes con insuficiencia respiratoria aguda hipercápnica. Intervenciones: Ninguna. Variables de interés: Infecciones (bacteriemia, neumonía intrahospitalaria, infección urinaria), necesidad de traqueotomía, insuficiencia renal aguda, síndrome de dificultad respiratoria aguda, estancias en la Unidad de Cuidados Intensivos y hospitalaria, duración de la ventilación mecánica y mortalidad en la Unidad de Cuidados Intensivos, hospitalaria y a los 6 meses.Resultados: Ciento veintiún pacientes (86%) recibieron ventilación no invasiva y 20 (14%), ventilación invasiva. Un paciente no recibió soporte ventilatorio. Al ingresar, el grupo de ventilación invasiva presentaba mayor deterioro gasométrico, hemodinámico y neurológico que el grupo de ventilación no invasiva. No hubo diferencias en la tasa de infecciones, la necesidad de traqueotomía, las complicaciones, la duración de la ventilación mecánica, las estancias, ni la mortalidad. Los pacientes en quienes fracasó la ventilación no invasiva presentaron mayor mortalidad comparados con el otro grupo. Conclusiones: La ventilación no invasiva fue el soporte ventilatorio más frecuente en los pacientes con exacerbación de la enfermedad pulmonar obstructiva crónica en nuestra Unidad. Los pacientes con ventilación invasiva tuvieron una evolución clínica muy semejante a la de aquellos sometidos a ventilación invasiva, sin que ello haya supuesto una mayor mortalidad. (AU)

Objective: Comparative analysis of non-invasive ventilation versus invasive ventilation in patients with exacerbation of chronic obstructive pulmonary disease. Design: Retrospective cohort (January 2006-December 2012). Setting: Medical-surgical Intensive Care Unit. Patients: One hundred and forty-two patients with exacerbation of chronic obstructive pulmonary disease were analyzed. Variables of interest: Infections (bacteremia, nosocomial pneumonia, urinary infection), need for tracheostomy, acute renal failure, acute respiratory disease syndrome, lenght of stay at the Intensive Care Unit and hospital, duration of mechanical ventilation and mortality at the Intensive Care Unit, hospital and after 6 months. Results: One hundred and twenty-one patients (86%) underwent non-invasive ventilation and 20 (14%) received invasive ventilation. One patient did not receive ventilatory support. At admission, blood gases, and hemodynamic and neurological parameters were worse in the invasive ventilation group compared with the non-invasive ventilation group. Infection rate, need for tracheostomy, complications, duration of mechanical ventilation, length of stay, and mortality did not show differences. Mortality was higher in patients who failed non-invasive ventilation. Conclusions: Non-invasive ventilation was the most common ventilatory support in patients with exacerbation of chronic obstructive pulmonary disease in our Intensive Care Unit. Patients with invasive ventilation had the same clinical course compared to the non-invasive group, without entailing increased mortality.(AU)

Relational and procedural memory systems in the goldfish brain revealed by trace and delay eyeblink-like conditioning.

The presence of multiple memory systems supported by different neural substrata has been demonstrated in animal and human studies. In mammals, two variants of eyeblink classical conditioning, differing only in the temporal relationships between the conditioned stimulus (CS) and the unconditioned stimulus (US), have been widely used to study the neural substrata of these different memory systems. Delay conditioning, in which both stimuli coincide in time, depends on a non-relational memory system supported by the cerebellum and associated brainstem circuits. In contrast, trace conditioning, in which a stimulus-free time gap separates the CS and the US, requires a declarative or relational memory system, thus depending on forebrain structures in addition to the cerebellum. The distinction between the explicit or relational and the implicit or procedural memory systems that support trace and delay classical conditioning has been extensively studied in mammals, but studies in other vertebrate groups are relatively scarce. In the present experiment we analyzed the differential involvement of the cerebellum and the telencephalon in delay and trace eyeblink-like classical conditioning in goldfish. The results show that whereas the cerebellum lesion prevented the eyeblink-like conditioning in both procedures, the telencephalon ablation impaired exclusively the acquisition of the trace conditioning. These data showing that comparable neural systems support delay and trace eyeblink conditioning in teleost fish and mammals suggest that these separate memory systems and their neural bases could be a shared ancestral brain feature of the vertebrate lineage.

