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The mouse visual system consists of several visual cortical areas thought to be specialized for different visual features and/or tasks. Previous studies have revealed differences between primary visual cortex (V1) and other higher visual areas, namely, anterolateral (AL) and posteromedial (PM), and their tuning preferences for spatial and temporal frequency. However, these differences have primarily been characterized using methods that are biased toward superficial layers of cortex, such as two-photon calcium imaging. Fewer studies have investigated cell types in deeper layers of these areas and their tuning preferences. Because superficial versus deep-layer neurons and different types of deep-layer neurons are known to have different feedforward and feedback inputs and outputs, comparing the tuning preferences of these groups is important for understanding cortical visual information processing. In this study, we used extracellular electrophysiology and two-photon calcium imaging targeted toward two different layer 5 cell classes to characterize their tuning properties in V1, AL, and PM. We find that deep-layer neurons, similar to superficial layer neurons, are also specialized for different spatial and temporal frequencies, with the strongest differences between AL and V1, and AL and PM, but not V1 and PM. However, we note that the deep-layer neuron populations preferred a larger range of SFs and TFs compared to previous studies. We also find that extratelencephalically projecting layer 5 neurons are more direction selective than intratelencephalically projecting layer 5 neurons.

The study determined the digital competencies and experiences public elementary and secondary school teachers encountered in using digital technologies. It investigated how often teachers use digital technologies in their teaching tasks. It also measured the level of digital competencies of teachers in terms of information and digital literacy, communication and collaboration, digital content creation, online safety, and problem-solving. The study identified if there is a significant difference between the digital competencies of public elementary and secondary teachers. It also determined the experiences of public school teachers in using digital technology in preparing lessons and instructional materials, delivering instruction, assessing students’ competencies, and administrative work. The study was conducted in the municipalities of Quezon, Alabat, and Perez; all are located in Alabat Island, Quezon province in the Philippines. In total, 161 public elementary and 115 public secondary teachers participated in this study. Data were gathered through a questionnaire designed by the researcher and validated by education and information technology experts. Findings show that respondents oftentimes utilize digital devices, productivity software, and messaging and social media platforms; while digital learning applications, learning management systems, electronic learning resources, and online meeting platforms are sometimes used. The teachers are highly competent at creating digital material. They are moderately competent in information and digital literacy, online safety, and problem solving; and less competent at communication and collaboration. Furthermore, a significant difference was noted between elementary and secondary school teachers' competencies in communication and collaboration, as well as in digital content development. Regarding information and digital literacy, online safety, and problem-solving, no significant difference in the teachers’ competencies was noted. Finally, the respondents frequently experienced the use of digital technologies in creating lessons and instructional materials, delivering instruction, assessing student competencies, and administrative works.

Single-cell genetic and epigenetic analyses parse the brain’s billions of neurons into thousands of “cell-type” clusters, each residing in different brain structures. Many of these cell types mediate their unique functions by virtue of targeted long-distance axonal projections to allow interactions between specific cell types. Here we have used Epi-Retro-Seq to link single cell epigenomes and associated cell types to their long-distance projections for 33,034 neurons dissected from 32 different source regions projecting to 24 different targets (225 source →target combinations) across the whole mouse brain. We highlight uses of this large data set for interrogating both overarching principles relating projection cell types to their transcriptomic and epigenomic properties and for addressing and developing specific hypotheses about cell types and connections as they relate to genetics. We provide an overall synthesis of the data set with 926 statistical comparisons of the discriminability of neurons projecting to each target for every dissected source region. We integrate this dataset into the larger, annotated BICCN cell type atlas composed of millions of neurons to link projection cell types to consensus clusters. Integration with spatial transcriptomic data further assigns projection-enriched clusters to much smaller source regions than afforded by the original dissections. We exemplify these capabilities by presenting in-depth analyses of neurons with identified projections from the hypothalamus, thalamus, hindbrain, amygdala, and midbrain to provide new insights into the properties of those cell types, including differentially expressed genes, their associated cis-regulatory elements and transcription factor binding motifs, and neurotransmitter usage.

