Characterizing the hippocampal theta's response to carbachol; using a complete septo-hippocampal preparation / Caracterización de la respuesta theta del hipocampo al carbacol en una preparación septo-hipocámpica completa

Abstract: The present study describes the pharmacological analysis of the effects of carbachol, a cholinergic agonist, on hippocampal theta activity. Knowing that this activity is critically related to cognitive function and altered in patients with neurodegeneration, pharmacological efforts aiming to directly modulate hippocampal theta activity becomes of central importance. In a recently developed complete septo-hippocampal preparation, carbachol elicited significant theta power enhancement with 1 μM. Concentrations under 1 μM and over 2 μM carbachol caused significant reduction in the power of hippocampal theta activity. Carbachol effects were completely blocked with the cholinergic antagonist scopolamine. At the experimental level, it is the first time the direct action of a cholinergic agonist is evaluated in the septo-hippocampal pathway completely isolated. However, carbachol as a cholinergic agonist is a drug with a certain level of nonspecific response. That is why to correct this experimental limitation, we used scopolamine (cholinergic antagonist) which allowed us to corroborate the effects on the cholinergic pathway. In summary, electrophysiological assays demonstrated an effective concentration range of carbachol specifically modulating hippocampal theta activity.

Resumen: El presente estudio describe el análisis farmacológico de los efectos de carbacol, un agonista colinérgico, sobre la actividad theta del hipocampo. Sabiendo que esta actividad está críticamente relacionada con la función cognitiva y alterada en pacientes con neurodegeneración, los esfuerzos farmacológicos destinados a modular directamente la actividad theta del hipocampo se vuelven de gran importancia. En una preparación completa que contiene la región septal media conectada al hipocampo, desarrollada recientemente, 1 μM de carbacol provocó un incremento significativo a nivel de potencia en la actividad theta del hipocampo. Las concentraciones menores de1 μM y mayores a 2 μM causaron una reducción significativa en la potencia de la actividad theta. Los efectos del carbacol fueron completamente bloqueados con la escopolamina, antagonista colinérgico. A nivel experimental, es la primera vez que se evalúa la acción directa de un agonista colinérgico en la vía septo-hipocámpica completamente aislada. Sin embargo, el carbacol como agonista colinérgico es un fármaco que presenta cierto nivel de respuesta inespecífica. Es por eso que para corregir esta limitante experimental, se utilizó escopolamina (antagonista colinérgico) lo que nos permitió corroborar los efectos sobre la vía colinérgica. En resumen, nuestros estudios electrofisiológicos demostraron un intervalo de concentración eficaz del carbacol que modula específicamente la actividad theta del hipocampo.

Respiratory symptoms and illnesses related to the concentration of airborne particulate matter among brick kiln workers in Kathmandu valley, Nepal

BACKGROUND: Bricks have been manufactured in Nepal for hundreds of years and are seen as a component of Nepalese sculpture and architecture. Large quantities of hazardous materials including high concentrations of particulate matter are emitted on a daily basis from brick kilns. Exposure to these hazardous materials can lead to adverse consequences on the environment and human health. This study was conducted to  estimate the prevalence of respiratory symptoms/illnesses and the magnitude of respirable and total dust exposures among Nepalese brick kiln workers. METHODS: Respiratory symptoms/illnesses were evaluated by questionnaire among brickfield workers (n = 400) and a referent group of grocery workers (n = 400) in Kathmandu valley. Work zones (WZs): green brick molding (GBM), green brick stacking/carrying (GBS/C), red brick loading/carrying (RBL/C), coal preparation (CP) and firemen (FM) were the similar exposure groups (SEGs) from where personal air samples and interviews were taken. Among brickfield workers, personal monitoring was conducted across SEGs for total (n = 89) and respirable (n = 72) dust during February–March 2015 and March–April 2016. Applying multi-stage probability proportionate to size sampling technique, 16 kilns and 400 brick workers for interview were selected. Proportions, means, medians and ranges were calculated for the demographics, samples and respiratory symptoms/illnesses. One-way ANOVA was applied to compare the significance differences of the level of particulate matter among SEGs. Bivariate and multivariate logistic regression analysis were performed to evaluate association between respiratory symptoms/illnesses and participants groups, and SEGs among brick kiln workers at 0.05 level. Statistical analyses were performed using IBM SPSS Statistics 21. RESULTS: Chronic cough (14.3%), phlegm (16.6%) and bronchitis (19.0%) were higher (P < 0.05) among brickfield compared with grocery workers (6.8, 5.8 and 10.8%). Mean respirable (5.888 mg/m3) and total (20.657 mg/m3) dust exposures were highest for red brick loading tasks. The prevalence of chronic cough, chronic phlegm, chronic bronchitis, wheezing and asthma were significantly higher for other WZs workers (p < 0.05) compared with CP; for GBM: 22.9, 34.6, 15.0 and 7.5%; for GBS/C: 13.5, 15.8, 10.0, 8.8 and 7.5%; for RBL/C: 11.1, 17.1, 27.4, 19.0 and 11.9%; for FM: 18.4, 12.5, 28.4, 4.9 and 0.0%; and for CP: 4.9, 6.3, 13.3, 9.3 and 4.0% respectively. CONCLUSION: High dust exposures identified in this study may explain the increased prevalence of respiratory symptoms/illnesses among Nepalese brickfield workers, warranting action to reduce exposures.

