Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Bioinformatics ; 38(12): 3315-3317, 2022 06 13.
Artículo en Inglés | MEDLINE | ID: mdl-35579370

RESUMEN

MOTIVATION: Lattice light-sheet microscopy (LLSM) is revolutionizing cell biology since it enables fast, high-resolution extended imaging in three dimensions combined with a drastic reduction in photo-toxicity and bleaching. However, analysis of such datasets still remains a major challenge. RESULTS: Automated tracking of kinetochores, the protein complex facilitating and controlling microtubule attachment of the chromosomes within the mitotic spindle, provides quantitative assessment of chromosome dynamics in mitosis. Here, we extend existing open-source kinetochore tracking software (KiT) to track (and pair) kinetochores throughout prometaphase to anaphase in LLSM data. One of the key improvements is a regularization term in the objective function to enforce biological information about the number of kinetochores in a human mitotic cell, as well as improved diagnostic tools. This software provides quantitative insights into how kinetochores robustly ensure congression and segregation of chromosomes during mitosis. AVAILABILITY AND IMPLEMENTATION: KiT is free, open-source software implemented in MATLAB and can be downloaded as a package from https://github.com/cmcb-warwick/KiT. The source repository is available at https://bitbucket.org/jarmond/kit (tag v2.4.0) and under continuing development. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Asunto(s)
Cinetocoros , Huso Acromático , Humanos , Huso Acromático/genética , Anafase , Microtúbulos/metabolismo , Programas Informáticos , Segregación Cromosómica
2.
J Card Surg ; 35(6): 1267-1274, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32353922

RESUMEN

OBJECTIVES: This study assessed the feasibility and outcomes of performing robotic cardiac surgery without lung isolation using single-lumen (SL) endotracheal tube intubation. METHODS: Between 2013 and 2017, 132 patients underwent robotically-assisted atrial septal defect closure. A retrospective analysis was performed of 23 patients (11 males, mean age 30.9 ± 5 years) who underwent robotic surgery with double-lumen (DL) endotracheal tube intubation (group 1) compared with 109 patients (57 males, mean age 32.4 ± 7.5 years) undergoing the same procedure with SL endotracheal intubation (group 2). The patient groups were compared in terms of demographic characteristics, operative data, and complications. The technical feasibility of the robotic procedure without lung isolation was evaluated. RESULTS: There were no mortality, intraoperative complication, and conversion. Mean total anesthesia time was significantly decreased in the SL intubation group (238.3 ± 22.4 vs 227.2 ± 21.2 minutes; P = .025). First-pass intubation success was significantly higher in the SL intubation group (17 [73.9%] vs 98 [89.9%] patients; P = .032). Mean ventilation time (10.9 ± 5.3 hours), intensive care unit stay (16.8 ± 10.1 hours), and the length of hospital stay (3.8 ± 1.2 days) was significantly decreased in patients with SL tube (P < .05). Unilateral reexpansion pulmonary edema was observed in five (21.7%) patients with DL tube, whereas no patient with SL tube had this complication. CONCLUSIONS: SL endotracheal tube intubation without lung isolation is a feasible and safe airway alternative in robotic cardiac procedures. This approach resulted in shorter anesthesia time, ventilation time and the length of hospital stay. Port placement and robotic set-up can be uneventfully performed without lung isolation.


Asunto(s)
Anestesia/métodos , Procedimientos Quirúrgicos Cardíacos/métodos , Intubación Intratraqueal/métodos , Procedimientos Quirúrgicos Robotizados/métodos , Adulto , Estudios de Factibilidad , Femenino , Humanos , Intubación Intratraqueal/efectos adversos , Tiempo de Internación , Pulmón , Masculino , Tempo Operativo , Estudios Retrospectivos , Resultado del Tratamiento
3.
J Card Surg ; 35(10): 2469-2476, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32789962