Retrograde monosynaptic tracing using glycoprotein-deleted rabies virus is an important component of the toolkit for investigation of neural circuit structure and connectivity. It allows for the identification of first-order presynaptic connections to cell populations of interest across both the central and peripheral nervous system, helping to decipher the complex connectivity patterns of neural networks that give rise to brain function. Despite its utility, the efficiency with which genetically modified rabies virus spreads retrogradely across synapses remains uncertain. While past studies have revealed conditions that can increase or decrease the numbers of presynaptic cells labeled, it is unknown what proportion of total inputs to a starter cell of interest are labeled. It is also unknown whether synapses that are more proximal or distal to the cell body are labeled with different efficiencies. Here we use a new rabies virus construct that allows for the simultaneous labeling of pre and postsynaptic specializations to quantify efficiency of spread at the synaptic level in mouse primary visual cortex. We demonstrate that with typical conditions about 40% of first-order presynaptic excitatory inputs are labeled. We show that using matched tracing conditions there is similar efficiency of spread from excitatory or inhibitory starter cell types. Furthermore, we find no difference in the efficiency of labeling of excitatory inputs to postsynaptic sites at different subcellular locations.

Cortical circuit tracing using modified rabies virus can identify input neurons making direct monosynaptic connections onto neurons of interest. However, challenges remain in our ability to establish the cell type identity of rabies-labeled input neurons. While transcriptomics may offer an avenue to characterize inputs, the extent of rabies-induced transcriptional changes in distinct neuronal cell types remains unclear, and whether these changes preclude characterization of rabies-infected neurons according to established transcriptomic cell types is unknown. We used single-nucleus RNA sequencing to survey the gene expression profiles of rabies-infected neurons and assessed their correspondence with established transcriptomic cell types. We demonstrated that when using transcriptome-wide RNA profiles, rabies-infected cortical neurons can be transcriptomically characterized despite global and cell-type-specific rabies-induced transcriptional changes. Notably, we found differential modulation of neuronal marker gene expression, suggesting that caution should be taken when attempting to characterize rabies-infected cells with single genes or small gene sets.

Cyanobacterial phycobilisomes are made up from phycobiliproteins held together by linker proteins. Incident photons are absorbed by the phycobiliproteins that carry linear tetrapyrrole chromophores with extended conjugated bond systems. The chemical structure of the chromophores also bestows the phycobiliproteins with excellent radical scavenging and antioxidant properties and phycobiliproteins have pharmaceutical value as such. We purified and characterized the phycobilisome and its major protein constituent C-phycocyanin from the freshwater filamentous cyanobacterium Aphanizomenon gracile. Isolated phycobilisomes were shown to be intact and contained the phycobiliproteins allophyco-cyanin and C-phycocyanin, but not phycoerythrin, together with the classic set of linker proteins. C-phycocyanin could be easily purified and was of analytical grade with spectral characteristics similar to that of other cyanobacterial species. To our best knowledge, this is the first study to report the purification and characterization of the Aphanizomenon gracile phycobilisome and C-phycocyanin.

Background Neosaxitoxin (NeoSTX) and related paralytics shellfish toxins has been successfully used as local anesthetic and muscle relaxants to treat a variety of ailments. The primary mechanism of action of these toxins occurs by blocking voltage-gated sodium channels with compounds such as TTX, lidocaine, or derivatives. However, most of these non-classical sodium channel blockers act with a reduced time effect as well as ensuing neurotoxicity. New method In this report, we show that the use of local NeoSTX injections inactivates the hippocampal neuronal activity reversibly with a by long-term dynamics, without neuronal damage. Results A single 10 ng/μl injection of NeoSTX in the dorsal CA1 region abolished for up to 48 h memory capacities and neuronal activity measured by the neuronal marker c-fos. After 72 h of toxin injection, the animals fully recover their memory capacities and hippocampal neuronal activity. The histological inspection of NeoSTX injected brain regions revealed no damage to the tissue or reactive gliosis, similar to vehicle injection. Acute electrophysiological recording in vivo shows, also, minimal spreading of the NeoSTX in the cerebral tissue. Comparison with existing methods Intracerebral NeoSTX injection showed longer effects than other voltage sodium channel blocker, with minimal spreading and no neuronal damage. Conclusion NeoSTX is a new useful tool that reversibly inactivates different brains region for a long time, with minimal diffusion and without neuronal damage. Moreover, NeoSTX can be used as a valuable sodium channel blocker for many studies in vivo and with potential therapeutic uses.

