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1.
Curr Oncol ; 31(1): 447-461, 2024 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-38248115

RESUMEN

The prognosis of early non-small-cell lung cancer (eNSCLC) remains poor. An understanding of current therapies and outcomes can provide insights into how novel therapies can be integrated into clinics. We conducted a large, retrospective, population-based cohort study of patients with de novo eNSCLC (stages IB, IIA, IIB, and IIIA) diagnosed in Alberta, Canada, between 2010 and 2019. The primary objectives were to describe treatment patterns and survival outcomes among patients with eNSCLC. A total of 5126 patients with eNSCLC were included. A total of 45.3% of patients were referred to a medical oncologist, ranging from 23.7% in stage IB to 58.3% in IIIA. A total of 23.6% of patients initiated systemic therapy (ST), ranging from 3.5% in stage IB to 38.5% in IIIA. For stage IIB and IIIA individuals who received surgery, adjuvant ST was associated with a decreased likelihood of death (hazard ratios (HR) of 0.77 (95% CI: 0.56-1.07) and 0.69 (95% CI: 0.54-0.89), respectively). In a Canadian real-world setting, stage IIB and IIIA patients who received adjuvant ST tended to have better survival than patients who did not, but future studies that provide adjustment of additional confounders are warranted. Examining referral pathways that account for disparities based on age, sex, and comorbidities in the real world would also provide further insights.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Carcinoma Pulmonar de Células Pequeñas , Humanos , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Estudios de Cohortes , Estudios Retrospectivos , Neoplasias Pulmonares/tratamiento farmacológico , Alberta , Atención a la Salud
2.
Cancer ; 130(4): 530-540, 2024 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-37933916

RESUMEN

BACKGROUND: This study aimed to describe treatment patterns and overall survival (OS) in patients with advanced non-small cell lung cancer (aNSCLC) in three countries between 2011 and 2020. METHODS: Three databases (US, Canada, Germany) were used to identify incident aNSCLC patients. OS was assessed from the date of incident aNSCLC diagnosis and, for patients who received at least a first line of therapy (1LOT), from the date of 1LOT initiation. In multivariable analyses, we analyzed the influence of index year and type of prescribed treatment on OS. FINDINGS: We included 51,318 patients with an incident aNSCLC diagnosis. The percentage of patients treated with a 1LOT differed substantially between countries, whereas the number of patients receiving immunotherapies/targeted treatments increased over time in all three countries. Median OS from the date of incident diagnosis was 9.9 months in the United States vs. 4.1 months in Canada. When measured from the start of 1LOT, patients had a median OS of 10.7 months in the United States, 10.9 months in Canada, and 10.9 months in Germany. OS from the start of 1LOT improved in all three countries from 2011 to 2020 by approximately 3 to 4 months. CONCLUSIONS: Observed continuous improvement in OS among patients receiving at least a 1LOT from 2011 to 2020 was likely driven by improved care and changes in the treatment landscape. The difference in the proportion of patients receiving a 1LOT in the observed countries requires further investigation.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Estados Unidos/epidemiología , Carcinoma de Pulmón de Células no Pequeñas/patología , Neoplasias Pulmonares/patología , Estudios Retrospectivos , Alemania/epidemiología , Canadá/epidemiología
3.
JAMA Netw Open ; 5(11): e2239874, 2022 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-36326765

