Adaptación lingüística y cultural del Oxford Cognitive Screen (OCS) en población española / Cultural and linguistic adaptation of the Oxford Cognitive Screen to the Spanish population

Introducción: En España el ictus es la sexta causa de discapacidad. Sus secuelas producen alteraciones motoras, sensoriales y cognitivas, que pueden minimizarse con una actuación terapéutica temprana. Por ello se necesitan instrumentos de evaluación rápida que detecten déficits en estas áreas. El Oxford Cognitive Screen Test (OCS) es un test breve diseñado para la valoración de funciones cognitivas en pacientes con ictus. Nuestro objetivo fue generar una versión española (OCS-E) realizando una adaptación lingüística y cultural.Material y métodosDiseño de validación lingüística con doble traducción y 10 reuniones de consenso del equipo investigador multidisciplinar. Tres estudios piloto administrando el test respectivamente a 5 usuarios potenciales, 23 personas sanas y 23 diagnosticadas de ictus isquémico (61%) o hemorrágico, con edades entre 31-88 años.ResultadosEl OCS-E mantiene las 10 tareas originales, la codificación de respuestas y el sistema de puntuación. Se modificaron y ampliaron las instrucciones de administración, lo que asegura la fiabilidad del contenido y de su aplicación. En 5 tareas se han modificado imágenes, números y frases. La tarea praxia se amplió para evaluar ambos miembros superiores. Los estudios piloto confirmaron que las personas de la población diana comprendían de forma adecuada las tareas, con independencia de la existencia de problemas cognitivos.ConclusionesLa adaptación cultural ha generado una versión lingüística y conceptualmente equivalente, permitiendo su estudio psicométrico y posterior aplicación en población española. El OCS-E puede ser un instrumento de cribado útil para evaluación rápida de funciones cognitivas postictus. (AU)

Introduction: Stroke is the sixth leading cause of disability in Spain. Patients may present motor, sensory, or cognitive sequelae, which can be minimised with early treatment. To this end, there is a need for quick-to-administer assessment tools to evaluate deficits in these areas. The Oxford Cognitive Screen (OCS) is a brief test specifically designed to assess cognitive function in patients with stroke. Our aim in this study is to report the linguistic and cultural adaptation of a Spanish-language version of the test (OCS-S).Material and methodsThe linguistic validation was conducted with a process of double translation and 10 consensus meetings of the multidisciplinary research team. We also performed 3 pilot studies, with 5 potential users, 23 healthy individuals, and 23 patients with stroke (ischaemic in 61% of cases and haemorrhagic in 39%), respectively; participants were aged between 31 and 88 years.ResultsThe OCS-S includes the 10 subtests, the coding of responses, and the scoring system from the original version. We modified and extended the instructions for administration in order to ensure the reliability of the content and its application. Five tasks were modified (images, numbers, and sentences) and the praxis subtest was modified to evaluate both hands. The pilot studies confirmed comprehension in the target population, independently of any cognitive problems.ConclusionsThe OCS-S is conceptually and linguistically equivalent to the original test, enabling psychometric assessment and application of the test in the Spanish population. The OCS-S may be a useful screening tool for quickly assessing cognitive function after stroke. (AU)

Psychometric properties of the Spanish version of the Frontal Assessment Battery (FAB-E) and normative values in a representative adult population sample.