espanolEl objetivo de este estudio fue analizar la capacidad predictiva de la autoefi cacia academica sobre las dimensiones del autoconcepto en una muestra de 860 estudiantes chilenos. El analisis de regresion logistica revelo que la autoefi cacia academica fue un predictor positivo y signifi cativo de las escalas academicas (Matematicas, Verbal y Academica General), no academicas (Habilidades Fisicas, Apariencia Fisica, Relaciones con el Sexo Opuesto, Relaciones con el Mismo Sexo, Relacion con los Padres, Sinceridad- Veracidad), y de la escala de Autoestima, excepto de la escala de Estabilidad Emocional. Esta relacion de prediccion fue de mayor magnitud con las escalas academicas y autoestima. EnglishThe aim of this study was to analyze the predictive power of academic self-effi cacy on academic self-concept dimensions in a sample of 860 Chilean students. Logistic regression analysis revealed that the academic self-effi cacy was a positive and signifi cant predictor of academic scales (Math, Verbal, and General Academic), not academic (Physical Abilities, Physical Appearance, Relationships with the Opposite Sex, Relationships with the Same Sex, Relationship with Parents, Sincerity-Veracity), and Self- Esteem scale, except for the Emotional Stability scale. The predictive value was stronger in the academic dimensions and self-esteem.

In the last decade, the risk benefits ratio of MHT has been evaluated mainly in terms of cardiovascular risk. Present Consensus Statement is largely inspired by the Global Consensus on Menopausal Hormone Therapy in 2013 and 2016 by leading global menopause societies (The American Society for Reproductive Medicine, The Asia Pacific Menopause Federation, The Endocrine Society, The European Menopause and Andropause Society, The International Menopause Society, The International Osteoporosis Foundation and The North American Menopause Society). The aim of these Recommendations is to provide a simple and updated reference on postmenopausal MHT. The term MHT typically includes estrogen replacement therapy (ERT) and estrogen-progestogen therapy (EPT). EPT can be sequential (Seq) when progestogen is added to ERT for 10-14 days a month, or continuous combined (CC) when progestogen is administered continuously every day along with a fixed amount of estrogen. MHT also includes Tibolone and the Tissue Selective Estrogen Complex (TSEC).

The optical absorption of nanowire arrays is calculated with the rigorous coupled wave analysis. The effect of different parameters such as periodicity, filling ratio and thickness are studied. There are potential applications of these arrays for photovoltaic applications and there are experiments on Si nanowire arrays. For that reason the main objective of this study is to find the maximum absorption of nanowire arrays over a frequency area that covers the visible spectrum. There is a random location and orientation of the nanowires in those experiments. For that reason the effect of disorder in the absorption results is also examined. Although, the main focus of this study is Si nanowires, other materials are also calculated.

Numerical investigation of a sensor based on a two micro disk system is performed with the finite difference time domain method. The results show that this two micro disk system is able to detect single nanoparticles unlike a similar one micro disk sensor. The sensitivity of this system relative to the gap between the micro disks, their thickness, and the surrounding media is also investigated.

The additive EuroSCORE system for predicting operative mortality of cardiac patients tends to underestimate the mortality risk of high risk patients and concomitantly to overestimate that of low risk patients. We propose a modification of stratification groups aiming at improving its precision. We also tested its ability to predict the length of postoperative mechanical ventilation of our patients.The high risk group of the EuroSCORE system (6 points) was divided into three additional groups (group I: 0-2 points, group II: 3-5 points, group III: 6-8 points, group IV: 9-13 points, group V:14 points) thus producing a 5 classes system. In a group of 301 cardiac surgery patients operated on in a low volume cardiac center, we calculated the expected mortality rate for each EuroSCORE class, the calibration of the modified scoring system, the ROC and the corresponding AUC values and the relative risk of each predisposing factor used by the original EuroSCORE sytem.The proposed modification increased the discrimination ability of EuroSCORE in predicting mortality (Hosmer-Lemeshow P=0.78, ROC size: 0.791) and marginally affected its accuracy in predicting length of postoperative mechanical ventilation (Hosmer-Lemeshow: 0.11, ROC size: 0.711). Combined operations of CABG and valve replacement were shown to exert a statistically significant effect on mortality (odds ratio 3.85, CI: 1.15-12.87, P=0.028).The proposed modification of additive EuroSCORE can presumably increase its discrimination ability in predicting mortality of cardiac patients handled in a low volume cardiac center. The need for prolonged mechanical ventilation could be predicted with acceptable accuracy, possibly providing support in resource management.

