Low Molecular Weight mRNA Encodes a Protein That Controls Serotonin 5-HT_(1c) and Acetylcholine M_1 Receptor Sensitivity in Xenopus Oocytes

Serotonin 5-HT_(1c) and acetylcholine M_1 receptors activate phosphoinositidase, resulting in an increased formation of IP_3 and 1,2 diacylglycerol. In Xenopus oocytes injected with mRNA encoding either of these receptors, Ca^(2+) released from intracellular stores in response to IP3 then opens Ca^(2+)-gated Cl^-channels. In the present experiments, oocytes expressing a transcript from a cloned mouse serotonin 5-HT_(1c) receptor were exposed to identical 15-s pulses of agonist, administered 2 min apart; the second current response was two to three times that of the first. However, in those oocytes coinjected with the 5-HT_(1c) receptor transcript and a low molecular weight fraction (0.3-1.5 kb) of rat brain mRNA, the second current response was ~50% of the first. Thus, the low molecular weight RNA encodes a protein (or proteins) that causes desensitization. Experiments using fura-2 or a Ca^(2+)-free superfusate indicated that desensitization of the 5-HT_(1c) receptor response does not result from a sustained elevation of intracellular Ca^(2+) level or require the entry of extracellular Ca^(2+). Photolysis of caged IP_3 demonstrated that an increase in IP_3 and a subsequent rise in Ca^(2+) do not produce desensitization of either the IP_3 or 5-HT_(1c) peak current responses. Furthermore, in oocytes coinjected with the low molecular weight RNA and a transcript from the rat M_1 acetylcholine receptor, the M_1 current response was greatly attenuated. Our data suggest that the proteins involved in attenuation of the M_1 current response and desensitization of the 5-HT_(1c) current response may be the same

Assembly of α4β2 Nicotinic Acetylcholine Receptors Assessed with Functional Fluorescently Labeled Subunits: Effects of Localization, Trafficking, and Nicotine-Induced Upregulation in Clonal Mammalian Cells and in Cultured Midbrain Neurons

Fura-2 recording of Ca^(2+) influx was used to show that incubation in 1 μM nicotine (2-6 d) upregulates several pharmacological components of acetylcholine (ACh) responses in ventral midbrain cultures, including a MLA-resistant, DHβE-sensitive component that presumably corresponds to α4β2 receptors. To study changes in α4β2 receptor levels and assembly during this upregulation, we incorporated yellow and cyan fluorescent proteins (YFPs and CFPs) into the α4 or β2 M3-M4 intracellular loops, and these subunits were coexpressed in human embryonic kidney (HEK) 293T cells and cultured ventral midbrain neurons. The fluorescent receptors resembled wild-type receptors in maximal responses to ACh, dose-response relations, ACh-induced Ca^(2+) influx, and somatic and dendritic distribution. Transfected midbrain neurons that were exposed to nicotine (1 d) displayed greater levels of fluorescent α4 and β2 nicotinic ACh receptor (nAChR) subunits. As expected from the hetero-multimeric nature of α4β2 receptors, coexpression of the α4-YFP and β2-CFP subunits resulted in robust fluorescence resonance energy transfer (FRET), with a FRET efficiency of 22%. In midbrain neurons, dendritic α4β2 nAChRs displayed greater FRET than receptors inside the soma, and in HEK293T cells, a similar increase was noted for receptors that were translocated to the surface during PKC stimulation. When cultured transfected midbrain neurons were incubated in 1 μMnicotine, there was increased FRET in the cell body, denoting increased assembly of α4β2 receptors. Thus, changes in α4β2 receptor assembly play a role in the regulation of α4β2 levels and responses in both clonal cell lines and midbrain neurons, and the regulation may result from Ca^(2+)-stimulated pathways

Estructuras reproductivas y polinización entomófila en tres lotes comerciales de palma aceitera (Elaeis guineensis Jacq.) en el estado Zulia, Venezuela

La palma aceitera (Elaeis guineensis Jacq.), es una oleaginosa perenne que inicia su producción después de 30 meses de transplantada. La polinización entomófila es de gran importancia en el rendimiento de éste cultivo, ya que una mayor proporción de frutos normales se asocia con altas poblaciones de insectos polinizadores durante el período de antesis de las inflorescencias femeninas. Con el fin de estudiar a los polinizadores y su fluctuación poblacional se llevó a cabo un estudio desde agosto de 2005 a julio de 2006 en tres plantaciones en edad productiva, de las principales zonas productoras del estado Zulia. Se disectaron espiguillas de inflorescencias masculinas en antesis (IMA), según su disponibilidad y se colocaron trampas en las inflorescencias femeninas en antesis (IFA), para capturar a los insectos, los cuales fueron separados, identificados por especie y contados. Se contabilizaron las inflorescencias masculinas (IM) y femeninas (IF) en las plantas marcadas, describiendo si estaban cerradas, en antesis y las femeninas polinizadas. También se registró la precipitación, la temperatura y la humedad relativa media mensual en cada plantación. Los resultados mostraron que el insecto Elaeidobius kamerunicus fue el más frecuentemente encontrado y en mayor proporción en las tres plantaciones estudiadas, el cual estuvo altamente correlacionado con las IMA y con la precipitación. Asimismo, se encontró algunas correlaciones positivas y significativas entre el número de IM e IF y la precipitación y negativas entre la temperatura y las IF. Concluyendo que variaciones en los factores climáticos causaron fluctuaciones en el número de IM e IF y por ende en la población de los polinizadores.Â

