2,139 research outputs found
In vivo assessment of gastrotomy closure with over-the-scope clips in an experimental model for varicocelectomy
BACKGROUND:
Gastrotomy closure remains the major limiting factor for human translation of transgastric surgery; the over-the-scope clip (OTSC) system was proposed as a possibility for this purpose. Transgastric access is good for a pelvic approach, making varicocelectomy a possible indication for natural orifice transluminal endoscopic surgery (NOTES).
OBJECTIVE:
To evaluate the reliability of the OTSC system in vivo after transgastric testicular vessel ligation (varicocelectomy model).
DESIGN:
There were 3 experimental groups (5 animals in each): groups 1 and 3, gastrotomy dilation up to 18 mm, surgery was performed with a double-channel endoscope; group 2, gastrotomy dilation up to 13 mm, surgery was performed with a single-channel endoscope.
SETTING:
Surgical Sciences Research Domain, Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal.
INTERVENTIONS:
Bilateral testicular vessel ligation by transgastric access. Gastrotomy closed with the largest version of OTSC system (12 mm): a single clip in groups 1 and 2, and 2 clips in group 3. Animals were monitored for 2 weeks, killed, and submitted for necropsy.
MAIN OUTCOME MEASUREMENTS:
Adequacy of closure and healing after the use of the OTSC system. Statistical analysis.
RESULTS:
Vessel ligation was easily achieved in all groups. Although differences in the complication rate did not reach statistical significance (P = .099), there was a clear tendency for a better prognosis in groups 2 and 3 than group 1. In fact, only 2 animals from group 1 had complications related to incomplete gastrotomy closure.
LIMITATIONS:
Small number of animals per group; nonrandomized study.
CONCLUSIONS:
The OTSC system was shown to be easy and efficient for gastrotomy closure in a survival experimental model of varicocelectomy, when correctly matching the gastrotomy size with the clip size and/or number
Hybrid endoscopic thymectomy : combined transesophageal and transthoracic approach in a survival porcine model with cadaver assessment
BACKGROUND:
Video-assisted thoracoscopic surgery thymectomy has been used in the treatment of Myastenia Gravis and thymomas (coexisting or not). In natural orifice transluminal endoscopic surgery, new approaches to the thorax are emerging as alternatives to the classic transthoracic endoscopic surgery. The aim of this study was to assess the feasibility and reliability of hybrid endoscopic thymectomy (HET) using a combined transthoracic and transesophageal approach.
METHODS:
Twelve consecutive in vivo experiments were undertaken in the porcine model (4 acute and 8 survival). The same procedure was assessed in a human cadaver afterward. For HET, an 11-mm trocar was inserted in the 2nd intercostal space in the left anterior axillary line. A 0° 10-mm thoracoscope with a 5-mm working channel was introduced. Transesophageal access was created through a submucosal tunnel using a flexible gastroscope with a single working channel introduced through the mouth. Using both flexible (gastroscope) and rigid (thoracoscope) instruments, the mediastinum was opened; the thymus was dissected, and the vessels were ligated using electrocautery alone.
RESULTS:
Submucosal tunnel creation and esophagotomy were performed safely without incidents in all animals. Complete thymectomy was achieved in all experiments. All animals in the survival group lived for 14 days. Thoracoscopic and postmortem examination revealed pleural adhesions on site of the surgical procedure with no signs of infection. Histological analysis of the proximal third of the esophagus revealed complete cicatrization of both mucosal defect and myotomy site. In the human cadaver, we were able to replicate all the procedure even though we were not able to identify the thymus.
CONCLUSIONS:
Hybrid endoscopic thymectomy is feasible and reliable. HET could be regarded as a possible alternative to classic thoracoscopic approach for patients requiring thymectomy.This project was funded by the FCT Grants project PTDC/SAU-OSM/105578/2008
Third-generation cholecystectomy by natural orifices: transgastric and transvesical combined approach (with video)
BACKGROUND:An isolated transgastric port has some limitations in performing transluminal endoscopic cholecystectomy. However, transvesical access to the peritoneal cavity has recently been reported to be feasible and safe.OBJECTIVE:To assess the feasibility and the technical benefits of transgastric and transvesical combined approach to overcome the limitations of isolated transgastric ports.DESIGN:We created a transgastric and transvesical combined approach to perform cholecystectomy in 7 consecutive anesthetized female pigs. The transgastric access was achieved after perforation and dilation of the gastric wall with a needle knife and with a balloon, respectively. Under cystoscopic control, an ureteral catheter, a guidewire, and a dilator of the ureteral sheath were used to place a transvesical 5-mm overtube into the peritoneal cavity. By using a gastroscope positioned transgastrically and a ureteroscope positioned transvesically, we carried out cholecystectomy in all animals.RESULTS:Establishment of transvesical and transgastric accesses took place without complications. Under a carbon dioxide pneumoperitoneum controlled by the transvesical port, gallbladder identification, cystic duct, and artery exposure were easily achieved in all cases. Transvesical gallbladder grasping and manipulation proved to be particularly valuable to enhance gastroscope-guided dissection. With the exclusion of 2 cases where mild liver-surface hemorrhage and bile leak secondary to the sliding of cystic clips occurred, all remaining cholecystectomies were carried out without incidents.LIMITATIONS:Once closure of the gastric hole proved to be unreliable when using endoclips, the animals were euthanized; necropsy was performed immediately after the surgical procedure.CONCLUSIONS:A transgastric and transvesical combined approach is feasible, and it was particularly useful to perform a cholecystectomy through exclusive natural orifices
Análise do acúmulo de transcritos de ?-3-dessaturases em genótipos de soja contrastantes para o teor de ácido linolênico.