This paper shows how product lifecycle information can be utilized to assist people engaged in product lifecycle tasks, in particular those concerned with product support. A progression of product data management methods based on knowledge engineering techniques is presented to allow the creation and delivery of effective, personalized performance support information. The product data management methods discussed include semantic hypermedia authoring, automated construction of product documentation, automated diagnostic module construction, and adaptive product support generation. These methods are utilized to improve the performance of product lifecycle actors, while reducing the time, knowledge, and input required from them, through increased task support and automation.

Zika virus (ZIKV) is an emerging mosquito-borne flavivirus circulating in Asia and Africa. In 2013, a large outbreak was reported on the archipelago of French Polynesia. In this study, we report the detection and molecular characterization of Zika virus for the first time in Chile from an outbreak among the inhabitants of Easter Island. A total of 89 samples from patients suspected of having ZIKV infection were collected between the period from January to May, 2014. Molecular diagnosis of the virus was performed by RT-PCR followed by the sequencing of the region containing the NS5 gene. A comparison of the viral nucleic acid sequence with those of other strains of ZIKA virus was performed using the MEGA software. Fifty-one samples were found positive for ZIKV by RT-PCR analysis. Further analysis of the NS5 gene revealed that the ZIKV strains identified in Easter Island were most closely related to those found in French Polynesia (99.8 to 99.9% nt and 100% aa sequence identity). These results strongly suggest that the transmission pathway leading to the introduction of Zika virus on Easter Island has its origin in French Polynesia.

The impact of an endurance race on pulmonary pro-oxidative formation and lipoperoxidation was evaluated using exhaled breath condensate (EBC). 3 groups of 12, 12 and 17 healthy recreational runners of both sexes ran 10, 21.1 and 42.2 km, respectively. EBC samples were obtained before the run and at 20 and 80 min post run. Concentrations of H 2 O 2 , NO 2 − , malondialdehyde and pH were determined. The 10 km group showed no post-run variations for H 2 O 2 and NO 2 − concentrations. The 21.1 km group showed significant increments for NO 2 − , and H 2 O 2 concentrations in 20 min and 80 min samples. The 42.2 km group, showed increased NO 2 − concentration in 20 min and 80 min samples, while H 2 O 2 concentration increased only in the 20 min sample. In the 10 and 42.2 km groups neither malondialdehyde concentration nor pH showed differences. The 42.2 km group exhibited ΔH 2 O 2 and ΔNO 2 − medians higher than the 10 km group. ΔpH median decreased in 21.1 and 42.2 km groups, exhibiting values significantly lower than the 10 km group. ΔH 2 O 2 y ΔNO 2 − correlated directly with race time, while ΔpH, correlated inversely. In conclusion, intense prolonged exercise favors the increase in pulmonary pro-oxidative levels, with no modifications on lipoperoxidation. Running time relates to the magnitude of acute post exercise pro-oxidative formation.

We derive analytical expressions for the absorption enhancement expected when dilute suspensions of small metallic nanoparticles are inserted inside an organic semiconductor. A comparison with accurate numerical simulations shows excellent agreement for a wide range of volume filling ratios and even in the case of mixing different types of metals. These results are invaluable tools in optimizing the absorption performance of plasmonic thin-film organic solar cells. (C) 2011 American Institute of Physics. [doi:10.1063/1.3623759] Applied Physics Letters

The goal of this paper is to promote a new research area named Computational Imagination, which is defined as the science of modeling human imagination by creating artificial agents with intelligence, emotions and imagination. The new discipline aims to (i) study the interplay between cognition, emotion and imagery, (ii) analyze the way perceptions, emotions, prior knowledge and context influence imagination, and (iii) design agents capable of forming concepts and images of something that is neither perceived nor sensed as real, and of dealing with the reality by using the creative power of their imagination. The paper outlines some of the most challenging and intriguing research questions, and directions for further research.

