Genotypic and phenotypic characterization of Bordetella pertussis strains used in different vaccine formulations in Latin America.

AIM: To characterize Bordetella pertussis vaccine strains in comparison with current circulating bacteria. METHODS AND RESULTS: Genomic and proteomic analyses of Bp137 were performed in comparison with other vaccine strains used in Latin America (Bp509 and Bp10536) and with the clinical Argentinean isolate Bp106. Tohama I strain was used as reference strain. Pulse-field gel electrophoresis (PFGE) and pertussis toxin promoter (ptxP) sequence analysis revealed that Bp137 groups with Bp509 in PFGE group III and contains ptxP2 sequence. Tohama I (group II) and Bp10536 (group I) contain ptxP1 sequence, while Bp106 belongs to a different PFGE cluster and contains ptxP3. Surface protein profiles diverged in at least 24 peptide subunits among the studied strains. From these 24 differential proteins, Bp10536 shared the expression of ten proteins with Tohama I and Bp509, but only three with Bp137. In contrast, seven proteins were detected exclusively in Bp137 and Bp106. CONCLUSIONS: Bp137 showed more features in common with the clinical isolate Bp106 than the other vaccine strains here included. SIGNIFICANCE AND IMPACT OF THE STUDY: The results presented show that the old strains included in vaccines are not all equal among them. These findings together with the data of circulating bacteria should be taken into account to select the best vaccine to be included in a national immunization programme.

Laboratory adaptation of Bordetella pertussis is associated with the loss of type three secretion system functionality.

Although Bordetella pertussis contains and transcribes loci encoding type III secretion system (TTSS) homologues, expression of TTSS-associated proteins has been reported only for non-laboratory-adapted Irish clinical isolates. Here we confirm such a result for clinical isolates obtained from patients treated in Argentinean hospitals. Moreover, we demonstrate that the expression of TTSS-associated proteins is independent both of the year in which the isolate was obtained and of the types of polymorphic alleles for other virulence factors but is dependent on environmental growth conditions. Interestingly, we observed that TTSS-associated protein expression is lost after successive in vitro passages but becomes operative again when bacteria come into contact with the host. This in vivo activation of TTSS expression was observed not only for clinical isolates previously adapted to the laboratory after successive in vitro passages but also for vaccine strains that did not express the system in vitro. The reversibility of TTSS expression, demonstrated by its switching off-on when the bacterium comes into contact with the host, appears to be an adaptive response of this pathogen.

Gamma band oscillations in parietooccipital areas during performance of a sensorimotor integration task: a qEEG coherence study / Oscilações na banda gama em áreas parieto-occipitais durante desempenho de uma tarefa sensório-motora: um estudo de coerência na EEGq

This study aimed to elucidate cortical mechanisms involved in anticipatory actions when 23 healthy right-handed subjects had to catch a free falling object through quantitative electroencephalogram (qEEG). For this reason, we used coherence that represents a measurement of linear covariation between two signals in the frequency domain. In addition, we investigated gamma-band (30-100 Hz) activity that is related to cognitive and somatosensory processes. We hypothesized that gamma coherence will be increase in both parietal and occipital areas during moment after ball drop, due to their involvement in manipulation of objects, visuospatial processing, visual perception, stimuli identification and attention processes. We confirmed our hypothesis, an increase in gamma coherence on P3-P4 (t= -2.15; p=0.033) and PZ-OZ (t= -2.16; p=0.034) electrode pairs was verified for a paired t-test. We conclude that to execute tasks involving anticipatory movements (feedforward mechanisms), like our own task, probably, there is no need of a strong participation of visual areas in the process of information organization to manipulate objects and to process visuospatial information regarding the contact hand-object.