RESUMEN

Importance: The external validity of survival outcomes derived from clinical practice data from US patients with advanced non-small cell lung cancer (NSCLC) is not known and is of potential importance because it may be used to support regulatory decision-making and health technology assessment outside of the US. Objective: To evaluate whether overall survival (OS) estimates for a selected group of patients with advanced NSCLC from a large US clinical practice database are transportable to Canadian patients receiving the same systemic therapies. Design, Setting, and Participants: This retrospective multicenter cohort study used transportability analysis to assess whether adjustment for pretreatment characteristics of eligible patient cohorts could reliably approximate OS estimated from US-based samples to Canadian populations. A total of 17 432 eligible adult patients who were diagnosed de novo with advanced NSCLC on or after January 1, 2011, were included in the analysis and followed up until September 30, 2020. Because data on race and ethnicity were available in the US database but not the Canadian database and because racial and ethnic distribution was likely to be similar between US and Canadian patients, these characteristics were not analyzed. Exposures: Initiation of platinum-doublet chemotherapy or pembrolizumab monotherapy as first-line systemic treatment for advanced NSCLC. Main Outcomes and Measures: OS measured from the time of initiation of the respective treatment regimen. Results: Among 17 432 eligible patients, 15 669 patients from the US and 1763 patients from Canada were included in the analysis. Of those, 11 863 patients (sample size-weighted estimates of mean [SD] age, 68.0 [9.3] years; 6606 [55.7%] male; 10 100 from the US and 1763 from Canada) were included in the subset of patients with complete data for baseline covariates. A total of 13 532 US patients received first-line chemotherapy, and 2137 received first-line pembrolizumab monotherapy. Of those, 8447 patients (62.4%) in the first-line chemotherapy group and 1653 patients (77.3%) in the first-line pembrolizumab group had complete data on baseline covariates for outcome model estimation. A total of 1476 Canadian patients who received first-line chemotherapy and 287 patients who received first-line pembrolizumab monotherapy were identified from the target population. After standardization to baseline patient covariates in the Canadian cohorts, transported OS estimates revealed a less than 5% mean absolute difference from the observed OS in the target population (0.56% over 60 months of follow-up in the first-line chemotherapy group and 4.54% over 30 months of follow-up in the first-line pembrolizumab group). Negative control analysis using a mismatched outcome model revealed a 6.64% discrepancy and an incompatible survival curve shape. The results were robust to assumptions of random missingness for baseline covariates, to unadjusted differences in baseline metastases and comorbidities, and to differences in the standard of care between the US and Canada related to administration of second-line anti-programmed cell death 1 ligand 1 immunotherapy for patients who initiated first-line chemotherapy. Conclusions and Relevance: The results of this cohort study suggest that, under specific circumstances, OS estimates from US clinical practice data can be adjusted using baseline clinical characteristics to closely approximate OS in selected groups of Canadian patients with advanced NSCLC. These results may have implications for regulatory decision-making and health technology assessment in target populations outside of the US.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Adulto , Humanos , Masculino , Anciano , Femenino , Carcinoma de Pulmón de Células no Pequeñas/patología , Neoplasias Pulmonares/patología , Evaluación de la Tecnología Biomédica , Estudios de Cohortes , Canadá/epidemiología
5.
J Neurotrauma ; 38(3): 309-321, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32940126

RESUMEN

High-level spinal cord injury (SCI) can disrupt cardiovascular autonomic function. However, the evolution of cardiovascular autonomic function in the acute phase following injury is unknown. We evaluated the timing, severity, progression, and implications of cardiovascular autonomic injury following acute SCI. We tested 63 individuals with acute traumatic SCI (aged 48 ± 2 years) at five time-points: <2 weeks, and 1, 3, 6-12, and >12 months post-injury. Supine beat-to-beat systolic arterial pressure (SAP) and R-R interval (RRI) were recorded and low-frequency variability (LF SAP and LF RRI) determined. Cross-spectral analyses were used to determine baroreflex function (low frequency) and cardiorespiratory interactions (high frequency). Known electrocardiographic (ECG) markers for arrhythmia and self-reported symptoms of cardiovascular dysfunction were determined. Comparisons were made with historical data from individuals with chronic SCI and able-bodied controls. Most individuals had high-level (74%) motor/sensory incomplete (63%) lesions. All participants had decreased LF SAP at <2 weeks (2.22 ± 0.65 mm Hg2). Autonomic injury was defined as high-level SCI with LF SAP <2 mm Hg2. Two distinct groups emerged by 1 month: autonomically complete SCI with sustained low LF SAP (0.76 ± 0.17 mm Hg2) and autonomically incomplete SCI with increased LF SAP (5.46 ± 1.0 mm Hg2, p < 0.05). Autonomically complete injuries did not recover over time. Cardiovascular symptoms were prevalent and worsened with time, especially in those with autonomically complete lesions, and chronic SCI. Baroreflex function and cardiorespiratory interactions were impaired after SCI. Risk of arrhythmia increased immediately after SCI, and remained elevated throughout the acute phase. Acute SCI is associated with severe cardiovascular dysfunction. LF SAP provides a simple, non-invasive, translatable, quantitative assessment of autonomic function, and is most informative 1 month after injury.


