2,945 research outputs found
Stathmin recruits tubulin to Listeria monocytogenes-induced actin comets and promotes bacterial dissemination
The tubulin cytoskeleton is one of the main components of the cytoarchitecture and is involved in several cellular functions. Here, we examine the interplay between Listeria monocytogenes (Lm) and the tubulin cytoskeleton upon cellular infection. We show that non-polymeric tubulin is present throughout Lm actin comet tails and, to a less extent, in actin clouds. Moreover, we demonstrate that stathmin, a regulator of microtubule dynamics, is also found in these Lm-associated actin structures and is required for tubulin recruitment. Depletion of host stathmin results in longer comets containing less F-actin, which may be correlated with higher levels of inactive cofilin in the comet, thus suggesting a defect on local F-actin dynamics. In addition, intracellular bacterial speed is significantly reduced in stathmin-depleted cells, revealing the importance of stathmin/tubulin in intracellular Lm motility. In agreement, the area of infection foci and the total bacterial loads are also significantly reduced in stathmin-depleted cells. Collectively, our results demonstrate that stathmin promotes efficient cellular infection, possibly through tubulin recruitment and control of actin dynamics at Lm-polymerized actin structures.This work received funding from Norte-01-0145-FEDER-000012—Structured program on bioengineered therapies for infectious diseases and tissue regeneration, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). ACC and FC were supported by a Fundação para a Ciência e Tecnologia (FCT) Post-doctoral Fellowship (SFRH/BPD/88769/2012) and Ph.D. fellowship (SFRH/BD/61825/2009), respectively, through FCT/MEC co-funded by QREN and POPH (Programa Operacional Potencial Humano). SS was supported by FCT Investigator program (COMPETE, POPH, and FCT). We thank ALM unit from IBMC/i3S for technical support, B. Fonseca (FFUP) for the BeWo cell line and H. Maiato, C. Sunkel and
J. B. Relvas laboratories (IBMC/i3S) for sharing reagents. We are also thankful to J. Ferreira and A. Pereira for fruitful discussions
New Functionalized Macroparticles for Environmentally Sustainable Biofilm Control in Water Systems
Reverse osmosis (RO) depends on biocidal agents to control the operating costs associated to biofouling, although this implies the discharge of undesired chemicals into the aquatic environment. Therefore, a system providing pre-treated water free of biocides arises as an interesting solution to minimize the discharge of chemicals while enhancing RO filtration performance by inactivating bacteria that could form biofilms on the membrane system. This work proposes a pretreatment approach based on the immobilization of an industrially used antimicrobial agent (benzalkonium chloride-BAC) into millimetric aluminum oxide particles with prior surface activation with DA-dopamine. The antimicrobial efficacy of the functionalized particles was assessed against Escherichia coli planktonic cells through culturability and cell membrane integrity analysis. The results showed total inactivation of bacterial cells within five min for the highest particle concentration and 100% of cell membrane damage after 15 min for all concentrations. When reusing the same particles, a higher contact time was needed to reach the total inactivation, possibly due to partial blocking of immobilized biocide by dead bacteria adhering to the particles and to the residual leaching of biocide. The overall results support the use of Al2O3-DA-BAC particles as antimicrobial agents for sustainable biocidal applications in continuous water treatment systems
Seroprevalence of Bordetella pertussis in healthcare workers in a Portuguese tertiary referral hospital
info:eu-repo/semantics/publishedVersio
Association of Intestinal Malrotation and Bochdalek Hernia in an Adult: a Case Report
Background
Late presentations of congenital diaphragmatic hernia are rare and differ from the classic neonatal presentation. The association with other congenital malformations in children, mainly intestinal malrotation, is well documented. The diagnosis of this association in adults is very rare, and depends on a high degree of suspicion.