BACKGROUND: The Frontal Assessment Battery is a short bedside test used to assess executive functions (EF). The aims of the present study were, first, to evaluate the psychometric proprieties of the Spanish version of the FAB (FAB-E) in a representative sample, and second, to establish cut-off points for impairment in executive function according to age and education level. METHODS: A sample of 798 healthy Spanish adult subjects aged 19 to 91 participated in this study. Neuropsychological assessment of participants was conducted using the FAB-E, Mini-Mental State Examination (MMSE) and Trail Making Test (TMT). We examined internal consistency, intraclass correlation, test-retest reliability, and concurrent and divergent validity. In addition, we established a cut-off point for detecting executive function impairment based on the 5th percentile by age group and education level. RESULTS: The analysis of the psychometric properties of the FAB-E showed good internal consistency (Cronbach's α = 0.60), intraclass correlation (0.72), test-retest reliability (0.70) and concurrent and divergent validity between the TMT (r = -0.523), MMSE (r = 0.426) and the FAB-E. The cut-off points for each age group were 16 points for the ≤ 29 group, 15 points for the 30-39 group, 14 points for the 40-49 and 50-59 groups, 12 points for the 60-69 group, and 10 points for the ≥ 70 age group. CONCLUSIONS: The psychometric analysis showed that the FAB-E has good validity and reliability. Thus, FAB-E may be a helpful tool to evaluate EF in a healthy Spanish population. In addition, this study provides information on reference data that will be very valuable for clinicians and researchers.

Cultural and linguistic adaptation of the Oxford Cognitive Screen to the Spanish population.

INTRODUCTION: Stroke is the sixth leading cause of disability in Spain. Patients may present motor, sensory, or cognitive sequelae, which can be minimised with early treatment. To this end, there is a need for quick-to-administer assessment tools to evaluate deficits in these areas. The Oxford Cognitive Screen (OCS) is a brief test specifically designed to assess cognitive function in patients with stroke. Our aim in this study is to report the linguistic and cultural adaptation of a Spanish-language version of the test (OCS-S). METHODS: The linguistic validation was conducted with a process of double translation and 10 consensus meetings of the multidisciplinary research team. We also performed 3 pilot studies, with 5 potential users, 23 healthy individuals, and 23 patients with stroke (ischaemic in 61% of cases and haemorrhagic in 39%), respectively; participants were aged between 31 and 88 years. RESULTS: The OCS-S includes the 10 subtests, the coding of responses, and the scoring system from the original version. We modified and extended the instructions for administration in order to ensure the reliability of the content and its application. Five tasks were modified (images, numbers, and sentences) and the praxis subtest was modified to evaluate both hands. The pilot studies confirmed comprehension in the target population, independently of any cognitive problems. CONCLUSION: The OCS-S is conceptually and linguistically equivalent to the original test, enabling psychometric assessment and application of the test in the Spanish population. The OCS-S may be a useful screening tool for quickly assessing cognitive function after stroke.

Animal and human RNA viruses: genetic variability and ability to overcome vaccines.

RNA viruses, in general, exhibit high mutation rates; this is mainly due to the low fidelity displayed by the RNA-dependent polymerases required for their replication that lack the proofreading machinery to correct misincorporated nucleotides and produce high mutation rates. This lack of replication fidelity, together with the fact that RNA viruses can undergo spontaneous mutations, results in genetic variants displaying different viral morphogenesis, as well as variation on their surface glycoproteins that affect viral antigenicity. This diverse viral population, routinely containing a variety of mutants, is known as a viral 'quasispecies'. The mutability of their virions allows for fast evolution of RNA viruses that develop antiviral resistance and overcome vaccines much more rapidly than DNA viruses. This also translates into the fact that pathogenic RNA viruses, that cause many diseases and deaths in humans, represent the major viral group involved in zoonotic disease transmission, and are responsible for worldwide pandemics.

La utilización de pilares transmucosos definitivos de colocación inmediata / The use of immediate placement of definitive transmucosal abutments