Asunto(s)
Enfermedades del Sistema Nervioso Autónomo/epidemiología , Presión Sanguínea/fisiología , Enfermedades Cardiovasculares/epidemiología , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/fisiopatología , Enfermedades del Sistema Nervioso Autónomo/diagnóstico , Enfermedades del Sistema Nervioso Autónomo/fisiopatología , Barorreflejo/fisiología , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/fisiopatología , Electrocardiografía , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Factores de Tiempo
6.
Spinal Cord ; 58(4): 430-440, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31767947

RESUMEN

STUDY DESIGN: Clinical trial. OBJECTIVE: Spinal cord injury (SCI) impacts autonomic function and bowel management. Bowel care is a potential trigger for autonomic dysreflexia (AD; paroxysmal hypertension elicited by sensory stimuli below the level of lesion). AD can be life threatening so strategies to minimise AD are prioritised after SCI. Lidocaine lubricant is recommended during bowel care with the rationale to minimise the sensory stimulus, reducing AD. The objective of this study was to assess whether lidocaine lubricant (Xylocaine 2%) ameliorates AD during at-home bowel care compared with standard lubricant (placebo). SETTING: Community. METHOD: Participants (n = 13; age 44.0 ± 3.3 years) with high-level SCI (C3-T4) performed their normal at-home bowel care on two days, each time using a different lubricant, with continuous non-invasive cardiovascular monitoring. Injury to spinal autonomic (sympathetic) nerves was determined from low-frequency systolic arterial pressure (LF SAP) variability. RESULTS: Participants displayed reduced autonomic function (LF SAP 3.02 ± 0.84 mmHg2), suggesting impaired autonomic control. Bowel care duration was increased with lidocaine (79.1 ± 10.0 min) compared to placebo (57.7 ± 6.3 min; p = 0.018). All participants experienced AD on both days, but maximum SAP was higher with lidocaine (214.3 ± 10.5 mmHg) than placebo (196.7 ± 10.0 mmHg; p = 0.046). Overall, SAP was higher for longer with lidocaine (6.5 × 105 ± 0.9 × 105 mmHg • beat) than placebo (4.4 × 105 ± 0.6 × 105 mmHg • beat; p = 0.018) indicating a higher burden of AD. Heart rate and rhythm disturbances were increased during AD, particularly with lidocaine use. CONCLUSIONS: At-home bowel care was a potent trigger for AD. Our findings contradict recommendations for lidocaine use during bowel care, suggesting that anaesthetic lubricants impair reflex bowel emptying, resulting in longer care routines with an increased burden of AD.


Asunto(s)
Disreflexia Autónoma/etiología , Disreflexia Autónoma/prevención & control , Defecación , Lidocaína/efectos adversos , Lubricantes/efectos adversos , Guías de Práctica Clínica como Asunto , Traumatismos de la Médula Espinal/complicaciones , Adulto , Estudios Cruzados , Método Doble Ciego , Femenino , Humanos , Lidocaína/administración & dosificación , Lubricantes/administración & dosificación , Masculino , Persona de Mediana Edad , Resultado del Tratamiento
7.
Chron Respir Dis ; 16: 1479973119872979, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31526037

RESUMEN

There is no accepted standard for measuring mobility in hospitalized patients with an acute exacerbation of chronic obstructive pulmonary disease (AECOPD). The objective of this study was to assess convergent, discriminant, and known-group validity and floor/ceiling effects of the de Morton Mobility Index (DEMMI) in hospitalized patients with AECOPD. Individuals with AECOPD (n = 22) admitted to an acute care hospital medical ward were recruited. Data on the DEMMI, gait speed, daytime energy expenditure, step counts, 6-minute walk distance (6MWD), dyspnea, respiratory and heart rates, quality of life, and oxygen supplementation were collected on day 3 of admission. The DEMMI demonstrated convergent validity with the 6MWD and gait velocity measures (Spearman's ρ 0.69 and 0.61, respectively; p < 0.003) but not with measures of physical activity or respiratory impairment. Discriminant validity was present, with no correlation between the DEMMI and quality of life and resting heart rate. Known-group validity (gait aids vs. no gait aids) was demonstrated (p = 0.009). There was no floor effect but there was evidence of a possible ceiling effect (14% of participants received a perfect score). The DEMMI is feasible and showed moderate to strong validity with measures of observed physical function in hospitalized patients with AECOPD.