Spatial learning-related changes in metabolic brain activity contribute to the delimitation of the hippocampal pallium in goldfish.

Comparative neuroanatomical, developmental and functional evidence suggests that the lateral division of the area dorsalis telencephali (Dl) of the teleost fish is homologous to the hippocampus of tetrapods. Nonetheless, some important aspects of the organization of the hippocampal pallium of teleosts are still under discussion and conflicting hypotheses regarding the extension and demarcation of this region have been proposed. Thus, whereas some authors suggest that the entire Dl region, including its dorsal (Dld) and ventral (Dlv) subdivisions, is homologue to the mammalian hippocampus, others claim that only Dlv should be considered as such. To further elucidate this debate, we investigated the role of Dld and Dlv in one of the most unambiguous functions of the hippocampus, spatial learning. We trained goldfish in a spatial constancy task and mapped the activity of Dld, Dlv, and the medial division of the area dorsalis telencephali (Dm) by means of cytochrome oxidase (CO) histochemistry. The results revealed that training goldfish in the spatial constancy task significantly increased the metabolic activity in Dlv, but not in Dld or Dm, suggesting that only Dlv is critically involved in spatial learning and in this regard comparable to the hippocampus. These data provide additional functional support to the hypotheses that consider Dl as a heterogeneous pallial region and propose that Dlv, but not Dld, might be homologous to the hippocampus.

Hepatitis virales en diferentes grupos étnicos del Paraguay / Viral hepatitis in different ethnic groups of Paraguay

La hepatitis viral es uno de los principales problemas de salud pública en las Américas. El virus de la hepatitis B (VHB) y el virus de la hepatitis C (VHC) se transmiten principalmente por vía sexual, intravenosa y perinatal. Estudios previos, en grupos indígenas Ayoreo­paraguayos, muestran una prevalencia de 17,4% para el antígeno de superficie de la Hepatitis B (HBsAg) y de 14,9% para VHC. El objetivo del presente trabajo fue determinar la prevalencia de la infección para el VHB y VHC en dos grupos étnicos bien diferenciados que habitan la región occidental: Mennonita y una población indígena Enxet ubicados en el Chaco central. Estas dos poblaciones son de poca movilidad territorial y bajo contacto con la sociedad nacional. Con un consentimiento previo se analizó un total de 74 sueros pertenecientes a los grupos étnicos Mennonita (52) y Enxet (22) en un rango de edad entre 16 y 65 años. La detección del antígeno de superficie de la Hepatitis B (HbsAg) y de los anticuerpos anti­VHC se realizó por el método ELISA (Human­Alemania). En ninguna de las dos poblaciones estudiadas se detectó la presencia del HBsAg y de anticuerpos anti­VHC. El aislamiento geográfico y normas socioculturales explicarían la ausencia de estas hepatitis virales en contraposición a los patrones culturales del grupo étnico de los Ayoreo del noreste del Chaco Paraguayo. En el diseño de programas de prevención de la transmisión de enfermedades de transmisión sexual se deben tener en cuenta estas pautas culturales.

Viral hepatitis is a main public health problem in the Americas. Hepatitis B (HBV) and hepatitis C (HCV) viruses are transmitted by sexual, intravenous and perinatal via. Previous studies in Ayoreo aborigine population of the eastern Paraguayan Chaco showed prevalences of 17.4% and 14.9% of HBV and HCV respectively. The objective of the present study was to determine the prevalence of HBV and HCV infection in two well differentiated ethnic groups from the western region of Paraguay: a Mennonite and an aborigine Enxet population located in the central Chaco. These two populations are from rural areas with low contact with urban society. After obtaining the previous informed consent, a total of 74 sera from Mennonite (52) and Enxet (22) individuals were analyzed with in an age range of 16 to 65 years. Detection of surface antigen of hepatitis B virus (HBsAg) and total antibodies anti­HCV was carried out using a commercial ELISA kit (Human­Germany). In none of the two populations, Mennonite and Enxet, the presence of HBsAg and anti­HCV antibodies was detected. Geographical isolation and sociocultural rules may explain the absence of the studied viral hepatitis in these populations in contrast to Ayoreo aborigine population that has different cultural patterns. When prevention programs of sexually transmitted infections are designed, these cultural patterns should be considered.