RESUMEN

BACKGROUND: Pulmonary artery perfusion during cardiopulmonary bypass (CPB) is a known but rarely used technique in adult cardiac surgery. In this study, we aimed to investigate biochemical and histopathological effects of pulmonary artery perfusion during CPB on lung functions. METHODS: Between May 2014 and August 2014, all patients (n = 24) who gave informed consent for participating this study with inclusion criteria were included. Patients undergoing isolated coronary artery bypass grafting were sequentially randomized to conventional CPB (control group, n = 12) and conventional CPB with selective pulmonary artery perfusion (study group, n = 12). Lung functions were monitored using PF ratio, alveolar-arterial oxygen gradient, and lactate levels. A small sample tissue from the left lung was excised for histopathologic examination. Immunocytochemistry analysis was performed using anti-rabbit polyclonal vascular endothelial growth factor (VEGF), rabbit polyclonal inducible nitric oxide synthase (i-NOS), and BCL-2 antibodies. RESULTS: Postoperative course of the patients were uneventful without any clinical outcome differences in terms of cardiopulmonary complications, ventilation time and hospital stay. Pulmonary perfusion group had significantly better oxygenation values after extubation and at postoperative 24-hour. Electron microscopy examinations revealed better preservation of the alveolar wall integrity with pulmonary perfusion. The intensity of VEGF, i-NOS, and BCL-2 antibody expressions in bronchial epithelial cells were more prominent in the pulmonary perfusion group. CONCLUSIONS: Pulmonary artery perfusion during aortic cross-clamping provides better oxygenation and preservation of the wall alveolar integrity after coronary artery bypass grafting surgery. This technique can be used as a protective strategy to minimize CPB-induced lung injury in adult cardiac surgery.


Asunto(s)
Lesión Pulmonar Aguda/etiología , Lesión Pulmonar Aguda/prevención & control , Puente Cardiopulmonar/efectos adversos , Perfusión/métodos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Arteria Pulmonar , Lesión Pulmonar Aguda/diagnóstico , Lesión Pulmonar Aguda/patología , Adulto , Anciano , Biomarcadores/análisis , Biomarcadores/sangre , Recuento de Células Sanguíneas , Proteína C-Reactiva , Puente de Arteria Coronaria/métodos , Femenino , Hemoglobinas , Humanos , Inflamación , Pulmón/patología , Pulmón/ultraestructura , Masculino , Persona de Mediana Edad , Óxido Nítrico Sintasa de Tipo II/análisis , Recuperación de la Función , Esternotomía , Factor A de Crecimiento Endotelial Vascular/análisis
4.
J Card Surg ; 35(12): 3623-3625, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33001482

RESUMEN

We present a case with a large left ventricular (LV) thrombus that presented to the emergency department with dyspnea. Bedside transthoracic echocardiography demonstrated a huge hypermobile thrombus with a maximum of 8.6 × 2 cm in size extending to the aortic valve originating from the aneurysmatic apical wall of the LV. Treatment of the patient included complete thrombus resection with aneurysmectomy.


Asunto(s)
Ventrículos Cardíacos , Trombosis , Válvula Aórtica , Ecocardiografía , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/cirugía , Humanos , Trombosis/diagnóstico por imagen , Trombosis/cirugía
5.
Heart Surg Forum ; 23(3): E258-E263, 2020 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-32524980

RESUMEN

BACKGROUND: This study aimed to examine the effect of pulsatile flow pattern on tissue perfusion, particularly cerebral tissue perfusion, at pre-determined intervals during CPB, as well as its effects on postoperative morbidity and mortality. METHODS: This retrospective study included 134 adult patients, who underwent cardiac surgery with cardiopulmonary bypass (CPB). Patients were grouped based on the flow pattern used during CPB: non-pulsatile CPB group (N = 82) and pulsatile CPB group (N = 52). Cerebral oxygen saturation, arterial pH and arterial lactate levels were measured at four time points, during the operation and the 2 groups were compared with regard to changes over time as well as differences in postoperative outcomes. RESULTS: The 2 groups were similar, in terms of mean values and intraoperative changes in cerebral oxygen saturation and arterial pH. Non-pulsatile CABG group had significantly higher arterial lactate levels over the measurement period, which was not affected by the timing of the measurements. Postoperative drainage, duration of ventilation and duration of hospital stay significantly were higher and postoperative blood urea nitrogen significantly was lower in the non-pulsatile CPB group. Other postoperative outcomes were similar across the groups. CONCLUSION: Findings of this study do not support the superiority of pulsatile flow pattern during CPB, in terms of cerebral oxygen saturation or postoperative mortality/morbidity. Further and larger comparative studies are warranted before pulsatile blood flow pattern can be established as a routine clinical method.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos/métodos , Puente Cardiopulmonar/métodos , Monitoreo Intraoperatorio/métodos , Consumo de Oxígeno/fisiología , Flujo Pulsátil/fisiología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
6.
Artif Organs ; 43(4): 342-349, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30207600

