Browsing by Author "Gomes, P."
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- APOBEC3 host factors modulate viral production and infectivity of HIV-2Publication . Bandarra, S.; Ribeiro, A. C.; Gomes, P.; Gonçalves, J.; Barahona, I.
- Biomechanical and physicochemical characterization of the rat’s osteoporotic bonePublication . Santos, C.; Carmezim, M. J.; Valido, A. J.; Colaço, B.; Fernandes, M. H.; Gomes, P.Osteoporosis is a clinical condition characterized by an increased risk of bone fracture. Structural fragility seems to result from a reduction in bone mass due to a decreased mineral content and impaired/altered protein synthesis. Despite the established knowledge on osteoporosis, little is known on how these compositional changes may affect the bone microarchitecture throughout different bones, and how these correlate with the attained increase of the fracture risk. This work aims to examine the relation between bone material properties and skeletal fragility in the femur, tibia, maxilla, mandible and calvarial structure of an animal model representative of the human osteoporotic condition, i.e., the ovariectomized Wistar rat. Two groups of animals, with 3 and 6 months following the induction of the osteoporotic condition were established, and bone tissue properties were compared to age-matched healthy controls. The biomechanical performance of different bones was tested by three-point bending. Structural (load-bearing capacity and stiffness), geometric (cross-sectional area, cortical sectional area, and moment of inertia) and material (modulus of elasticity and maximum elastic stress) properties were also evaluated, while morphological characterization was performed by FEGSEM. The organic content was determined by ash measurements and confocal Raman microscopy was used to evaluate compositional differences. Reported analyses showed that osteoporotic bones presented significant mechanical and morphological differences when compared with those from age-matched controls. Moreover, osteoporotic bones displayed a high ultimate tensile strength and were found to be more brittle than control bones. Attained differences could be related to the reduction in the collagen content, verified in osteoporotic conditions. These results highlight the role of the collagenous component in the structural and material properties of trabecular bone, and may account for the attained reduced bone mass in osteoporotic conditions.
- Coaching in pharmaceutical sciencesPublication . Moutinho, M. G. M.; Costa, I. M.; Cavaco-Silva, P.; Gomes, P.
- Evaluation of an in-house molecular HIV-1 test to assess mother-to-child HIV-1 transmission in Angola (the APEHC cohort)Publication . Martin, F.; Palladino, C.; Mateus, R.; Clemente, S.; Gomes, P.; Taveira, N."Mother-to-child-transmission (MTCT) rate has decreased sharply in recent years in most of the sub-Saharan Africa, however 220,000 children acquired HIV-1 in 2014. PCR detection of proviral DNA is the most sensitive method for early infant diagnosis (EID) of HIV-1 infection. Commercial kits are available but they have poor sensitivity with divergent non-B subtypes and high costs (≈30€ per test) which limit their use in resource-limited settings. The HIV-1 epidemic in Angola is driven by highly divergent strains of all group M subtypes, except B, as well as multiple recombinant forms (CRFs and URFs) making EID a challenge in this setting. The aim of this study was to develop and validate a qualitative, inexpensive and sensitive “inhouse” HIV-1 EID assay on heel prick dried blood spots (DBS) from infants of the Hospital da Divina Providência (HDP) in Luanda, Angola and determine the current HIV-1 MTCT rate in the Angolan PErinatal HIV Cohort (APEHC)."
- New findings in HCV genotype distribution in selected West European, Russian and Israeli regionsPublication . Kartashev, Vladimir; Döring, Matthias; Nieto, Leonardo; Coletta, Eleda; Kaiser, Rolf; Sierra, Saleta; HCV EuResist Study group; Guerrero, A.; Stoiber, H.; Paar, C.; Vandamme, A. M.; Nevens, F.; Ranst, M. Van; Cuypers, L.; Braun, P.; Ehret, R.; Obermeier, M.; Schneeweiss, S.; Scholten, S.; Römer, K.; Isernhagen, K.; Qurashi, N.; Heger, E.; Knops, E.; Neumann-Fraune, M.; Timm, J.; Walker, A.; Lübke, N.; Wedemeyer, H.; Wiesch, J. Schulze zur; Lütgehetmann, M.; Polywka, S.; Däumer, M.; Hoffmann, D.; Protzer, U.; Marascio, N.; Foca, A.; Liberto, M. C.; Barreca, G. S.; Galati, L.; Torti, C.; Pisani, V.; Perno, C. F.; Ceccherini-Silberstein, F.; Cento, V.; Ciotti, M.; Zazzi, M.; Rossetti, A.; De Luca, A.; Caudai, C.; Mor, O.; Devaux, C.; Staub, T.; Araujo, F.; Gomes, P.; Cabanas, J.; Markin, N.; Khomenko, I.; Govorukhina, M.; Lugovskaya, G.; Dontsov, D.; Mas, A.; Martró, E.; Saludes, V.; Rodríguez-Frías, F.; García, F.; Casas, P.; Iglesia, A. de