Aorto-left atrial fistula secondary to aortic infective endocarditis in a dog with a bicuspid aortic valve.

An 11-year-old male neutered American bulldog was presented for evaluation of thrombocytopenia, acute onset of ataxia, and vomiting. A new murmur was auscultated on physical examination. Transthoracic echocardiographic examination revealed a bicuspid aortic valve, vegetative lesions on the aortic valve, and continuous shunting from the aortic root to the left atrium through an aorta to left atrial fistula. The dog was euthanized due to its guarded prognosis and critical condition. Pathological examination confirmed presence of a bicuspid aortic valve, aorto-left atrial fistula, and aortic infective endocarditis. Antemortem blood culture revealed two unusual organisms: Achromobacter xylosoxidans and Fusobacterium mortiferum.

Management of open wounds in dogs using a bioresorbable polymeric wound matrix: 14 Cases (2019-2021).

The objective of this retrospective case series is to evaluate clinical outcomes associated with the use of a bioresorbable polymeric wound matrix (MicroLyte Vet; Imbed Biosciences) for the management of soft tissue wounds of various etiologies in dogs. Medical records were reviewed between August 2019 and November 2021 for signalment, wound etiology, location, size, initial wound management, antibiotic therapy, time to initial application, number of applications, time between applications, secondary dressing used, time to wound closure, complications, and clinical outcomes. Time to initial application ranged from 1 to 61 days (median, 7.5). The number of applications ranged from 1 to 15 (median, 4.5). Time between applications ranged from 1 to 8 days (median, 3.7). Additional surgical interventions were implemented in 3 dogs. Wound closure by second intention healing (n=14) ranged from 2 to 12 weeks (median, 5). There were no adverse events attributed to the use of bioresorbable polymeric wound matrix. Complete wound healing occurred with use of the bioresorbable polymeric wound matrix in all dogs.

Validation of the adaptive scan method in the quest for time-efficient methods of testing auditory processes.

A major barrier to the clinical application of psychophysical testing of central auditory processes is the time required to obtain precise estimates of different listening abilities. In this study, we validate a novel adaptive scan (AS) method of threshold estimation that is designed to adapt on a range of values around threshold rather than on a single threshold value. This method has the advantage of providing the listener with greater familiarity with the stimulus characteristics near threshold while maintaining precise measurement and increasing time-efficiency. Additionally, we explore the time-efficiency of AS through comparison with two more conventional adaptive algorithms and the method of constant stimuli in two common psychophysical tasks: the detection of a gap in noise and the detection of a tone in noise. Seventy undergraduates without hearing complaints were tested using all four methods. The AS method provided similar threshold estimates with similar precision to those from the other adaptive methods and, thus, it is a valid adaptive method of psychophysical testing. We also provide an analysis of the AS method based on precision metrics to propose a shortened version of the algorithm that maximizes the time/precision tradeoff and can achieve similar thresholds to the adaptive methods tested in the validation. This work lays the foundation for using AS across a wide variety of psychophysical assessments and experimental situations where different levels of precision and/or time-efficiency may be required.

Prevalence and incidence of stroke in Latin America and the Caribbean: a systematic review and meta-analysis.

Stroke is a recurrent and well-known cardiovascular event and a leading cause of death worldwide. We identified reliable epidemiological evidence of stroke in Latin America and the Caribbean (LAC) and estimated the prevalence and incidence of stroke, overall and by sex, in that region. A systematic search in OVID (Medline, Embase and Global Health) and in the Latin America and Caribbean Health Sciences Literature (LILACS) until the end of 2020 was made for all cross-sectional or longitudinal studies estimating (or allowing the estimation of) the prevalence or incidence of stroke among individuals of the general population ≥ 18 years from LAC countries. No language restriction was applied. Studies were assessed for methodological quality and risk of bias. Pooled estimates were calculated using random effect meta-analysis as high heterogeneity was expected. A total of 31 papers for prevalence and 11 papers for incidence were included in the review for analysis. The overall pooled stroke prevalence was 32 (95% CI 26-38) per 1000 subjects and were similar among men (21; 95% CI 17-25) and women (20; 95% CI 16-23) per 1000 subjects. The overall pooled stroke incidence was 255 (95% CI 217-293) per 100 000 person-years, being higher in men (261; 95% CI 221-301) compared to women (217; 95% CI 184-250) per 100 000 person-years. Our results highlight the relevance of the prevalence and incidence of stroke in the LAC region. The estimates were similar in stroke prevalence by sex, but with higher incidence rates among males than females. Subgroup analyses highlight the need for standardized methodologies to obtain appropriate prevalence and incidence estimates at the population level in a region with a great burden of cardiovascular events.

