327 research outputs found
First record of Alosa fallax (Lacépède, 1803) (Teleostei: Clupeiformes:Clupeidae) in the Azores Archipelago, Portugal (NE Atlantic)
Copyright © 2014 All rights reserved.This note reports the first record of Alosa fallax (Lacépède, 1803) in the Azores Archipelago (NE Atlantic, Portugal). Being an anadromous species, this occurrence is quite unexpected since there are no suitable breeding habitats for this species in these volcanic islands, isolated and river less. Although A. fallax is known to migrate offshore, it has never been previously reported in oceanic environments. We discuss this occurrence and theorize on the possibility of the species’ being found in Madeira, another Macaronesian Archipelago, albeit much older and closer to European coasts and thus more suitable to be crossed by A. fallax during their migration routes in pelagic environments. With this record, the number of Clupeid fishes for Azorean waters increases to two, the other being the well known and resident Sardina pilchardus
Occurrence of Grammicolepis brachiusculus Poey, 1873 (Pisces: Grammicolepididae) in the Azores Archipelago
Three specimens of Grammicolepis brachiusculus were caught by the commercial bottom hand and longline fisheries off Terceira and Faial Islands, Azores Archipelago. This is the first record of the species for the region, and one of few ever caught in the NE Atlantic
Stratégie alimentaire et ontogénie trophique de Scorpaena maderensis (Scorpaeniformes: Scorpaenidae) des Açores, Atlantique NE
Copyright © 2014 Société Française d'Ichtyologie.Feeding habits of Scorpaena maderensis Valenciennes, 1833 from the Azores archipelago were investigated. The stomach contents of 245 specimens, collected between August 1997 and July 1999, were analysed. Decapod crustaceans and teleost fishes constitute the main food items, revealing a high level of specialization by S. maderensis. Ontogenic shifts and seasonal changes in the diet composition were observed, unveiling the adaptability and opportunistic predatory behaviour of this scorpaenid.RÉSUMÉ: Les habitudes alimentaires de Scorpaena maderensis Valenciennes, 1833 de l'archipel des Açores ont été étudiées. Les contenus stomacaux de 245 spécimens, récoltés entre août 1997 et juillet 1999, ont été analysés. Les crustacés décapodes et les téléostéens sont les principales proies de S. maderensis, indiquant un fort degré de spécialisation chez cette espèce. Des changements ontogénétiques et saisonniers de la composition du régime alimentaire révèlent l’adaptabilité et le comportement prédateur opportuniste de ce scorpaenidé
Detection of Escherichia coli O157 by Peptide Nucleic Acid Fluorescence In Situ Hybridization (PNA-FISH) and Comparison to a Standard Culture Method
Despite the emergence of non-O157 shiga toxin-producing Escherichia coli (STEC) infections, E. coli O157 serotype is still the most commonly identified STEC in world. It causes high morbidity and mortality, and has been responsible for a number of outbreaks in many parts of the world. Various methods have been developed to detect this particular serotype, but standard bacteriological methods remain as the gold standard.In here, we propose a new peptide nucleic acid fluorescence in situ hybridization (PNA-FISH) method for the rapid detection of E. coli O157.Testing on 54 representative strains showed that the PNA probe is highly sensitive and specific to E. coli O157. Then, the method was optimized for the detection in food samples. Ground beef and unpasteurized milk samples were artificially contaminated with E. coli O157 concentrations ranging from 1×10-2 to 1×102 CFU per 25g or ml of food. Samples were then pre-enriched and analyzed by both the traditional bacteriological method (ISO 16654:2001) and PNA-FISH. The PNA-FISH method performed well in both types of food matrixes with a detection limit of 1 CFU/25 g or ml of food samples. Tests on 60 food samples have shown a specificity value of 100% (95% CI 82.83 - 100), a sensitivity of 97.22% (95% CI, 83.79 - 99.85) and an accuracy of 98,33% (CI 95%, 83.41 - 99.91). Results indicate that PNA-FISH performed as well as the traditional culture methods and can reduce the diagnosis time to 1 day.This work was supported by the Portuguese Institute Fundacao para a Ciencia e Tecnologia (FCT), project PIC/IC/82815/2007. C.A. acknowledges FCT for individual postdoctoral fellowship SFRH/BPD/74480/2010. We also acknowledge Biomode S.A. for providing some supplies for this project
Application of fluorescence in situ hybridisation using peptide nucleic acid probes in gastric samples for detection of Helicobacter pylori clarithromycin resistance
Microorganisms are responsible for several infectious diseases that can cause severe problems to patients and their treatment success is seriously correlated with the fast detection of the infectious agent. Some of the standard methods used, such as culturing methods are fastidious and time-consuming and do not give any information about the antibiotic resistance profile. Therefore, molecular methods have been developed during the last several years in order to overcome these shortcomings. In this work a new genotypic method that permits the identification of the microorganism in clinical samples in a prompt way is proposed. This technique is based on Fluorescence in situ hybridization with PNA probes that are synthetic molecules, complementary to a specific rRNA sequence of the microorganism.