Este estudo teve como objetivo elucidar os mecanismos corticais envolvidos em ações antecipatórias quando 23 indivíduos saudáveis destros tinham que apreender um objeto em queda livre, através da eletroencefalografia quantitativa (EEGq). Por esta razão, usamos a coerência que representa a covariação linear entre dois sinais no domínio da frequência. Além disso, investigamos a atividade da banda gama (30-100 Hz), que está relacionada à processos cognitivos e somato-sensoriais. Nossa hipótese é que a coerência de gama estará aumentada em ambas as áreas parietais e occipitais durante o momento pós-queda da bola, devido ao seu envolvimento na manipulação de objetos, processamento visuo-espacial, percepção visual, identificação de estímulos e processos de atenção. Confirmamos nossa hipótese. Um aumento de coerência em gama nos pares de eletrodos P3-P4 (t= -2,15; p=0,033) e PZ-OZ (t= -2,16; p=0,034) foi verificado por teste-t pareado. Conclui-se que, para executar tarefas que envolvem movimentos de antecipação (mecanismos de retro-alimentação) como a nossa própria tarefa, provavelmente, não há necessidade de forte participação de áreas visuais no processo de organização da informação como para manipular objetos e processar a informação visuo-espacial no contato mão-objeto.

[The effects of bromazepam on the performance of a sensory-motor activity: an electroencephalographic study]. / Efectos del bromacepam en el desarrollo de una actividad sensoriomotora: un estudio electroencefalográfico.

AIMS: To investigate the effects of using bromazepam on the relative power in alpha while performing a typing task. Bearing in mind the particularities of each brain hemisphere, our hypothesis was that measuring the relative power would allow us to investigate the effects of bromazepam on specific areas of the cortex. More specifically, we expected to observe different patterns of powers in sensory-motor integration, attention and activation processes. SUBJECTS AND METHODS: The sample was made up of 39 subjects (15 males and 24 females) with a mean age of 30 +/- 10 years. The control (placebo) and experimental (3 mg and 6 mg of bromazepam) groups were trained in the typing task with a randomised double-blind model. RESULTS: A three-way ANOVA and Scheffé test were used to analyse interactions between the factors condition and moment, and between condition and sector. CONCLUSIONS: The doses used in this study facilitated motor performance of the typing task. In this study, the use of the drug did not prevent learning of the task, but it did appear to concentrate mental effort on more restricted and specific aspects of typing. It also seemed to influence the rhythm and effectiveness of the operations performed during mechanisms related to the encoding and storage of new information. Likewise, a predominance of activity was observed in the left (dominant) frontal area in the 3 mg bromazepam group, which indicates that this dose of the drug affords the subject a greater degree of directionality of cortical activity for planning and performing the task.

[The role played by the parietooccipital cortex in the process of sensory-motor integration: an electroencephalographic study]. / Participación de la corteza parietooccipital en el proceso de integración sensoriomotora: estudio electroencefalográfico.

INTRODUCTION: A fundamental aspect of planning future actions is the performance and control of motor tasks. This behaviour is done through sensory-motor integration. AIM: To explain the electrophysiological mechanisms in the cortex (modifications to the alpha band) that are involved in anticipatory actions when individuals have to catch a free-falling object. SUBJECTS AND METHODS: The sample was made up of 20 healthy subjects of both sexes (11 males and 9 females) with ages ranging between 25 and 40 years (32.5 +/- 7.5) who were free of mental or physical diseases (previous medical history); the subjects were right-handed (Edinburgh Inventory) and were not taking any psychoactive or psychotropic substances at the time of the study. The experiment consisted in a task in which subjects had to catch freely falling objects. The experiment was made up of six blocks of 15 tests, each of which lasted 2 minutes and 30 seconds, with a break of one minute between blocks. Data were captured by means of a quantitative electroencephalogram two seconds before and two seconds after each ball was dropped. RESULTS: An interaction of the factors moment and position was only observed for the right parietooccipital cortex, in the combination of electrodes P4-O2. CONCLUSION: These findings suggest that the right parietooccipital cortex plays an important role in increasing expectation and swiftness in the processes of preparing for a motor task.