Case presentation
We report a case of a 50-year-old female Caucasian patient with a previous history of intestinal malrotation diagnosed in adolescence and treated conservatively. She was referred to the hospital with signs and symptoms of intestinal obstruction. The patient undertook computed tomography that confirmed small bowel obstruction with no obvious cause, and a right subphrenic abscess with right empyema was also present. An exploratory laparotomy was performed that revealed an intestinal malrotation associated with a right gangrenous and perforated Bochdalek hernia. Resection of the affected small bowel, closure of the Bochdalek foramen and the Ladd procedure were carried out.
Conclusion
This case shows a rare association of two rare conditions in adults, and highlights the challenge in reaching the diagnosis and management options
Combined low-carbohydrate diet and long-term exercise in hypoxia in type 2 diabetes: A randomized controlled trial protocol to assess glycemic control, cardiovascular risk factors and body composition
Background: Cardiovascular disease is the leading cause of mortality associated with diabetes, which is characterized by chronic hyperglycemia. Low-carbohydrate diet has gained popularity as an intervention in patients with type 2 diabetes mellitus, acting to improve glycemic profile and serum lipids. In its turn, exercise in hypoxia induces specific adaptations, mostly modulated via hypoxia-induced transcription factor signaling cascade, which increases with exposure to altitude, and promotes angiogenesis, glycogen supply, glucose tolerance, and raises GLUT-4 expression. Aim: Given that hyperglycemia decreases HIF-1 and it is better controlled when following a low-carbohydrate diet, this study aims to examine the hypothesis that a combination of both low-carbohydrate diet and chronic exercise in hypoxia in type 2 diabetes mellitus is associated with improved glycemic control and cardiovascular parameters, whose protocol is described. Methods: Patients with type 2 diabetes mellitus ( n=48) will be recruited and randomized into one of the three groups: (a) Control group: Control diet (low-fat and moderate-carbohydrate diet)+exercise in normoxia; (2) exercise in hypoxia group: Control diet+exercise in hypoxia; (3) intervention group: Low-carbohydrate diet (low-carbohydrate and high-fat diet)+exercise in hypoxia. Before and after 8 weeks of interventions, cardiopulmonary tests (Bruce protocol), body composition and blood pressure will be evaluated. Blood samples will be collected to measure hypoxia-induced transcription factor, C-reactive protein, glycemic and lipid profiles. Summary: This will be the first trial to examine the isolated and combined effect of chronic exercise in hypoxia and low-carbohydrate diet in type 2 diabetes mellitus. This trial will help to fill a significant research gap, guide future research and contribute to the combined nutrition and exercise approach to type 2 diabetes mellitus. </jats:p
Gastric Outlet Obstruction in a Patient with Bouveret's Syndrome: a Case Report
BACKGROUND: Gallstone ileus accounts for 1% to 4% of cases of mechanical bowel obstruction, but may be responsible for up to 25% of cases in older age groups. In non-iatrogenic cases, gallstone migration occurs after formation of a biliary-enteric fistula. In fewer than 10% of patients with gallstone ileus, the impacted gallstones are located in the pylorus or duodenum, resulting in gastric outlet obstruction, known as Bouveret's syndrome.
CASE PRESENTATION: We report an 86-year-old female who was admitted to hospital with a 10-day history of persistent vomiting and prostration. She was in hypovolemic shock at the time of arrival in the emergency department. Investigations revealed a gallstone in the duodenal bulb and a cholecystoduodenal fistula. She underwent surgical gastrolithotomy. Unfortunately, she died of aspiration pneumonia on the fourth postoperative day.
