The Hunga Tonga-Hunga Ha'apai Hydration of the Stratosphere.

Following the 15 January 2022 Hunga Tonga-Hunga Ha'apai eruption, several trace gases measured by the Aura Microwave Limb Sounder (MLS) displayed anomalous stratospheric values. Trajectories and radiance simulations confirm that the H2O, SO2, and HCl enhancements were injected by the eruption. In comparison with those from previous eruptions, the SO2 and HCl mass injections were unexceptional, although they reached higher altitudes. In contrast, the H2O injection was unprecedented in both magnitude (far exceeding any previous values in the 17-year MLS record) and altitude (penetrating into the mesosphere). We estimate the mass of H2O injected into the stratosphere to be 146 ± 5 Tg, or ∼10% of the stratospheric burden. It may take several years for the H2O plume to dissipate. This eruption could impact climate not through surface cooling due to sulfate aerosols, but rather through surface warming due to the radiative forcing from the excess stratospheric H2O.

Analysis of outcomes of emergency general and gastrointestinal surgery during the COVID-19 pandemic.

BACKGROUND: Few surgical studies have provided adjusted comparative postoperative outcome data among contemporary patients with and without COVID-19 infection and patients treated before the pandemic. The aim of this study was to determine the impact of performing emergency surgery in patients with concomitant COVID-19 infection. METHODS: Patients who underwent emergency general and gastrointestinal surgery from March to June 2020, and from March to June 2019 in 25 Spanish hospitals were included in a retrospective study (COVID-CIR). The main outcome was 30-day mortality. Secondary outcomes included postoperative complications and failure to rescue (mortality among patients who developed complications). Propensity score-matched comparisons were performed between patients who were positive and those who were negative for COVID-19; and between COVID-19-negative cohorts before and during the pandemic. RESULTS: Some 5307 patients were included in the study (183 COVID-19-positive and 2132 COVID-19-negative during pandemic; 2992 treated before pandemic). During the pandemic, patients with COVID-19 infection had greater 30-day mortality than those without (12.6 versus 4.6 per cent), but this difference was not statistically significant after propensity score matching (odds ratio (OR) 1.58, 95 per cent c.i. 0.88 to 2.74). Those positive for COVID-19 had more complications (41.5 versus 23.9 per cent; OR 1.61, 1.11 to 2.33) and a higher likelihood of failure to rescue (30.3 versus 19.3 per cent; OR 1.10, 0.57 to 2.12). Patients who were negative for COVID-19 during the pandemic had similar rates of 30-day mortality (4.6 versus 3.2 per cent; OR 1.35, 0.98 to 1.86) and complications (23.9 versus 25.2 per cent; OR 0.89, 0.77 to 1.02), but a greater likelihood of failure to rescue (19.3 versus 12.9 per cent; OR 1.56, 95 per cent 1.10 to 2.19) than prepandemic controls. CONCLUSION: Patients with COVID-19 infection undergoing emergency general and gastrointestinal surgery had worse postoperative outcomes than contemporary patients without COVID-19. COVID-19-negative patients operated on during the COVID-19 pandemic had a likelihood of greater failure-to-rescue than prepandemic controls.

[Experience with nebulised colistin in patients with non-cystic fibrosis bronchiectasis colonised with Pseudomonas aeruginosa]. / Experiencia con colistina nebulizada en pacientes con bronquiectasias no fibrosis quística colonizadas por Pseudomonas aeruginosa.