[Learning and implicit memory: mechanisms and neuroplasticity]. / Aprendizaje y memoria implícita: mecanismos y neuroplasticidad.

INTRODUCTION: Learning and memory are complex processes that researchers have been attempting to unravel for over a century in order to gain a clear view of the underlying mechanisms. AIMS: To review the basic cellular and molecular mechanisms involved in the process of procedural retention, to offer an overall view of the fundamental mechanisms involved in storing information by means of theories and models of memory, and to discuss the different types of memory and the role played by the cerebellum as a modulator of procedural memory. DEVELOPMENT: Experimental results from recent decades have opened up new areas of study regarding the participation of the biochemical and cellular processes related to the consolidation of information in the nervous system. CONCLUSIONS: The neuronal circuits involved in acquiring and consolidating memory are still not fully understood and the exact location of memory in the nervous system remains unknown. A number of intrinsic and extrinsic factors interfere in these processes, such as molecular (long-term potentiation and depression) and cellular mechanisms, which respond to communication and transmission between nerve cells. There are also factors that have their origin in the outside environment, which use the association of events to bring about the formation of new memories or may divert the subject from his or her main focus. Memory is not a singular occurrence; it is sub-divided into declarative and non-declarative or, when talking about the time it lasts, into short and long-term memory. Moreover, given its relation with neuronal mechanisms of learning, memory cannot be said to constitute an isolated process.

[The effects of bromazepam on contingent negative variation and reaction time in a visuomotor task]. / Efectos del bromacepam sobre la variación negativa contingente y el tiempo de reacción en una tarea visuomotora.

INTRODUCTION: Bromazepam is the second most commonly used benzodiazepine in Brazil. Psychophysiological research on this substance is still in its early stages. AIM: To determine the neurotoxicity of bromazepam by examining reaction times (RT) and contingent negative variations (CNV). SUBJECTS AND METHODS: Using a videogame produced in our laboratory for psychophysiological research purposes (Car Acquisition), 14 healthy volunteers (9 males) aged between 23 and 42 drove a vehicle along a road full of curves (i.e. distractors) while they had to respond to imperative stimuli (i.e. orders to press the button on the joystick) that were preceded by warnings (S1-S2-RM paradigm with distractor). We compared RT, amplitudes and latencies of the CNV at each of the three electrodes on the median line (Fz, Cz and Pz) one hour after random, double-blind and crossed administration of placebo (P), 3 mg of bromazepam (B3) or 6 mg of bromazepam (B6) on different days. STATISTICS: one-way ANOVA and Post Hoc Scheffé. RESULTS: No significant differences were observed in the RT. At Pz, the CNV amplitudes displayed significant differences for P, B3 and B6 (p = 0.006), and also for B3 and B6 (p = 0.018), with B6 > B3 = P. At Fz, a non-significant tendency (p = 0.074) suggested a difference between the latencies, shorter in B6 than in B3 (p = 0.098), both equivalent to placebo. The mean amplitudes ranged between 2.4 and 5.9 microV. CONCLUSIONS: Behavioural and neurophysiological neurotoxicity was insignificant one hour after administration of a single 3 or 6 mg dose of bromazepam in healthy young adults. Low mean amplitudes were compatible with the interference from distractors and did not result in floor effect.