CONCLUSION: This case shows the importance of considering Bouveret's syndrome in the differential diagnosis of gastric outlet obstruction, especially in the elderly, even in patients with no previous history of gallbladder disease
The Need for Robust, Consistent Methods in Societal Exergy Accounting
© 2017 The AuthorsStudies of societal exergy use have the common aim of tracing the flow of exergy along society, and are used to gain insights into the efficiency of energy use and linkages to economic growth. However, their methodological approaches vary greatly, with significant impacts on results. Therefore, we make a review of past studies to identify, synthesize and discuss methodological differences, to contribute to a more consistent and robust approach to societal exergy accounting. Issues that should be taken into account when making methodological options are discussed and key insights are presented: (1) For mapping of primary inputs and useful exergy categories, the inclusion of all natural resources is more consistent but it has the cost of not being able to distinguish the various energy end-uses in the production of materials. (2) To estimate primary electricity, none of the methods currently used is able to capture simultaneously the efficiency of the renewable energy sector, the environmental impact and the efficiency of energy use in society. (3) To estimate final-to-useful exergy conversion efficiencies, standard thermodynamic definitions should be used because the use of proxies fails to distinguish between increases in exergy efficiency and increases in the efficiency of providing energy services
Síndrome de Bouveret. Entidade Rara e de Elevada Mortalidade
O íleus biliar representa 1 a 4% das obstruções intestinais mecânicas, podendo no entanto ser responsável até 25% dos casos, em faixas etárias superiores. O mecanismo não iatrogénico subjacente à migração do cálculo é a formação de uma fístula bilio-entérica. Em menos de 10% dos doentes com íleus biliar, a localização do cálculo impactado é o duodeno ou piloro, o que resulta numa obstrução ao esvaziamento gástrico e conhecido por síndrome de Bouveret.
Apresentamos um caso de uma doente de 86 anos admitida no hospital por quadro clínico de oclusão intestinal alta com instabilidade hemodinâmica. Após estabilização, esta foi submetida a exames complementares de diagnóstico que revelaram presença de cálculo biliar a nível do bulbo duodenal e fístula colecisto-duodenal. Foi abordada cirurgicamente com realização de gastrolitotomia. No primeiro dia de pós-operatório, como intercorrência a doente exteriorizou a sonda naso-gástrica e em consequência apresentou um episódio de vómito com aspiração. Faleceu no quarto dia de pós-operatório por pneumonia de aspiração.
Este caso pretende mostrar a importância da inclusão desta entidade no diagnóstico diferencial de uma obstrução ao esvaziamento gástrico, sobretudo na população geriátrica mesmo que sem antecedentes de litíase vesicular sintomática
In vitro and in vivo characterization of PLLA-316L stainless steel electromechanical devices for bone tissue engineering—A preliminary study
Bone injuries represent a major social and financial impairment, commonly requiring surgical intervention due to a limited healing capacity of the tissue, particularly regarding critical-sized defects and non-union fractures. Regenerative medicine with the application of bone implants has been developing in the past decades towards the manufacturing of appropriate devices. This work intended to evaluate medical 316L stainless steel (SS)-based devices covered by a polymer poly (L-lactic acid) (PLLA) coating for bone lesion mechanical and functional support. SS316L devices were subjected to a previously described silanization process, following a three-layer PLLA film coating. Devices were further characterized and evaluated towards their cytocompatibility and osteogenic potential using human dental pulp stem cells, and biocompatibility via subcutaneous implantation in a rat animal model. Results demonstrated PLLA-SS316L devices to present superior in vitro and in vivo outcomes and suggested the PLLA coating to provide osteo-inductive properties to the device. Overall, this work represents a preliminary study on PLLA-SS316L devices’ potential towards bone tissue regenerative techniques, showing promising outcomes for bone lesion support.This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, FCT Ref. UID/CTM/50011/2019, financed by national funds through the FCT/MCTES and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. This work was also financed by Portugal 2020 through the European Regional Development Fund (ERDF), in the frame of Operational Competitiveness and Internationalization Programme (POCI), in the scope of the project “Advanced BioMEMs for tissue engineering: Applications in hard tissue (BioMEMs)”, POCI-01-0145-FEDER-032095. Mariana Vieira Branquinho (SFRH/BD/146172/2019), Ana Catarina Sousa (SFRH/BD/146689/2019), and Rui Damásio Alvites (SFRH/BD/116118/2016), acknowledge FCT, for financial support
- …