Compared to other product lifecycle phases, the development of product documentation and technical manuals in particular, is an area currently undersupported by tools. This is in contrast with the benefits associated with the production of high quality product documentation, and the effort involved to produce it. This paper addresses this problem by proposing three complementary semantic-based methods for modeling product manuals. The first approach is based on using semantically linked information objects. The second approach focuses on abstracting the intended purpose, user tasks and the functional characteristics of the product data elements. The third approach uses ontologies to capture the semantic complexity of the product support domain.

Authoring of technical documentation is a knowledge-intensive activity that requires knowledge of various domains and information from several product life-cycle phases. This paper presents two complementary semantic-based methods for creating product support documentation and delivering it to the user. The first approach is based on using concurrent engineering and product data management (PDM) technology. The second approach uses ontologies to capture the semantic complexity of the product support domain. Promising direction for further research is the integration of these two approaches.

Publisher Summary This chapter discusses and defines product support knowledge. Product support can be analyzed in terms of the tasks involved. A task is defined as a strategy, which is followed in order to achieve a specific goal and can be decomposed into several subtasks, and actions. An action is a primitive operation needed for a task to take place. The first step towards developing product support that is up-to-date, accurate, coherent, and personalized is to define the knowledge contained within a product support system. The chapter analyzes product support from a task-based point of view and introduces the concept of a PRoduct Support System (PRSS). It then outlines the constituents that form product support knowledge and illustrates their definitions. Finally, the chapter states that semantically rich models are needed in order to express the multidimensionality of product support knowledge.

Lung oxidative stress (OS) was explored in resting and in exercising subjects exposed to moderate and high altitude. Exhaled breath condensate (EBC) was collected under field conditions in male high-competition mountain bikers performing a maximal cycloergometric exercise at 670 m and at 2,160 m, as well as, in male soldiers climbing up to 6,125 m in Northern Chile. Malondialdehyde concentration [MDA] was measured by high-performance liquid chromatography in EBC and in serum samples. Hydrogen peroxide concentration [H(2)O(2)] was analysed in EBC according to the spectrophotometric FOX(2) assay. [MDA] in EBC of bikers did not change while exercising at 670 m, but increased from 30.0+/-8.0 to 50.0+/-11.0 nmol l(-1) (P

This paper presents a state-of-the-art review of reconfigurability and reconfigurable manufacturing systems. Reconfigurability is defined as the ability to repeatedly change and rearrange the components of a system in a cost-effective way. This concept is illustrated through its application in computing, automated assembly and robotics. Then, the evolution of manufacturing, from dedicated to flexible manufacturing systems, is briefly discussed and the need for reconfigurable manufacturing systems is outlined. These are further studied by analysing their key features (modularity, integrability, customisation, convertibility, and diagnosability) and challenges (product variability, responsiveness, nonobsolescence, cost-effectiveness, reliability and simplicity). It is shown that there are common research issues in reconfigurable computing, robotics and manufacturing such as system-module-component interfaces, design methodologies, modularity, tools and toolsuites development, strategic analysis and business modelling, training, and support. Finally, the research priorities of the I*PROMS Network of Excellence in the area of reconfigurable manufacturing are outlined