RESUMEN

Robotic surgery for intracardiac pathologies in children is relatively uncommon. This study presents our initial experience with robotic-assisted cardiac surgery in children. We also present the feasibility and safety of robotic surgery in children. From May 2013 to June 2018, 30 children underwent totally endoscopic robotic atrial septal defect closure (n = 22), right-sided (n = 5) or left-sided (n = 1) partial anomalous pulmonary venous connection repair, tricuspid valve annuloplasty (n = 4), and mitral valve replacement (n = 2, due to Barlow and rheumatic diseases). The mean age of the patients was 16.1 ± 1.1 years (range, 13-17) and the mean weight was 56.7 ± 0.1 kg (range, 42-77). Associated anomalies included left persistent superior vena cava (n = 2) and the absence of innominate vein (n = 1). All procedures were completed uneventfully. Operation time was 4.1 ± 0.6 h. No patient was converted to thoracotomy or sternotomy. Cardiopulmonary bypass and aortic clamping times were 90.6 ± 28.0 (range, 45-136) and 48.6 ± 24.9 (range, 15-94) min, respectively. The mean ventilation time was 3.7 ± 1.2 h and hospital stay time was 3.3 ± 0.7 days. No right phrenic nerve injury, hemorrhage, or blood transfusion were noted. One patient had postoperative pneumothorax, and 1 had supraventricular arrhythmia. Follow-up was a mean of 1.7 years (range, 1-52 months). Patients were healthy and no residual intracardiac defect was observed on echocardiography examinations. There was no operative or follow-up mortality. Robotically assisted cardiac surgery is a feasible and safe approach in selected pediatric patients. In the future, new generation robotic devices may offer an alternative surgical approach in cardiac surgery for younger children with lower body weight.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos/métodos , Procedimientos Quirúrgicos Robotizados/métodos , Adolescente , Endoscopía/métodos , Femenino , Defectos del Tabique Interatrial/cirugía , Humanos , Masculino , Válvula Mitral/cirugía , Venas Pulmonares/anomalías , Venas Pulmonares/cirugía , Válvula Tricúspide/cirugía
7.
PLoS Genet ; 12(2): e1005834, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26882497

RESUMEN

The spindle checkpoint is a mitotic surveillance system which ensures equal segregation of sister chromatids. It delays anaphase onset by inhibiting the action of the E3 ubiquitin ligase known as the anaphase promoting complex or cyclosome (APC/C). Mad3/BubR1 is a key component of the mitotic checkpoint complex (MCC) which binds and inhibits the APC/C early in mitosis. Mps1(Mph1) kinase is critical for checkpoint signalling and MCC-APC/C inhibition, yet few substrates have been identified. Here we identify Mad3 as a substrate of fission yeast Mps1(Mph1) kinase. We map and mutate phosphorylation sites in Mad3, producing mutants that are targeted to kinetochores and assembled into MCC, yet display reduced APC/C binding and are unable to maintain checkpoint arrests. We show biochemically that Mad3 phospho-mimics are potent APC/C inhibitors in vitro, demonstrating that Mad3p modification can directly influence Cdc20(Slp1)-APC/C activity. This genetic dissection of APC/C inhibition demonstrates that Mps1(Mph1) kinase-dependent modifications of Mad3 and Mad2 act in a concerted manner to maintain spindle checkpoint arrests.


Asunto(s)
Ciclosoma-Complejo Promotor de la Anafase/metabolismo , Proteínas Cdc20/metabolismo , Puntos de Control del Ciclo Celular , Proteínas de Ciclo Celular/metabolismo , Proteínas Quinasas/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/metabolismo , Huso Acromático/metabolismo , Secuencia de Aminoácidos , Proteínas de Ciclo Celular/química , Datos de Secuencia Molecular , Mutación , Fosforilación , Unión Proteica , Schizosaccharomyces/citología , Proteínas de Schizosaccharomyces pombe/química
8.
Heart Surg Forum ; 21(5): E418-E422, 2018 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-30311897