Asunto(s)
Limitación de la Movilidad , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Índice de Severidad de la Enfermedad , Enfermedad Aguda , Anciano , Progresión de la Enfermedad , Disnea/etiología , Metabolismo Energético , Estudios de Factibilidad , Femenino , Frecuencia Cardíaca , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Terapia por Inhalación de Oxígeno , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Enfermedad Pulmonar Obstructiva Crónica/terapia , Calidad de Vida , Frecuencia Respiratoria , Prueba de Paso , Velocidad al Caminar
8.
J Neurotrauma ; 35(9): 1091-1105, 2018 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-29239268

RESUMEN

Autonomic dysfunction is common in individuals with spinal cord injury (SCI) and leads to numerous abnormalities, including profound cardiovascular and bowel dysfunction. In those with high-level lesions, bowel management is a common trigger for autonomic dysreflexia (AD; hypertension provoked by sensory stimuli below the injury level). Improving bowel care is integral for enhancing quality of life (QoL). We aimed to describe the relationships between bowel care, AD, and QoL in individuals with SCI. We performed an online community survey of individuals with SCI. Those with injury at or above T7 were considered at risk for AD. Responses were received from 287 individuals with SCI (injury levels C1-sacral and average duration of injury 17.1 ± 12.9 [standard deviation] years). Survey completion rate was 73% (n = 210). Bowel management was a problem for 78%: it interfered with personal relationships (60%) and prevented staying (62%) and working (41%) away from home. The normal bowel care duration was >60 min in 24% and most used digital rectal stimulation (59%); 33% reported bowel incontinence at least monthly. Of those at risk for AD (n = 163), 74% had AD symptoms during bowel care; 32% described palpitations. AD interfered with activities of daily living in 51%. Longer durations of bowel care (p < 0.001) and more severe AD (p = 0.04) were associated with lower QoL. Bowel management is a key concern for individuals with SCI and is commonly associated with symptoms of AD. Further studies should explore ways to manage bowel dysfunction, increase self-efficacy, and ameliorate the impact of AD to improve QoL.


Asunto(s)
Disreflexia Autónoma/etiología , Disreflexia Autónoma/psicología , Intestino Neurogénico/etiología , Intestino Neurogénico/psicología , Traumatismos de la Médula Espinal/complicaciones , Actividades Cotidianas , Adulto , Anciano , Anciano de 80 o más Años , Manejo de la Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Intestino Neurogénico/terapia , Calidad de Vida , Encuestas y Cuestionarios , Adulto Joven
9.
PLoS One ; 12(6): e0180195, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28666000

RESUMEN

BACKGROUND: Innovative wheelchairs allow individuals to change position easily for comfort and social situations. While these wheelchairs are beneficial in multiple ways, the effects of position changes on blood pressure might exacerbate hypotension and cerebral hypoperfusion, particularly in those with spinal cord injury (SCI) who can have injury to autonomic nerves that regulate cardiovascular control. Conversely, cardiovascular benefits may be obtained with lowered seating. Here we investigate the effect of moderate changes in wheelchair position on orthostatic cardiovascular and cerebrovascular reflex control. METHODS: Nineteen individuals with SCI and ten neurologically-intact controls were tested in supine and seated positions (neutral, lowered, and elevated) in the Elevation™ wheelchair. Participants with SCI were stratified into two groups by the severity of injury to cardiovascular autonomic pathways. Beat-to-beat blood pressure, heart rate and middle cerebral artery blood flow velocity (MCAv) were recorded non-invasively. RESULTS: Supine blood pressure and MCAv were reduced in individuals with lesions to autonomic pathways, and declined further with standard seating compared to those with preserved autonomic control. Movement to the elevated position triggered pronounced blood pressure and MCAv falls in those with autonomic lesions, with minimum values significantly reduced compared to the seated and lowered positions. The cumulative duration spent below supine blood pressure was greatest in this group. Lowered seating bolstered blood pressure in those with lesions to autonomic pathways. CONCLUSIONS: Integrity of the autonomic nervous system is an important variable that affects cardiovascular responses to orthostatic stress and should be considered when individuals with SCI or autonomic dysfunction are selecting wheelchairs. SPONSORSHIP: This work was supported in part by the Heart and Stroke Foundation of British Columbia and the Yukon (V.E.C).