El uso de pilares de cicatrización transmucosos previos a la colocación del pilar protésico definitivo es una técnica que se ha desarrollado durante muchos años en la implantología clásica. La desconexión y conexión de forma repetida de estos pilares o aditamentos dan lugar a una respuesta ósea negativa que se manifiesta en forma de pérdida de hueso a nivel de la cresta marginal, acompañada por una migración apical de tejidos blandos. Este artículo pretende realizar una revisión de la literatura del estado actual del uso de los pilares transmucosos definitivos con colocación inmediata el día de la inserción de los implantes y el mantenimiento del sellado biológico, minimizando la pérdida ósea periimplantaria y remodelando de forma adecuada los tejidos blandos adyacentes, frente al protocolo tradiciónal del uso de aditamentos que se desconectan en multiples ocasiones produciendo pérdida ósea periimplantaria. La evidencia científica sugiere que los mejores resultados biológicos, estéticos y funciónales se consiguen con el uso del pilar definitivo colocado de forma inmediata a la inserción del implante, especialmente en implantes colocados de forma yuxtacrestal y en implantes postextracción

The use of transmucosal healing abutments before the placement of the definitive prosthetic abutment is a technique that has been developed for many years in classical implantology. Repeated disconnection and connection of theses abutments result in a negative bone response that manifests as bone loss at the marginal ridge level, accompanied by apical soft tissue migration. This article aims to review the current status in the scientific literature of the use of the definitive transepithelial abutments with immediate placement on the day of implant insertion and maintenance of the biological seal, minimizing peri-implant bone loss and adequately remodeling the adjacent soft tissues, compared to the traditional protocol of the use of abutments that are disconnected on multiple occasions producing peri-implant bone loss. Scientific evidence suggests that the best biological, aesthetic, and functional results are achieved with the use of the definitive abutment placed immediately after implant insertion, especially in yuxtacrestal implants and post-extraction implants

Prokaryotic sigma factors and their transcriptional counterparts in Archaea and Eukarya.

RNA polymerases (RNAPs) carry out transcription in the three domains of life, Bacteria, Archaea, and Eukarya. Transcription initiation is highly regulated by a variety of transcription factors, whose number and subunit complexity increase during evolution. This process is regulated in Bacteria by the σ factor, while the three eukaryotic RNAPs require a complex set of transcription factors (TFs) and a TATA-binding protein (TBP). The archaeal transcription system appears to be an ancestral version of the eukaryotic RNAPII, requiring transcription factor B (TFB), TBP, and transcription factor E (TFE). The function of the bacterial sigma (σ) factor has been correlated to the roles played by the eukaryotic RNAP II and the archaeal RNAP. In addition, σ factors, TFB, and TFIIB all contain multiple DNA binding helix-turn-helix (HTH) structural motifs; although TFIIB and TFB display two HTH domains, while the bacterial σ factor spans 4 HTH motifs. The sequence similarities and structure alignments of the bacterial σ factor, eukaryotic TFIIB, and archaeal TFB evidence that these three proteins are homologs.Key Points• Transcription initiation is highly regulated by TFs.• Transcription is finely regulated in all domains of life by different sets of TFs.• Specific TFs in Bacteria, Eukarya and Archaea are homologs.

Cultural and linguistic adaptation of the Oxford Cognitive Screen to the Spanish population. / Adaptación lingüística y cultural del Oxford Cognitive Screen (OCS) en población española.

INTRODUCTION: Stroke is the sixth leading cause of disability in Spain. Patients may present motor, sensory, or cognitive sequelae, which can be minimised with early treatment. To this end, there is a need for quick-to-administer assessment tools to evaluate deficits in these areas. The Oxford Cognitive Screen (OCS) is a brief test specifically designed to assess cognitive function in patients with stroke. Our aim in this study is to report the linguistic and cultural adaptation of a Spanish-language version of the test (OCS-S). MATERIAL AND METHODS: The linguistic validation was conducted with a process of double translation and 10 consensus meetings of the multidisciplinary research team. We also performed 3 pilot studies, with 5 potential users, 23 healthy individuals, and 23 patients with stroke (ischaemic in 61% of cases and haemorrhagic in 39%), respectively; participants were aged between 31 and 88 years. RESULTS: The OCS-S includes the 10 subtests, the coding of responses, and the scoring system from the original version. We modified and extended the instructions for administration in order to ensure the reliability of the content and its application. Five tasks were modified (images, numbers, and sentences) and the praxis subtest was modified to evaluate both hands. The pilot studies confirmed comprehension in the target population, independently of any cognitive problems. CONCLUSIONS: The OCS-S is conceptually and linguistically equivalent to the original test, enabling psychometric assessment and application of the test in the Spanish population. The OCS-S may be a useful screening tool for quickly assessing cognitive function after stroke.