OBJECTIVE: Chronic colonisation/infection by Pseudomonas aeruginosa of the bronchiectasis is related to a faster deterioration of lung function, an increase in the number of exacerbations and a higher morbidity and mortality. Nebulised colistin decreases bacteria load. Therefore, a reduction in the number and in the severity of exacerbations and a delay of pulmonary decline is expected. The main objective is to evaluate if the treatment with nebulised colistin, for at least 6 months reduces the number of admissions and visits to the emergency department. METHODS: Observational, retrospective and non-interventionist study carried out in an organizational structure with an integrated management. Patients with non-cystic fibrosis bronchiectasis colonised / infected by P. aeruginosa, older than 18 years, were selected. Patients must have received nebulized colistin during at least 6 months. Clinical, microbiological and therapeutic data from the patients were collected from the SERGAS computerized clinical history (IANUS® v.4.20.0503) and the electronic prescription, which were divided into two time periods: 1) 6 months pre-treatment and during the treatment and 2) 12 months pre-treatment and during the treatment, in those who completed 1 year of treatment. RESULTS: Forty-four patients were included and of these, 29 (65.9%) had a follow-up of 12 months. The use of nebulized colistin decreased significantly the number of visits to the emergency (at 6 months), the frequency and duration of hospitalizations admissions (at 6 and 12 months), the antibiotic consumption (at 6 and 12 months) and the positive cultures. The treatment was well tolerated in almost all patients. CONCLUSIONS: The treatment with nebulised colistin during 6 and 12 months of non-cystic fibrosis bronchiectasis, colonised/infected by P. aeruginosa, seems beneficial for the patient, from the clinical and quality of life point of view, and could reduce the economic cost of the process.

Effect of tyrosine kinase inhibitors on the glucose levels in diabetic and nondiabetic patients.

CONTEXT: Tyrosine kinase inhibitors (TKIs) are used in different types of cancers due to their good profile of adverse reactions and their convenience in the oral administration. Some studies describe that certain TKIs are associated with changes in the glycemic profile of the patients. AIMS: This study aims to determine if treatment with ITK affects to serum glucose levels in clinical practice. SETTINGS AND DESIGN: A retrospective study was carried out in 136 episodes (112 patients treated with sorafenib, sunitinib, imatinib, dasatinib, or nilotinib). SUBJECTS AND METHODS: The serum glucose levels were analyzed before treatment and after months 1, 2, 3, 6, 9, and 12 of treatment. STATISTICAL ANALYSIS USED: Statistical analysis was completed with SPSS version 20 for Windows. RESULTS: There were significant differences in the serum glucose levels before treatment between diabetic and nondiabetic patients, but not between the average blood glucose readings before treatment and the average of the subsequent readings, once their treatment had begun. CONCLUSIONS: The results of this study do not reproduce the results of the literature since changes in the serum glucose levels have not been found in this sample of patients.

Docosahexaenoic Acid Reduces Cerebral Damage and Ameliorates Long-Term Cognitive Impairments Caused by Neonatal Hypoxia-Ischemia in Rats.

As the interest in the neuroprotective possibilities of docosahexaenoic acid (DHA) for brain injury has grown in the recent years, we aimed to investigate the long-term effects of this fatty acid in an experimental model of perinatal hypoxia-ischemia in rats. To this end, motor activity, aspects of learning, and memory function and anxiety, as well as corticofugal connections visualized by using tracer injections, were evaluated at adulthood. We found that in the hours immediately following the insult, DHA maintained mitochondrial inner membrane integrity and transmembrane potential, as well as the integrity of synaptic processes. Seven days later, morphological damage at the level of the middle hippocampus was reduced, since neurons and myelin were preserved and the astroglial reactive response and microglial activation were seen to be diminished. At adulthood, the behavioral tests revealed that treated animals presented better long-term working memory and less anxiety than non-treated hypoxic-ischemic animals, while no difference was found in the spontaneous locomotor activity. Interestingly, hypoxic-ischemic injury caused alterations in the anterograde corticofugal neuronal connections which were not so evident in rats treated with DHA. Thus, our results indicate that DHA treatment can lead to long-lasting neuroprotective effects in this experimental model of neonatal hypoxia-ischemic brain injury, not only by mitigating axonal changes but also by enhancing cognitive performance at adulthood.

Profilin1 regulates invadopodium maturation in human breast cancer cells.