RESUMEN

BACKGROUND: Our goal is to evaluate postoperative outcomes of continuous versus interrupted suturing techniques in ventricular septal defect (VSD) closure surgery. METHODS: The study included 286 patients with isolated VSD who underwent VSD closure surgery between June 2010 and April 2017. VSD closure was performed by using the interrupted suturing technique in group 1 (n = 74, 25.9%) and the continuous suturing technique in group 2 (n = 212, 74.1%). The groups were compared in terms of mortality and rates of clinical morbidities such as infection and complete atrioventricular (AV) block. RESULTS: Early mortality occurred in 3 cases in group 1 (4.0%) and 5 cases in group 2 (2.3%). There was no late mortality in either group. One patient from both groups required extracorporeal membrane oxygenation (ECMO) at postoperative 48 hours. Five patients in group 1 (6.8%) and 11 patients in group 2 (5.2%) developed complete AV block postoperatively and received permanent pacemaker implants. CONCLUSION: Complication rates were similar between the patient groups operated on by using continuous and interrupted suturing techniques in our study, suggesting that neither technique is superior for VSD closure surgery.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos/métodos , Defectos del Tabique Interventricular/cirugía , Técnicas de Sutura/instrumentación , Suturas , Niño , Preescolar , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Masculino , Estudios Retrospectivos , Resultado del Tratamiento
9.
Heart Lung Circ ; 27(7): 872-877, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28867176

RESUMEN

BACKGROUND: The left internal thoracic artery (LITA) is the most commonly used arterial bypass conduit in coronary artery bypass graft (CABG) patients and inadequate LITA flow can result in an increase in morbidity and mortality. In this study, we evaluated the effect of excision of the distal spasmodic segment of the LITA on the free flow in CABG patients. METHODS: This study consisted of 47 patients who underwent elective CABG performed with or without other cardiac surgery, between July 2015 and December 2015. Excised LITA length was shorter than 15mm in group 1, between 15mm and 30mm in group 2 and longer than 30mm in group 3. Left ITA free flow was measured for 60seconds into a container before and after the distal LITA excision. The inter-measurement differences were calculated for the three groups. Thereafter, the comparison was performed in terms of free flow difference amongst the three groups. RESULTS: The mean difference of LITA free flow was 27.6±22.7ml/minute in group 1, 35.4±26.7ml/minute in group 2, and 52.6±26.1ml/minute in group 3. There were significant differences in terms of free flow difference between the groups (p=0.008). Also, differences were statistically significant in group 1 versus group 3 (p=0.003) and group 2 versus group 3 (p=0.038) in the intergroup comparisons. CONCLUSIONS: The distal part of the LITA has more spasmodic potential than other segments. This spasm may result in low flow of LITA grafts. Therefore, an as long as possible excision of the distal LITA segment may be required to avoid the spasmodic effect.


Asunto(s)
Puente de Arteria Coronaria/métodos , Enfermedad de la Arteria Coronaria/cirugía , Circulación Coronaria/fisiología , Arterias Mamarias/diagnóstico por imagen , Flujo Sanguíneo Regional/fisiología , Grado de Desobstrucción Vascular , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico , Enfermedad de la Arteria Coronaria/fisiopatología , Femenino , Humanos , Masculino , Arterias Mamarias/fisiopatología , Arterias Mamarias/trasplante , Persona de Mediana Edad , Resultado del Tratamiento
10.
Artif Organs ; 41(3): 253-261, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27862027

RESUMEN

The objective is to demonstrate safety and early clinical results of surgical transapical closure of paravalvular leaks (PVLs) following mitral valve replacement in significant regurgitation. Between March 2014 and February 2015, 12 patients (mean age 52.1 ± 6.0 years, 66.6% male) with severe symptomatic mitral PVLs (n = 13) underwent surgical transapical closure procedure through left mini-thoracotomy. All patients were in NYHA functional class III-IV and median logistic EuroSCORE was 24.2 ± 6.4% (range, 13.5-34.6%). Indications were heart failure (n = 10) and symptomatic hemolysis (n = 2) due to severe mitral regurgitation (MR). Amplatzer Vascular Plug-III devices (n = 9) were used for smaller and regular defects; whereas Atrial Septal Defect closure devices (n = 4) were used for larger defects. Technical success was achieved in 10 (83.3%) patients. One (8.5%) patient with 2 + MR was treated medically. A patient with residual 4 + MR underwent re-operation. There was no procedure-related complication including mortality, device migration, embolization, or cardiac laceration. Mean procedure and fluoroscopy times were 166.4 ± 39.5 (range, 90-210) and 25.7 ± 17.3 (range, 16-64) minutes, respectively. The mean intensive care and hospital stays were 2.1 ± 1.3 and 10.3 ± 6.5 days, respectively. Clinical efficacy was achieved in 9 (75%) of 12 patients at early follow-up of 8.5 ± 2.1 months. NYHA status was class II in two patients, and no hemolytic anemia was diagnosed. Echocardiographic studies revealed a significant reduction of preoperative MR (3-4+) to less than 1+ MR after operations (P < 0.05). Surgical transapical approach to PVL closure is a safe and effective procedure following mitral valve replacement. Early results show that this procedure can be an alternative to re-operation for high-risk patients. Further studies are needed to prove its effectiveness in the long term.