Nucleus incertus ablation disrupted conspecific recognition and modified immediate early gene expression patterns in 'social brain' circuits of rats.

Social interaction involves neural activity in prefrontal cortex, septum, hippocampus, amygdala and hypothalamus. Notably, these areas all receive projections from the nucleus incertus (NI) in the pontine tegmentum. Therefore, we investigated the effect of excitotoxic lesions of NI neurons in adult male, Wistar rats on performance in a social discrimination test, and associated changes in immediate-early gene protein levels. NI was lesioned with quinolinic acid, and after recovery, rats underwent two trials in the 3-chamber test. In the first trial, NI-lesioned and sham-lesioned rats spent longer exploring a conspecific than an inanimate object. By contrast, in the second trial, NI-lesioned rats visited the familiar and novel conspecific chambers equally, whereas sham-lesioned rats spent longer engaging with the novel rat. Quantification of Fos- and Egr-1-immunoreactivity (IR) levels in brain areas implicated in social behaviour, revealed that social encounter and NI lesion produced complex, differential changes. For example, Egr-1-IR was broadly decreased in several amygdala nuclei in NI-lesioned rats relative to sham, but Fos-IR levels were unaltered. In hippocampus, NI-lesioned rats displayed decreased Fos-IR in CA2 and CA3, while Egr-1-IR was increased in the polymorphic dentate gyrus, CA1, CA2 and subiculum of NI-lesioned rats, relative to sham. Social encounter-related Egr-1-IR was also decreased in septum and anterior and lateral hypothalamus of NI-lesioned rats. Overall, these data suggest NI networks can modulate the activity of sensory, emotional and executive brain areas involved in social recognition, with a likely involvement of neuronal Egr-1 activation in amygdala, septum and hypothalamus, and Erg-1 inhibition in hippocampus.

A short voyage into the past: former misconceptions and misinterpretations in the etiology of some viral diseases.

The advancement of human knowledge has historically followed the pattern of one-step growth (the same pattern followed by microorganisms in laboratory culture conditions). In this way, each new important discovery opened the door to multiple secondary breakthroughs, eventually reaching a "plateau" when new findings emerged. Microbiology research has usually followed this pattern, but often the conclusions attained from experimentation/observation were either equivocal or altogether false, causing important delays in the advancement of this science. This mini-review deals with some of these documented scientific errors, but the aim is not to include every mistake, but to select those that are paramount to the advance of Microbiology.

Phenotypic and molecular characterization of Klebsiella spp. isolates causing community-acquired infections.

Klebsiella spp. isolates from community-acquired infections were characterized. A total of 39 Klebsiella spp. isolates were obtained from outpatients at four rural hospitals in Mexico (2013-2014). The biochemical tests identified all as being K. pneumoniae. The molecular multiplex-PCR test identified 36 (92.4%) K. pneumoniae isolates and one (2.5%) K. variicola isolate, and phylogenetic analysis of the rpoB gene identified two isolates (5.1%) belonging to K. quasipneumoniae subsp. quasipneumoniae and K. quasivariicola. The last one was confirmed by phylogenetic analysis of six-loci concatenated genes. Mostly the isolates were multidrug resistant; however, a minority were extended-spectrum ß-lactamase producing (10.2%). The extended-spectrum ß-lactamase CTX-M-15 gene was identified in these isolates. Analysis of biofilm production and the hypermucoviscosity phenotype showed a total of 35 (92.3%) and seven (17.9%) of the isolates were positive for these phenotypes respectively. The K2 (4/39, 10.2%), K5 (2/39, 5.1%) and K54 (1/39, 2.5%) serotypes were identified in seven (17.9%) of the isolates, and only 28.5% (2/7) hypermucoviscous isolates were positive for the K2 and K5 serotypes. In general, the sequence type (ST) analysis and phylogenetic analysis of seven multilocus sequence typing loci were heterogeneous; however, ST29 was the most prevalent ST in the analysed isolates, accounting for 19% (4/21) of the total isolates. Two of the four ST29 isolates had the hypermucoviscosity phenotype. The virulence factors for fimbriae were the most prevalent, followed by siderophores. Community-acquired infections are caused by various species from Klebsiella genus, with different profiles of antibiotic resistance and heterogeneous virulence factors.