Protein phosphatases are involved in many cellular processes. One of the most abundant and best studied members of this class is protein phosphatase type-2A (PP2A). In this study, PP2A was purified from the mussel Mytilus chilensis. Using both SDS-PAGE and size exclusion gel filtration under denaturant conditions, it was confirmed that the PP2A fraction was essentially pure. The isolated enzyme is a heterodimer and the molecular estimated masses of the subunits are 62 and 28 kDa. The isolated PP2A fraction has a notably high p-NPP phosphatase activity, which is inhibited by NaCl. The hydrolytic p-NPP phosphatase activity is independent of the MgCl2 concentration. The time courses of the inhibition of the PP2A activity of p-NPP hydrolysis by increasing concentrations of three phycotoxins that are specific inhibitors of PP2A are shown. Inhibitions caused by Okadaic acid, dinophysistoxin-1 (DTX1, 35-methylokadiac acid) and Microcystine L-R are dose-dependent with inhibition constants (Ki) of 1.68, 0.40 and 0.27 nM respectively. Microcystine L-R, the most potent phycotoxin inhibitor of PP2A isolated from Mytilus chilensis with an IC50 = 0.25 ng/ml, showed the highest specific inhibition effect an the p-NPP hydrolisis. The calculated IC50 for DTX1 and OA was 0.75 ng/ml and 1.8 ng/ml respectively.

Traditionally performance support and e-Learning have been considered as two separate research fields. This paper integrates them by introducing the concept of context-aware product support systems, which utilizes the notions of context, information object and ontology. The context signifies whether learning or performing goals are pursued in different situations and defines the configuration of the domain knowledge accordingly. An information object is viewed as an enabler of a modular virtual documentation, advancing information reuse. The ontology formalizes the representation of the knowledge contained in the system, facilitates interoperability, and constitutes one of the main building blocks of context-aware product support systems. The prototype system developed illustrates the applicability of the approach.

The hypothesis that intracellular [Ca2+] is a cell parameter responsive to extreme temperatures in rat meiotic and postmeiotic spermatogenic cells was tested using intracellular fluorescent probes for Ca2+ and pH. In agreement with this hypothesis, extreme temperatures induced a rapid increase of cytosolic [Ca2+] in rat pachytene spermatocytes and round spermatids. Oscillatory changes in temperature can induce oscillations in cytosolic [Ca2+] in these cells. Intracellular [Ca2+] homeostasis in round spermatids was more sensitive to high temperatures compared with pachytene spermatocytes. The calculated activation energies for SERCA ATPase-mediated fluxes in pachytene spermatocytes and round spermatids were 62 and 75 kJ mol(-1), respectively. The activation energies for leak fluxes from intracellular Ca2+ stores were 55 and 68 kJ mol(-1) for pachytene spermatocytes and round spermatids, respectively. Together with changes in cytosolic [Ca2+], round spermatids undergo a decrease in pH(i) at high temperatures. This temperature-induced decrease in pH(i) appears to be partially responsible for the increase in cytosolic [Ca2+] of round spermatids induced by high temperatures. This characteristic of rat meiotic and postmeiotic spermatogenic cells to undergo an increment in cytosolic Ca2+ at temperatures > 33 degrees C can be related to the induction of programmed cell death by high temperatures in these cells.

Studies have shown a promoting effect of food on small intestinal absorption. Casein hydrolysate seems be more effective in increasing of D-xylose absorption in dogs than the whole protein and lactulose. The purpose this study was to analyze the effect of groups of peptides derived from casein hydrolysate on the absorption of D-Xylose and intestinal transit time in normal subjects. Seven normal volunteers participated in the study. Three peptide fractions were isolated from casein enzymatic hydrolysate by means of a preparative HPLC silica column. On separate days subjects drank test solutions containing lactulose, D-xylose, and D-xylose with one of three peptide groups. The hydrogen breath test was used to indirectly estimate D-xylose absorption and orocecal transit time. Two peptide fractions when added to D-xylose were followed by an increased absorption characterized by decreased H2 production. A nonstatistically significant increase of orocecal transit time was observed with these peptides.

Ecological and health problems posed by microalgal blooms (red tides) occurring in the Southern part of Chile are reviewed. Out of the six human illnesses provoked by microalgal toxins, paralytic shellfish poisoning is the most important, because of its high mortality rate and the high levels of phycotoxins found in contaminated molluscs. Saxitoxin and its analogues bind to a receptor in the voltage-gated sodium channel of neural membranes. The most important toxin-producer microalgae are Alexandrium catenella and Dinophysis acuta. Phycotoxins become concentrated by filter-feeding shellfish, like Mytilus chilensis. Highly sensitive methods available for detection of microalgal toxins are analyzed.