Asunto(s)
Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Implantación de Prótesis de Válvulas Cardíacas/instrumentación , Prótesis Valvulares Cardíacas , Insuficiencia de la Válvula Mitral/cirugía , Válvula Mitral/cirugía , Ecocardiografía Doppler en Color , Ecocardiografía Tridimensional , Ecocardiografía Transesofágica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Válvula Mitral/diagnóstico por imagen , Válvula Mitral/fisiopatología , Insuficiencia de la Válvula Mitral/diagnóstico por imagen , Insuficiencia de la Válvula Mitral/fisiopatología , Estudios Prospectivos , Falla de Prótesis , Reoperación , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento
12.
J Cell Sci ; 124(Pt 24): 4332-45, 2011 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-22193957

RESUMEN

The spindle assembly checkpoint (SAC) is a signalling network that delays anaphase onset until all the chromosomes are attached to the mitotic spindle through their kinetochores. The downstream target of the spindle checkpoint is the anaphase-promoting complex/cyclosome (APC/C), an E3 ubiquitin ligase that targets several anaphase inhibitors for proteolysis, including securin and cyclin B1. In the presence of unattached kinetochores, the APC/C is inhibited by the mitotic checkpoint complex (MCC), a tetrameric complex composed of three SAC components, namely BubR1, Bub3 and Mad2, and the APC/C co-activator Cdc20. The molecular mechanisms underlying exactly how unattached kinetochores catalyse MCC formation and how the MCC then inhibits the APC/C remain obscure. Here, using RNAi complementation and in vitro ubiquitylation assays, we investigate the domains in BubR1 required for APC/C inhibition. We observe that kinetochore localisation of BubR1 is required for efficient MCC assembly and SAC response. Furthermore, in contrast to previous studies, we show that the N-terminal domain of BubR1 is the only domain involved in binding to Cdc20-Mad2 and the APC/C. Within this region, an N-terminal KEN box (KEN1) is essential for these interactions. By contrast, mutation of the second KEN box (KEN2) of BubR1 does not interfere with MCC assembly or APC/C binding. However, both in cells and in vitro, the KEN2 box is required for inhibition of APC/C when activated by Cdc20 (APC/C(Cdc20)). Indeed, we show that this second KEN box promotes SAC function by blocking the recruitment of substrates to the APC/C. Thus, we propose a model in which the BubR1 KEN boxes play two very different roles, the first to promote MCC assembly and the second to block substrate recruitment to APC/C(Cdc20).


Asunto(s)
Puntos de Control de la Fase M del Ciclo Celular , Proteínas Serina-Treonina Quinasas/química , Proteínas Serina-Treonina Quinasas/metabolismo , Complejos de Ubiquitina-Proteína Ligasa/metabolismo , Ciclosoma-Complejo Promotor de la Anafase , Sitios de Unión , Proteínas de Ciclo Celular/metabolismo , Células HeLa , Humanos , Estructura Terciaria de Proteína , Ubiquitinación
13.
Heart Surg Forum ; 16(4): E177-83, 2013 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-23958526