Osseointegration mechanisms: a proteomic approach.

The prime objectives in the development of biomaterials for dental applications are to improve the quality of osseointegration and to short the time needed to achieve it. Design of implants nowadays involves changes in the surface characteristics to obtain a good cellular response. Incorporating osteoinductive elements is one way to achieve the best regeneration possible post-implantation. This study examined the osteointegrative potential of two distinct biomaterials: sandblasted acid-etched titanium and a silica sol-gel hybrid coating, 70% MTMOS-30% TEOS. In vitro, in vivo, and proteomic characterisations of the two materials were conducted. Enhanced expression levels of ALP and IL-6 in the MC3T3-E1 cells cultured with coated discs, suggest that growing cells on such surfaces may increase mineralisation levels. 70M30T-coated implants showed improved bone growth in vivo compared to uncoated titanium. Complete osseointegration was achieved on both. However, coated implants displayed osteoinductive properties, while uncoated implants demonstrated osteoconductive characteristics. Coagulation-related proteins attached predominantly to SAE-Ti surface. Surface properties of the material might drive the regenerative process of the affected tissue. Analysis of the proteins on the coated dental implant showed that few proteins specifically attached to its surface, possibly indicating that its osteoinductive properties depend on the silicon delivery from the implant.

Bioactive potential of silica coatings and its effect on the adhesion of proteins to titanium implants.

There is an ever-increasing need to develop dental implants with ideal characteristics to achieve specific and desired biological response in the scope of improve the healing process post-implantation. Following that premise, enhancing and optimizing titanium implants through superficial treatments, like silica sol-gel hybrid coatings, are regarded as a route of future research in this area. These coatings change the physicochemical properties of the implant, ultimately affecting its biological characteristics. Sandblasted acid-etched titanium (SAE-Ti) and a silica hybrid sol-gel coating (35M35G30T) applied onto the Ti substrate were examined. The results of in vitro and in vivo tests and the analysis of the protein layer adsorbed to each surface were compared and discussed. In vitro analysis with MC3T3-E1 osteoblastic cells, showed that the sol-gel coating raised the osteogenic activity potential of the implants (the expression of osteogenic markers, the alkaline phosphatase (ALP) and IL-6 mRNAs, increased). In the in vivo experiments using as model rabbit tibiae, both types of surfaces promoted osseointegration. However, the coated implants demonstrated a clear increase in the inflammatory activity in comparison with SAE-Ti. Mass spectrometry (LC-MS/MS) analysis showed differences in the composition of protein layers formed on the two tested surfaces. Large quantities of apolipoproteins were found attached predominantly to SAE-Ti. The 35M35G30T coating adsorbed a significant quantity of complement proteins, which might be related to the material intrinsic bioactivity, following an associated, natural and controlled immune response. The correlation between the proteomic data and the in vitro and in vivo outcomes is discussed on this experimental work.

Proteomic analysis of silica hybrid sol-gel coatings: a potential tool for predicting the biocompatibility of implants in vivo.

