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Jorge Almeida

Publications and source records attributed to Jorge Almeida.

9 recordsLinked to original sources
PubMed2026

The Convergence of Antimicrobial Resistance and Virulence in Streptococcus pneumoniae: A Molecular and Clinical Perspective.

Antimicrobial resistance (AMR) and virulence have traditionally been viewed as competing traits in bacterial evolution due to fitness costs. However, Streptococcus pneumoniae has emerged as a paradigm of successful coevolution, with multidrug-resistant clones simultaneously maintaining or enhancing pathogenic potential. This review examines the molecular mechanisms, epidemiological patterns, and clinical consequences of the convergence between AMR and virulence in Streptococcus pneumoniae. Resistance to β-lactams is driven by mosaic penicillin-binding protein genes (pbp1a, pbp2b, pbp2x), while macrolide resistance is mediated primarily by the erm(B) gene (MLS phenotype) and mef(A/E)-msr(D) genes encoding an efflux system. These determinants are frequently co-localized on integrative and conjugative elements, ICEs, (e.g., Tn916 family) within successful clonal complexes such as CC271/320 and lineages including ST320 and GPSC10. Contrary to the classical fitness cost hypothesis, compensatory epistasis, capsular recombination, metabolic adaptations, and intra-serotype phenotypic variation enable certain clones to combine high-level resistance to β-lactams, macrolides, and tetracyclines with enhanced colonization, biofilm formation, immune evasion, and invasive capacity. Post-pneumococcal conjugate vaccine (PCV) surveillance reveals the persistence and expansion of these high-risk lineages, contributing to treatment-refractory invasive pneumococcal disease (IPD), increased morbidity, and mortality. Although PCVs have reduced vaccine-type resistant strains in some settings, serotype replacement and emerging metabolic genotypes continue to drive adaptation. This review highlights the need for integrated genomic surveillance, novel therapeutics (e.g., omadacycline, lefamulin, endolysins), monoclonal antibodies, and next-generation vaccines targeting both resistance and conserved virulence determinants. A multifaceted strategy combining antimicrobial stewardship, strengthened surveillance, and innovative interventions is essential to curb the evolving threat of resistant and virulent S. pneumoniae.

Streptococcus pneumoniae↗
PubMed2006

[Portal pseudo-hypertension].

Authors present a case report of a 51 years old man, with a past history of peptic ulcer, arterial hypertension and dislipidemia. Three weeks before hospitalization he did a upper endoscopy that revealed a duodenal ulcer and oesophageal varices (grade II/III). During etiologic investigation, hepatic disease and portal hypertension were excluded. He had a goiter that invaded the anterior mediastinum. After thyroidectomy the oesophageal varices disappeared.

Diagnosis, Differential↗
PubMed2006

Lexical selection in bilingual speech production does not involve language suppression.

The "hard problem" in bilingual lexical access arises when translation-equivalent lexical representations are activated to roughly equal levels and, thus, compete equally for lexical selection. The language suppression hypothesis (D. W. Green, 1998) solves this hard problem through the suppression of lexical representations in the nontarget language. Following from this proposal is the prediction that lexical selection should take longer on a language switch trial because the to-be-selected representation was just suppressed on the previous trial. Inconsistent with this prediction, participants took no longer to name pictures in their dominant language on language switch trials than they did on nonswitch trials. These findings indicate that nontarget lexical representations are not suppressed. The authors suggest that these results undermine the viability of the language suppression hypothesis as a possible solution to the hard problem in bilingual lexical access.

Adolescent↗
PubMed2005

Flower symmetry and shape in Antirrhinum.

According to their symmetry, flowers are classified as radially symmetrical or bilaterally symmetrical. Bilateral symmetry, which is thought to have evolved from radial symmetry, results from establishment of asymmetry relative to a dorsoventral axis of flowers. Here we consider developmental genetic mechanisms underlying the generation of this asymmetry and how they relate to controls of petal shape and growth in Antirrhinum. Two genes, CYC and DICH, are expressed in dorsal domains of the Antirrhinum flower and determine its overall dorsoventral asymmetry and the asymmetries and shapes of individual floral organs, by influencing regional growth. Another gene, DIV, influences regional asymmetries and shapes in ventral regions of the flower through a quantitative effect on growth. However, DIV is not involved in determining the overall dorsoventral asymmetry of the flower and its effects on regional asymmetries depend on interactions with CYC/DICH. These interactions illustrate how gene activity, symmetry, shape and growth may be related.

Antirrhinum↗
PubMed2002

Role of DIVARICATA in the control of dorsoventral asymmetry in Antirrhinum flowers.