[Restoring horizontal stability in III-V acromioclavicular dislocations by anatomic reconstruction of the coracoclavicular and acromioclavicular ligaments; surgical technique]. / Restablecimiento de la estabilidad horizontal en luxaciones acromioclaviculares III-V mediante la reconstrucción anatómica de los ligamentos coracoclaviculares y acromioclaviculares; técnica quirúrgica.

INTRODUCTION: dislocation of the acromioclavicular (AC) joint is a common injury seen in young adults. The objective is to describe a surgical technique that can restore the horizontal and vertical stability of the AC joint. MATERIAL AND METHODS: we describe a surgical technique that can restore horizontal and vertical stability using an allograft for the anatomical reconstruction of the CC and AC ligaments, for AC grade III-V dislocations according to the Rockwood classification. RESULTS: this is a surgical technique with anatomical and biological reconstruction of the CC and AC ligaments, using an allograft. Two bone tunnels are made in the clavicle, passing the lateral end of the graft below the acromion; then the two ends are fixed with two bioabsorbable screws, restoring vertical and horizontal stability. CONCLUSION: this procedure allows to restore the vertical and horizontal stability of the AC joint. Follow up studies are required to report functional and radiological results, in order to ensure advantages compared to existing techniques.

INTRODUCCIÓN: la luxación de la articulación acromioclavicular (AC) es una lesión frecuente que se observa en adultos jóvenes. El objetivo es describir una técnica quirúrgica que pueda restablecer la estabilidad horizontal y vertical de la articulación AC. MATERIAL Y MÉTODOS: se describe una técnica quirúrgica utilizando un aloinjerto para la reconstrucción anatómica de los ligamentos coracoclaviculares (CC) y AC para luxaciones AC grado III-V de acuerdo con la clasificación de Rockwood. RESULTADOS: es una técnica quirúrgica con reconstrucción anatómica y biológica de los ligamentos CC y AC con injerto. Se realizan dos túneles óseos en la clavícula pasando el cabo lateral del injerto por debajo del acromion; posteriormente se fijan los dos cabos con dos tornillos bioabsorbibles, restaurando de esta manera la estabilidad vertical y horizontal. CONCLUSIÓN: este procedimiento permite restablecer la estabilidad vertical y horizontal de la articulación AC. Se requieren estudios de seguimiento para reportar resultados funcionales y radiológicos con el fin de poder asegurar ventajas en comparación con las técnicas existentes.

Endarterectomy, Stenting, or Medical Treatment for Symptomatic Carotid Near-Occlusion: Results from CAOS, a Multicenter Registry Study.