The interactions of implanted biomaterials with the host organism determine the success or failure of an implantation. Normally, their biocompatibility is assessed using in vitro tests. Unfortunately, in vitro and in vivo results are not always concordant; new, effective methods of biomaterial characterisation are urgently needed to predict the in vivo outcome. As the first layer of proteins adsorbed onto the biomaterial surfaces might condition the host response, mass spectrometry analysis was performed to characterise these proteins. Four distinct hybrid sol-gel biomaterials were tested. The in vitro results were similar for all the materials examined here. However, in vivo, the materials behaved differently. Six of the 171 adsorbed proteins were significantly more abundant on the materials with weak biocompatibility; these proteins are associated with the complement pathway. Thus, protein analysis might be a suitable tool to predict the in vivo outcomes of implantations using newly formulated biomaterials.

Antimicrobial peptides (AMPs): Ancient compounds that represent novel weapons in the fight against bacteria.

Antimicrobial peptides (AMPs) are short peptidic molecules produced by most living creatures. They help unicellular organisms to successfully compete for nutrients with other organisms sharing their biological niche, while AMPs form part of the immune system of multicellular creatures. Thus, these molecules represent biological weapons that have evolved over millions of years as a result of an escalating arms race for survival among living organisms. All AMPs share common features, such as a small size, with cationic and hydrophobic sequences within a linear or cyclic structure. AMPs can inhibit or kill bacteria at micromolar concentrations, often by non-specific mechanisms; hence the appearance of resistance to these antimicrobials is rare. Moreover, AMPs can kill antibiotic-resistant bacteria, including insidious microbes such as Acinetobacter baumannii and the methicillin-resistant Staphylococcus aureus. This review gives a detailed insight into a selection of the most prominent and interesting AMPs with antibacterial activity. In the near future AMPs, due to their properties and despite their ancient origin, should represent a novel alternative to antibiotics in the struggle to control pathogenic microorganisms and maintain the current human life expectancy.

¿Tiene utilidad el recuento cellular en el cáncer de colon? / In the cell count useful in colon cáncer?

Introducción: Proponemos valorar la utilidad del recuento celular en el cáncer de colon en nuestro medio. Material y Métodos. Realizamos un estudio observacional, analítico, longitudinal y retrospectivo, basado en un esquema de cohortes. Se reclutan a 47 pacientes intervenidos de cáncer de colon en 2015. Se establecieron dos grupos según estadio anato-mopatológico final (grupo 1: estadios 0 y I y grupo 2: estadios II, III y IV) y se recogen sus datos analíticos en distintos momentos. Con los recuentos celulares se calcularon las curvas ROC para varias ratios, para establecer el punto de corte a partir del cual la probabilidad de pertenecer al grupo 1 es más alta. Se forman dos grupos, A y B, según sus valores de ratio y tomando el punto de corte para dividirlos y se comparan factores anatomopatológicos de mal pronóstico, datos quirúrgicos y clínicos. Se describe también el valor de la NLR en pacientes con mala evolución de la enfermedad. Resultados: No encontramos diferencias estadísticamente significativas en la evolución de ambos grupos, A y B, tampoco en cuanto a su relación con factores de mal pronóstico anatomopatológicos o clínicos. Se realiza también un seguimiento de los valores del NLR en pacientes que presentaron recidiva o metástasis, exponiendo resultados descriptivos. Conclusiones. Se trata de una medida sencilla de determinar, por lo que a pesar de no haber encontrado diferencias significativas, valoramos su utilidad cómo elemento informativo y consideramos su interés en demostrar la significancia estadística aumentando tamaño muestral y periodo de seguimiento en trabajos posteriores