Topographic abnormality of slow cortical potentials in schizophrenia

A recent study from our laboratory has provided evidence for the generation of slow potentials occurring in anticipation to task-performance feedback stimuli, in multiple association cortical areas, consistently including two prefrontal areas. In the present study, we intended to determine whether these slow potentials would indicate some abnormality (topographic) in schizophrenic patients, and thus serve as an indication of abnormal association cortex activity. We recorded slow potentials while subjects performed a paired-associates memory task. A 123-channel EEG montage and common average reference were used for 20 unmedicated schizophrenic (mean duration of illness: 11.3 ± 9.2 years; mean number of previous hospitalizations: 1.2 ± 1.9) and 22 healthy control subjects during a visual paired-associates matching task. For the topographic analysis, we used a simple index of individual topographic deviation from normality, corrected for absolute potential intensities. Slow potentials were observed in all subjects. Control subjects showed a simple spatial pattern of voltage extrema (left central positive and right prefrontal negative), whereas schizophrenic patients presented a more complex, fragmented pattern. Topographic deviation was significantly different between groups (P < 0.001). The increased topographic complexity in schizophrenics could be visualized in grand averages computed across subjects. Increased topographic complexity could also be seen when grand averages were computed for subgroups of patients assembled either according to task-performance (high versus low) or by their scores on psychopathological scales. There was no significant correlation between topographic deviation and psychopathology scores. We conclude that the slow potential topographic abnormalities of schizophrenia indicate an abnormality in the configuration of large-scale electrical activity in association cortices.

Topographic abnormality of slow cortical potentials in schizophrenia.

A recent study from our laboratory has provided evidence for the generation of slow potentials occurring in anticipation to task-performance feedback stimuli, in multiple association cortical areas, consistently including two prefrontal areas. In the present study, we intended to determine whether these slow potentials would indicate some abnormality (topographic) in schizophrenic patients, and thus serve as an indication of abnormal association cortex activity. We recorded slow potentials while subjects performed a paired-associates memory task. A 123-channel EEG montage and common average reference were used for 20 unmedicated schizophrenic (mean duration of illness: 11.3 +/- 9.2 years; mean number of previous hospitalizations: 1.2 +/- 1.9) and 22 healthy control subjects during a visual paired-associates matching task. For the topographic analysis, we used a simple index of individual topographic deviation from normality, corrected for absolute potential intensities. Slow potentials were observed in all subjects. Control subjects showed a simple spatial pattern of voltage extrema (left central positive and right prefrontal negative), whereas schizophrenic patients presented a more complex, fragmented pattern. Topographic deviation was significantly different between groups (P<0.001). The increased topographic complexity in schizophrenics could be visualized in grand averages computed across subjects. Increased topographic complexity could also be seen when grand averages were computed for subgroups of patients assembled either according to task-performance (high versus low) or by their scores on psychopathological scales. There was no significant correlation between topographic deviation and psychopathology scores. We conclude that the slow potential topographic abnormalities of schizophrenia indicate an abnormality in the configuration of large-scale electrical activity in association cortices.

Colangiopancreatografia por resonancia magnética: estudio comparativo con la coloangiografía directa / Magnetic resonance cholangiopancreatography: comparative study with direct cholangiography

Magnetic Resonance Cholangiopancreatography (MRCP) is an emergent non invasive diagnostic technique for the study of pancreaticobiliary system. Following the contraindications of traditional Magnetic Resonance, the MRCP is safe for the patient. Images can be obtained without administration of any contrast and not using Rx. The objective of this study is to evaluate the sensitivity and the specificity of MRCP respect direct cholangiography ([endoscopic retrograde cholangiography (ERCP) and percutaneous transhepatic cholangiography (PTC)]. Forty one patients older than 60 years old were included, 19 male and 22 female, 73.5 median age. All of them have clinical diagnosis of obstructive jaundice. The patients were tested with MRCP first, and blinded of this results a direct cholangiography (DC) were done (ERCP 34 and PTC 8), less than 48 hs after MRCP. For the present study, the sensitivity was 100 per cent and specificity was 90 per cent of MRCP in the diagnosis of normal biliary tract. For the dilated biliary tract the sensitivity was 93 per cent and the specificity was 92 per cent . In bile duct obstruction the sensitivity was 88 per cent without false positive. MRCP diagnosed the presence of choledocholithiasis with a sensitivity of 74 per cent and specificity of 95 per cent, lower than reported in other studies. 73 per cent of our patients required some kind of therapeutic intervention. MRCP has high sensibility and specificity in the initial evaluation of patients with clinical obstructive jaundice and could replace the DC when is used for diagnostic purpose. (Au)

