506 resultados para sheath
Resumo:
Objective: The aim of this study was to investigate the feasibility of transventricular-transseptal approach (TVSA) for extrapleural transcatheter aortic valved stent implantation via a subxyphoidian access. Methods: In five porcine experiments (52.3 +/- 10.9 kg) the right ventricle was exposed via subxyphoidian access. Under the guidance of intracardiac echocardiography (ICE) and fluoroscopy, the transseptal access from right ventricle to left ventricle was created progressively by puncture and dilation with dilators (8F-26F). Valved stents built in-house from commercial tanned pericardium and self-expandable Nitinol stents were loaded into a cartridge. A delivery sheath was then introduced from the right ventricle into the left ventricle and then into the ascending aorta. The cartridge was connected and the valved stent was deployed in the aortic position. Then, the ventricular septal access was sealed with an Amplatzer septal occluder device and the right ventricular access was closed by tying prepared purse-string suture directly. Thirty minutes after the whole procedure, the animals were sacrificed for macroscopic evaluation of the position of valved stent and septal closure device. Result: Procedural success of TVSA was 100% at the first attempt. Mean procedure time was 49 +/- 4 min. Progressive dilatation of the transseptal access resulted in a measurable ventricular septal defect (VSD) after dilator sizes 18F and more. All valved stents were delivered at the target site over the native aortic valve with good acute valve function and no paravalvular leaks. During the procedure, premature beats (5/5) and supraventriclar tachycardias (5/5) were observed, but no atrial-ventricular block (0/5) occurred. Heart rate before (after) was 90 +/- 3 beats min(-1) (100 +/- 2 beats min(-1): p < 0.05), whereas blood pressure was 60 + 1 mm Hg (55 + 2 mm Hg (p < 0.05)). Total blood loss was 280 + 10 ml. The Amplatzer septal occluder devices were fully deployed and the ventricular septal accesses were sealed successfully, without detectable residual shunt. Conclusion: Trans-catheter implantation of aortic valved stent via extrapleural transventricular-transseptal access is technically feasible and has the potential for a simplified procedure under local anaesthesia. (C) 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B. V. All rights reserved.
Resumo:
A method for hemodialysis catheter placement in patients with central thoracic venous stenosis or occlusion is described and initial results are analyzed. Twelve patients, with a mean age of 63.2 years (42-80 years), with central venous stenosis or occlusion, and who required a hemodialysis catheter were reviewed. All lesions were confirmed by helical CT or phlebography. Five patients had stenosis while seven patients were diagnosed with an occlusion of thoracic central veins. All patients were asymptomatic, without sign of superior vena cava syndrome. After percutaneous transstenotic catheterization or guidewire-based recannalization in occlusions, a balloon dilatation was performed and a stent was placed, when necessary, prior to catheter placement. Technical success was 92%. Three patients had angioplasty alone and nine patients had angioplasty with stent placement. Dialysis catheters were successfully inserted through all recannalized accesses. No immediate complication occurred, nor did any patient develop superior vena cava syndrome after the procedure. The mean follow-up was 21.8 months (range, 8-48 months). Three patients developed a catheter dysfunction with fibrin sheath formation (at 7, 11, and 12 months after catheter placement, respectively). Two were successfully managed by percutaneous endovascular approach and one catheter was removed. In conclusion, for patients with central venous stenosis or occlusion and those who need a hemodialysis catheter, catheter insertion can be reliably achieved immediately after endovascular recannalization with acceptable technical and long-term success rates. This technique should be considered as an alternative procedure for placing a new hemodialysis catheter through a patent vein.
Resumo:
Several anatomical parameters of the reproductive system have been used to distinguish Lymnaea cubensis from L. viatrix, the snail hosts of fascioliasis in South America and the Caribbean area. Three samples have been collected in the type localities of L. cubensis (Cuba), L. viatrix var. A ventricosa (Argentina, Río Negro Lower Valley), and L. viatrix var. B elongata (Peru, Lima), respectively. Only one parameter, the relative lengths of the penis sheath and preputium, showed significant differences between L. viatrix var. ventricosa and the two other taxa. None of the studied parameters separated L. cubensis from L. viatrix var. elongata.