Asunto(s)
Sistema Cardiovascular/fisiopatología , Postura , Traumatismos de la Médula Espinal/fisiopatología , Silla de Ruedas , Estudios de Casos y Controles , Humanos
10.
Can J Respir Ther ; 52(4): 105-109, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-30996618

RESUMEN

This article suggests a method for integrating the principles of Aboriginal knowledge translation (KT) in the implementation of a pilot for chronic obstructive pulmonary disease (COPD) screening to improve current practice and provide health programming that is culturally sensitive and relevant. The elements of the Consolidated Framework for Implementation Research model guided a community informed design for the Lung Health Day that was planned with two communities of the Secwepemc Nation in British Columbia. By integrating the principles of Aboriginal KT, program implementation design can address the current disparities in respiratory care and management of COPD and improve the health status of First Nations patients.

11.
J Vis Exp ; (73): e4315, 2013 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-23542558

RESUMEN

Orthostatic tolerance (OT) refers to the ability to maintain cardiovascular stability when upright, against the hydrostatic effects of gravity, and hence to maintain cerebral perfusion and prevent syncope (fainting). Various techniques are available to assess OT and the effects of gravitational stress upon the circulation, typically by reproducing a presyncopal event (near-fainting episode) in a controlled laboratory environment. The time and/or degree of stress required to provoke this response provides the measure of OT. Any technique used to determine OT should: enable distinction between patients with orthostatic intolerance (of various causes) and asymptomatic control subjects; be highly reproducible, enabling evaluation of therapeutic interventions; avoid invasive procedures, which are known to impair OT(1). In the late 1980s head-upright tilt testing was first utilized for diagnosing syncope(2). Since then it has been used to assess OT in patients with syncope of unknown cause, as well as in healthy subjects to study postural cardiovascular reflexes(2-6). Tilting protocols comprise three categories: passive tilt; passive tilt accompanied by pharmacological provocation; and passive tilt with combined lower body negative pressure (LBNP). However, the effects of tilt testing (and other orthostatic stress testing modalities) are often poorly reproducible, with low sensitivity and specificity to diagnose orthostatic intolerance(7). Typically, a passive tilt includes 20-60 min of orthostatic stress continued until the onset of presyncope in patients(2-6). However, the main drawback of this procedure is its inability to invoke presyncope in all individuals undergoing the test, and corresponding low sensitivity(8,9). Thus, different methods were explored to increase the orthostatic stress and improve sensitivity. Pharmacological provocation has been used to increase the orthostatic challenge, for example using isoprenaline(4,7,10,11) or sublingual nitrate(12,13). However, the main drawback of these approaches are increases in sensitivity at the cost of unacceptable decreases in specificity(10,14), with a high positive response rate immediately after administration(15). Furthermore, invasive procedures associated with some pharmacological provocations greatly increase the false positive rate(1). Another approach is to combine passive tilt testing with LBNP, providing a stronger orthostatic stress without invasive procedures or drug side-effects, using the technique pioneered by Professor Roger Hainsworth in the 1990s(16-18). This approach provokes presyncope in almost all subjects (allowing for symptom recognition in patients with syncope), while discriminating between patients with syncope and healthy controls, with a specificity of 92%, sensitivity of 85%, and repeatability of 1.1±0.6 min(16,17). This allows not only diagnosis and pathophysiological assessment(19-22), but also the evaluation of treatments for orthostatic intolerance due to its high repeatability(23-30). For these reasons, we argue this should be the "gold standard" for orthostatic stress testing, and accordingly this will be the method described in this paper.


Asunto(s)
Intolerancia Ortostática/diagnóstico , Intolerancia Ortostática/fisiopatología , Pruebas de Mesa Inclinada/instrumentación , Pruebas de Mesa Inclinada/métodos , Presión Sanguínea/fisiología , Dióxido de Carbono/metabolismo , Electrocardiografía/métodos , Femenino , Humanos , Oxígeno/metabolismo , Presión Parcial , Síncope/diagnóstico , Síncope/fisiopatología
12.
Front Physiol ; 3: 257, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22934013