Methods: A set of PNA probes were designed concerning H. pylori point mutations regarding clarithromycin resistance which is the main problem of gastric diseases treatment failure. An additional probe concerning susceptibility was also designed. After hybridization conditions optimization, probes were applied to H. pylori smears to achieve their practical sensitivity and specificity. At the end they were applied to gastric biopsies in a retrospective study for method validation in real samples. E-test and PCR-sequencing were used to evaluate the results.
Results: The probes concerning clarithromycin resistance hybridized only with the resistant strains that had the corresponding point mutations and as such presented 100% sensitivity (95% CI, 79.9-100) and 100% specificity (95% CI, 71.6-100). Results also showed that it is possible to discriminate susceptible from resistant H. pylori strains in gastric biopsy samples since it was presented similar results between the 3 tests used. Overall, the PNA-FISH method was in full agreement with PCR-sequencing although it was a little bit lower when compared to E-test that it was used as gold standard method in this retrospective study (86%).
Conclusion: PNA-FISH proved to be an important in situ method for detection of microorganisms in clinical samples in a more prompt way than the standard methods. Due to high H. pylori probes sensitivity and specificity it is proved the applicability of PNA-FISH methodology to clinical material, thus overcoming the need of culturing steps and/or PCR/sequencing procedures and enabling rapid initiation of appropriate antibiotic therapy until culture confirmation several days later
Multi-biologic group analysis for an ecosystem response to longitudinal river regulation gradients
This work assesses the effects of river regulation on the diversity of different instream and riparian biological communities along a relieve gradient of disturbance in regulated rivers. Two case studies in Portugal were used, with different river regulation typology (downstream of run-of-river and reservoir dams), where regulated and free-flowing river stretches were surveyed for riparian vegetation, macrophytes, bryophytes, macroalgae, diatoms and macroinvertebrates. The assessment of the regulation effects on biological communities was approached by both biological and functional diversity analysis. Results of this investigation endorse river regulation as a major factor differentiating fluvial biological communities through an artificial environmental filtering that governs species assemblages by accentuating species traits related to river regulation tolerance. Communities' response to regulation gradient seem to be similar and insensitive to river regulation typology. Biological communities respond to this regulation gradient with different sensibilities and rates of response, with riparian vegetation and macroinvertebrates being the most responsive to river regulation and its gradient. Richness appears to be the best indicator for general fluvial ecological quality facing river regulation. Nevertheless, there are high correlations between the biological and functional diversity indices of different biological groups, which denotes biological connections indicative of a cascade of effects leading to an indirect influence of river regulation even on non-responsive facets of communities' biological and functional diversities. These results highlight the necessary holistic perspective of the fluvial system when assessing the effects of river regulation and the proposal of restoration measures.publishe
PNA-FISH as a new diagnostic method for the determination of clarithromycin resistance of Helicobacter pylori
<p>Abstract</p> <p>Background</p> <p>Triple therapy is the gold standard treatment for <it>Helicobacter pylori </it>eradication from the human stomach, but increased resistance to clarithromycin became the main factor of treatment failure. Until now, fastidious culturing methods are generally the method of choice to assess resistance status. In this study, a new genotypic method to detect clarithromycin resistance in clinical samples, based on fluorescent <it>in situ </it>hybridization (FISH) using a set of peptide nucleic acid probes (PNA), is proposed.</p> <p>Results</p> <p>The set of probes targeting the point mutations responsible for clarithromycin resistance was applied to <it>H. pylori </it>suspensions and showed 100% sensitivity and specificity (95% CI, 79.9-100 and 95% CI, 71.6-100 respectively). This method can also be amenable for application to gastric biopsy samples, as resistance to clarithromycin was also detected when histological slides were tested.</p> <p>Conclusions</p> <p>The optimized PNA-FISH based diagnostic method to detect <it>H. pylori </it>clarithromycin resistance shown to be a very sensitive and specific method for the detection of clarithromycin resistance in the <it>H. pylori </it>smears and also proved to be a reliable method for the diagnosis of this pathogen in clinical samples and an alternative to existing plating methods.</p