RESUMEN

BACKGROUND: Optimization of saphenous vein patency for myocardial revascularization. OBJECTIVE: The goal of this study was to present the no-touch technique of saphenous vein preparation. This technique consists of harvesting the vein with a pedicle of surrounding tissue, which protects the vein from distension pressure. METHODS: We performed a prospective, randomized study that compared 2 techniques for harvesting saphenous vein-conventional and no-touchin 40 patients undergoing coronary artery bypass grafting. We carried out a morphologic study of the endothelium with the aid of light and transmission electron microscopy and an immunohistochemical assessment to identify adenosine, inducible nitric oxide synthase (iNOS), and vascular endothelial growth factor (VEGF) in the vein wall. RESULTS: The integrity of endothelial cell and all vascular layers was maintained better with the no-touch technique than with the conventional procedure. The immunohistochemical assessment revealed that adenosine receptor, iNOS, and VEGF immunoexpression levels were normal or lower in the no-touch group than in the conventional-harvest group, as shown by the staining densities in all layers of the vein wall. CONCLUSION: Endothelial integrity and adenosine, iNOS, and VEGF immunoreactivities were better preserved when the no-touch technique was used for vein graft harvesting. The mechanical protection provided by the cushion of surrounding tissue in the no-touch group and the vasorelaxation and thromboresistant activities of nitric oxide may be responsible for the reduction in vasospasms and the improved patency rate.


Asunto(s)
Puente de Arteria Coronaria/métodos , Enfermedad de la Arteria Coronaria/inmunología , Enfermedad de la Arteria Coronaria/cirugía , Endotelio Vascular/inmunología , Vena Safena/inmunología , Vena Safena/trasplante , Recolección de Tejidos y Órganos/métodos , Adulto , Puente de Arteria Coronaria/instrumentación , Endotelio Vascular/lesiones , Endotelio Vascular/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Óxido Nítrico Sintasa de Tipo II/inmunología , Estudios Prospectivos , Resultado del Tratamiento , Factor A de Crecimiento Endotelial Vascular/inmunología
14.
Rev Sci Instrum ; 94(9)2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37712779

RESUMEN

This paper proposes a drop-on-demand (DOD) system that can produce single droplets of highly repeatable size in the order of 2 mm. This system utilizes an on-the-shelf solenoid injector used in automotive applications. The design methodology is explained along with the necessary measurements and numerical simulations of droplet generation. The invention consists of a solenoid injector that produces monodisperse single or in-series droplets with the help of a developed pulse width modulated signal generator. Mass per injection is measured over a range of supply pressures and injection durations to find the operation window to generate 2 mm droplets. Later, various nozzle geometries are designed and tested by flow simulations. The contracting nozzle is found suitable for generating single droplets, so the design is implemented at the tip of the solenoid injector. The effects of different opening times, pressures, and nozzle's orifice diameters were tested to observe the operating window of the newly designed DOD system and the repeatability of generated droplets by utilizing a coherent circular Hough transform image processing algorithm to measure droplet sizes. The standard deviation of measured diameters is less than 5% of the mean droplet diameter, which is in the range of 1.68-2.07 mm. Next, the voltage and current signals are measured per injection, and exact instants for the initiation and ending for both opening and closing are determined to construct transient mass flow rate functions for flow simulations in which the dependence of droplet formation on the speed of closing is revealed. The numerical and experimental results indicate the repeatability and consistency of the invention.

15.
Braz J Cardiovasc Surg ; 37(5): 680-687, 2022 10 08.
Artículo en Inglés | MEDLINE | ID: mdl-35244373

RESUMEN

INTRODUCTION: Custodiol (histidine-tryptophan-ketoglutarate) and repetitive blood cardioplegia are the solutions for myocardial protection and cardiac arrest. In this study, we aimed to compare immunohistochemical analysis, clinical outcomes, and cardiac enzyme values of Custodiol and blood cardioplegia groups. METHODS: This was a randomized prospective study consisting of 2 groups and 20 patients, 10 patients for each group, who underwent mitral and mitral/tricuspid valve surgery. Group 1 was formed for Custodiol cardioplegia and group 2 for blood cardioplegia. Perioperative and postoperative cardiac events were recorded, cardiac enzymes were analyzed with intervals, and myocardial samples were taken for immunohistochemical analysis. Recorded data were statistically evaluated. RESULTS: There was no significant difference for the Custodiol and blood cardioplegia groups in perioperative and postoperative cardiac performance and adverse events. Cardiac enzyme analysis showed no significant difference between groups. However, two parameters (eNOS, Bcl-2) were in favor of the Custodiol group in immunohistochemical studies. Custodiol performed better in cellular oxidative stress resistance and cellular viability. CONCLUSION: Clinical outcomes and cardiac enzyme analysis results were similar regarding myocardial protection. However, Custodiol performed better in the immunohistochemical analysis.