BACKGROUND AND PURPOSE: The treatment of symptomatic carotid near-occlusion is controversial. Our aim was to analyze the results of carotid endarterectomy and carotid artery stent placement in patients with symptomatic carotid near-occlusion and to identify factors related to technical failure, periprocedural complications, and restenosis. MATERIALS AND METHODS: We conducted a multicenter, prospective nonrandomized study. Patients with angiography-confirmed carotid near-occlusion were included. We assessed the revascularization rate and periprocedural stroke or death. Twenty-four-month clinical and carotid imaging follow-up was performed, and rates of carotid restenosis or occlusion, ipsilateral stroke, and mortality were analyzed. Carotid artery stent placement, carotid endarterectomy, and medical treatment were compared. RESULTS: One hundred forty-one patients were included. Forty-four carotid artery stent placement and 23 carotid endarterectomy procedures were performed within 6 months after the event. Complete revascularization was achieved in 83.6%, 81.8% in the carotid artery stent placement group and 87% with carotid endarterectomy (P = .360). Periprocedural stroke or death occurred in 6% (carotid artery stent placement = 2.3%; carotid endarterectomy = 13%; P = .077) and was not related to revascularization failure. The carotid restenosis or occlusion rate was 8.3% (5% restenosis, 3.3% occlusion); with carotid artery stent placement it was 10.5%; and with carotid endarterectomy it was 4.5% (P = .419). The 24-month cumulative rate of ipsilateral stroke was 4.8% in the carotid artery stent placement group, 17.4% for carotid endarterectomy, and 13.1% for medical treatment (P = .223). Mortality was 12%, 4.5%, and 5.6%, respectively (P = .422). Revascularization failure and restenosis occurred more frequently in patients with full collapse compared with patients without full collapse (33.3% versus 5.6%, P = .009; 21.4% versus 2.9%, P = .032, respectively). CONCLUSIONS: Carotid artery stent placement and carotid endarterectomy are associated with high rates of failure and periprocedural stroke. Carotid near-occlusion with full collapse appears to be associated with an increased risk of technical failure and restenosis. Carotid near-occlusion revascularization does not seem to reduce the risk of stroke at follow-up compared with medical treatment.

Restablecimiento de la estabilidad horizontal en luxaciones acromioclaviculares III-V mediante la reconstrucción anatómica de los ligamentos coracoclaviculares y acromioclaviculares; técnica quirúrgica / Restoring horizontal stability in III-V acromioclavicular dislocations by anatomic reconstruction of the coracoclavicular and acromioclavicular ligaments; surgical technique

Resumen: Introducción: la luxación de la articulación acromioclavicular (AC) es una lesión frecuente que se observa en adultos jóvenes. El objetivo es describir una técnica quirúrgica que pueda restablecer la estabilidad horizontal y vertical de la articulación AC. Material y métodos: se describe una técnica quirúrgica utilizando un aloinjerto para la reconstrucción anatómica de los ligamentos coracoclaviculares (CC) y AC para luxaciones AC grado III-V de acuerdo con la clasificación de Rockwood. Resultados: es una técnica quirúrgica con reconstrucción anatómica y biológica de los ligamentos CC y AC con injerto. Se realizan dos túneles óseos en la clavícula pasando el cabo lateral del injerto por debajo del acromion; posteriormente se fijan los dos cabos con dos tornillos bioabsorbibles, restaurando de esta manera la estabilidad vertical y horizontal. Conclusión: este procedimiento permite restablecer la estabilidad vertical y horizontal de la articulación AC. Se requieren estudios de seguimiento para reportar resultados funcionales y radiológicos con el fin de poder asegurar ventajas en comparación con las técnicas existentes.

Abstract: Introduction: dislocation of the acromioclavicular (AC) joint is a common injury seen in young adults. The objective is to describe a surgical technique that can restore the horizontal and vertical stability of the AC joint. Material and methods: we describe a surgical technique that can restore horizontal and vertical stability using an allograft for the anatomical reconstruction of the CC and AC ligaments, for AC grade III-V dislocations according to the Rockwood classification. Results: this is a surgical technique with anatomical and biological reconstruction of the CC and AC ligaments, using an allograft. Two bone tunnels are made in the clavicle, passing the lateral end of the graft below the acromion; then the two ends are fixed with two bioabsorbable screws, restoring vertical and horizontal stability. Conclusion: this procedure allows to restore the vertical and horizontal stability of the AC joint. Follow up studies are required to report functional and radiological results, in order to ensure advantages compared to existing techniques.

Paraneoplastic syndromes in ophthalmology.