Antifungal activity of a new derivative of 5-aminoimidazole-4-carbohydrazonamide
[Excerpt] Fungal infections, as recognized by the World Health Organization (WHO), are among the most
worrying challenges for the medical community due to their high incidence, recurrence, and the
emergence of resistance to the few available drugs and therapies. The discovery of new molecules
with antifungal activity, exhibiting new mechanisms of action and less side effects, thus represents an
important step forward in the development of alternative treatments [1]
Reproduction of the blue jack mackerel, Trachurus picturatus, in western Portugal: microscopic gonad analysis reveals indeterminate fecundity and skipped spawning patterns
Blue jack mackerel, Trachurus picturatus, is the fifth most landed fish species in mainland Portugal, but
information on its reproductive biology is scarce. From September 2018 to August 2019, 626 specimens
were collected from commercial vessels to clarify the reproductive strategy of the T. picturatus population
off the west coast of Portugal. The proportion and length range of males and females were similar. Only
three of the specimens collected were categorized as immature, indicating that the fish caught in the
fishery are primarily mature. The spawning season lasted from late January until the end of March, with
gonadosomatic indices being similar for males and females. Fecundity was indeterminate, and estimated
batch fecundity ranged between 6,798 (at 25.4 cm TL) and 302,358 oocytes (at 33.8 cm TL). The low
number of females showing direct evidence of imminent or recent spawning suggests a low number
of spawning events. In addition, 12.7% of females were considered non-reproductive due to ovary
abnormalities including parasitic infection by Kudoa species, atretic structures and skipped spawning
events. This study highlights the importance of accounting for skipped spawning events and ovary
abnormalities in the management of species fisheries.info:eu-repo/semantics/publishedVersio
Expression of tumor suppressors miR-195 and let-7a as potential biomarkers of invasive breast cancer
OBJECTIVE: MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at the posttranscriptional level. Some miRNAs, including let-7a and miR-195, have been described as tumor suppressors. However, the roles of these microRNAs in breast cancer progression remain controversial. The aim of this study is to evaluate miR-195 and let-7a expression as potential biomarkers of invasive breast cancer. METHODS: In the present study, 200 individuals were separated into three groups: (i) 72 women constituting the control group who were selected according to rigorous and well-established criteria; (ii) 56 patients with benign breast tumors; and (iii) 72 patients with malignant breast cancers of different clinical stages. The miR-195 and let-7a expression levels in serum were evaluated by real-time PCR. The results were assessed alone and in combination, and the analysis included an estimation of sensitivity and specificity in ROC curves. RESULTS: Compared with the benign and control groups, both microRNAs were downregulated in the malignant breast cancer patient group. Compared with the malignant group, the combination of both biomarkers in the control and benign groups showed good sensitivity and specificity in the serum with AUCs of 0.75 and 0.72, respectively. The biomarker combination for the control group versus the malignant group exhibited a better sensitivity and specificity than for the benign group versus the malignant group. CONCLUSION: These findings support the evidence that the analysis of miR-195 and let-7a can be used as a noninvasive biomarker for breast cancer detection
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