Role of carbonic anhydrases in skin wound healing

Skin wound closure occurs when keratinocytes migrate from the edge of the wound and re-epithelialize the epidermis. Their migration takes place primarily before any vascularization is established, that is, under hypoxia, but relatively little is known regarding the factors that stimulate this migration. Hypoxia and an acidic environment are well-established stimuli for cancer cell migration. The carbonic anhydrases (CAs) contribute to tumor cell migration by generating an acidic environment through the conversion of carbon dioxide to bicarbonate and a proton. On this basis, we explored the possible role of CAs in tissue regeneration using mouse skin wound models. We show that the expression of mRNAs encoding CA isoforms IV and IX are increased (~25 × and 4 ×, respectively) during the wound hypoxic period (days 2–5) and that cells expressing CAs form a band-like structure beneath the migrating epidermis. RNA-Seq analysis suggested that the CA IV-specific signal in the wound is mainly derived from neutrophils. Due to the high level of induction of CA IV in the wound, we treated skin wounds locally with recombinant human CA IV enzyme. Recombinant CA IV significantly accelerated wound re-epithelialization. Thus, CA IV could contribute to wound healing by providing an acidic environment in which the migrating epidermis and neutrophils can survive and may offer novel opportunities to accelerate wound healing under compromised conditions.

Leiomyosarcoma of the kidney / El Leiomiosarcoma del riñón

The case of a 42- year old woman with leiomyosarcoma of the kidney, a very rare renal lesion, is presented. Leiomyosarcomas are the most common of the primary renal sarcomas which account for less than 1% of renal tumours in adults.

Se presenta el caso de una mujer de 43 años de edad con un leiomiosarcoma del riñón - una lesión renal muy rara. Los leiomiosarcomas son los más comunes de los sarcomas renales primarios, y representan menos del 1% de los tumores renales en adultos.

Utilización de un modelo animal para entrenamiento, en oxigenación por membrana extracorporea (ECMO) / The use of an animal model for extracorporeal membrane oxygenation (ECMO) training

ECMO es un procedimiento de rescate de recién nacidos (RN) con fallo respiratorio hipoxémico severo que no responde al tratamiento convencional. Previo a la instrumentación de esta técnica en pacientes, se realizó el entrenamiento experimental en animales. Existe escasa bibliografía sobre la utilización de porcinos como modelo animal en ECMO. Se reportan, en cambio, la implementación de otros animales, tales como el cordero. Objetivo: determinar la utilidad y el comportamiento modelo animal eligido, su respuesta al procedimiento de ECMO, describir la técnica utilizada y sus resultados. Método: se utilizaron dos porcinos de la raza Landrace, de 30 y 45 días de vida. Se canularon la vena yugular interna y la arteria carótida interna derechas; se realizó el ensamblado y purgado del circuito. El bypass se inició con un flujo de bomba de 20 mL/K/min, aumentandose hasta 100-120 mL/K/min; logrado un flujo de 80 mL/K/min se disminuyeron los parámetros de Asistencia Respiratoria Mecánica (ARM) a nivel de reposo. Durante el curso de ECMO se practicaron diferentes acciones relacionadas con el manejo del sistema de perfusión y evaluación del comportamiento clínico del modelo. Finalmente se suspendió electivamente el procedimiento; luego el animal fue dacanulado y recuperado. Resultados: tiempo promedio de ECMO: 24.5 horas. Signos vitales del animal estables. No hubo complicaciones relacionadas con el circito, ni presencia de sangrado sistémico. Se lograron tasas deseadas de hemofiltración. Ambos animales sobrevivieron. Como complicación se registró hematuria en un caso. Conclusión: El modelo animal elegido, para el entrenamiento en el manejo de ECMO, fue satisfactorio.