Os ácidos graxos poliinsaturados, como linoléico e linolênico, são os principais responsáveis pela alta instabilidade oxidativa a altas temperaturas do óleo destinado a frituras e à fabricação de biodiesel. A biossÃntese de ácidos graxos poliinsaturados é catalisada pelas dessaturases. A -6-dessaturase converte ácido oléico (18:19) a linoléico (18:29,12) e a -3-dessaturase produz ácido linolênico (18:39,12,15) a partir de 18:29,12. Três genes principais (GmFAD3A, GmFAD3B e GmFAD3C) foram caracterizados como responsáveis pela produção de -3-dessaturase em soja. Os mecanismos precisos de regulação da produção de ácido linolênico ainda não são muito claros, o que dificulta o processo de obtenção de genótipos com baixo conteúdo desse ácido graxo. A análise molecular de mutantes de soja com baixo conteúdo de ácido linolênico poderá ajudar a elucidar tais mecanismos. Os objetivos principais deste trabalho foram determinar os nÃveis de mRNAs das principais -3-dessaturases, correlacionando-os com as concentrações relativas de ácidos linolênico durante a ontogenia da semente de soja em genótipos normais e mutantes. Para isso, foram utilizados três genótipos contrastantes para essa caracterÃstica: A29, (~1% 18:315,12,9); N85-2176 (~3% 18:315,12,9) e Tucunaré (Variedade comercial, ~8% 18:315,12,9). As plantas foram cultivadas em casa de vegetação e suas sementes foram coletadas separadamente em 5 estádios de desenvolvimento de acordo com o peso úmido da semente: 1º estádio: 0 a 125 mg; 2º estádio: 126 a 250 mg; 3º estádio: 251 a 375 mg; 4º estádio: superior a 376 mg; 5 º estádio: semente madura. Os teores de ácidos graxos na fração óleo das sementes nos cinco estádios de desenvolvimento foram determinados por cromatografia gasosa e a expressão gênica, por PCR quantitativo, utilizando como o controle endógeno o gene da GAPDH (gliceraldeÃdo-3-fosfato desidrogenase). De modo geral, o conteúdo de 18:39,12,15 decresceu drasticamente nos estádios iniciais em todos os genótipos. No entanto, não foi observada expressão diferencial entre os genes GmFAD3A, GmFAD3B e GmFAD3C, que pudessem explicar tais alterações. O genótipo A29, seguido de N85-2176, apresentou a menor concentração de 18:39,12,15 durante todo o desenvolvimento da semente. Estes genótipos apresentaram expressão praticamente nula do gene GmFAD3A. Além disso, A29 apresentou expressão reduzida do gene GmFAD3B. Assim, pelo menos em parte, os nÃveis de transcritos dos genes GmFAD3A e GmFAD3B explicam as diferenças na concentração de ácidos graxos da fração óleo em A29 e N85-2176. Apoio financeiro: CNPq e CAPES
Health Care Workers Occupational Accidents in a Brazilian Hospital
Universidade Federal de São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc
Health Care Worker Immune Status and Risk Perception of Acquisition of Vaccine Preventable Diseases
Universidade Federal de São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc
Expressão de genes de referência para uso em reações de qPCR em genótipos de soja contrastantes para o conteúdo de ácido oléico cultivados sob diferentes temperaturas.
Swimming and risk of asthma and allergies in Portuguese school aged children
[resumo][abstract
Insights into corrosion behaviour of uncoated Mg alloys for biomedical applications in different aqueous media
MgCa and MgGd series of alloys are often reported as promising candidates for biomedical
applications. In the present study, cytotoxicity and corrosion behavior of Mg1Ca and
Mg10Gd alloys in different electrolytes (NaCl, PBS, MEM) have been investigated in order to
make a direct comparison and understand the mechanisms behind their performance.
Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were
employed to analyze corrosion processes depending on media composition, whereas X-Ray
diffraction (XRD) and scanning electron microscopy (SEM) were used to evaluate crystalline
structure, phase composition and surface morphology of the corroded substrates after
immersion in the different electrolytes. Moreover, cytotoxicity of the Mg alloys was
assessed using the WST-1 reduction and lactate dehydrogenase (LDH) release assays in
L929 mouse fibroblasts. The electrochemical results showed that Mg1Ca has a lower
degradation rate when compared to Mg10Gd, due to the lower microgalvanic effects and
the presence of Ca as an alloying element. Furthermore, the corrosion activity is reduced in
MEM, for both alloys, when compared to NaCl and PBS. The cytotoxicity assays revealed
that Mg10Gd was cytotoxic in all the conditions tested, while the toxicity of Mg1Ca was
low. Overall, these findings show that Mg1Ca alloy presents a higher corrosion resistance
and biocompatibility and is a promising material to be used in biomedical implants.This work was financed by Portugal 2020 through European
Regional Development Fund (ERDF) in the frame of Operational
Competitiveness and Internationalization Programme (POCI),
in the scope of the project MAGICOAT POCI-01-0145-FEDER016597/PTDC/CTM-BIO/2170/2014 and in the scope of the project CICECO - Aveiro Institute of Materials, UIDB/50011/2020 &
UIDP/50011/2020, financed by national funds through
the Portuguese Foundation for Science and Technology/
MCTES. Furthermore, thanks are due to Portuguese Foundation
for Science and Technology/MCTES for the financial support
through national funds to EPI Unit (UIDB/04750/2020).info:eu-repo/semantics/publishedVersio
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