Introduction. We propose to evaluate the utility of cell counts in colon cancer in our environment. Material and Methods. We conducted an observational, analytical, longitudinal and retrospective study, based on a cohort scheme. 47 patients were recruited who underwent colon cancer in 2015. Two groups were established according to the final anato-mopathological stage (group 1: stages 0 and I and group 2: stages II, III and IV) and their analytical data were collected at different times. With the cell counts the ROC curves were calculated for several ratios, to establish the cut-off point from which the probability of belonging to group 1 is higher. Two groups are formed, A and B, according to their ratio values and taking the cut-off point to divide them and comparing anatomopathological factors of poor prognosis, surgical and clinical data. The value of the NLR is also described in patients with poor evolution of the disease. Results. We did not find statistically significant differences in the evolution of both groups, A and B, neither in relation to their relationship with poor pathological or clinical prognostic factors. The NLR values were also monitored in patients with recurrence or metastasis, with descriptive results. Conclusions. This is a simple measure to determine, so despite not having found significant differences, we value its usefulness as an informative element and we consider its interest in demonstrating statistical significance by increasing sample size and follow-up period in subsequent studies

Descemetorrexis y aclaramiento corneal: una nueva perspectiva en el tratamiento de las enfermedades del endotelio / Descemetorhexis and corneal clearing: A new perspective on the treatment of endothelial diseases

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Identification of OXA-23 carbapenemases: novel variant OXA-239 in Acinetobacter baumannii ST758 clinical isolates in Mexico.

A collection of 15 carbapenem-resistance Acinetobacter baumannii clinical isolates was analysed on two tertiary hospitals in Mexico. The OXA-51 was identified in all isolates, followed by OXA-239 and OXA-58; OXA-239 is described as a new OXA-23-like allele. These carbapenemases were identified on four clonal groups, distributed between two neighbouring hospitals. Acinetobacter baumannii is poorly studied in Mexico; this situation urges the implementation of strategies to prevent its dissemination.

Electrolytic lesion of the nucleus incertus retards extinction of auditory conditioned fear.

Fear memory circuits in the brain function to allow animals and humans to recognize putative sources of danger and adopt an appropriate behavioral response; and research on animal models of fear have helped reveal the anatomical and neurochemical nature of these circuits. The nucleus (n.) incertus in the dorsal pontine tegmentum provides a strong GABAergic projection to forebrain 'fear centers' and is strongly activated by neurogenic stressors. In this study in adult male rats, we examined the effect of electrolytic lesions of n. incertus on different stages of the fear conditioning-extinction process and correlated the outcomes with anatomical data on the distribution of n. incertus-derived nerve fibers in areas implicated in fear circuits. In a contextual auditory fear conditioning paradigm, we compared freezing behavior in control (naïve) rats (n=23) and rats with sham- or electrolytic lesions of n. incertus (n=13/group). The effectiveness and extent of the lesions was assessed post-mortem using immunohistochemical markers for n. incertus neurons-calretinin and relaxin-3. There were no differences between the three experimental groups in the habituation, acquisition, or context conditioning phases; but n. incertus lesioned rats displayed a markedly slower, 'delayed' extinction of conditioned freezing responses compared to sham-lesion and control rats, but no differences in retrieval of extinguished fear. These and earlier findings suggest that n. incertus-related circuits normally promote extinction through inhibitory projections to the amygdala, which is involved in acquisition of extinction memories.

Cell aggregations in yeasts and their applications.

Yeasts can display four types of cellular aggregation: sexual, flocculation, biofilm formation, and filamentous growth. These cell aggregations arise, in some yeast strains, as a response to environmental or physiological changes. Sexual aggregation is part of the yeast mating process, representing the first step of meiotic recombination. The flocculation phenomenon is a calcium-dependent asexual reversible cellular aggregation that allows the yeast to withstand adverse conditions. Biofilm formation consists of multicellular aggregates that adhere to solid surfaces and are embedded in a protein matrix; this gives the yeast strain either the ability to colonize new environments or to survive harsh environmental conditions. Finally, the filamentous growth is the ability of some yeast strains to grow in filament forms. Filamentous growth can be attained by two different means, with the formation of either hyphae or pseudohyphae. Both hyphae and pseudohyphae arise when the yeast strain is under nutrient starvation conditions and they represent a means for the microbial strain to spread over a wide area to survey for food sources, without increasing its biomass. Additionally, this filamentous growth is also responsible for the invasive growth of some yeast.