Resumo:
Remyelination can be studied in aggregating rat brain cell cultures after limited demyelination. Demyelination was induced using a monoclonal antibody against myelin/oligodendrocyte glycoprotein (MOG mAb), in the presence of complement. De- and remyelination were assessed by measuring myelin basic protein (MBP). Two days after removing the MOG mAb, MBP levels reached 50% of controls and after 7 days 93%. During this period, cell proliferation determined by [14C]thymidine incorporation was similar in remyelinating and control cultures. Hormones and growth factors were tested for possible stimulatory effect on remyelinating cultures. Bovine growth hormone (bGH), triiodothyronine (T3), basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF) did not improve remyelination. Only epidermal growth factor (EGF) increased the level of remyelination. PDGF increased the rate of cell proliferation in both control and remyelinating cultures. A significant proportion of oligodendrocytes entered the cell division cycle and were not available for remyelination. The results obtained with PDGF and FGF (inhibition) support the idea that a pool of progenitor cells was still present and able to proliferate and differentiate into myelinating oligodendrocytes. The levels of myelin protein mRNAs were investigated during de- and remyelination. During demyelination, myelin protein mRNA levels decreased to approximately 50% of control cultures and returned to normal during remyelination. These preliminary results indicate that normal levels of gene transcription are sufficient to meet the increased need for newly synthesized myelin proteins during remyelination.
Resumo:
To link the presence of intrathecal virus-specific oligoclonal immunoglobulin G (IgG) in multiple sclerosis patients to a demyelinating activity, aggregating rat brain cell cultures were treated with antibodies directed against two viruses, namely, rubella (RV) and hepatitis B (HB). Anti-RV antibodies in the presence of complement decreased myelin basic protein concentrations in a dose-dependent manner, whereas anti-HB antibodies had no effect. A similar but less pronounced effect was observed on the enzymatic activity of 2',3'-cyclic nucleotide 3'-phosphohydrolase, which is enriched in noncompact membranes of oligodendrocytes. These effects were comparable to those in cultures treated with antibodies directed against myelin oligodendrocyte glycoprotein (MOG), previously found to be myelinotoxic both in vitro and in vivo. Sequence homologies were found between structural glycoprotein E(2) of RV and MOG, suggesting that demyelination was due to molecular mimicry. To support the hypothesis that demyelination was caused by anti-RV IgG that recognized an MOG epitope, we found that anti-RV antibodies depleted MOG in a dose-dependent manner. Further evidence came from the demonstration that anti-RV and anti-MOG IgG colocalized on oligodendrocyte processes and that both revealed by Western blot a 28 kDa protein in CNS myelin, a molecular weight corresponding to MOG. These findings suggest that a virus such as RV exhibiting molecular mimicry with MOG can trigger an autoimmune demyelination.
Resumo:
Capillary zone electrophoresis (CZE) with UV detection has been widely used for the determination of carbohydrate-deficient transferrin (CDT), an indirect marker of the chronic alcohol consumption (≥60-80g/day). A commercially available method (CEofix? CDT kit), containing a bilayer anionic coating, allows for the analysis of CDT with a high resolution between transferrin (Tf) glycoforms with reduced protein adsorption onto the capillary wall. Although widely used in routine analysis, this procedure presents some limitations in terms of selectivity and sensitivity which may be overcome with mass spectrometry (MS). However, the available method is not MS-compatible due to the non-volatile coating as well as the phosphate and borate buffers present in the background electrolyte (BGE). This study firstly consisted in developing MS-compatible separation conditions, i.e., coating and BGE compositions. Numerous cationic, neutral, and anionic coatings were evaluated in combination with BGEs covering a broad range of pH values. A bilayer coating composed of a cationic layer of 10% polybrene (m/v) and an anionic layer of 10% dextran sulfate (m/v) combined with a BGE composed of 20mM ammonium acetate at pH 8.5 provided the best results in terms of glycoforms' resolution, efficiency, adsorption reduction, migration times' repeatability, and coating stability. The method was then transferred to CZE-MS after investigations of the electrospray ionization (ESI) source, equipped with a sheath-flow interface, and the time-of-flight (TOF/MS) parameters. A successful MS detection of tetrasialo-Tf was obtained during infusion, while the experiments highlighted the challenges and issues encountered with intact glycoprotein analysis by CZE-ESI-MS.