Invadopodia are actin-driven membrane protrusions that show oscillatory assembly and disassembly causing matrix degradation to support invasion and dissemination of cancer cells in vitro and in vivo. Profilin1, an actin and phosphoinositide binding protein, is downregulated in several adenocarcinomas and it is been shown that its depletion enhances invasiveness and motility of breast cancer cells by increasing PI(3,4)P2 levels at the leading edge. In this study, we show for the first time that depletion of profilin1 leads to an increase in the number of mature invadopodia and these assemble and disassemble more rapidly than in control cells. Previous work by Sharma et al. (2013a), has shown that the binding of the protein Tks5 with PI(3,4)P2 confers stability to the invadopodium precursor causing it to mature into a degradation-competent structure. We found that loss of profilin1 expression increases the levels of PI(3,4)P2 at the invadopodium and as a result, enhances recruitment of the interacting adaptor Tks5. The increased PI(3,4)P2-Tks5 interaction accelerates the rate of invadopodium anchorage, maturation, and turnover. Our results indicate that profilin1 acts as a molecular regulator of the levels of PI(3,4)P2 and Tks5 recruitment in invadopodia to control the invasion efficiency of invadopodia.

Comparative morphometric analysis of 5 interpositional arterial autograft options for adult living donor liver transplantation.

UNLABELLED: In living donor liver transplantation, the right-sided graft presents thin and short vessels, bringing forward a more difficult anastomosis. In these cases, an interpositional arterial autograft can be used to favor the performance of the arterial anastomosis, making the procedure easier and avoiding surgical complications. OBJECTIVE: We compared the inferior mesenteric artery (IMA), the splenic artery (SA), the inferior epigastric artery (IEA), the descending branch of the lateral circumflex femoral artery (LCFA), and the proper hepatic artery (PHA) as options for interpositional autograft in living donor liver transplantation. METHOD: Segments of at least 3 cm of all 5 arteries were harvested from 16 fresh adult cadavers from both genders through standardized dissection. The analyzed measures were proximal and distal diameter and length. The proximal diameter of the RHA and the distal diameter of the SA, IMA, IEA and the LCFA were compared to the distal diameter of the RHA. The proximal and distal diameters of the SA, IEA and LCFA were compared to study caliber gain of each artery. RESULTS: All arteries except the IMA showed statistical significant difference in relation to the RHA in terms of diameter. Regarding caliber gain, the arteries demonstrated statistical significant difference. All the harvested arteries except PHA were 3 cm in length. CONCLUSION: The IMA demonstrated the best compatibility with the RHA in terms of diameter and showed sufficient length to be employed as interpositional graft. The PHA, the SA, the IEA and the LCFA presented statistically significant different diameters when compared to the RHA. Among these vessels, only the PHA did not show sufficient mean length.

Quiste de duplicación duodenal, diagnóstico prenatal y exéresis postnatal / Duodenal duplication cyst, prenatal diagnosis and postnatal excision

Introduction: duodenal duplication cysts are rare congenital anomalies, usually originate in the 2nd -3rd portion of the duodenum. The prenatal echography diagnosis shows a cyst in the right hypochondrium, and we should perform a differential diagnosis with other pathologies. Prenatal diagnosis will allow a correct and precocious postnatal management. Elective excision is the treatment of election preventing the development of complications. Clinical case: We present a rare case of duplication of the first portion of the duodenum that required precocious excision because obstruction to gastric emptying.

Introducción: Los quistes de duplicidad duodenal son anomalías congênitas raras, que generalmente se originan en la 2ª-3ª porción duodenal. Ante el hallazgo en la ecografía prenatal de un quiste en hipocondrio derecho se debe realizar un diagnóstico diferencial con otras patologías. El diagnóstico prenatal, permitirá un correcto y precoz manejo postnatal. La exéresis electiva es el tratamiento de elección evitando la aparición de complicaciones posteriores. Caso clínico: Presentamos un caso excepcional de duplicidad de la primera porción duodenal, que precisó de exêresis precoz por causar obstrucción al vaciamiento gástrico.