la; Alados, J. C.; Pena-López, M. J.; Rodríguez, M. J.; Galán, J. C.; Suárez, A.; Cardeñoso, L.; Guerrero, M. D.; Vegas-Dominguez, C.; Blas-Espada, J.; García, R.; García-Bujalance, S.; Benítez-Gutiérrez, L.; Mendoza, C. de; Montiel, N.; Santos, J.; Viciana, I.; Delgado, A.; Martínez-Sanchez, P. A.; Fernández-Alonso, M.; Reina, G.; Trigo, M.; Echeverría, M. J.; Aguilera, A.; Navarro, D.; Bernal, S.; Lozano, M. C.; Fernández-Cuenca, F.; Orduña, A.; Eiros, J. M.; Ortíz de Lejarazu, R.; Martínez-Sapiña, A. M.; García-Díaz, A.; Haque, T.BACKGROUND: HCV affects 185 million people worldwide and leads to death and morbidities. HCV has a high genetic diversity and is classified into seven genotypes and 67 subtypes. Novel anti-HCV drugs (Direct-Acting-Antivirals) eligibility, resistance and cure rates depend on HCV geno/subtype (GT). OBJECTIVES: Analysis of epidemiological information and viral GT from patients undergoing viral genotyping in 2011-2015. STUDY DESIGN: Anonymized information from 52 centers was analyzed retrospectively. RESULTS: 37,839 samples were included in the study. We show that the GT distribution is similar throughout Western European countries, with some local differences. Here GTs 1 and 2 prevalences are lower and of GT4 higher than in all previous reports. Israel has a unique GT pattern and in South Russia the GT proportions are more similar to Asia. GTs 5 and 6 were detected in very low proportions. Three cases of the recombinant genotype P were reported in Munich (Germany). In addition, we observed that GT proportion was dependant on patientś gender, age and transmission route: GTs 1b and 2 were significantly more common in female, older, nosocomially-infected patients, while GTs 1a, 3 and 4 were more frequent in male, younger patients infected by tattooing, drug consume, and/or sexual practices. In infections acquired by drug consume, GTs 1a (35.0%) and 3 (28.1%) prevailed. In infections related to sexual practices lower proportion of GT3 (14.0%) and higher of GT4 (20.2%) were detected. GT4 was mostly abundant in MSM (29.6%). HIV coinfection was significantly associated with higher proportions GTs 1a and 4 (42.5% and 19.3%, respectively). CONCLUSION: Genotype prevalence evolves and correlates to epidemiological factors. Continuous surveillance is necessary to better assess hepatitis C infection in Europe and to take appropriate actions
- Predicted residual activity of rilpivirine in HIV-1 infected patients failing therapy including NNRTIs efavirenz or nevirapinePublication . Theys, K.; Camacho, R. J.; Gomes, P.; Vandamme, A. M.; Rhee, S. Y.; on behalf of the Portuguese HIV-1 Resistance Study Group"Rilpivirine is a second-generation nonnucleoside reverse-transcriptase inhibitor (NNRTI) currently indicated for first-line therapy, but its clinical benefit for HIV-1 infected patients failing first-generation NNRTIs is largely undefined. This study quantified the extent of genotypic rilpivirine resistance in viral isolates from 1212 patients upon failure of efavirenz- or nevirapine-containing antiretroviral treatment, of whom more than respectively 80% and 90% showed high-level genotypic resistance to the failing NNRTI. Of all study patients, 47% showed a rilpivirine resistance-associated mutation (RPV-RAM), whereas preserved residual rilpivirine activity was predicted in half of the patients by three genotypic drug resistance interpretation algorithms. An NNRTI-dependent impact on rilpivirine resistance was detected. Compared with the use of nevirapine, the use of efavirenz was associated with a 32% lower risk of having a RPV-RAM and a 50% lower risk of predicted reduced rilpivirine susceptibility. Most prevalent RPV-RAMs after nevirapine experience were Y181C and H221Y, whereas L100I+K103N, Y188L and K101E occurred most in efavirenz-experienced patients. Predicted rilpivirine activity was not affected by HIV-1 subtype, although frequency of individual mutations differed across subtypes. In conclusion, this genotypic resistance analysis strongly suggests that the latest NNRTI, rilpivirine, may retain activity in a large proportion of HIV-1 patients in whom resistance failed while they were on an efavirenz- or nevirapine-containing regimen, and may present an attractive option for second-line treatment given its good safety profile and dosing convenience. However, prospective clinical studies assessing the effectiveness of rilpivirine for NNRTI-experienced patients are warranted to validate knowledge derived from genotypic and phenotypic drug resistance studies."
- Resistance associated mutations to protease inhibitors on HIV-2 infected patients in PortugalPublication . Lopes, J.; Gonçalves, F.; Cabanas, J.; Costa, I.; Fernandes, S.; Diogo, I.; Pingarilho, M.; Gomes, P.