Colangiopancreatografia por resonancia magnética: estudio comparativo con la coloangiografía directa / Magnetic resonance cholangiopancreatography: comparative study with direct cholangiography

Magnetic Resonance Cholangiopancreatography (MRCP) is an emergent non invasive diagnostic technique for the study of pancreaticobiliary system. Following the contraindications of traditional Magnetic Resonance, the MRCP is safe for the patient. Images can be obtained without administration of any contrast and not using Rx. The objective of this study is to evaluate the sensitivity and the specificity of MRCP respect direct cholangiography ([endoscopic retrograde cholangiography (ERCP) and percutaneous transhepatic cholangiography (PTC)]. Forty one patients older than 60 years old were included, 19 male and 22 female, 73.5 median age. All of them have clinical diagnosis of obstructive jaundice. The patients were tested with MRCP first, and blinded of this results a direct cholangiography (DC) were done (ERCP 34 and PTC 8), less than 48 hs after MRCP. For the present study, the sensitivity was 100 per cent and specificity was 90 per cent of MRCP in the diagnosis of normal biliary tract. For the dilated biliary tract the sensitivity was 93 per cent and the specificity was 92 per cent . In bile duct obstruction the sensitivity was 88 per cent without false positive. MRCP diagnosed the presence of choledocholithiasis with a sensitivity of 74 per cent and specificity of 95 per cent, lower than reported in other studies. 73 per cent of our patients required some kind of therapeutic intervention. MRCP has high sensibility and specificity in the initial evaluation of patients with clinical obstructive jaundice and could replace the DC when is used for diagnostic purpose.

[Magnetic resonance cholangiopancreatography: comparative study with direct cholangiography]. / Colangiopancreatografía por resonancia magnética: estudio comparativo con la colangiografía directa.

Magnetic Resonance Cholangiopancreatography (MRCP) is an emergent non invasive diagnostic technique for the study of pancreaticobiliary system. Following the contraindications of traditional Magnetic Resonance, the MRCP is safe for the patient. Images can be obtained without administration of any contrast and not using Rx. The objective of this study is to evaluate the sensitivity and the specificity of MRCP respect direct cholangiography ([endoscopic retrograde cholangiography (ERCP) and percutaneous transhepatic cholangiography (PTC)]. Forty one patients older than 60 years old were included, 19 male and 22 female, 73.5 median age. All of them have clinical diagnosis of obstructive jaundice. The patients were tested with MRCP first, and blinded of this results a direct cholangiography (DC) were done (ERCP 34 and PTC 8), less than 48 hs after MRCP. For the present study, the sensitivity was 100% and specificity was 90% of MRCP in the diagnosis of normal biliary tract. For the dilated biliary tract the sensitivity was 93% and the specificity was 92%. In bile duct obstruction the sensitivity was 88% without false positive. MRCP diagnosed the presence of choledocholithiasis with a sensitivity of 74% and specificity of 95%, lower than reported in other studies. 73% of our patients required some kind of therapeutic intervention. MRCP has high sensibility and specificity in the initial evaluation of patients with clinical obstructive jaundice and could replace the DC when is used for diagnostic purpose.

Colangiopancreatografía por resonancia magnética: estudio comparativo con la colangiografía directa. / [Magnetic resonance cholangiopancreatography: comparative study with direct cholangiography]