RESUMEN

Spinal cord injury (SCI) triggers profound changes in visceral and somatic targets of sensory neurons below the level of injury. Despite this, little is known about the influence of injury to the spinal cord on sensory ganglia. One of the defining characteristics of sensory neurons is the size of their cell body: for example, nociceptors are smaller in size than mechanoreceptors or proprioceptors. In these experiments, we first used a comprehensive immunohistochemical approach to characterize the size distribution of sensory neurons after high- and low-thoracic SCI. Male Wistar rats (300 g) received a spinal cord transection (T3 or T10) or sham-injury. At 30 days post-injury, dorsal root ganglia (DRGs) and spinal cords were harvested and analyzed immunohistochemically. In a wide survey of primary afferents, only those expressing the capsaicin receptor (TRPV1) exhibited somal hypertrophy after T3 SCI. Hypertrophy only occurred caudal to SCI and was pronounced in ganglia far distal to SCI (i.e., in L4-S1 DRGs). Injury-induced hypertrophy was accompanied by a small expansion of central territory in the lumbar spinal dorsal horn and by evidence of TRPV1 upregulation. Importantly, hypertrophy of TRPV1-positive neurons was modest after T10 SCI. Given the specific effects of T3 SCI on TRPV1-positive afferents, we hypothesized that these afferents contribute to autonomic dysreflexia (AD). Rats with T3 SCI received vehicle or capsaicin via intrathecal injection at 2 or 28 days post-SCI; at 30 days, AD was assessed by recording intra-arterial blood pressure during colo-rectal distension (CRD). In both groups of capsaicin-treated animals, the severity of AD was dramatically reduced. While AD is multi-factorial in origin, TRPV1-positive afferents are clearly involved in AD elicited by CRD. These findings implicate TRPV1-positive afferents in the initiation of AD and suggest that TRPV1 may be a therapeutic target for amelioration or prevention of AD after high SCI.

13.
J Neurotrauma ; 29(8): 1638-49, 2012 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-22260380

RESUMEN

The severity of injury to cardiovascular autonomic pathways following clinical spinal cord injury (SCI) can be evaluated with spectral analyses. Whether this technique provides a translatable assessment of cardiovascular autonomic function in rodent SCI is unknown. Beat-to-beat blood pressure and pulse interval were measured in male rats 1 month after complete T3 or T10 SCI, and in uninjured control animals. Univariate autoregressive spectral analyses were performed and the power of the low frequency (LF), high frequency (HF), and very low frequency (VLF) peaks identified. Frequency domain variables were correlated with the severity of orthostatic hypotension (OH) and the severity of hypertension during autonomic dysreflexia (AD). Total heart rate variability (HRV) and blood pressure variability (BPV) were reduced in animals with T3, but not T10, SCI. VLF and LF HRV were reduced and HF HRV was increased in animals with T3 SCI compared to controls; there were no changes in animals with T10 SCI. BPV in the VLF and LF range was reduced in animals with T3 SCI, but not T10 SCI. In all animals with SCI, severity of OH was positively correlated with LF BPV, and negatively correlated with HF BPV. Severity of AD was positively correlated with HF BPV and HF HRV, and negatively correlated with VLF HRV. Spectral analyses can detect alterations in cardiovascular autonomic function in animals with SCI at rest. These parameters underscore the distinct cardiovascular ramifications of high- versus low-thoracic SCI, and correlate with the severity of AD and OH, clinically-relevant measures of abnormal blood pressure control.


Asunto(s)
Vías Autónomas/fisiopatología , Presión Sanguínea/fisiología , Sistema Cardiovascular/fisiopatología , Frecuencia Cardíaca/fisiología , Traumatismos de la Médula Espinal/fisiopatología , Animales , Disreflexia Autónoma/fisiopatología , Hipotensión Ortostática/fisiopatología , Masculino , Ratas , Ratas Wistar
14.
Spine J ; 10(12): 1108-17, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21094471