Resumo:
INTRODUCTION: Smoothelin is a cytoskeletal protein of differentiated smooth muscle cells with contractile capacity, distinguishing it from other smooth muscle proteins, such as smooth muscle actin (SMA). OBJECTIVE: To evaluate the expression of smoothelin and SMA in the skin in order to establish specific localizations of smoothelin in smooth muscle cells with high contractile capacity and in the epithelial component of cutaneous adnexal structures. Methods: Immunohistochemical analysis (smoothelin and SMA) was performed in 18 patients with normal skin. RESULTS: SMA was expressed by the vascular structures of superficial, deep, intermediate and adventitial plexuses, whereas smoothelin was specifically expressed in the cytoplasm of smooth muscle cells of the deepest vascular plexus and in no other plexus of the dermis. The hair erector muscle showed intense expression of smoothelin and SMA. Cells with nuclear expression of smoothelin and cytoplasmic expression of SMA were observed in the outer root sheath of the inferior portion of the hair follicles and intense cytoplasmic expression in cells of the dermal sheath to SMA. CONCLUSIONS: We report the first study of smoothelin expression in normal skin, which differentiates the superficial vascular plexus from the deep. The deep plexus comprises vessels with high contractile capacity, which is important for understanding dermal hemodynamics in normal skin and pathological processes. We suggest that the function of smoothelin in the outer root sheath may be to enhance the function of SMA, which has been related to mechanical stress. Smoothelin has not been studied in cutaneous pathology; however we believe it may be a marker specific for the diagnosis of leiomyomas and leiomyosarcomas of the skin. Also, smoothelin could differentiate arteriovenous malformations of cavernous hemangioma of the skin
Resumo:
Proliferating trichilemmal cyst is a benign tumor that originates in the outer root sheath of hair follicle. Usually, it is located on the scalp in older women, but also have been reported in other sites such as back, chest, axilla, groin, gluteal region, thigh, vulva, and face. Malignant transformation of proliferating trichilemmal cyst is confirmed only on histological findings. This tumor has a variable biologic behavior with local recurrence and lymph node metastasis.
Resumo:
A clinically significant proportion of couples experience difficulty in conceiving a child. In about half of these cases male infertility is the cause and often genetic factors are involved. Despite advances in clinical diagnostics ∼50% of male infertility cases remain idiopathic. Based on this, further analysis of infertile males is required to identify new genetic factors involved in male infertility. This review focuses on cation channel of sperm (CATSPER)-related male infertility. It is based on PubMed literature searches using the keywords 'CATSPER', 'male infertility', 'male contraception', 'immunocontraception' and 'pharmacologic contraception' (publication dates from January 1979 to December 2009). Previously, contiguous gene deletions including the CATSPER2 gene implicated the sperm-specific CATSPER channel in syndromic male infertility (SMI). Recently, we identified insertion mutations of the CATSPER1 gene in families with recessively inherited nonsyndromic male infertility (NSMI). The CATSPER channel therefore represents a novel human male fertility factor. In this review we summarize the genetic and clinical data showing the role of CATSPER mutation in human forms of NSMI and SMI. In addition, we discuss clinical management and therapeutic options for these patients. Finally, we describe how the CATSPER channel could be used as a target for development of a male contraceptive.
Resumo:
OBJECTIVE: Off-pump trans left ventricular approach provides more precise deployment of stented aortic valve of any size with respect to the endovascular replacement. One of the key steps of this procedure is the ventricle repair after catheter withdrawing. We designed an animal study to compare the consistency of a sutureless repair of the left ventricle access using nitinol occluder with and without pericardial cuff on the ventricular side. METHODS: Material description: The Amplatz-nitinol occluder consists of two square heads squeezing ventricle wall in between them, sealing the defect. To improve its sealing property, a pericardial patch was sutured to the ventricular head of the occluder. Animal study setup: In adult pigs, a 30F sheath was inserted into the epigastric area through the cardiac apex, up to the left ventricle, simulating the approach for off-pump aortic valve replacement. The sheath was then removed and the ventricle closed with standard occluder in half of the animals, and cuffed occluder in the other half. Animals were followed-up for 3h, collecting haemodynamics data and pericardial bleeding. RESULTS: Device was successfully deployed in 12 animals in less than 1min. In the group where the standard occluder was used, bleeding during the deployment was 80+/-20ml and after the deployment was 800+/-20ml over 3h. In the group where the cuffed occluder was used, bleeding during the deployment was 85+/-20ml and after the deployment was 100+/-5ml over 3h. In the cuffed group, bleeding was significantly lower than the standard group, p-value being <0.001. CONCLUSIONS: The occluder is easy to use and the pericardial cuff dramatically increases its efficacy as demonstrated by a significant reduction of blood loss. The cuffed occluder opens the way for endoscopic, off-pump, transventricular aortic valve replacement.