Paraneoplastic syndromes consist on systemic manifestations associated with certain cancers which are not a direct consequence of tumor invasion or its metastases. It is known that autoimmunity and autoantibody synthesis play an important role in its pathophysiology due to a process of molecular mimicry. Paraneoplastic syndromes in ophthalmology are rare, but it is important to recognize them clinically because in some cases symptoms preceded the diagnosis of an underlying neoplasia. Most frequently involved cancer is small cell lung carcinoma, but there is also a relationship with other tumor etiologies such as thymoma, gynecological tumors or neuroblastoma in children. Paraneoplastic syndromes with ocular involvement can be divided into those that affect the afferent visual pathway, such as cancer-associated retinopathy, melanoma-associated retinopathy, or paraneoplastic optic neuropathy; and the ones that affect the efferent visual pathway, such as bilateral tonic pupils, Myasthenia Gravis, Lambert-Eaton syndrome or paraneoplastic cerebellar degeneration. The presence of autoantibodies is helpful in clinical practice but negativity does not exclude this diagnosis. Although evolution and prognosis is linked to primary disease, in some cases specific treatment, usually immunosuppressive therapy, can help improving patients quality of life.

Evaluación funcional del manejo de rupturas masivas del manguito de los rotadores con el uso del balón subacromial / Functional evaluation of the management of massive rotator cuff ruptures with the use of the subacromial balloo

Resumen: Introducción: Las rupturas del manguito de los rotadores (MR) se presentan en más de 50% de los pacientes mayores de 60 años y pueden causar cambios en la biomecánica normal del hombro que pueden desencadenar una artropatía por desgarro del MR. Actualmente, no existe un consenso sobre el tratamiento para el desgarro masivo del MR. Objetivo: Evaluar los resultados clínicos y radiográficos de la colocación del balón subacromial en estas lesiones. Material y métodos: Estudio analítico, longitudinal y retrospectivo de 10 pacientes consecutivos tratados con el uso del balón subacromial. Se utilizaron escalas de Constant (CS) y ASES prequirúrgicas, a los seis y 12 meses de seguimiento postquirúrgico. Los resultados radiográficos fueron valorados por medio del intervalo acromio-humeral (IAH) en una radiografía anteroposterior (AP) verdadera de hombro. Resultados: La mejoría promedio en la CS fue de 41.7 ± 8.93 a los 12 meses de seguimiento, la escala de ASES mostró una mejoría promedio de 64.6 ± 4.9 a los 12 meses de seguimiento. El IAH prequirúrgico fue de 6.1 ± 1.10 y la media a los 12 meses de seguimiento fue de 7.1 ± 0.9. Se observó una mejoría clínica y radiográfica en todas las escalas; sin embargo, no se encontraron resultados estadísticamente significativos. Conclusión: El balón subacromial previene el ascenso de la cabeza humeral en los primeros 12 meses de colocado; suponemos que podría restaurar la cinemática glenohumeral normal mejorando movilidad y disminuyendo dolor.

Abstract: Introduction: Rotator cuff (MR) ruptures occur in more than 50% of patients over the age of 60, and can cause changes in normal shoulder biomechanics that can trigger rotator cuff tear arthropathy. There is currently no consensus on treatment for massive rotator cuff tears. Objective: To evaluate the clinical and radiographic outcomes of subacromial balloon placement in these lesions. Material and methods: Analytical, longitudinal and retrospective study of 10 consecutive patients treated with the use of the subacromial balloon. Constant (CS) and ASES scales were used preoperatively and at 6, 12 months of post-surgical follow-up. Radiographic results were assessed using the Acromio-humeral Interval (AHI) on a true AP shoulder X-ray. Results: The average improvement in CS was 41.7 ± 8.93 at 12 months of follow-up, the ASES scale showed an average improvement of 64.6 ± 4.9 at 12 months of follow-up. The presurgical AHI was 6.1 ± 1.10 and the mean at 12 months of follow-up was 7.1 ± 0.9. Clinical and radiographic improvement was observed at all scales, however no statistically significant results were found. Conclusion: The subacromial balloon prevents the ascent of the humeral head in the first 12 months of placement; we assume that it could restore normal glenohumeral kinematics by improving mobility and decreasing pain.

[Functional evaluation of the management of massive rotator cuff ruptures with the use of the subacromial balloo]. / Evaluación funcional del manejo de rupturas masivas del manguito de los rotadores con el uso del balón subacromial.