Asunto(s)
Soluciones Cardiopléjicas , Manitol , Humanos , Soluciones Cardiopléjicas/farmacología , Soluciones Cardiopléjicas/uso terapéutico , Estudios Prospectivos , Cloruro de Potasio , Glucosa , Paro Cardíaco Inducido/métodos
16.
Nat Commun ; 13(1): 4704, 2022 08 10.
Artículo en Inglés | MEDLINE | ID: mdl-35948594

RESUMEN

Current models infer that the microtubule-based mitotic spindle is built from GDP-tubulin with small GTP caps at microtubule plus-ends, including those that attach to kinetochores, forming the kinetochore-fibres. Here we reveal that kinetochore-fibres additionally contain a dynamic mixed-nucleotide zone that reaches several microns in length. This zone becomes visible in cells expressing fluorescently labelled end-binding proteins, a known marker for GTP-tubulin, and endogenously-labelled HURP - a protein which we show to preferentially bind the GDP microtubule lattice in vitro and in vivo. We find that in mitotic cells HURP accumulates on the kinetochore-proximal region of depolymerising kinetochore-fibres, whilst avoiding recruitment to nascent polymerising K-fibres, giving rise to a growing "HURP-gap". The absence of end-binding proteins in the HURP-gaps leads us to postulate that they reflect a mixed-nucleotide zone. We generate a minimal quantitative model based on the preferential binding of HURP to GDP-tubulin to show that such a mixed-nucleotide zone is sufficient to recapitulate the observed in vivo dynamics of HURP-gaps.


Asunto(s)
Cinetocoros , Tubulina (Proteína) , Guanosina Trifosfato/metabolismo , Cinetocoros/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Microtúbulos/metabolismo , Nucleótidos/metabolismo , Huso Acromático/metabolismo , Tubulina (Proteína)/metabolismo
17.
Dev Cell ; 56(22): 3082-3099.e5, 2021 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-34758290

RESUMEN

Chromosome mis-segregation during mitosis leads to aneuploidy, which is a hallmark of cancer and linked to cancer genome evolution. Errors can manifest as "lagging chromosomes" in anaphase, although their mechanistic origins and likelihood of correction are incompletely understood. Here, we combine lattice light-sheet microscopy, endogenous protein labeling, and computational analysis to define the life history of >104 kinetochores. By defining the "laziness" of kinetochores in anaphase, we reveal that chromosomes are at a considerable risk of mis-segregation. We show that the majority of lazy kinetochores are corrected rapidly in anaphase by Aurora B; if uncorrected, they result in a higher rate of micronuclei formation. Quantitative analyses of the kinetochore life histories reveal a dynamic signature of metaphase kinetochore oscillations that forecasts their anaphase fate. We propose that in diploid human cells chromosome segregation is fundamentally error prone, with an additional layer of anaphase error correction required for stable karyotype propagation.


Asunto(s)
Anafase/fisiología , Aurora Quinasa B/metabolismo , Cinetocoros/metabolismo , Segregación Cromosómica/fisiología , Humanos , Metafase/fisiología , Microtúbulos/metabolismo , Mitosis/fisiología , Huso Acromático/metabolismo
18.
Kardiochir Torakochirurgia Pol ; 18(4): 195-202, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35079259

RESUMEN

INTRODUCTION: Mediastinitis after cardiac surgery is a rare complication, but with high morbidity and mortality. AIM: To determine its risk factors and to investigate the efficacy of vacuum-assisted closure (VAC). MATERIAL AND METHODS: Nine thousand one hundred sixty cases of patients who underwent cardiac surgery during 2010-2017 were reviewed retrospectively. One hundred and twenty-seven patients, the case group, were treated by VAC. Three hundred cases with no diagnosis of mediastinitis were selected as the control group. Both groups' clinical and demographic characteristics, preoperative variables, and postoperative follow-up parameters were compared. Factors affecting treatment were analyzed. RESULTS: We found that the presence of diabetes mellitus, bilateral internal thoracic artery and intra-aortic balloon pump usage are independent risk factors for the development of mediastinitis (p < 0.05). It was found that 74% of tissue cultures were positive and the most common detected organism was Staphylococcus. It was found that many perioperative parameters had a significant effect on the duration of treatment (p < 0.05). However, regression analysis revealed that bacterial growth was the only independent variable in prolonging the treatment period. CONCLUSIONS: We believe that the establishment of perioperative blood glucose regulation, patient selection to use bilateral internal thoracic artery grafts, and maximum attention to sepsis and antisepsis rules in patients who need mechanical support devices such as intra-aortic balloon pump, will significantly reduce the development of mediastinitis. Since we could not find an independent risk factor for the duration of VAC treatment other than culture growth, we think that VAC therapy is successful and safe in the treatment of mediastinitis and should be used more widely.