Magnetic Resonance Cholangiopancreatography (MRCP) is an emergent non invasive diagnostic technique for the study of pancreaticobiliary system. Following the contraindications of traditional Magnetic Resonance, the MRCP is safe for the patient. Images can be obtained without administration of any contrast and not using Rx. The objective of this study is to evaluate the sensitivity and the specificity of MRCP respect direct cholangiography ([endoscopic retrograde cholangiography (ERCP) and percutaneous transhepatic cholangiography (PTC)]. Forty one patients older than 60 years old were included, 19 male and 22 female, 73.5 median age. All of them have clinical diagnosis of obstructive jaundice. The patients were tested with MRCP first, and blinded of this results a direct cholangiography (DC) were done (ERCP 34 and PTC 8), less than 48 hs after MRCP. For the present study, the sensitivity was 100

and specificity was 90

of MRCP in the diagnosis of normal biliary tract. For the dilated biliary tract the sensitivity was 93

and the specificity was 92

. In bile duct obstruction the sensitivity was 88

without false positive. MRCP diagnosed the presence of choledocholithiasis with a sensitivity of 74

and specificity of 95

, lower than reported in other studies. 73

of our patients required some kind of therapeutic intervention. MRCP has high sensibility and specificity in the initial evaluation of patients with clinical obstructive jaundice and could replace the DC when is used for diagnostic purpose.

[Salami worker's lung]. / Pulmón del sopleteador de salamines.

Hypersensitivity pneumonitis (HP) is the clinical manifestation of an pulmonary immunological reaction to inhaled antigens. The list of provocative antigens and specific illnesses grows permanently. A woman of 56 years consulted for dyspnea and cough of two months of evolution. She worked in a factory of sausages removing the dust that recovers the salamis during their stationing. She presented hypoxemia and the pulmonary function test revealed a predominantly obstructive pattern. The x-ray of the thorax was normal and the high resolution computed tomography showed a mosaic pattern. A lung biopsy confirmed the diagnosis of HP. She improved with systemic corticosteroids and the avoidance of antigen exposure. In the cultures of the material that recovers the salamis, Penicillium spp. was recovered and was interpreted as the probable etiological agent of this HP, which we have denominated "the salami worker's lung".

Pulmón del sopleteador de salamines. / [Salami workers lung]

Hypersensitivity pneumonitis (HP) is the clinical manifestation of an pulmonary immunological reaction to inhaled antigens. The list of provocative antigens and specific illnesses grows permanently. A woman of 56 years consulted for dyspnea and cough of two months of evolution. She worked in a factory of sausages removing the dust that recovers the salamis during their stationing. She presented hypoxemia and the pulmonary function test revealed a predominantly obstructive pattern. The x-ray of the thorax was normal and the high resolution computed tomography showed a mosaic pattern. A lung biopsy confirmed the diagnosis of HP. She improved with systemic corticosteroids and the avoidance of antigen exposure. In the cultures of the material that recovers the salamis, Penicillium spp. was recovered and was interpreted as the probable etiological agent of this HP, which we have denominated [quot ]the salami workers lung[quot ].

Efeito da época do ano na transferência de embriöes em vacas holandesas superovualdas com PMSG / Effect of season on embryo transfer in superovulated Holstein cows with PMSG

Estudou-se a influência de fatores sazonais na performance de 21 vacas da raça Holandesa submetidas a 37 superovulaçöes com 3.000 U.I. de PMSG. Os resultados das transferências de embriöes foram analisados segundo o efeito da época do ano: chuvosa (outubro a março) com temperatura máxima média = 30,0 ñ 0,8ºC e precipitaçäo pluviométrica mensal = 153,1 ñ 78,8 mm elevado ao cubo e seca (abril a setembro) com temperatura máxima média = 26,5 ñ 1,6ºC e precipitaçäo pluviométrica mensal = 59,2 ñ 53,8 mm elevado ao cubo. Registrou-se variaçäo climática entre as estaçöes (p<0,05), mas näo houve diferença significativa (p>0,05) entre épocas do ano quando foi comparado o número médio de estruturas por superovulaçäo (5,4 ñ 2,63 e 4,3 ñ 4,00), o percentual de embriöes viáveis (50,0 por cento e 57,6 por cento) e o percentual de prenhezes obtidas: 44,4 por cento e 35,2 por cento, respectivamente. Concluiu-se, portanto, que as diferentes condiçöes climáticas das épocas do ano näo influíram nas transferências de embriöes em vacas holandesas superovuladas com PMSG