A recent increase in the abundance of the echinoid Diadema antillarum in Dominica (Lesser Antilles): 2001-2005 / Un aumento reciente en la abundancia del equinoideo Diadema antillarum en Dominica (Antillas Menores): 2001-2005

Diadema antillarum populations at many Caribbean locations have failed to recover from the pathogen-induced mortality events of the 1980s. It has become clear that the massive decline of this herbivorous urchin and the wide-spread absence of a population recovery lead to numerous long-term ecological consequences and reef degradation. While few quantitative studies on pre-mortality exist, great effort has been put forth to monitor remaining populations and their recovery. However, the patchy distribution of D. antillarum coupled with paucity of long-term studies based on the same methods applied at the same locations undermines the value of local as well as regional comparisons. In Dominica, ongoing quantitative assessments of D. antillarum began in 2001. Surveys of D. antillarum abundance are being carried out in 4-month intervals at six 100 m² sites; spread over 38 km along the west coast. The density of D. antillarum has differed significantly between sites, ranging from 0.81(SD= 0.04) to 3.13 m-2 (SD= 2.10), and increased by 61.11% during the first five years of this study. Seasonal fluctuations, possibly related to spawning aggregations, are also evident. The current abundance of D. antillarum on Dominican reefs contrasts that of Caribbean locations with recorded incidents of mass mortality events, and in some cases resembles pre-mortality densities from the early 1970s. Prior to this study, no systematic quantitative assessments of D. antillarum were carried out in Dominica. It is thus unclear in what way Dominica’s D. antillarum were affected by the mass mortality events observed elsewhere in the 1980s. The increase in D. antillarum density so far observed may thus be the recovery from a pathogen-induced disturbance or from Hurricane Lenny in November 1999. Locally, D. antillarum is important grazer on Dominican’s reefs, where over-fishing has drastically reduced the number of herbivorous fishes. On a regional scale, the island’s D. antillarum may represent a source of larvae for downstream islands, given the duration of the echinoplutei stage and a range of larval dispersal of hundreds of kilometers. Rev. Biol. Trop. 54 (Suppl. 3): 97-103. Epub 2007 Jan. 15.

Las poblaciones de Diadema antillarum de muchas localidades del Caribe, no se han recuperado después de los eventos de mortandad, inducidos por un patógeno, en la década de 1980. Se ha podido demostrar que la muerte masiva de este erizo herbívoro y la ausencia de recuperación, han tenido consecuencias ecológicas que han producido la degradación de los arrecifes. Existen pocos estudios pre-mortalidad, pero se han realizado grandes esfuerzos para monitorear las poblaciones restantes y su recuperación. Sin embargo, la distribución en parches de D. antillarum combinado con pocos estudios a largo plazo usando la misma metodología en los mismos sitios, mina la posibilidad de comparaciones locales y regionales. En Dominica, el monitoreo cuantitativo de D. antillarum empezó en 2001. Cada cuatro meses se realizan determinaciones de abundancia de D. antillarum en seis sitios de 100 m²; distribuidos a lo largo de 38 km de la costa oeste. La densidad de D. antillarum, fue significativamente diferente entre sitios, con ámbitos de 0.81 (SD= 0.04) a 3.13 m-2 (SD= 2.10), y aumentó 61.11% durante los primeros cinco años de estudio. Fluctuaciones estacionales, posiblemente relacionadas con agregaciones reproductivas, son evidentes. La abundancia actual de D. antillarum en los arrecifes de Dominica contrasta con otros sitios en el Caribe que sufrieron mortandades masivas y en algunos casos se parece a densidades pre-mortalidad de inicios de la década de 1970. Antes de este trabajo, no se había realizado ningún estudio sistemático de Diadema en Dominica, por lo que no es claro como fueron afectadas las poblaciones en este sitio. El aumento en la densidad de D. antillarum observado hasta ahora puede deberse a recuperación tras una perturbación por un patógeno o por el Huracán Lenny de noviembre 1999. Localmente, D. antillarum es un herbívoro importante en los arrecifes de Dominica donde la sobrepesca ha disminuido el número de peces herbívoros. En escala regional, las poblaciones de D. antillarum de la isla de Dominica pueden representar una fuente de larvas corriente abajo, dada la duración de estadio equiinopluteo y el ámbito de dispersión de las larvas, que es de cientos de kilómetros.