INTRODUCTION: Rotator cuff (MR) ruptures occur in more than 50% of patients over the age of 60, and can cause changes in normal shoulder biomechanics that can trigger rotator cuff tear arthropathy. There is currently no consensus on treatment for massive rotator cuff tears. OBJECTIVE: To evaluate the clinical and radiographic outcomes of subacromial balloon placement in these lesions. MATERIAL AND METHODS: Analytical, longitudinal and retrospective study of 10 consecutive patients treated with the use of the subacromial balloon. Constant (CS) and ASES scales were used preoperatively and at 6, 12 months of post-surgical follow-up. Radiographic results were assessed using the Acromio-humeral Interval (AHI) on a true AP shoulder X-ray. RESULTS: The average improvement in CS was 41.7 ± 8.93 at 12 months of follow-up, the ASES scale showed an average improvement of 64.6 ± 4.9 at 12 months of follow-up. The presurgical AHI was 6.1 ± 1.10 and the mean at 12 months of follow-up was 7.1 ± 0.9. Clinical and radiographic improvement was observed at all scales, however no statistically significant results were found. CONCLUSION: The subacromial balloon prevents the ascent of the humeral head in the first 12 months of placement; we assume that it could restore normal glenohumeral kinematics by improving mobility and decreasing pain.

INTRODUCCIÓN: Las rupturas del manguito de los rotadores (MR) se presentan en más de 50% de los pacientes mayores de 60 años y pueden causar cambios en la biomecánica normal del hombro que pueden desencadenar una artropatía por desgarro del MR. Actualmente, no existe un consenso sobre el tratamiento para el desgarro masivo del MR. OBJETIVO: Evaluar los resultados clínicos y radiográficos de la colocación del balón subacromial en estas lesiones. MATERIAL Y MÉTODOS: Estudio analítico, longitudinal y retrospectivo de 10 pacientes consecutivos tratados con el uso del balón subacromial. Se utilizaron escalas de Constant (CS) y ASES prequirúrgicas, a los seis y 12 meses de seguimiento postquirúrgico. Los resultados radiográficos fueron valorados por medio del intervalo acromio-humeral (IAH) en una radiografía anteroposterior (AP) verdadera de hombro. RESULTADOS: La mejoría promedio en la CS fue de 41.7 ± 8.93 a los 12 meses de seguimiento, la escala de ASES mostró una mejoría promedio de 64.6 ± 4.9 a los 12 meses de seguimiento. El IAH prequirúrgico fue de 6.1 ± 1.10 y la media a los 12 meses de seguimiento fue de 7.1 ± 0.9. Se observó una mejoría clínica y radiográfica en todas las escalas; sin embargo, no se encontraron resultados estadísticamente significativos. CONCLUSIÓN: El balón subacromial previene el ascenso de la cabeza humeral en los primeros 12 meses de colocado; suponemos que podría restaurar la cinemática glenohumeral normal mejorando movilidad y disminuyendo dolor.

[Multiple cerebral haemorrhages secondary to disseminated intravascular coagulation in a patient with COVID-19]. / Hemorragias cerebrales múltiples secundarias a coagulación intravascular diseminada en un paciente con COVID-19.

TITLE: Hemorragias cerebrales múltiples secundarias a coagulación intravascular diseminada en un paciente con COVID-19.

Ultrasonographic and hemodynamic characteristics of patients with symptomatic carotid near-occlusion: results from a multicenter registry study.