The structure of the tetrasialoganglioside from human brain

Autosomal dominant retinal vasculopathy with cerebral leukodystrophy is a microvascular endotheliopathy with middle- age onset. In nine families, we identified heterozygous C- terminal frameshift mutations in TREX1, which encodes a 3'-5' exonuclease. These truncated proteins retain exonuclease activity but lose normal perinuclear localization. These data have implications for the maintenance of vascular integrity in the degenerative cerebral microangiopathies leading to stroke and dementias

Antimicrobial consumption and resistance in adult hospital inpatients in 53 countries:results of an internet-based global point prevalence survey

Summary: Background: The Global Point Prevalence Survey (Global-PPS) established an international network of hospitals to measure antimicrobial prescribing and resistance worldwide. We aimed to assess antimicrobial prescribing and resistance in hospital inpatients. Methods: We used a standardised surveillance method to collect detailed data about antimicrobial prescribing and resistance from hospitals worldwide, which were grouped by UN region. The internet-based survey included all inpatients (adults, children, and neonates) receiving an antimicrobial who were on the ward at 0800 h on one specific day between January and September, 2015. Hospitals were classified as primary, secondary, tertiary (including infectious diseases hospitals), and paediatric hospitals. Five main ward types were defined: medical wards, surgical wards, intensive-care units, haematology oncology wards, and medical transplantation (bone marrow or solid transplants) wards. Data recorded included patient characteristics, antimicrobials received, diagnosis, therapeutic indication according to predefined lists, and markers of prescribing quality (eg, whether a stop or review date were recorded, and whether local prescribing guidelines existed and were adhered to). We report findings for adult inpatients. Findings: The Global-PPS for 2015 included adult data from 303 hospitals in 53 countries, including eight lower-middle-income and 17 upper-middle-income countries. 86 776 inpatients were admitted to 3315 adult wards, of whom 29 891 (34·4%) received at least one antimicrobial. 41 213 antimicrobial prescriptions were issued, of which 36 792 (89·3%) were antibacterial agents for systemic use. The top three antibiotics prescribed worldwide were penicillins with β-lactamase inhibitors, third-generation cephalosporins, and fluoroquinolones. Carbapenems were most frequently prescribed in Latin America and west and central Asia. Of patients who received at least one antimicrobial, 5926 (19·8%) received a targeted antibacterial treatment for systemic use, and 1769 (5·9%) received a treatment targeting at least one multidrug-resistant organism. The frequency of health-care-associated infections was highest in Latin America (1518 [11·9%]) and east and south Asia (5363 [10·1%]). Overall, the reason for treatment was recorded in 31 694 (76·9%) of antimicrobial prescriptions, and a stop or review date in 15 778 (38·3%). Local antibiotic guidelines were missing for 7050 (19·2%) of the 36 792 antibiotic prescriptions, and guideline compliance was 77·4%. Interpretation: The Global-PPS showed that worldwide surveillance can be accomplished with voluntary participation. It provided quantifiable measures to assess and compare the quantity and quality of antibiotic prescribing and resistance in hospital patients worldwide. These data will help to improve the quality of antibiotic prescribing through education and practice changes, particularly in low-income and middle-income countries that have no tools to monitor antibiotic prescribing in hospitals. Funding: bioMérieux

"Relación entre las Inflorescencias, el Clima y los Polinizadores en el Cultivo de la Palma Aceitera (Elaeis Guineensis Jacquin) en el Sur del Lago de Maracaibo"

La alta productividad de la palma aceitera, está dada por una producción permanente de racimos, la cual a su vez depende de una adecuada polinización que en su mayoría es entomófila. Al respecto, se estudió la fluctuación poblacional de las diferentes especies de polinizadores, para conocer su situación actual en ésta zona, así como su relación con la presencia de inflorescencias masculinas y femeninas en el campo. Para ello se llevó a cabo un muestreo desde diciembre de 2002 hasta noviembre de 2003, en un lote comercial de palma aceitera de tres años de edad, ubicado en el municipio Francisco Javier Pulgar del estado Zulia. Se tomaron según su disponibilidad espiguillas de inflorescencias masculinas en antesis (IMA) y se colocaron trampas en inflorescencias femeninas en antesis (IFA) para capturar a los insectos, los cuales se separaron, identificaron por especie y se contaron. De igual forma se contabilizaron mensualmente el número de IM e IF según su estado, encontradas en las plantas marcadas. Las principales especies recolectadas fueron Elaeidobius kamerunicus, E. subvittatus y Mistrops costaricensis; además, se identificó la presencia de Thrips hawaiiensis y de un coleóptero de la familia Smicripidae. Asimismo, se obtuvo una correlación significativa entre el número de IMA y los insectos polinizadores  recolectados, excepto para la especie T. hawaiiensis, mientras que la correlación con las IFA sólo fue significativa para la especie E. subvittatus. También se registró la precipitación y la temperatura mensual de la zona para observar su efecto sobre la disponibilidad de IMA e IFA, concluyendo que las variaciones en la precipitación mensual causaron fluctuaciones en el número de inflorescencia