The presence of food in the intestinal lumen increases absorption from an isolated intestinal loop, the mechanisms involved are unknown. Casein, and its respective hydrolysate, increased D-xylose absorption in both normal volunteers and experimental animals; this effect was associated with prolonged small intestinal transit time and a decrease of motor activity.To separate from casein hydrolysate, groups of peptides and to investigate their effects on both D-xylose absorption and small intestinal motility.Studies were performed on five dogs with a surgically implanted duodenal cannula. Three groups of peptides were separated by means of a Silica Gel 60 column and were continuously infused through the duodenal cannula. After 15 min, 5 g of D-xylose were injected in the duodenum, plasma levels were measured, and the area under the curve was estimated. Motility was recorded by means of infused catheters and external transducers.Plasma levels of D-xylose were significantly increased during the infusion of one group of peptides compared to the others. In addition, the area under the curve: 3366 +/- 885 mg x min-1 observed with this group was significantly greater than the other two groups: 1432 +/- 183 mg x min-1 and 1137 +/- 280 mg x min-1 respectively. No statistically significant differences in motor activity were observed between the different groups of peptides.A group of peptides derived from casein was characterized by increasing D-xylose absorption. The presence of beta casomorphines might be the possible mechanism involved.

Major intrinsic polypeptide (MIP), a 28-kDa protein isolated from lens fiber cell membranes, forms large, nonselective channels when reconstituted into lipid bilayers. MIP channels are regulated by voltage, such that these channels close when the potential across the membrane is greater than 30 mV. We have investigated the modulation of the voltage-dependent closure of MIP channels by phosphorylation. In this report, we describe the isolation of two isomers of MIP from lens fiber cell membranes. These isomers differ by a single phosphate at a protein kinase A phosphorylation site. The phosphorylated isomer produces channels that close in response to applied voltages when reconstituted into bilayers. The nonphosphorylated isomer produces voltage-independent channels. Direct phosphorylation with protein kinase A converts voltage-independent channels to voltage-dependent channels in situ. Analyses of macroscopic and single-channel currents suggest that phosphorylation increases the voltage-dependent closure of MIP channels by increasing closed channel lifetimes and the rate of channel closure following the application of voltage.

Incubation of human peripheral blood lymphocytes (PBL) in the presence of interleukin-2 results in the generation of lymphokine-activated killer (LAK) cells that are highly cytotoxic to a variety of autologous and allogenic tumor targets. We have identified a noncytotoxic, soluble factor, produced by human squamous cell cancers of the head and neck, that profoundly inhibits the generation of LAK cytotoxicity. Inhibition of the generation of cytotoxicity was demonstrated with coculture of PBL and freshly disaggregated tumor cells in a Transwell two-chamber system. Alternatively, inhibition occurred when LAK cells were generated in the presence of tumor-conditioned supernatants alone. These effects were not observed with conditioned supernatants from autologous or allogenic lymphocytes, human fibroblasts, or the erythroleukemia cell line K562. The presence of this inhibitory factor(s) was not required during the entire period of LAK generation. Suppression of cytotoxicity, measured after 4 days of LAK generation, could also be demonstrated when the conditioned tumor supernatant was present in only the last 24 hours of incubation. Suppression is mediated by a heat-labile factor with a molecular weight of greater than 75 kd. These results suggest that LAK cytotoxicity may be significantly impaired by soluble immunoregulatory factors present within the tumor milieu of squamous cell carcinomas of the head and neck. Further characterization of these factors may lead to the development of more rational and effective forms of immunotherapy.