RESUMEN

BACKGROUND CONTEXT: Individuals with high spinal cord injury (SCI) are prone to significant fluctuation in blood pressure with episodes of very high and low blood pressure during autonomic dysreflexia (AD) and orthostatic hypotension, respectively. We do not know how such blood pressure lability affects the vasculature. PURPOSE: We used a well-characterized animal model of AD to determine whether increasing the frequency of AD during recovery from SCI would exacerbate injury-induced dysfunction in resistance vessels. STUDY DESIGN/SETTING: Experimental animal study. International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Canada. METHODS: Complete transection of the T3 spinal cord was performed in male Wistar rats. For 14 days after injury, AD was induced via colorectal distension (CRD; 30 minutes per day) in the experimental group (SCI-CRD). One month after SCI, baseline cardiovascular parameters and severity of CRD-induced AD were assessed in SCI-CRD animals and SCI-only controls. Mesenteric arteries were harvested for in vitro myography to characterize vasoactive responses to phenylephrine (PE) and acetylcholine (ACh). RESULTS: Mesenteric arteries from SCI-CRD animals exhibited larger maximal responses to PE than arteries from SCI-only controls. Hyperresponsiveness to PE was not a product of endothelial dysfunction because mesenteric arteries from both groups had similar vasodilator responses to ACh. Both SCI-only controls and SCI-CRD animals exhibited CRD-evoked AD 1 month after SCI; however, CRD-induced hypertension was less pronounced in animals that were previously exposed to CRD. CONCLUSIONS: Injury-induced changes within the vasculature may contribute to the development of AD after SCI. Here, we provide evidence that AD itself has significant and long-lasting effects on vascular function. This finding has implications for the medical management of AD and provides an impetus for maintaining stable blood pressure.


Asunto(s)
Disreflexia Autónoma/complicaciones , Endotelio Vascular/fisiopatología , Traumatismos de la Médula Espinal/complicaciones , Enfermedades Vasculares/etiología , Acetilcolina/farmacología , Análisis de Varianza , Animales , Disreflexia Autónoma/fisiopatología , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/fisiología , Relación Dosis-Respuesta a Droga , Endotelio Vascular/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Frecuencia Cardíaca/fisiología , Masculino , Miografía , Fenilefrina/farmacología , Ratas , Ratas Wistar , Traumatismos de la Médula Espinal/fisiopatología , Vértebras Torácicas , Enfermedades Vasculares/fisiopatología , Vasoconstrictores/farmacología , Vasodilatación/efectos de los fármacos , Vasodilatación/fisiología
15.
J Neurotrauma ; 27(9): 1709-22, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20597687

RESUMEN

The complications of spinal cord injury (SCI) increase in number and severity with the level of injury. A recent survey of SCI researchers reveals that animal models of high SCI are essential. Despite this consensus, most laboratories continue to work with mid- or low-thoracic SCI. The available data on cervical SCI in animals characterize incomplete injuries; for example, nearly all studies published in 2009 examine discrete, tract-specific lesions that are not clinically-relevant. A primary barrier to developing animal models of severe, higher SCI is the challenge of animal care, a critical determinant of experimental outcome. Currently, many of these practices vary substantially between laboratories, and are passed down anecdotally within institutions. The care of animals with SCI is complex, and becomes much more challenging as the lesion level ascends. In our experience, the care of animals with high-thoracic (T3) SCI is much more demanding than the care of animals with low-thoracic SCI, even though both injuries result in paraplegia. We have developed an animal care regimen for rats with complete high-thoracic SCI. Our practices have been refined over the past 7 years, in collaboration with animal care centre staff and veterinarians. During this time, we have cared for more than 300 rats with T3 complete transection SCI, with experimental end-points of up to 3 months. Here we provide details of our animal care procedures, including acclimatization, housing, diet, antibiotic prophylaxis, surgical procedures, post-operative monitoring, and prevention of complications. In our laboratory, this comprehensive approach consistently produces good outcomes following T3 complete transection SCI: using body weight as an objective indicator of animal health, we have found that our rats typically return to pre-operative weights within 10 days of T3 complete SCI. It is our hope that the information provided here will improve care of experimental animals, and facilitate adoption of models that directly address the complications associated with higher level injuries.


Asunto(s)
Bienestar del Animal , Modelos Animales de Enfermedad , Vivienda para Animales , Ciencia de los Animales de Laboratorio/métodos , Traumatismos de la Médula Espinal/terapia , Bienestar del Animal/normas , Animales , Vivienda para Animales/normas , Masculino , Complicaciones Posoperatorias/prevención & control , Complicaciones Posoperatorias/terapia , Ratas , Ratas Wistar , Traumatismos de la Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/rehabilitación , Vértebras Torácicas
16.
PLoS One ; 5(5): e10872, 2010 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-20531934