Evaluación de sustratos orgánicos y en combinación con insecticida para la captura de adultos de Opsiphanes cassina Felder en una plantación de palma aceitera (Elaeis guineensis Jacquin.) en el estado Zulia, Venezuela

Se evaluaron diferentes sustratos orgánicos y en combinación con insecticida monocrotofos (Azodrin) con el propósito de determinar el más efectivo para la captura de adultos de Opsiphanes cassina Felder. en una plantación comercial de palma aceitera. Los tratamientos utilizados fueron: melaza, frutos (guayaba, lechosa y cambur), y la combinación de cada uno de ellos, con ó sin insecticida. Los diferentes atrayentes se distribuyeron al azar en trampas plásticas transparentes, en una superficie de 8,93ha. Cada trampa se ubicó en el centro del área conformada por 18 plantas para un total de 8 tratamientos. Se realizaron conteos a lo largo de 8 semanas, divididas en 2 fases de 4 semanas cada una con 2 semanas de separación entre las fases. Durante los lapsos evaluados, para los sustratos sin insecticida se capturó un promedio de 12,95 adultos, en contraste con 11,5 adultos, en los tratamientos donde se utilizó insecticida. Estos resultados nos permiten confirmar, que no es necesario el uso de insecticidas en combinación con sustratos orgánicos como atrayentes. En los sustratos sin insecticida, se evidenció la superioridad (P < 0,01) de la melaza (23,52 adultos) en comparación con los demás tratamientos. Los resultados demuestran la posibilidad de manejar las poblaciones de adultos de O. cassina, mediante el uso de trampas de melaza como sustrato atrayente, sin causar efecto negativo sobre el agroecosistema de la palma aceitera

Human chondrocytes in tridimensional culture.

peer reviewedCartilage was taken from the macroscopically normal part of human femoral heads immediately after orthopedic surgical operations for total prothesis consecutive to hip arthrosis. After clostridial collagenase digestion and repeated washings, chondrocytes (10(6) cells) were cultivated in a gyrotory shaker (100 rpm). Under these conditions, cells were kept in suspension and after 3 to 5 d formed a flaky aggregate which, on Day 10, became dense. These chondrocytes were morphologically differentiated: they had a round shape, were situated inside cavities, and were surrounded by a new matrix. Histochemical methods showed the presence of collagen and polysaccharides in cell cytoplasm and in intercellular matrix, and the immunofluorescence method using specific antisera (anticartilage proteoglycans and anti-type II collagen) showed that these two constituents were in intercellular matrix. The measurement of the amounts of proteoglycans (PG) released into culture medium and those present in chondrocyte aggregate (by a specific PG radioimmunoassay) showed a maximum production on Days 3 to 5 of culture, then the production decreased and stabilized (from Day 10 to the end of culture). The observed difference between the amounts of PG in aggregates after 20 d and those after 2 h of culture demonstrated that PG neosynthesis did occur during cultivation. This conclusion was supported by other results obtained by [14C]glucosamine incorporation in chondrocyte aggregates. Moreover, the aggregate fresh weight related to cell number (appreciated by DNA assay) increased significantly with culture duration. Three-dimensional chondrocyte culture represents an interesting model: chondrocytes were differentiated morphologically as well as biosynthetically and synthesized a new cartilage matrix

Aclimatización de vitroplantas sin raíces de zábila (Aloe vera (L.) Burm. f.) de diferentes tamaños

En el propagador del Vivero Universitario, Facultad de Agronomía, Universidad del Zulia, se evaluó el efecto del tamaño de vitroplantas sin raíces sobre la aclimatización de zábila ((Aloe vera (L.) Burm. f.). Se sembraron vitroplantas pequeñas, medianas y grandes (4, 6 y 11 cm, aproximadamente) en bandejas con una mezcla de carbón activado y abono de río (6:3) más 20 g de Stockosorb 500 (hidrogel que permite conservar la humedad). La sobrevivencia y el enraizamiento de las plantas fue de 100%. Se incrementó significativamente (P < 0,05) la masa fresca y seca de las pencas, raíces y brotes generados. Las vitroplantas grandes y sin raíces respondieron mejor a la aclimatización en el propagador durante el período de estudio