Enterocolitis necrotizante fulminante en un bebé colodión: caso clínico / Fulminant necrotizing enterocolitis in a collodion baby: a case report

Introducción: El bebé colodión es una ictiosis neonatal muy poco frecuente. La piel apergaminada, amarilla y dura que recubre el cuerpo resulta ser una barrera ineficaz, que predispone a la deshidratación, pérdida de calor e infecciones. El mejor manejo de estos pacientes ha permitido aumentar su supervivencia, pero su comorbi-lidad requiere de un seguimiento estricto y cauteloso. Objetivo: Describir un caso de enterocolitis fulminante desarrollada en un bebé colodión, con el fin de ayudar a la identificación más precoz de esta patología. Caso clínico: Recién nacido de 34 semanas, con membrana colodión, que ingresa en la unidad de cuidados intensivo con dificultad respiratoria severa. Se mantiene en una incubadora con humedad, aplicando emolientes y lubricación cutánea y oftalmológica. Se inició tratamiento antibiótico de amplio espectro. El quinto día de vida, comenzó con intolerancia a la alimentación, desarrollándose una enterocolitis fulminante que le ocasionó el fallecimiento. Conclusiones: La asociación con enterocolitis necrosante en un bebé colodión no ha sido descrita en la literatura, por lo que, ocasiona una demora diagnóstica y esto contribuye a una evolución fulminante que puede ocasionar la muerte. El tener presente esta infrecuente comorbilidad podrá favorecer su pesquisa para el manejo oportuno.

Introduction: Collodion baby is a rare neonatal ichthyosis. The leathery, hard and yellow skin that covers the body is an ineffective barrier that predisposes to dehydration, heat loss and infections. A better management of these patients has been shown to increase survival, but the comorbidity requires strict and cautious monitoring. Objective: To describe a case of fulminant enterocolitis in a collodion infant in order to help to identify early this pathology. Case report: A 34-week newborn with collodion membrane was admitted to the intensive care unit with severe respiratory distress. The baby was maintained in an incubator with humidity, applying emollients and skin and eye lubrication. Broad-spectrum antibiotic treatment was initiated. The patient presented feeding intolerance on the fifth day of life, developing a fulminant enterocolitis resulting in death. Conclusion: The necrotizing enterocolitis associated with a collodion baby has not been described in the literature, causing a delay in diagnosis and contributing to a fulminant course that can lead to death. Keeping in mind this rare comorbidity may facilitate a timely management.

Functional and morphological characterization of glutamate transporters in the rat locus coeruleus.

BACKGROUND AND PURPOSE: Excitatory amino acid transporters (EAATs) in the CNS contribute to the clearance of glutamate released during neurotransmission. The aim of this study was to explore the role of EAATs in the regulation of locus coeruleus (LC) neurons by glutamate. EXPERIMENTAL APPROACH: We measured the effect of different EAAT subtype inhibitors/enhancers on glutamate- and KCl-induced activation of LC neurons in rat slices. EAAT2-3 expression in the LC was also characterized by immunohistochemistry. KEY RESULTS: The EAAT2-5 inhibitor DL-threo-ß-benzyloxaspartic acid (100 µM), but not the EAAT2, 4, 5 inhibitor L-trans-pyrrolidine-2,4-dicarboxylic acid (100 µM) or the EAAT2 inhibitor dihydrokainic acid (DHK; 100 µM), enhanced the glutamate- and KCl-induced activation of the firing rate of LC neurons. These effects were blocked by ionotropic, but not metabotrobic, glutamate receptor antagonists. DHK (100 µM) was the only EAAT inhibitor that increased the spontaneous firing rate of LC cells, an effect that was due to inhibition of EAAT2 and subsequent AMPA receptor activation. Chronic treatment with ceftriaxone (200 mg·kg(-1) i.p., once daily, 7 days), an EAAT2 expression enhancer, increased the actions of glutamate and DHK, suggesting a functional impact of EAAT2 up-regulation on the glutamatergic system. Immuhistochemical data revealed the presence of EAAT2 and EAAT3 surrounding noradrenergic neurons and EAAT2 on glial cells in the LC. CONCLUSIONS AND IMPLICATIONS: These results remark the importance of EAAT2 and EAAT3 in the regulation of rat LC by glutamate. Neuronal EAAT3 would be responsible for terminating the action of synaptically released glutamate, whereas glial EAAT2 would regulate tonic glutamate concentrations in this nucleus.