Dorsoventral asymmetry of the Antirrhinum corolla depends on expression of the CYC and DICH genes in dorsal petals. One role of these genes is to inhibit DIVARICATA (DIV), a determinant of ventral identity. Therefore, in cyc;dich double mutants ventral identity spreads all around the flower. We show that DIV encodes a protein belonging to the MYB family of transcription factors. Early on in corolla development, DIV affects specifically the growth of ventral and lateral petals but is transcribed in all petals. Analysis of a closely related gene suggests that the lack of effect on dorsal petals is not due to redundancy. More likely, therefore, DIV is regulated posttranscriptionally through a mechanism that depends on CYC and DICH. Later on, DIV affects growth and cell types and is transcribed mostly in a single layer of cells of ventral and lateral petals. This late pattern may itself depend on DIV activity because it fails to be established in a transcribed but inactive div mutant and, conversely, spreads all around the flower in cyc;dich double mutants.

Alleles↗
PubMed2002

Pseudoaneurysm of the mitral-aortic fibrosa: myocardial ischemia secondary to left coronary compression.

In the current study we describe the cases of 2 patients operated on for left-sided endocarditis, who later had myocardial ischemia develop secondary to left coronary artery compression from a pseudoaneurysm of the mitral-aortic fibrosa. Because the symptoms of angina persisted despite medical treatment, both patients had second surgeries. Myocardial revascularization was performed in 1 patient; the other patient, who had a severely depressed ventricular function, was given an orthotopic cardiac transplant.

Adult↗
PubMedDate not supplied

Mitral valve regurgitation--quantification by Doppler echo (quantitative versus semi-quantitative methods).

Quantification of mitral regurgitation is still a controversial issue. Because quantitative analysis using the volumetric method is time-consuming, semi-quantitative analysis based on the characteristics of the regurgitant jet in the left atrium is the method used in daily clinical practice, despite its recognized limitations. In the last ten years various papers have proposed the PISA method as an alternative to the volumetric one, as the same quantitative parameters--regurgitant volume (RV) and effective regurgitant orifice (ERO)--can be obtained with a small number of measurements. The aim of the present study was to determine the degree of correlation and agreement between the two quantitative methods and to what extent the semi-quantitative analysis parameters correlated with the quantitative ones. We also compared the performance of the PISA method and semi-quantitative analysis in grading mitral regurgitation severity, using the volumetric method as gold standard. The study enrolled 77 patients (pts) aged 62 +/- 13 years (43 M and 34 F) with at least moderate mitral regurgitation determined by standard two-dimensional Doppler echo color flow imaging. The etiology of mitral valve regurgitation was: degenerative prolapse--40 pts (52%), ischemic--24 (31%), dilated cardiomyopathy--4 (5%), other pathologies-9 (12%). A sonographer performed the examinations under the supervision of one of two senior cardiologists. All quantitative Doppler measurements and calculations were performed on-line and the examinations recorded on videotape. Good correlations were found between RV (r = 0.81, p < 0.001, SE +/- 25) and ERO (r = 0.85, p < 0.001, SE +/- 17) measurements obtained by the two quantitative methods. However, the agreement was weakened by significant individual differences, particularly in the patients with degenerative prolapse. A satisfactory correlation was found between the jet area (JA) evaluated by semi-quantitative analysis and the RV and ERO calculated by both quantitative methods, with JA showing a tendency to underestimate the degree of mitral regurgitation in eccentric jets and to overestimate it in jets with central orientation. ROC curve analysis was used to evaluate the accuracy of ERO calculated by PISA and the JA by color Doppler in identifying different grades of mitral regurgitation defined by the values of ERO in the volumetric method. The calculated values of the area under the curve for the PISA ERO were higher than those for JA in the identification of patients with mild 0.93 (0.84-0.97) vs. 0.80 (0.70-0.89) p = 0.005 as well as severe mitral regurgitation 0.95 (0.87-0.98) vs. 0.81 (0.71-0.90) p = 0.006).

Adult↗
PubMedDate not supplied

[Isolated surgery of tricuspid insufficiency in valvular reoperation].

BACKGROUND AND AIMS OF THE STUDY: Development of late tricuspid regurgitation (TR) following prior operation on left heart valves is associated with an important impairement of functional status and adverse prognosis. Indications and outcomes of surgery in this setting are not well defined. Our Department experience in isolated TR in valve reoperation is evaluated. METHODS: Twenty-four patients underwent isolated tricuspid valve surgery because of severe TR following a prior operation on left heart valves between January/1990 and July/2003. Patients with congenital heart disease, traumatic TR, infectious endocarditis or left heart valve disfunction were excluded. The retrospective and observational study of this group of patients included clinical echocardiographic, haemodynamic and surgical data evaluation. RESULTS: Mean follow-up time was 4.4+/-3.5 years and included all patients. There was no operative mortality but actuarial survival at six years was 48%. No risk factors for late death were identified. CONCLUSIONS: Isolated tricuspid surgery for severe TR in patients with previous left heart valve surgery can be done with acceptable hospital mortality. Low operative mortality does not mean medium term good results. High late mortality and unsatisfactory functional results should lead us to consider other options when treating tricuspid valve regurgitation.

Cardiac Surgical Procedures↗