Trend of blood group distribution among the Jirels of Nepal.

This study was undertaken to find out the trend of blood group distribution among the Jirels, a small tribe, descended from Kirat tribe and to compare with other castes within Nepal and with people of other continents. Blood group distribution (ABO grouping and Rh typing) was studied among 2093 Jirels (Male-1057 and Female-1036). The frequency of distribution of A, B, O and AB was 55.05%, 14.72%, 21.64% and 8.6% respectively. The group A was found to be most common among the Jirels where as O is most common in the world. Only 0.14%of the Jirels were was found to be Rhesus Negative (Rh -ve).

Psychological distress among students from five universities in Sri Lanka.

OBJECTIVE: To determine the proportion of university students that are psychologically distressed when compared to an age and sex matched population sample and to describe the factors that may contribute to their distress. DESIGN: A cross-sectional comparison study. METHODS: The general health questionnaire (GHQ 30), previously validated in Sinhala, was administered as a screening test to random samples of undergraduates in 5 universities. Age and sex matched controls from the respective communities were also administered the screening test. The undergraduates also filled in a pre-tested questionnaire with personal details. Chi-square tests were used to determine statistical significance between groups. RESULTS: Among the undergraduates, 104 (39.8%) had scores for psychological distress whereas only 67 (25.7%) from the community sample had scores for similar distress. This difference was significant (p = 0.0007). A significantly greater proportion (p = 0.009) of those entering from rural schools were psychologically distressed than those from suburban and urban schools, and a greater proportion living in rented rooms and hostels were (p = 0.001) distressed than those travelling from their homes. CONCLUSIONS: The psychological distress among undergraduates was significantly greater than among the general population. More students who enter from rural schools seem to be distressed than those who enter from suburban and urban schools.

Recent advances in the application of molecular biology in filariasis.

Monitoring of filarial parasites in the host and vector has traditionally depended on morphological identification. Recently, species-specific DNA probes have been developed for Brugia malayi, Brugia pahangi and Wuchereria bancrofti. Repeated DNA sequences are useful in developing DNA probes because they evolve more rapidly then coding sequences and their high copy number increases the sensitivity of detection. The Hhal repeated DNA family represents 12% of the total B. malayi DNA. This DNA family is present in species of Brugia (B. malayi, B. timori and B. pahangi) but not W. bancrofti. Sequence analysis of the repeated DNA in B. malayi and B. pahangi has allowed construction of two species-specific DNA probes. These probes were used in a double blind field study in Indonesia. Microfilariae (mf) from infected cats and humans were identified by classical morphological methods and DNA probes. Agreement was found in 98.6% of the 642 samples tested by the two different techniques. Besides mf identification DNA probes can be used to determine the species of infective larvae (L3s) in infected mosquitos. This is useful because the L3s have similar morphology. DNA probes for the identification of W. bancrofti have recently been developed and are in the initial stages of testing in China (Piessens, personal communication) and Egypt (Williams, personal communication). An alternative approach for identification of infected individuals is to detect specific parasite antigens in circulation. A WHO initiative to use either an antigen or antibody assay to replace night blood is presently underway. This approach, if successful would not require the presence of microfilariae, but could detect occult infections.

Vitrectomía a cielo abierto en el estadio cicatrizal grado V: desprendimiento de retina total con configuración en embudo cerrado / Open vitrectomy in cicatricial stage V: total retinal detachment with close funel configuration

Se efectuó vitrectomía a cielo abierto en 23 ojos de 18 niños (entre 4 y 35 meses de edad) que presentaban una Retinopatia del prematuro (R.P.) en etapa cicatrizal grado V - desprendimiento de retina total con configuración en embudo cerrado. Al finalizar el seguimiento, la retina estaba aplicada en el polo posterior en 8 ojos (8/23 = 34,7%). El seguimiento osciló entre 1 y 48 meses (media = 14 meses; mediana = 12 meses). Se analiza la posible influencia de factores clínico-patológicos y quirúrgicos en el resultado anatómico

Serum angiotensin-converting enzyme in leprosy.

Serum angiotensin-converting enzyme activity was measured in 91 adult healthy and lepromatous armadillos before inoculation with M. leprae and at necropsises. Mean ACE values were significantly elevated in armadillos with leprosy and the degree of elevation was roughly proportional to the extent of infection. There was also significant difference in the serum ACE levels between Florida and Louisiana armadillos. The dapsone treatment resulted in bringing these levels to normal. Serial assays of serum, ACE provided information on the response of armadillos to dapsone therapy.