Sedimentation and prefermentation of domestic wastewater in a fixed bed biofilm reactor.

This investigation was undertaken with the aim of developing a new wastewater prefermentator reactor in order to increase the percentages of sedimentation, hydrolysis and prefermentation of all the organic matter present in the raw wastewater, using only one unit of pre-treatment. The study was carried out using a pilot fixed bed biofilm reactor of 43.3 L in net volume. HRT of 0.5, 1, 2 and 4 h were applied. The reactor has been operating for 403 days during which it has been fed on raw wastewater from the city of Santander, in Spain. The results showed that it is possible to carry out the sedimentation and prefermentation of the organic matter contained in the raw wastewater in this reactor. The TSS average elimination percentage was higher than 50% during the whole testing period. The highest percentage of TSS retained in the reactor was 70% with a HRT of 4 hours and a flow rate of 0.3 m/h. The maximum COD(Total) elimination percentage was 30% for any of the four OL tried. The COD(Particulate) average solubility was greater than 40%. About 44% of the COD(Dissolved) in the effluent consisted of VFA. The highest concentration of VFA measured in the effluent was 44 mg COD/L, applying a HRT of 1 h. The average acidising was slightly higher than 30%. The acetic, propionic, butyric and valeric acids were the species of VFA detected, the acetic acid being the one present in a larger amount (> 50%). The production rate of VFA increases as the HRT decreases.

Population dynamics in an aerobic submerged fixed bed reactor (ASFBR) process.

In this study, an aerobic submerged fixed bed reactor's (ASFBR) population dynamics has been studied in order to know its behavior in different conditions of organic load and oxygen concentration. The reactor was fed with synthetic wastewater. Tested variables and applied values were: 1) Variations in organic load (OL): 16-65 g COD/m2/d. 2) Variations in influent's COD concentration: 40-400 g COD/m3. 3) Variations in specific air flow (SAF): 15-127 m3air/kgCOD. Biofilm samples were taken at the top of the reactor. This study showed important variations in the composition and abundance of the microfauna depending on the experimental conditions. Variations in influent concentration had no significant effect on the abundance of the studied groups. However, differences depending on organic load and aeration conditions were observed. Organic load influenced every group studied but with different results. Sessile cilliates, metazoa and flagellates were abundant in low load, while crawling ones were in high load. Aeration intensity influenced most of the groups except Peranema and Vorticella spp. Despite obtaining good yields, not many protozoa, typical of biofilms under conventional processes, were found. Thus, a great variety of microorganisms, such as many classes of sessile and crawling cilliates, were not found. Important nitrifying activity was obtained at 20 cm depth in a bed. From this point, the heterotrophic and nitrifying populations exist but are inactive.

[Detection of the cutaneous melanomas, their metastasis and relapses by scintigraphies with 99MTC-HMPAO]. / Detección de melanomas cutáneos, sus metástasis y recidivas mediante gammagrafías con 99mTc-HMPAO.

A pilot study was carried out in the Nuclear Medicine Department of the National Institute of Oncology and Radiobiology to learn the diagnostic efficacy of the 99mTc-HMPAO scintigraphy in the detection of cutaneous melanoma, distant and local metastases, in patients with a confirmed histological diagnosis. The planar and/or SPECT scintigraphy was performed in 17 patients and revealed 90% sensitivity for the detection of the disease. We calculated the tumor/background index in all the images obtained and found a value greater than 1 in every case. Thus, we can affirm that the 99mTc-HMPAO accumulation in tumors was higher than the background in all cases. We recommend that this procedure be considered in the follow up of these patients as a new diagnostic method which is very useful in the determination of the patient stage and prognostic evaluation.