Objectives: To asses the implementation of antenatal screening for Down syndrome using individual risk estimates based on maternal age, nuchal translucency and three serum markers; alpha fetoprotein, unconjugated estriol and human chorionic gonadotrophin (hCG) in maternal blood. Women with an estimated risk of 1 in 250 or greater were classified as screen positive and offered diagnostic amniocentesis. Subjects: A total of 1956 women of all ages with singleton pregnancies seen between June 1999 and March 2001. Results: The screening result of combination of first trimester ultrasonographic and serum screening was 85% Down syndrome detection and the false positive rate was 3%. The median gestational age of nuchal translucency was 11 weeks and the time of serum screening was 16 weeks. Conclusion: The combination of nuchal translucency and serum screening increases the Down syndrome detection and decreases the false positive rate. Is very important because the amniocentesis is associated with a risk of pregnancy loss from 0.5 to 1%. Besides, it is cost-effective and performs better than the selection for amniocentesis on the basis of maternal age only, nuchal translucency only or serum screening.

Objective Congenital complete heart block (CCHB) affects 1:20.000 live births. This condition reappears in 18–24% of future pregnancys. 50% of the fetuses have a structural cardiac anomalies. It may present isolated or in mothers with autoinmune disease, or positive anti-Ro (SSA) and anti-La (SSB) antibodies. Our purpose is to show the improvement in perinatal outcome using 2D echocardiografy and foetal Doppler to diagnose CCHB in the prenatal period. Case report We present a 36-year-old female patient with 2 previous stillborns due to CCHB. She was positive for anti SSA and anti SSB antibodies and was evaluated for the first time at 22 weeks of her third pregnancy. An Echography showed foetal hydrops, and echocardiography showed an anatomically normal heart, with a complete heart block. The atrial rate was 120/min. and the ventricular rate was 60/min. Treatment was started with dexametasone 4 mg/day, salbutamol 12 mg/day and Sandoglubulin (Novartis) 400 mg/kg. Following sonographys showed resolution of fetal hydrops, improvement in cardiac function and cardiac rates. Cesarian section at 34 weeks, newborn 2420 g. At day 7 a permanent pacemaker was implanted. Conclusions Fetal echocardiography is the best method to diagnose and treat CCHB in the prenatal period. The use of glucocorticoids, betamimetics and immunoglobulins has shown to be of benefit.

Background Schizencephaly is a rare congenital malformation of the central nervous system. It consists in the finding of unilateral or bilateral clefts in the cerebral hemispheres. Case report 36-year-old patient, at week 22, an ultrasound showed hydrocephaly with a 19-mm atrium. At week 27, a 6-mm diameter defect was shown in the cerebral parenchyma of the right hemisphere, that was comunicated with the lateral ventricle, with normal atrium. The conclusion was Schizencephaly. Magnetic resonance imaging (MRI) also showed the parenchymal defect, with comunication to the lateral ventricle, and no hydrocephalus. Cesarian section was performed at week 38, with a 2780 g. Newborn Postnatal echography and computed tomography showed no changes. Discussion Two types of schizencephaly have been described: Type I, in which the defect is closed-lip, because the lips of the clefts are fused within a pia-ependymal seam that is continous with the ependyma of the lateral ventricle, and type II, in which the lips remain open, and the clefts are more extensive. Pathogenesis is unclear but anomalies of neuronal migration during the third to fifth gestational months are invoked. Clinically, patients have seizures, developmental delay and hemiparesias. In this case, diagnosis was suspected by ultrasound and confirmed by MRI, which is the best method. Ultrasound permited us to follow the defect and best decide when to interrupt pregnancy.

Rat brain cortex synaptic vesicles have been isolated by 3 different procedures. The one of Hata et al. (J. Neurochem., 27 (1976) 139) gave synaptic vesicles with a high glutamate content, but also, as judged by [3H]ouabain binding and electron microscopy, with considerable contamination by plasma membrane vesicles. This did not allow a precise estimation of the glutamate content of each synaptic vesicle. The second procedure used (Life Sci., 21 (1977) 1075), in which the tissue is homogenized with an all glass homogenizer, yielded vesicles of higher purity, but with no glutamate. A slightly modified Kadota and Kadota procedure (J. Cell Biol., 58 (1973) 135) gave synaptic vesicles of a very high purity that were filtered on a Sepharose 4B column, and there, the synaptic vesicle fraction of highest purity was estimated to contain 3640 glutamate molecules in each glutamatergic vesicle. This is equivalent to an intravesicular concentration of 0.21 M, that is, at least 10 times higher than the glutamate concentration in the rat brain cortex.