Brain Abscess Caused by Listeria monocytogenes: A Rare Case of Supratentorial Neurolisteriosis.

Listeria monocytogenes is a Gram-positive bacillus that presents a tropism for the central nervous system (CNS). In fact, CNS involvement occurs in over two-thirds of infections caused by this agent. Meningitis is the most common manifestation, while brain abscess is rare. We present the case of a 77-year-old male patient on corticosteroid treatment for bronchiolitis obliterans organizing pneumonia with a history of unpasteurized cheese consumption, who presented with fever and altered mental status. Brain computerized tomography scan revealed left frontal cortico-subcortical hypodensity mimicking an ischemic stroke. Subsequent magnetic resonance imaging revealed a brain abscess, and blood cultures yielded Listeria monocytogenes. A good clinical outcome was achieved after appropriate antimicrobial therapy and abscess drainage. This case underscores the importance of considering Listeria monocytogenes in CNS infections, especially in immunocompromised individuals over 65 years of age. The atypical supratentorial involvement challenges the more common rhombencephalitis presentation. Maintaining a high level of suspicion in relevant populations is crucial for timely diagnosis and intervention, especially in patients with comorbidities, who present particularly high mortality rates.

Abordagem ao período pós-operatório inicial no transplante de fígado: um ponto de vista institucional / Approach to the liver transplant early postoperative period: an institutional standpoint

RESUMO O programa de transplante de fígado teve início em nosso centro em 1992, e pacientes em pós-operatório de transplante hepático ainda são admitidos à unidade de terapia intensiva. Uma curva de aprendizado do médico intensivista teve então início, com aquisição de habilidades e estabelecimento de uma prática específica. Contudo, muitos dos conceitos se modificaram com o tempo, o que conduziu a uma melhora nos cuidados proporcionados a esses pacientes. A abordagem prática varia entre diferentes centros de transplante de fígado, segundo especificidades locais. Assim, ensejamos apresentar nossa prática para estimular o debate entre diferentes equipes dedicadas, o que tem potencial de permitir a introdução de novas ideias e, possivelmente, melhorar o padrão de cuidados em cada instituição.

ABSTRACT The liver transplant program in our center started in 1992, and post-liver transplant patients are still admitted to the intensive care unit. For the intensive care physician, a learning curve started then, skills were acquired, and a specific practice was established. Throughout this time, several concepts changed, improving the care of these patients. The practical approach varies between liver transplant centers, according to local specificities. Hence, we wanted to present our routine practice to stimulate the debate between dedicated teams, which can allow the introduction of new ideas and potentially improve each local standard of care.

Approach to the liver transplant early postoperative period: an institutional standpoint. / Abordagem ao período pós-operatório inicial no transplante de fígado: um ponto de vista institucional.

The liver transplant program in our center started in 1992, and post-liver transplant patients are still admitted to the intensive care unit. For the intensive care physician, a learning curve started then, skills were acquired, and a specific practice was established. Throughout this time, several concepts changed, improving the care of these patients. The practical approach varies between liver transplant centers, according to local specificities. Hence, we wanted to present our routine practice to stimulate the debate between dedicated teams, which can allow the introduction of new ideas and potentially improve each local standard of care.

O programa de transplante de fígado teve início em nosso centro em 1992, e pacientes em pós-operatório de transplante hepático ainda são admitidos à unidade de terapia intensiva. Uma curva de aprendizado do médico intensivista teve então início, com aquisição de habilidades e estabelecimento de uma prática específica. Contudo, muitos dos conceitos se modificaram com o tempo, o que conduziu a uma melhora nos cuidados proporcionados a esses pacientes. A abordagem prática varia entre diferentes centros de transplante de fígado, segundo especificidades locais. Assim, ensejamos apresentar nossa prática para estimular o debate entre diferentes equipes dedicadas, o que tem potencial de permitir a introdução de novas ideias e, possivelmente, melhorar o padrão de cuidados em cada instituição.

Dynamics of Rex3 in the genomes of endangered Iberian Leuciscinae (Teleostei, Cyprinidae) and their natural hybrids.

BACKGROUND: Iberian Leuciscinae are greatly diverse comprising taxa of hybrid origin. With highly conservative karyotypes, Iberian Chondrostoma s.l. have recently demonstrated sub-chromosomal differentiation and rapid genome restructuring in natural hybrids, which was confirmed by ribosomal DNA (rDNA) transposition and/or multiplication. To understand the role of repetitive DNAs in the differentiation of their genomes, a genetic and molecular cytogenetic survey was conducted in Achondrostoma oligolepis, Anaecypris hispanica, Iberochondrostoma lemmingii, I. lusitanicum, Pseudochondrostoma duriense, P. polylepis, Squalius pyrenaicus and hybrids between A. oligolepis x (P. duriense/P. polylepis), representing 'alburnine', chondrostomine and Squalius lineages. RESULTS: Partial Rex3 sequences evidenced high sequence homology among Leuciscinae (≥98 %) and different fish families (80-95 %) proposing a relatively recent activity of these elements in the species inspected. Low nucleotide substitution rates (<20 %) and intact ORFs suggests that Rex3 may in fact be active in these genomes. The chromosomal distribution of Rex3 retroelement was found highly concentrated at pericentromeric and moderately at subtelomeric blocks, co-localizing with 5S rDNA loci, and correlating with blocks of heterochromatin and C0t-1 DNA. This accumulation was evident in at least 10 chromosome pairs, a pattern that seemed to be shared among the different species, likely pre-dating their divergence. Nevertheless, species-specific clusters were detected in I. lusitanicum, P. duriense, P. polylepis and S. pyrenaicus demonstrating rapid and independent differentiation. Natural hybrids followed the same patterns of accumulation and association with repetitive sequences. An increased number of Rex3 clusters now associating also with translocated 45S rDNA clusters vouched for other genomic rearrangements in hybrids. Rex3 sequence phylogeny did not agree with its hosts' phylogeny but the observed distribution pattern is congruent with an evolutionary tendency to protect its activity, a robust regulatory system and/or events of horizontal transfer. CONCLUSIONS: This is the first report directed at retroelement physical mapping in Cyprinidae. It helped outlining conceivable ancestral homologies and recognizing retrotransposon activation in hybrids, being possibly associated with genome diversification within the subfamily. The extensive diversity of Iberian Leuciscinae makes them excellent candidates to explore the processes and mechanisms behind the great plasticity distinguishing vertebrate genomes.