[Temporal orientation and cognitive impairment]. / Orientacion en el tiempo y deterioro cognitivo.

INTRODUCTION: Temporal orientation is a component of most screening tests for diagnosing cognitive impairment. Correct temporal orientation involves activating both semantic information (concepts of the calendar date) and episodic information (remembering the current date). AIMS: The aim of this study was to assess the diagnostic usefulness of a technique for evaluating temporal orientation, which was open-ended, and scoring the semantic and episodic information thus generated (0-10 points). SUBJECTS AND METHODS: A total of 24 subjects without impairment, 77 patients with mild cognitive impairment (MCI) and 62 patients with dementia were evaluated by means of a 30-point mini-mental/mini-examination, semantic verbal fluency test, global deterioration scale, mini-mental-type temporal orientation and open-ended temporal orientation tests. The areas under the curve (aROC), sensitivity and specificity for dementia and cognitive impairment at any degree (MCI and dementia) were analysed. RESULTS: Open-ended temporal orientation presented a greater area under the curve (aROC: 0.90) for discrimination between patients with dementia and without dementia (MCI and without impairment) and an aROC of 0.83 for discrimination between patients with MCI or dementia and without impairment. For dementia, with a cut-off point equal to or below 6, sensitivity was 0.96 and specificity was 0.68, and for MCI with dementia, with a cut-off point equal to or below 7, sensitivity was 0.72 and specificity was 0.92. CONCLUSIONS: The usefulness, conciseness and strategic position of this technique in examining mental status make it suitable as an instrument for screening for cognitive impairment. It has a high level of sensitivity with low specificity for dementia and low sensitivity with high specificity for any degree of impairment.

Somatosensory cross-modal plasticity in the superior colliculus of visually deafferented rats.

The effects of neonatal visual deafferentation on the final adult pattern of cortico-collicular connections from the rat primary somatosensory cortex barrel field were studied by injecting an anterograde tracer (BDA) into different locations of the barrel cortex. Collicular afferents originating in the barrel cortex normally end in the intermediate collicular strata (SGI and SAI). However, neonatal visual deafferentation caused an invasion of abundant somatosensory cortical afferents into the lateral portions of the superficial collicular strata (SGS and SO). Moreover, anterograde-labelled fibers in the intermediate strata were more densely packed in visually deafferented animals. In order to study the activity of the altered somatosensory cortico-collicular connection, the effects of two different types of whisker stimuli on c-fos expression in the SC were analyzed (apomorphine treatment and enriched environment exploration). In stimulated control animals, c-fos expression was clearly evident in neurons of the intermediate layers 2 h after whisker stimulation. Similar stimulation in adult animals that underwent neonatal visual deafferentation triggered higher levels of c-fos expression in the superficial collicular layers that were invaded by cortico-collicular axonal branches. In exploration experiments, increased levels of c-fos expression were also detected in lateral parts of the intermediate layers of visually deafferented animals. These results suggest that the ascending fibers of somatosensory cortical origin can recruit deafferented superficial collicular neurons that enabling them to participate in extravisual behavioural responses mediated by collicular circuits.

Interaction of the cationic peptide bactenecin with phospholipid monolayers at the air-water interface: i interaction with 1,2-dipalmitoyl-sn-glycero-3-phosphatidilcholine.

In this work we have investigated the influence of NaCl on the adsorption of the antimicrobial cationic peptide bactenecin in the monolayer of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) at the air-water interface, as a function of NaCl concentrations in the subphase. We show that the effect of the salt concentration on DPPC monolayers is a monotonic decrease of the liquid-condensed-liquid-expanded (LC-LE) coexistence region. By contrast, the effect of the bactenecin adsorption at the DPPC monolayer not only removed the LC-LE coexistence region plateau, but also shifted the DPPC isotherms to higher pressures and increased the compressibility of the DPPC/bactenecin monolayers with respect to the pure DPPC monolayer around the LC phase. Analysis of the domain structure, obtained by Brewster angle and atomic force microscopes, indicates that the salt concentration in the subphase builds an electrostatic barrier, increasing the rigidity of DPPC monolayers and limiting the bactenecin adsorption at the LC-LE phase coexistence.