19.
Turk Gogus Kalp Damar Cerrahisi Derg ; 28(3): 450-459, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32953207

RESUMEN

BACKGROUND: In this study, we present our single-center experience in robotically-assisted endoscopic surgery versus conventional median sternotomy approach in patients undergoing cardiac myxoma excision. METHODS: Between January 2011 and September 2019, a total of 46 patients (24 males, 22 females; mean age 54.1±12.5 years; range, 25 to 79 years) who had a confirmed diagnosis of isolated cardiac myxoma were included in the study. The patients were divided into two groups as those undergoing robotic-assisted surgery (n=16) and those undergoing conventional median sternotomy (n=30). Clinical characteristics, operative, and postoperative outcomes were compared. Robotic approach to right or left-sided tumors and postoperative pain scores were also analyzed. RESULTS: There was no mortality or major complication. No conversion to sternotomy was needed in robotic procedures. The mean cardiopulmonary bypass and aortic cross-clamp times were significantly shorter in the median sternotomy group (p=0.001 for both). The mean ventilation time and the length of hospital stay were significantly shorter in robotic surgery than sternotomy group (p=0.043 and p=0.048, respectively). The mean amount of postoperative blood loss and transfusion rate were significantly lower in robotic surgery patients (p=0.001 and p=0.022, respectively). The mean postoperative pain scores were significantly lower in patients undergoing robotic surgery (p=0.022). CONCLUSION: Robotic-assisted endoscopic surgery can be performed safely and effectively for cardiac myxoma excision with shorter hospital stay, less pain, and less amount of blood product use, as well as more favorable cosmetic results compared to conventional median sternotomy.

20.
J Robot Surg ; 14(1): 101-107, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30828770

RESUMEN

This study reports our initial experience with robotic-assisted partial anomalous pulmonary venous connection (PAPVC) repair. From May 2013 through September 2018, 20 patients (12 male and 8 female) underwent robotic-assisted repair of a right-sided (n = 19) or a left-sided (n = 1) PAPVC. The mean age was 24.6 ± 9.4 years (range 14-44) and the mean body mass index was 22.3 ± 4.6. Seventeen patients had a right-sided supra-cardiac PAPVC with sinus venosus atrial septal defect, two had a right-sided cardiac PAPVC to the right atrium and one had a left-sided cardiac PAPVC to the coronary sinus. Associated anomalies included patent foramen ovale (n = 2) and left persistent superior vena cava (n = 1). All patients were operated on successfully. No conversion to mini-thoracotomy or sternotomy was needed. Cardiopulmonary bypass and aortic clamping times were 114.8 ± 17.3 (range 90-150) and 66.5 ± 15.8 (range 44-90) minutes, respectively. Repair techniques included the single-patch repair with baffle through right atriotomy (n = 16), the 2-patch repair (n = 1) using lateral transcaval incision and intracardiac re-routing (n = 3). The mean ventilation time was 4.2 ± 1.2 h and hospital stay was 3.1 ± 0.1 days. No phrenic nerve injury, sinus node dysfunction, re-exploration or blood transfusion was noted. No residual shunting or venous obstruction was found on echocardiograms. Follow-up was a mean of 1.7 years (range 3-36 months). There was no follow-up mortality. Totally, endoscopic robotic-assisted PAPVC repair is a feasible procedure in selected adult patients. It is a less invasive alternative to traditional incisions, mini-thoracotomy and endoscopic approaches. In the future, new generation robotic devices may offer an alternative for younger patients with this pathology.


Asunto(s)
Procedimientos Quirúrgicos Robotizados/métodos , Síndrome de Cimitarra/cirugía , Procedimientos Quirúrgicos Vasculares/métodos , Humanos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA