Cardiac surgical simulation program during general surgery residency increases resident physician exposure to cardiac surgery and technical expertise.

Objective: The changing surgical education landscape in surgical training pathways greatly diminished cardiac surgical knowledge, interest, and skills among general surgery trainees. To address this issue, our department developed a cardiac surgery simulation program. Methods: All simulation sessions lasted at least 2 hours and occurred during resident physician protected education time. Participants were postgraduate year 2 through 5 general surgery residents assisted by staff and led by cardiac surgery faculty. Five of the 6 sessions were porcine heart wet labs simulating coronary anastomoses, surgical aortic valve replacement, mitral valve repair and replacement, and left ventricular assist device implantation. The transcatheter aortic valve replacement session was designed as a video simulation and a manikin for wire manipulation and implantation. At the end of each lab, all participants were surveyed about their experiences. Results: An average of 10 resident physicians participated in each session (range, 8-13), for a total of 120 simulation hours. One hundred percent of residents surveyed agreed that the labs improved knowledge and understanding of the disease process, improved understanding of cardiac surgical principles, and helped acquire skills for surgical residency and treatment. Factors that residents cited for increased attendance rate included protected education time, hands-on experience, and a high faculty-to-resident ratio. Conclusions: This program successfully demonstrates that cardiac surgery training and simulation can be integrated into general surgery residency programs, despite the lack of cardiac surgery requirements. Additional metrics for future study includes technical grades on resident physicians' performance to further assess the value of this program.

Gastrointestinal Bleeding as a Complication in Continuous Flow Ventricular Assist Devices: A Systematic Review With Meta-Analysis.

BACKGROUND: The use of ventricular assist devices (VADs) has become predominant in this era of medicine. It is commonly used as a bridge to transplant, recovery and as a destination therapy for patients with severe heart failure, who are not responsive to maximum optimal management or ineligible for transplant. However, several complications are known to occur with the use of these devices. In this research, we will compare gastrointestinal bleeding in patients who used centrifugal flow versus axial flow VADs. We hope that the result of this meta-analysis and the review presented provide adequate information to future researchers, physicians and other healthcare professionals who are interested in this topic. METHODS: Published articles evaluated for inclusion were obtained from MEDLINE (PubMed), Cochrane, EBSCO, clinicaltrials.gov, and international clinical trials registry. This research was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Procured articles were reviewed by two independent reviewers. Only randomized control trials and observational studies were used. Quality assessment was done with Cochrane Collaboration's tool (RoB.2 with visualization through robviz) and Newcastle-Ottawa Scale (NOS). Data analysis was carried out with the use of R data analysis tool (version 4.0.0; release date: April 24th, 2020). RESULTS: At the end of this meta-analysis, the occurrence of gastrointestinal bleeding was not significantly different between both groups; with odds ratio (OR): 0.81; 95% confidence interval (CI): 0.65 - 1.00; P value = 0.05. Between-study variance (Tau-squared) was zero (0), standard error (SE) = 0.06. The degree of heterogeneity measured with I-squared statistic was 0% (minimal). Egger's regression test was not statistically significant, P = 0.93. Symmetry of distribution was observed on the funnel plot. Trim and fill analysis showed no missing studies on the left; SE = 1.68. CONCLUSIONS: The result obtained from this research indicates that the occurrence of gastrointestinal bleeding is not significantly different in both groups of patients, irrespective of the type of continuous flow VAD used. Although, the study sample used in this meta-analysis was limited.

Diagnostic relevance of spatial orientation for vascular dementia: A case study.

Spatial orientation is emerging as an early and reliable cognitive biomarker of Alzheimer's disease (AD) pathophysiology. However, no evidence exists as to whether spatial orientation is also affected in vascular dementia (VaD). OBJECTIVE: To examine allocentric (map-based) and egocentric (viewpoint-based) spatial orientation in an early stage VaD case. METHODS: A spatial test battery was administered following clinical and neuropsychological cognitive evaluation. RESULTS: Despite the patient's complaints, little evidence of episodic memory deficits were detected when cueing was provided to overcome executive dysfunction. Similarly, medial temporal lobe-mediated allocentric orientation was intact. By contrast, medial parietal-mediated egocentric orientation was impaired, despite normal performance on standard visuospatial tasks. CONCLUSION: To our knowledge, this is the first in-depth investigation of spatial orientation deficits in VaD. Isolated egocentric deficits were observed. This differs from AD orientation deficits which encompass both allocentric and egocentric orientation deficits. A combination of egocentric orientation and executive function tests could serve as a promising cognitive marker for VaD pathophysiology.

A orientação espacial está emergindo como um biomarcador cognitivo precoce e confiável da fisiopatologia da doença de Alzheimer (DA). No entanto, não existe evidência de que a orientação espacial também seja afetada na demência vascular (DVa). OBJETIVO: Examinar a orientação espacial alocêntrica (baseada em mapas) e egocêntrica (baseada no ponto de vista) em um caso de DVa em fase incial. MÉTODOS: Uma bateria de testes espaciais foi administrada após avaliação clínica e neuropsicológica cognitiva. RESULTADOS: Apesar das queixas do paciente, poucas evidências de déficits de memória episódica foram detectadas quando foram fornecidas pistas para superar a disfunção executiva. Da mesma forma, a orientação alocêntrica mediada pelo lobo temporal medial estava intacta. Em contrapartida, a orientação egocêntrica mediada pela região parietal medial estava comprometida, apesar do desempenho normal em tarefas visuoespaciais padrão. CONCLUSÃO: Pelo nosso conhecimento, esta é a primeira investigação aprofundada dos déficits de orientação espacial na DVa. Foram observados déficits egocêntricos isolados. Isso difere dos déficits de orientação da DA que abrangem déficits de orientação alocêntricos e egocêntricos. Uma combinação de orientação egocêntrica e testes de função executiva poderia servir como um marcador cognitivo promissor para a fisiopatologia de DVa.

Detección Automática y Clasificación de Eventos en Sonidos Cardiopulmonares de Sujetos Saludables / Automatic Detection and Classification of Cardiopulmonary Events

Resumen: La auscultación de señales basada en un estetoscopio estándar y/o electrónico no solo incluye sonidos internos del cuerpo, también incluye frecuentemente ruido externo de interferencia con componentes en el mismo rango. Esta forma de examinar es incluso afectada por los umbrales auditivos variantes de los profesionales de la salud y el grado de experiencia en reconocimiento de indicadores peculiares. Además, los resultados son a menudo caracterizados en términos cualitativos descriptivos sujetos a interpretaciones individuales. Para direccionar esta preocupación, los estudios presentados en este artículo contienen un procesamiento concurrente de las componentes dominantes de sonidos del corazón (HS) y del pulmón (HS), y una etapa de acondicionamiento que incluye la reducción de HS presente en señales LS. Específicamente, la transformada de Hilbert fue una técnica de caracterización para HS. En el caso de señales enfocadas a LS, las técnicas de detección de actividad de voz y el cálculo de umbrales de algunos componentes de los vectores acústicos de Coeficientes Cepstrales en Frecuencia Mel (MFCC), fueron útiles en la caracterización de eventos acústicos asociados. Las fases de inspiración y expiración fueron diferenciadas por medio de la sexta componente de MFCC. Con el fin de evaluar la eficiencia de esta aproximación, proponemos los Modelos Ocultos de Markov con Modelos Mesclados Gaussianos (HMM-GMM). Los resultados utilizando esta forma de detección son superiores cuando se desarrolla la clasificación con modelos HMM-GMM, la cual refleja las ventajas de la forma de detección cuantificable y clasificación sobre la aproximación clínica tradicional.

Abstract: A standard and/or electronic stethoscope based auscultatory signals include not only the internal sounds of the body but also interfering external noise often with similar frequency components. This form of examination is also affected by varying thresholds of clinical practitioner's hearing and degree of experience in recognition of peculiar auscultatory indicators. Further, the results are often characterized in qualitative descriptive terms subject to individual's interpretation. To address these concerns, presented studies include concurrent processing of dominant heart (HS) and lung (LS) sounds components and a conditioning stage involving HS presence reduction within LS focused signals. Specifically as determined, the Hilbert transform was a technique of choice in HS characterization. In the case of LS focused signals, the speech activity detection techniques (VAD) and the thresholds calculation of some components of acoustic vectors of Cepstral Coefficients in Mel Frequency (MFCC), were useful in characterization of associated acoustic events. The phases of inspiration and expiration were differentiated by means of the sixth component of MFCC. In order to evaluate the efficiency of this approach, we propose Hidden Markov Models with Mixed Gaussian Models (HMM-GMM). The results utilizing this form of detection are superior when performing classification with HMM-GMM models, which reflect the advantages of presented form of quantifiable detection and classification over traditional clinical approach.

Diagnostic relevance of spatial orientation for vascular dementia: A case study / Relevância da orientação espacial para o diagnóstico de demência vascular: um estudo de caso

ABSTRACT Spatial orientation is emerging as an early and reliable cognitive biomarker of Alzheimer's disease (AD) pathophysiology. However, no evidence exists as to whether spatial orientation is also affected in vascular dementia (VaD). Objective: To examine allocentric (map-based) and egocentric (viewpoint-based) spatial orientation in an early stage VaD case. Methods: A spatial test battery was administered following clinical and neuropsychological cognitive evaluation. Results: Despite the patient's complaints, little evidence of episodic memory deficits were detected when cueing was provided to overcome executive dysfunction. Similarly, medial temporal lobe-mediated allocentric orientation was intact. By contrast, medial parietal-mediated egocentric orientation was impaired, despite normal performance on standard visuospatial tasks. Conclusion: To our knowledge, this is the first in-depth investigation of spatial orientation deficits in VaD. Isolated egocentric deficits were observed. This differs from AD orientation deficits which encompass both allocentric and egocentric orientation deficits. A combination of egocentric orientation and executive function tests could serve as a promising cognitive marker for VaD pathophysiology.

RESUMO A orientação espacial está emergindo como um biomarcador cognitivo precoce e confiável da fisiopatologia da doença de Alzheimer (DA). No entanto, não existe evidência de que a orientação espacial também seja afetada na demência vascular (DVa). Objetivo: Examinar a orientação espacial alocêntrica (baseada em mapas) e egocêntrica (baseada no ponto de vista) em um caso de DVa em fase incial. Métodos: Uma bateria de testes espaciais foi administrada após avaliação clínica e neuropsicológica cognitiva. Resultados: Apesar das queixas do paciente, poucas evidências de déficits de memória episódica foram detectadas quando foram fornecidas pistas para superar a disfunção executiva. Da mesma forma, a orientação alocêntrica mediada pelo lobo temporal medial estava intacta. Em contrapartida, a orientação egocêntrica mediada pela região parietal medial estava comprometida, apesar do desempenho normal em tarefas visuoespaciais padrão. Conclusão: Pelo nosso conhecimento, esta é a primeira investigação aprofundada dos déficits de orientação espacial na DVa. Foram observados déficits egocêntricos isolados. Isso difere dos déficits de orientação da DA que abrangem déficits de orientação alocêntricos e egocêntricos. Uma combinação de orientação egocêntrica e testes de função executiva poderia servir como um marcador cognitivo promissor para a fisiopatologia de DVa.

Subcortical Vascular Cognitive Impairment staged through cdr's functional subsum (cdr-func): Preliminary results from an outpatient sample.

BACKGROUND: Staging vascular cognitive impairment (VCI) might be useful for sample selection in clinical trials and for guiding clinical decision-making. Clinical dementia rating (CDR) has been applied for staging cognitive impairments of different etiologies, but it may underestimate severity of non-Alzheimer's disease cognitive deficits. METHODS: Out of a total of 147 elderly subjects, 23 (mean age: 72.95 ± 7.51 years; 56% female; mean schooling: 9.52 ± 5.11 years) fulfilled clinical and neuroimaging criteria for VCI. Correlations among cognitive and functional status and scores in CDR and its subsums (CDR Sum of Boxes - CDR-SoB - and CDR Functional Subsum - CDR-FUNC) were performed. RESULTS: Both CDR-SoB and CDR-FUNC correlated with global cognitive performance, functional status, CLOX 2, working memory and abstraction tests. CDR global score only correlated with functional status. DISCUSSION: CDR-FUNC, as well as CDR-SoB, appear to be better indexes of severity in VCI than CDR global score.

High-speed visualization of disturbed pathlines in axial flow ventricular assist device under pulsatile conditions.

OBJECTIVE: To investigate potentially prothrombotic flow patterns within an axial flow ventricular assist device under clinically relevant pulsatile hemodynamic conditions. METHODS: A transparent replica of the HeartMate-II left ventricular assist device (Thoratec, Pleasanton, Calif) was visualized using a high speed camera at both low and high frame rates (125 and 3000 fps). Three steady-state conditions were studied: nominal (4.5 lpm), low flow (3.0 lpm), and high flow (6.0 lpm). Time-varying conditions were introduced with an external pulsatile pump that modulated the flow rate by approximately ± 50% of the mean, corresponding to a pulsatility index of 1.0. RESULTS: At nominal and high flow rates, the path lines within the upstream region were generally stable, well attached, and streamlined. As the flow rate was reduced below 3.8 lpm, a rapid transition to a chaotic velocity field occurred, exhibiting a large toroidal vortex adjacent to the upstream bearing. The pathlines in the downstream stator section were consistently chaotic for all hemodynamic conditions investigated. It was common to observe tracer particles trapped within recirculation bubbles and drawn retrograde, causing repeated contact with the bearing surfaces. The addition of pulsatility caused the flow field to become periodically chaotic during the diastolic portion of the cardiac cycle depending on the instantaneous flow rate and acceleration. CONCLUSIONS: The contribution of pulsatility by the native heart may induce a periodic disturbance to an otherwise stable flow field within an axial flow ventricular assist device, particularly during the diastolic and decelerating portion of the cardiac cycle. Potentially prothrombotic flow features were found to occur periodically in the region of the upstream bearing.

Infecciones asociadas a dispositivos de soporte circulatorio mecánico / Ventricular assist device-related infections

El dispositivo de asistencia ventricular asistida (DAV) se utiliza como terapéutica final o puente al trasplante cardíaco. La tasa de complicaciones infecciosas asociada a este dispositivo es elevada. La experiencia con este tipo de complicación en pediatría es escasa. Objetivo: conocer las características clínicas, microbiológicas y de evolución de pacientes con DAV. Material y métodos: pacientes internados en el Hospital Garrahan desde marzo del 2006 a marzo 2014 con DAV. Estudio retrospectivo, descriptivo. Se analizaron: edad, sexo, tipo de enfermedad de base, características clínicas, microbiológicas y de evolución de los pacientes con DAV. Resultados: se incluyeron 33 pacientes. La mediana de edad fue 79 meses (rango:13-133). La indicación de colocación del DAV fue miocardiopatía dilatada en el 81.8% (27). Los días acumulados de uso del DAV fue de 4.638 días. Diecisiete pacientes (51.5%) presentaron 23 episodios de infección. La infección pericánula se presentó 10 casos (43.4%), bacteriemias primarias en 4 (17.4%), bacteriemia asociada a catéter de corta permanencia 5 (21.7%), mediastinitis 3 (13%) y un caso de sepsis (4.3%). Los microorganismos prevalentes fueron los cocos gram positivos. Fallecieron 12 pacientes en DAV a la espera del trasplante, uno de ellos con sepsis y mediastinitis por S. aureus meticilino sensible. Conclusiones: La infección asociada a DAV fue frecuente en nuestros pacientes y dentro de ellas la infección pericánula fue la más común. Los cocos gran positivos fueron los microorganismos predominantes. Los pacientes con mayor tiempo de permanencia del DAV presentaron varios episodios de infección. Las infecciones asociadas al DAV no impidieron el éxito del trasplante cardíaco (AU)

Lysosomal and mitochondrial permeabilization mediates zinc(II) cationic phthalocyanine phototoxicity.

In order to find a novel photosensitizer to be used in photodynamic therapy for cancer treatment, we have previously showed that the cationic zinc(II) phthalocyanine named Pc13, the sulfur-linked dye 2,9(10),16(17),23(24)-tetrakis[(2-trimethylammonium) ethylsulfanyl]phthalocyaninatozinc(II) tetraiodide, exerts a selective phototoxic effect on human nasopharynx KB carcinoma cells and induces an apoptotic response characterized by an increase in the activity of caspase-3. Since the activation of an apoptotic pathway by chemotherapeutic agents contributes to the elimination of malignant cells, in this study we investigated the molecular mechanisms underlying the antitumor action of Pc13. We found that after light exposure, Pc13 induced the production of reactive oxygen species (ROS), which are mediating the resultant cytotoxic action on KB cells. ROS led to an early permeabilization of lysosomal membranes as demonstrated by the reduction of lysosome fluorescence with acridine orange and the release of lysosomal proteases to cytosol. Treatment with antioxidants inhibited ROS generation, preserved the integrity of lysosomal membrane and increased cell proliferation in a concentration-dependent manner. Lysosome disruption was followed by mitochondrial depolarization, cytosolic release of cytochrome C and caspases activation. Although no change in the total amount of Bax was observed, the translocation of Bax from cytosol to mitochondria, the cleavage of the pro-apoptotic protein Bid, together with the decrease of the anti-apoptotic proteins Bcl-XL and Bcl-2 indicated the involvement of Bcl-2 family proteins in the induction of the mitochondrial pathway. It was also demonstrated that cathepsin D, but not caspase-8, contributed to Bid cleavage. In conclusion, Pc13-induced cell photodamage is triggered by ROS generation and activation of the mitochondrial apoptotic pathway through the release of lysosomal proteases. In addition, our results also indicated that Pc13 induced a caspase-dependent apoptotic response, being activation of caspase-8, -9 and -3 the result of a post-mitochondrial event.

Weaning of extracorporeal membrane oxygenation using continuous hemodynamic transesophageal echocardiography.

BACKGROUND: Venoarterial extracorporeal membrane oxygenation (VA ECMO) has been used for profound cardiogenic shock to bridge to decision, ventricular assist device(s) (VADs), or transplant. To assess ventricular function and volume status along with hemodynamics during ECMO weaning, we developed a standardized weaning protocol, guided by a miniaturized transesophageal echocardiography probe designed for continuous hemodynamic monitoring (hemodynamic transesophageal echocardiography [hTEE]). We reviewed our experience with this weaning protocol with hTEE guidance to assess if we could predict patient outcomes. METHODS: During the academic year of 2011, hTEE-guided ECMO weaning was performed in 21 patients on VA ECMO. Left and right ventricular function and volume status were assessed by continuous hTEE, while attempting to wean ECMO after a standardized protocol. The clinical outcomes, management, and positive predictive value of the device were investigated and analyzed for this cohort of patients. RESULTS: Of the 21 patients, 6 (29%) had left and right ventricular recovery and underwent optimal medical therapy or revascularization for underlying coronary artery disease; 7 (33%) had nonrecoverable left and right ventricular function; and 8 (38%) had right ventricular recovery without improvement of the left ventricular function. These 8 patients underwent left VAD placement; none subsequently developed profound right ventricular failure. The positive predictive value for ventricular recovery by hTEE was 100% using our standardized ECMO weaning protocol (95% confidence interval, 73%-100%). CONCLUSIONS: The hTEE-guided ECMO weaning protocol accurately predicted the ability to wean ECMO to decision. This protocol can be applied by cardiac intensivists as a part of standard bedside intensive care unit assessment.

Epidemiology of early-onset dementia: a review of the literature.

Presenile Dementia or Early Onset Dementia (EOD) is a public health problem, it differs from Senile Dementia, and encloses a significant number of cases; nevertheless, it is still poorly understood and underdiagnosed. This study aims to review the prevalence and etiology of EOD, comparing EOD with Senile Dementia, as well as to show the main causes of EOD and their prevalence in population and non-population based studies. The computer-supported search used the following databases: Pubmed/Medline, ISI Web of Knowledge and Scielo. The search terms were alcohol-associated dementia, Alzheimer's disease, dementia, Creutzfeldt-jakob disease, dementia with lewy bodies, early onset dementia, frontotemporal lobar degeneration, Huntington's disease, mixed dementia, neurodegenerative disorders, Parkinson's disease dementia, presenile dementia, traumatic brain injury, vascular dementia. Only papers published in English and conducted from 1985 up to 2012 were preferentially reviewed. Neurodegenerative diseases are the most common etiologies seen in EOD. Among the general population, the prevalence of EOD was found to range between 0 to 700 per 100.000 habitants in groups of 25-64 years old, with an increasing incidence with age. The progression of EOD was found to range between 8.3 to 22.8 new cases per 100.000 in those aged under 65 years. Alzheimer's disease (AD) is the major etiology, followed by Vascular Dementia (VaD) and Frontotemporal Lobar Degeneration (FTLD). A larger number of epidemiological studies to elucidate how environmental issues contribute to EOD are necessary, thus, we can collaborate in the planning and prevention of services toward dementia patients.