Electrical burns: a retrospective analysis across a 5-year period.

This study aims to review the experience, at an institution, with patients who suffered electrical burns and study the peculiar characteristics of this type of burn as well as its complications and epidemiological aspects. The study includes medical records of patients with electrical burns who were admitted to the Burn Unit of Hospital das Clínicas in São Paulo, Brazil, from November 2001 to October 2006. They were classified into four categories: high voltage (> or =1000 V), low voltage (<1000 V), 'flash burn' (in which there is no electrical current flow through the body of the patient) and burns caused by lightning. The complications were more severe and common in the high-voltage group, while longer hospital stays and more complex surgical procedures due to the greater depth of burns were also observed in this group. High-voltage burns are mainly labour-/occupation-related. The majority of the patients were young men at the beginning of their professional lives. This factor generates an important socio-economic impact due to the high incidence of sequelae, resulting in amputations, rendering them unable to maintain their occupations.

Interaction of N-nitrosodiethylamine/bovine serum albumin complexes with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine monolayers at the air-water interface.

We report the effect of N-nitrosodiethylamine (NDA) on the interaction between bovine serum albumin (BSA) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine monolayers (DPPC) at the air-water interface. We prepared aqueous solutions of NDA/BSA complexes maintaining a constant concentration of BSA of 1.49 x 10(-9) M and using NDA concentrations to obtain 2000, 4000, 6000, 12,500, and 25,000 NDA/BSA molar ratios. The hysteresis area and the compressional modulus of the compression-expansion cycles performed at different times were dependent on the NDA concentration. The cycles performed demonstrate the stability of the new phase of DPPC/BSA and DPPC/NDA/BSA monolayers. This was achieved probably because the BSA concentration used was lower than the one needed for BSA to inhibit the return of DPPC molecules to the interface. Results of the compressional modulus at the onset of the new phase, obtained around 17 mN/m, 15 min and 1, 3, 5, and 12 h after DPPC deposition, indicated that the 3.0 x 10(-6) M NDA concentration produced a more rigid film, probably due to the higher alpha-helix content of BSA. AFM images were obtained for DPPC/BSA and two DPPC/NDA/BSA complexes. Our images show that 12,500 NDA/BSA molecules were mostly adsorbed in the liquid condensed phase. However, BSA molecules were distributed more homogeneously.

[Model of analysis in two halves for semantic fluency tasks]. / Modelo de análisis en dos mitades para tareas de fluidez semántica.

INTRODUCTION: Semantic verbal fluency (SVF) tasks involve the activation of language, semantic memory, working memory and the executive functions. The second half of the test increases the demands on working memory and search for lexical items, which can make it more difficult than the first half. AIM: To conduct a pilot study in order to standardise the two halves of the SVF test ('animals' category) in adults over 50 years of age. SUBJECTS AND METHODS: Two verbal fluency tasks (semantic and phonological) and the Spanish version of the Mini-Mental State Examination with working memory were applied in 122 controls (range: 50-89 years), who were distributed according to age and schooling. RESULTS: There is a significant difference between the two halves of the test adjusted for age and schooling (p < 0.0001). Scoring in the second half showed a higher correlation with age, schooling and working memory than the first half. Performance in the two halves was standardised for three age groups (50-59, 60-79 and 80-89 years) and two levels of schooling (high and low). CONCLUSIONS: The number of names in the second half of the SVF test was lower than in the first half in all the groups, which supports the hypothesis of a greater cognitive demand, probably on working memory and the search for lexical items in semantic memory. Having normative values available for the two halves of the SVF test allows simultaneous and independent interpretation of the performance at two levels of intra-task difficulty. This model of analysis complements the traditional assessment and can easily be applied in day-to-day clinical practice.

Interfacial behavior of N-nitrosodiethylamine/bovine serum albumin complexes at the air-water and the chloroform-water interfaces by axisymmetric drop tensiometry.