Resumo:
A 2-kilogram child had a pacemaker implanted by a subxyphoid approach with the generator located under the rectus sheath. Days later, the battery eroded the abdominal wall and the peritoneum. The whole system was removed and a new one was implanted inside the pericardium on an emergent basis.
Resumo:
The case of a 38-year old man with recurrent adenocarcinoma of the right lung and infiltration of the thoracic wall, who underwent a right pneumonectomy with thoracic wall resection, is described. Dissection of the right pulmonary hilous was extremely difficult due to the previous operations. The superior vena cava (SVC) was accidentally ligated, resulting in profound hypotension and increased venous pressure in the internal jugular vein. Immediate blood aspiration through a 8.5-French introducer sheath lowered the venous congestion. After the SVC was cross-clamped, the Bispectral Index (BIS) acutely decreased to 0 and remained low during the resuscitation. Over the next 5 hours, BIS was directly affected by mean arterial pressure. Four days postoperatively, the patient was neurologically intact.
Resumo:
Multiple sclerosis is an inflammatory demyelinating disease affecting the central nervous system and considered one of the leading causes of disability in young adults. The precise cause of multiple sclerosis is unknown, although the current evidence points towards a combination of genetic and environmental factors leading to an autoimmune response that promotes neuronal degeneration. In this review, we will describe the association between the immune response and neurodegeneration in multiple sclerosis.
Resumo:
There is an ever-growing trend towards less-invasive procedures in all fields of medicine. We designed an animal study to prove the concept that trans-apical aortic valve replacement from an incision within the umbilicus through a single channel for instruments is feasible, which would be a major leap towards no-scar cardiac surgery. In three adult pigs, after creating a single 3-cm incision at a place where the human umbilicus would be, we introduced a 30F sheath through a tunnel created by an endoscopic vein-harvesting device up to the cardiac apex, through it and up to the left ventricle simulating the approach for trans-apical aortic valve replacement. We used a standard Amplatz nitinol occluder to seal the defect in ventricle wall later. The animals were followed up for 1h. Blood loss was minimal, and no tamponade occurred in any of the animals. In addition, we performed a test with water column static pressure to evaluate the impact of preclotting on the sealing properties of the occluders: 1 min flow-through was 2860+/-176 ml for the standard occluders and 348+/-56 ml for preclotted occluders (p<0.001).
Resumo:
The D2-protein is a high molecular weight protein involved in interneuronal adhesion. The concentration of D2-protein was measured both in aggregates of fetal rat telencephalic cells cultured in a chemically defined medium and in developing forebrain. Both the concentration of the D2-protein and the degree of sialylation were changed in the cultures in parallel with the corresponding values obtained from postnatal forebrain. In the cultures the highest specific concentration of D2-protein was observed after 12 days in culture. This value was 2.7 times higher than the average value of adult rat forebrain. Antibodies to D2-protein have previously been shown to inhibit fasciculation of neuritic fibers extending from cultured explants of sympathetic ganglia. We investigated the effect of such antibodies on the differentiation of aggregating telencephalic cells. By adding surplus antibodies to the cultures from day 11 to day 16 we were able to decrease the specific concentration of D2-protein on the neurons by 53% measured at day 19. The decrease was not compensated fully even after further 10 days in the culture. Although the concentration of D2-protein was decreased during the period of synaptogenesis no change was found in the specific concentration of a marker of mature synapses, the D3-protein. Thus, in this culture system synaptogenesis could proceed to an unimpaired extent in the presence of a decreased concentration of a putatively involved adhesion molecule. However, the specific concentration of two markers of myelination, 2',3'-cyclic nucleotide 3'-phosphodiesterase and myelin basic protein, were both increased, suggesting an antibody-induced stimulation of myelination in the cultured aggregates.