RESUMEN

Membranous compartments of neurons such as axons, dendrites and modified primary cilia are defining features of neuronal phenotype. This is unlike organelles deep to the plasma membrane, which are for the most part generic and not related directly to morphological, neurochemical or functional specializations. However, here we use multi-label immunohistochemistry combined with confocal and electron microscopy to identify a very large (approximately 6 microns in diameter), entirely intracellular neuronal organelle which occurs singly in a ubiquitous but neurochemically distinct and morphologically simple subset of sympathetic ganglion neurons. Although usually toroidal, it also occurs as twists or rods depending on its intracellular position: tori are most often perinuclear whereas rods are often found in axons. These 'loukoumasomes' (doughnut-like bodies) bind a monoclonal antibody raised against beta-III-tubulin (SDL.3D10), although their inability to bind other beta-III-tubulin monoclonal antibodies indicate that the responsible antigen is not known. Position-morphology relationships within neurons and their expression of non-muscle heavy chain myosin suggest a dynamic structure. They associate with nematosomes, enigmatic nucleolus-like organelles present in many neural and non-neural tissues, which we now show to be composed of filamentous actin. Loukoumasomes also separately interact with mother centrioles forming the basal body of primary cilia. They express gamma tubulin, a microtubule nucleator which localizes to non-neuronal centrosomes, and cenexin, a mother centriole-associated protein required for ciliogenesis. These data reveal a hitherto undescribed organelle, and depict it as an intracellular transport machine, shuttling material between the primary cilium, the nematosome, and the axon.


Asunto(s)
Neuronas/metabolismo , Orgánulos/metabolismo , Sistema Nervioso Simpático/citología , Animales , Citoesqueleto/metabolismo , Femenino , Ganglios/ultraestructura , Masculino , Neuronas/ultraestructura , Orgánulos/ultraestructura , Proteínas/metabolismo , Ratas , Ratas Long-Evans , Ratas Sprague-Dawley , Fracciones Subcelulares/metabolismo , Sistema Nervioso Simpático/ultraestructura
17.
J Neurotrauma ; 27(1): 275-85, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19772460

RESUMEN

Cardiometabolic risk factors are sorely underreported after spinal cord injury (SCI), despite the high prevalence of metabolic disorders and cardiovascular mortality in this population. Body-composition analysis and serum-lipid profiling are two assessments that are beginning to be more widely used to document metabolic changes after clinical SCI. Individuals with SCI have been reported to carry increased visceral fat and to exhibit altered serum-lipid levels. However, little is known about the development of these cardiometabolic risk factors in animal models. Using a combination of magnetic resonance imaging (MRI) and adipose tissue dissection, we show that visceral and subcutaneous adipose tissue were both increased at 1 month, but not at 1 week, after complete T3 SCI in rats. Additionally, at 1 month post injury, T3 SCI rats exhibited nonfasting serum hypertriglyceridemia, a result obtained using both standard clinical methods and a home cholesterol monitoring device (CardioChek). Interestingly, at 1 month post injury, rats with complete T10 SCI did not show an increase in either visceral adiposity or serum triglyceride levels. The fact that complete high-thoracic SCI disrupts lipid metabolism and perturbs fat storage in the subacute period, while low-thoracic SCI does not, suggests that differences in descending sympathetic control of adipose tissue might play a role in these changes. These results provide the first evidence of cardiometabolic risk factors in experimental animals with SCI, and are a starting point for investigations of the etiology of obesity and metabolic dysfunctions that often accompany SCI.


Asunto(s)
Enfermedades Cardiovasculares/etiología , Enfermedades Cardiovasculares/metabolismo , Trastornos del Metabolismo de los Lípidos/etiología , Trastornos del Metabolismo de los Lípidos/metabolismo , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/metabolismo , Animales , Enfermedades del Sistema Nervioso Autónomo/complicaciones , Enfermedades del Sistema Nervioso Autónomo/fisiopatología , Enfermedades Cardiovasculares/fisiopatología , Modelos Animales de Enfermedad , Disección , Hiperlipidemias/etiología , Hiperlipidemias/metabolismo , Hiperlipidemias/fisiopatología , Grasa Intraabdominal/inervación , Grasa Intraabdominal/metabolismo , Grasa Intraabdominal/fisiopatología , Metabolismo de los Lípidos/fisiología , Trastornos del Metabolismo de los Lípidos/fisiopatología , Imagen por Resonancia Magnética , Masculino , Ratas , Ratas Wistar , Factores de Riesgo , Traumatismos de la Médula Espinal/fisiopatología , Triglicéridos/sangre
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