Interfacial properties of N-nitrosodiethylamine/bovine serum albumin (NDA/BSA) complexes were investigated at the air-water interface. The interfacial behavior at the chloroform-water interface of the interaction product of phospholipid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), dissolved in the chloroform phase, and NDA/BSA complex, in the aqueous phase, were also analyzed by using a drop tensiometer. The secondary structure changes of BSA with different NDA concentrations were monitored by circular dichroism spectroscopy at different pH and the NDA/BSA interaction was probed by fluorescence spectroscopy. Different NDA/BSA mixtures were prepared from 0, 7.5 x 10(-5), 2.2 x 10(-4), 3.7 x 10(-4), 5 x 10(-4), 1.6 x 10(-3), and 3.1 x 10(-3) M NDA solutions in order to afford 0, 300/1, 900/1, 1 500/1, 2 000/1, 6 000/1, and 12 500/1 NDA/BSA molar ratios, respectively, in the aqueous solutions. Increments of BSA alpha-helix contents were obtained up to the 2 000/1 NDA/BSA molar ratio, but at ratios beyond this value, the alpha-helix content practically disappeared. These BSA structure changes produced an increment of the surface pressure at the air-water interface, as the alpha-helix content increased with the concentration of NDA. On the contrary, when alpha-helix content decreased, the surface pressure also appeared lower than the one obtained with pure BSA solutions. The interaction of DPPC with NDA/BSA molecules at the chloroform-water interface produced also a small, but measurable, pressure increment with the addition of NDA molecules. Dynamic light scattering measurements of the molecular sizes of NDA/BSA complex at pH 4.6, 7.1, and 8.4 indicated that the size of extended BSA molecules at pH 4.6 increased in a greater proportion with the increment in NDA concentration than at the other studied pH values. Diffusion coefficients calculated from dynamic surface tension values, using a short-term solution of the general adsorption model of Ward and Tordai, also showed differences with pH and the NDA concentration. Both, the storage and loss dilatational elastic modulus were obtained at the air-water and at the chloroform-water interfaces. The interaction of NDA/BSA with DPPC at the chloroform-water produced a less rigid monolayer than the one obtained with pure DPPC (1 x 10(-5) M), indicating a significant penetration of NDA/BSA molecules at the interface. At short times and pH 4.6, the values of the storage elastic modulus were larger and more sensible to the NDA addition than the ones at pH 7.1 and 8.4, probably due to a gel-like network formation at the air-water interface.

[Language and cognitive impairment: a semiological study into visual naming]. / Lenguaje y deterioro cognitivo: un estudio semiológico en denominación visual.

INTRODUCTION: The presence of anomia and/or paraphasias in patients with cognitive impairment suggests an associated deterioration of their language. Visual naming makes it possible to examine these signs in a controlled manner as the target word is already known. AIM. To conduct a semiological study of naming in normal aging, cognitive impairment and language impairment conditions. SUBJECTS AND METHODS: The study consisted in an analysis of nine types of signs (correct response, increased latencies, circumlocutions, absence of response, semantic verbal paraphasias, verbal paraphasias with a similar form, unrelated verbal paraphasias, phonemic paraphasias and neologisms) in a visual naming task (6 items), in two groups with normal language--controls > 70 years and patients with Alzheimer's disease (AD) with onset of amnesia--and two groups with language impairment--vascular aphasia and anomic AD-. RESULTS: Patients failed to perform naming correctly in 4.2% of the responses in controls, 10% in patients with amnesic AD, 30% in patients with vascular aphasia and 50% in patients with anomic AD. Semantic paraphasias were observed in the two groups with normal language abilities (controls and amnesic AD), although frequencies were low. Signs that suggest difficulties in accessing/retrieving lexical items were more frequent in patients with AD and ran parallel to the degree of anomia. One notable finding was the absence of signs of phonological dysfunction in the two groups with AD, regardless of the degree of anomia. CONCLUSIONS: Semiological quantification makes it possible to distinguish differences in the degree of anomia and in the pattern of errors both in controls and in patients with amnesic onset AD and among patients with vascular aphasia and neurodegenerative anomia.