PURPOSE: The ultrasonographic and hemodynamic features of patients with carotid near-occlusion (CNO) are still not well known. Our aim was to describe the ultrasonographic and hemodynamic characteristics of a cohort of patients with CNO. METHODS: A prospective, observational, nationwide, and multicenter study was conducted from January/2010 to May/2016. Patients with digital subtraction angiography (DSA)-confirmed CNO were included. We collected information on clinical and demographic characteristics, carotid and transcranial ultrasonography and DSA findings, presence of full-collapse, collateral circulation, and cerebrovascular reactivity (CVR). RESULTS: One hundred thirty-five patients were analyzed. Ultrasonographic and DSA diagnosis of CNO were concordant in only 44%. This disagreement was related to the presence/absence of full-collapse: 45% of patients with CNO with full-collapse were classified as a complete carotid occlusion, and 40% with a CNO without full-collapse were interpreted as severe stenosis (p < 0.001). Mean velocities (mV) and pulsatility indexes (PIs) were significantly lower in the ipsilateral middle cerebral artery compared with the contralateral (43 cm/s vs 58 cm/s, p < 0.001; 0.80 vs 1.00, p < 0.001). Collateral circulation was identified in 92% of patients, with the anterior communicating artery (73%) being the most frequent. CVR was decreased or exhausted in 66% of cases and was more frequent in patients with a poor or absent collateral network compared with patients with ≥ 2 collateral arteries (82% vs 56%, p = 0.051). CONCLUSION: The accuracy of carotid ultrasonography in the diagnosis of CNO seems to be limited, with significant discrepancies with DSA. Decreased ipsilateral mV, PI, and CVR suggest a hemodynamic compromise in patients with CNO.

Synergies of THESEUS with the large facilities of the 2030s and guest observer opportunities.

The proposed THESEUS mission will vastly expand the capabilities to monitor the high-energy sky. It will specifically exploit large samples of gamma-ray bursts to probe the early universe back to the first generation of stars, and to advance multi-messenger astrophysics by detecting and localizing the counterparts of gravitational waves and cosmic neutrino sources. The combination and coordination of these activities with multi-wavelength, multi-messenger facilities expected to be operating in the 2030s will open new avenues of exploration in many areas of astrophysics, cosmology and fundamental physics, thus adding considerable strength to the overall scientific impact of THESEUS and these facilities. We discuss here a number of these powerful synergies and guest observer opportunities.

Contraindications to intravenous thrombolysis in prehospital triage of thrombectomy candidates.

BACKGROUND AND PURPOSE: The existence of contraindications to intravenous thrombolysis (IVT) is considered a criterion for direct transfer of patients with suspected acute stroke to thrombectomy-capable centers in the prehospital setting. Our aim was to assess the utility of this criterion in a setting where routing protocols are defined by the Madrid - Direct Referral to Endovascular Center (M-DIRECT) prehospital scale. METHODS: This was a post hoc analysis of the M-DIRECT study. Reported contraindications to IVT were retrospectively collected from emergency medical services reports and categorized into late window, anticoagulant treatment and other contraindications. Final diagnosis and treatment rates were compared between patients with and without reported IVT contraindications and according to anticoagulant treatment or late window categories. RESULTS: The M-DIRECT study included 541 patients. Reported IVT contraindications were present in 227 (42.0%) patients. Regarding final diagnosis no significant differences were found between patients with or without reported IVT contraindications: ischaemic stroke (any) 65.6% vs. 62.1%, ischaemic stroke with large vessel occlusion (LVO) 32.2% vs. 28.3%, hemorrhagic stroke 15.4% vs. 15.6%, stroke mimic 18.9% vs. 22.3% respectively. Amongst patients with LVO, endovascular thrombectomy (EVT) was performed less often in the presence of IVT contraindications (56.2% vs. 74.2%). M-DIRECT-positive patients had higher rates of LVO and EVT compared with M-DIRECT-negative patients independent of reported IVT contraindications. CONCLUSIONS: Reported IVT contraindications alone do not increase EVT likelihood and should not be considered to determine routing in urban stroke networks.

Impact of the COVID-19 pandemic on the organisation of stroke care. Madrid Stroke Care Plan. / Impacto de la pandemia de COVID-19 en la organización asistencial del ictus. Plan Ictus Madrid.

