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1.
Curr Oncol ; 31(1): 447-461, 2024 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-38248115

RESUMO

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.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Estudos de Coortes , Estudos Retrospectivos , Neoplasias Pulmonares/tratamento farmacológico , Alberta , Atenção à Saúde
3.
J Neurotrauma ; 38(3): 309-321, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32940126

RESUMO

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.


Assuntos
Doenças do Sistema Nervoso Autônomo/epidemiologia , Pressão Sanguínea/fisiologia , Doenças Cardiovasculares/epidemiologia , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/fisiopatologia , Doenças do Sistema Nervoso Autônomo/diagnóstico , Doenças do Sistema Nervoso Autônomo/fisiopatologia , Barorreflexo/fisiologia , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/fisiopatologia , Eletrocardiografia , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
4.
Spinal Cord ; 58(4): 430-440, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31767947

RESUMO

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.


Assuntos
Disreflexia Autonômica/etiologia , Disreflexia Autonômica/prevenção & controle , Defecação , Lidocaína/efeitos adversos , Lubrificantes/efeitos adversos , Guias de Prática Clínica como Assunto , Traumatismos da Medula Espinal/complicações , Adulto , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Lidocaína/administração & dosagem , Lubrificantes/administração & dosagem , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
5.
Chron Respir Dis ; 16: 1479973119872979, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31526037

RESUMO

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.


Assuntos
Limitação da Mobilidade , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Índice de Gravidade de Doença , Doença Aguda , Idoso , Progressão da Doença , Dispneia/etiologia , Metabolismo Energético , Estudos de Viabilidade , Feminino , Frequência Cardíaca , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Oxigenoterapia , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/terapia , Qualidade de Vida , Taxa Respiratória , Teste de Caminhada , Velocidade de Caminhada
6.
J Neurotrauma ; 35(9): 1091-1105, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29239268

RESUMO

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.


Assuntos
Disreflexia Autonômica/etiologia , Disreflexia Autonômica/psicologia , Intestino Neurogênico/etiologia , Intestino Neurogênico/psicologia , Traumatismos da Medula Espinal/complicações , Atividades Cotidianas , Adulto , Idoso , Idoso de 80 Anos ou mais , Gerenciamento Clínico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Intestino Neurogênico/terapia , Qualidade de Vida , Inquéritos e Questionários , Adulto Jovem
7.
PLoS One ; 12(6): e0180195, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28666000

RESUMO

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).


Assuntos
Sistema Cardiovascular/fisiopatologia , Postura , Traumatismos da Medula Espinal/fisiopatologia , Cadeiras de Rodas , Estudos de Casos e Controles , Humanos
8.
J Vis Exp ; (73): e4315, 2013 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-23542558

RESUMO

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.


Assuntos
Intolerância Ortostática/diagnóstico , Intolerância Ortostática/fisiopatologia , Teste da Mesa Inclinada/instrumentação , Teste da Mesa Inclinada/métodos , Pressão Sanguínea/fisiologia , Dióxido de Carbono/metabolismo , Eletrocardiografia/métodos , Feminino , Humanos , Oxigênio/metabolismo , Pressão Parcial , Síncope/diagnóstico , Síncope/fisiopatologia
9.
Front Physiol ; 3: 257, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22934013

RESUMO

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.

10.
J Neurotrauma ; 29(8): 1638-49, 2012 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-22260380

RESUMO

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.


Assuntos
Vias Autônomas/fisiopatologia , Pressão Sanguínea/fisiologia , Sistema Cardiovascular/fisiopatologia , Frequência Cardíaca/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Animais , Disreflexia Autonômica/fisiopatologia , Hipotensão Ortostática/fisiopatologia , Masculino , Ratos , Ratos Wistar
11.
Spine J ; 10(12): 1108-17, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21094471

RESUMO

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.


Assuntos
Disreflexia Autonômica/complicações , Endotélio Vascular/fisiopatologia , Traumatismos da Medula Espinal/complicações , Doenças Vasculares/etiologia , Acetilcolina/farmacologia , Análise de Variância , Animais , Disreflexia Autonômica/fisiopatologia , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Relação Dose-Resposta a Droga , Endotélio Vascular/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Frequência Cardíaca/fisiologia , Masculino , Miografia , Fenilefrina/farmacologia , Ratos , Ratos Wistar , Traumatismos da Medula Espinal/fisiopatologia , Vértebras Torácicas , Doenças Vasculares/fisiopatologia , Vasoconstritores/farmacologia , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologia
12.
J Neurotrauma ; 27(9): 1709-22, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20597687

RESUMO

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.


Assuntos
Bem-Estar do Animal , Modelos Animais de Doenças , Abrigo para Animais , Ciência dos Animais de Laboratório/métodos , Traumatismos da Medula Espinal/terapia , Bem-Estar do Animal/normas , Animais , Abrigo para Animais/normas , Masculino , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/terapia , Ratos , Ratos Wistar , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/reabilitação , Vértebras Torácicas
13.
PLoS One ; 5(5): e10872, 2010 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-20531934

RESUMO

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.


Assuntos
Neurônios/metabolismo , Organelas/metabolismo , Sistema Nervoso Simpático/citologia , Animais , Citoesqueleto/metabolismo , Feminino , Gânglios/ultraestrutura , Masculino , Neurônios/ultraestrutura , Organelas/ultraestrutura , Proteínas/metabolismo , Ratos , Ratos Long-Evans , Ratos Sprague-Dawley , Frações Subcelulares/metabolismo , Sistema Nervoso Simpático/ultraestrutura
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