Chromosomes of European cyprinid fishes: comparative cytogenetics and chromosomal characteristics of ribosomal DNAs in nine Iberian chondrostomine species (Leuciscinae).

Karyotypes and chromosomal features of both minor and major ribosomal RNA genes (rDNA) were investigated in nine Iberian chondrostomine species by fluorescent in situ hybridization (FISH) with 5S and 45S rDNA probes. All species presented invariably diploid values of 2n = 50 and the characteristic leuciscin karyotype pattern with 6-7 metacentric (m), 15-16 submetacentric (sm) and 3-4 subtelo- to acrocentric (st/a) chromosome pairs. The largest chromosome pair of the set was st/a as typical of Leuciscinae and no heteromorphic chromosomes could be unequivocally associated to sex determination. Achondrostoma occidentale and Pseudochondrostoma willkommii were cytogenetically characterized for the first time while Achondrostoma arcasii and Iberochondrostoma lemmingii were revisited regarding previous karyotype descriptions. Remarkable variability in number and location was observed for both molecular chromosome markers, especially within Achondrostoma and Iberochondrostoma genera. Clusters of 5S rDNA were mostly terminally associated to st/a chromosomes varying from four to eight positive signals, whilst NOR sites directly detected by the 45S rDNA probe were identified in sm chromosomes varying from three to six independent clusters. Frequent population bottlenecks in Mediterranean-type semiarid habitats were hypothesized to explain not only such extensive polymorphism which seems unique among leuciscin cyprinids but also the increased probability of fixation of rDNA translocation events.

Evaluation of DNA damage induced by environmental exposure to mercury in Liza aurata using the comet assay.

Mercury (Hg) is one of the major aquatic contaminants even though emissions have been reduced over the years. Despite the relative abundance of investigations carried out on Hg toxicity, there is a scarcity of studies on its DNA damaging effects in fish under realistic exposure conditions. This study assessed the Hg genotoxicity in Golden grey mullets (Liza aurata) at Laranjo basin, a particularly contaminated area of Ria de Aveiro (Portugal) well known for its Hg contamination gradient. (1) Fish were seasonally caught at Laranjo basin and at a reference site (S. Jacinto), and (2) animals from the reference site were transplanted and caged (at bottom and surface), for 3 days, in two different locations within Laranjo basin. Using the comet assay, blood was analyzed for genetic damage and apoptotic cell frequency. The seasonal survey showed greater DNA damage in the Hg-contaminated area for all sampling seasons excluding winter. The temporal variation pattern of DNA lesions was: summer approximately autumn > winter > spring. Fish caged at Laranjo also exhibited greater DNA damage than those caged at the reference site, highlighting the importance of gill uptake on the toxicity of this metal. No increased susceptibility to apoptosis was detected in either wild or caged fish, indicating that mercury damages DNA of blood cells by a nonapoptotic mechanism. Both L. aurata and the comet assay proved to be sensitive and suitable for genotoxicity biomonitoring in mercury-contaminated coastal systems.

Chromosome studies of European cyprinid fishes: interspecific homology of leuciscine cytotaxonomic marker-the largest subtelocentric chromosome pair as revealed by cross-species painting.

Leuciscine cyprinids possess a nearly invariant diploid number (2n = 50) with an extremely uniform karyotype comprising of 8 pairs of metacentric, 13-15 pairs of submetacentric and 2-4 pairs of subtelocentric (st) to acrocentric (a) chromosomes. The largest pair is characteristically an st/a element-the 'leuciscine' cytotaxonomic marker. Previously, the interspecific homology of this chromosome pair could not be assessed owing to the inability to produce euchromatic or serial banding patterns. In the present study, we used laser-microdissection (15-20 copies of the marker chromosome) to construct a whole chromosome probe (WCP) from the marker chromosome of the roach Rutilus rutilus to ascertain the interspecific homology of marker chromosomes by cross-species in-situ hybridization. WCP was hybridized to chromosomes of widely distributed (Abramis brama, Alburnoides bipunctatus, Alburnus alburnus, Aspius aspius, Ballerus ballerus, B. sapa, Blicca bjoerkna, Chondrostoma nasus, Leucaspius delineatus, Leuciscus leuciscus, L. idus, R. rutilus, Scardinius erythrophthalmus, Squalius cephalus, and Vimba vimba) and Iberian endemic species (Achondrostoma oligolepis, Iberochondrostoma almacai, I. lusitanicum, Pseudochondrostoma duriense, S. alburnoides and S. pyrenaicus). Cross-species in-situ hybridization to chromosomes of Phoxinus phoxinus, a representative of leuciscine sister lineage, showed the same pattern as in all of the leuciscins. The probe consistently hybridized to the distal part of the short arm of the marker chromosome, indicating sequence homology.