INTRODUCTION: The overload of the healthcare system and the organisational changes made in response to the COVID-19 pandemic may be having an impact on acute stroke care in the Region of Madrid. METHODS: We conducted a survey with sections addressing hospital characteristics, changes in infrastructure and resources, code stroke clinical pathways, diagnostic testing, rehabilitation, and outpatient care. We performed a descriptive analysis of results according to the level of complexity of stroke care (availability of stroke units and mechanical thrombectomy). RESULTS: The survey was completed by 22 of the 26 hospitals in the Madrid Regional Health System that attend adult emergencies, between 16 and 27 April 2020. Ninety-five percent of hospitals had reallocated neurologists to care for patients with COVID-19. The numbers of neurology ward beds were reduced in 89.4% of hospitals; emergency department stroke care pathways were modified in 81%, with specific pathways for suspected SARS-CoV2 infection established in 50% of hospitals; and SARS-CoV2-positive patients with acute stroke were not admitted to neurology wards in 42%. Twenty-four hour on-site availability of mechanical thrombectomy was improved in 10 hospitals, which resulted in a reduction in the number of secondary hospital transfers. The admission of patients with transient ischaemic attack or minor stroke was avoided in 45% of hospitals, and follow-up through telephone consultations was implemented in 100%. CONCLUSIONS: The organisational changes made in response to the SARS-Co2 pandemic in hospitals in the Region of Madrid have modified the allocation of neurology department staff and infrastructure, stroke units and stroke care pathways, diagnostic testing, hospital admissions, and outpatient follow-up.

Comparación de Algoritmos Lineales y no Lineales para la Detección del Desacoplamiento Cardiorrespiratorio en Ratas Endotoxémicas / Comparison of Linear and Nonlinear Algorithms for Detection of Cardiorespiratory Uncoupling in Endotoxemic Rats

Resumen En estudios previos se ha demostrado que la endotoxemia inducida por lipopolisacárido (LPS) produce un desacoplamiento cardiorrespiratorio (CRP) debido a los efectos fisiológicos de la inflamación sistémica. Adicionalmente se sabe que la oxitocina tiene efectos antiinflamatorios y propiedades cardioprotectoras; sin embargo, se desconoce si ésta modifica el acoplamiento CRP. El objetivo del presente estudio fue comparar diferentes métodos matemáticos lineales y no lineales para la detección del desacoplamiento cardiorrespiratorio entre series de tiempo cardiacas y respiratorias. Se estudiaron series de tiempo R-R obtenidas de electrocardiogramas de grupos de roedores macho a los cuales se les administró solución salina o vehículo (V); lipopolisacárido (LPS); oxitocina (O) y LPS + oxitocina (LPS+Ox). Las series R-R y respiratorias derivadas del electrocardiograma (EDR) se analizaron en conjunto para cuantificar su grado de acoplamiento a través de las técnicas de correlación cruzada; entropía muestral cruzada; entropía condicional; información mutua; e información mutua de Rényi para los cuatro grupos. Se observó que la oxitocina no parece favorecer el acoplamiento CRP durante la endotoxemia inducida por LPS. Finalmente, se encontró que la entropía muestral cruzada y la entropía condicional presentaron las mayores diferencias estadísticas para identificar el desacoplamiento CRP producido por el LPS.

Abstract Previous studies have shown that LPS-induced endotoxemia causes a cardiorespiratory (CRP) uncoupling owing to the physiological effects of systemic inflammation. Also, it is known that oxytocin has anti-inflammatory effects and cardioprotective properties; however, it is unknown whether it can modify the CRP coupling. This study aimed to compare different linear and nonlinear mathematics methods for the detection of cardiorespiratory uncoupling between cardiac and respiratory time series. The R-R time series of electrocardiograms of male rodents that were administered with saline solution (V); lipopolysaccharide (LPS); oxytocin (O) and LPS + oxytocin (LPS + Ox) were studied. We tested the R-R and respiratory series derived from the electrocardiogram (EDR) for the four groups to quantify the degree of coupling with cross-correlation; cross sample entropy; conditional entropy; mutual information; and Rényi's mutual information. We found that oxytocin does not seem to favor the CRP coupling during endotoxemia induced by LPS. Finally, we observed that the cross-sample entropy and the conditional entropy presented the highest statistical differences to identify the CRP uncoupling produced by LPS.