Detección de melanomas cutáneos, sus metástasis y recidivas mediante gammagrafías con 99mtc-hmpao / Detection of the cutaneous melanomas, their metastasis and relapses by scintigraphies with 99mtc-hmpao

Se realiza un estudio piloto para comprobar la eficacia diagnóstica de la gammagrafía con 99mTcHMPAO en la detección del melanoma cutáneo, sus metástasis y recidivas en pacientes del INOR con diagnóstico histológico confirmado. Las gammagrafías planas y/o SPECT realizadas con este radiofármaco a 17 pacientes aquejados de la enfermedad demostraron una sensibilidad del 90 por ciento para esta serie. Se calculó el Índice Tumor/Fondo en cada imagen obtenida, encontrándose que en todos los casos el mismo resultaba mayor que 1, por lo que puede afirmarse que la acumulación del 99mTc-HMPAO en los tumores fue mayor que en el fondo radiactivo en todos los casos. Se recomienda tener en cuenta este proceder diagnóstico en el seguimiento evolutivo de estos pacientes ya que puede emplearse como un nuevo método de diagnóstico muy útil en el estadiamiento y evaluación pronóstica de estos pacientes (AU)

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[Radionuclide study of cutaneous melanomas with 99m Tc-HMPAO: visualization of metastases and recurrence]. / Estudio gammagráfico de los melanomas cutáneos con 99m Tc-HMPAO: visualización de metástasis y recidivas.

Malignant cutaneous melanoma (MCM) is a very aggressive disease that becomes in a true problem of health because of the increase in the last 5 years. In the present paper, authors report the detection of the tumor, metastases and recurrences mean 99mTc HMPAO. We presented 5 cases of MCM patients and observed the radiopharmaceutical uptake in skin, nodules and recurrent tumor lesions. Because of the number of patients was limited, authors recommended the research with a lot of patients. The gammagraphic studies could be very important for the staging of the disease and early detection of metastases and recurrent lesions.

[Radiolabeling of a new agent for the study of colorectal tumors]. / Radiomarcaje de un nuevo agente para el estudio de tumores colorrectales.

A new Monoclonal Antibody (AcMo) ior-C5, highly specific for the most part of colorectal adenocarcinomas has been developed. The AcMo was labeled with 99mTc by the Schwarz's direct method using molar ratios MAb: reductant of 1:1,000 and 1:2,000. The first molar ratio was the most adequate for the preparation of the radiopharmaceutical. A labeling yield greater than 95% was obtained. Several <> assays were carried out in order to evaluate the stability of the preparation, whose results reflected the presence of the stable complex 99mTc-IgG. The biodistribution patterns for both preparations were similar. The excreting organs behaved like normal. Nevertheless, a greater renal excretion was observed for the preparation of the molar ratio of 1:2.000, which could be due to the presence of low affinity sites observed in this preparation. They are vulnerable to the trans-chelation of the 99mTc toward cysteine or glutathione present in plasma and tissues.

[The weighted health care unit: a new tool for hospital budgeting]. / La unidad ponderada asistencial (UPA): nueva herramienta para la presupuestación hospitalaria.

Hospital budgets must be based on estimated workload in order to fairly distribute available financial resources. A tool to measure hospital production is need to achieve this aim. We present in this article the results of a study on hospital cost which was carried out to design a new unit for measuring intermediate hospital products: the Weighted Health Care Unit (Unidad Ponderada Asistencial: UPA). Thereafter we use multiple regression to find out structure, services and activity variables which explain the variations in expenses per UPA among 64 hospitals of INSALUD. Significant variables include: doctors per hospital bed, hospital staff (sanitary personnel except doctors plus administrative assistants) per bed, hospital size (less than 200 beds), ICU beds percentage, oncology service, UPAs per bed average length of stay. These variables, along with interactions between them, explain 91.4% of the variance of expenses per UPA. The UPA and statistical modeling allow a better understanding of hospital expenses and can be very useful in coordinating budgets to hospital activity taking into account the different characteristics of each hospital.