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1.
BMJ Mil Health ; 2023 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-37172981

RESUMEN

INTRODUCTION: Identifying barriers to care in veteran populations is critical, as veterans face increased social isolation, relationship strains and financial insecurities. For Canadian veterans experiencing barriers to accessing healthcare, telehealth may be a promising alternative with comparable effectiveness to in-person services; however, the potential benefits and limitations of telehealth require further examination to determine its long-term utility, and to inform health policy and planning. The goal of the present research was to identify predictors and barriers to telehealth usage in Canadian veterans in the context of the COVID-19 pandemic. METHODS: Data were drawn from baseline data of a longitudinal survey examining the psychological functioning of Canadian veterans during the COVID-19 pandemic. Participants were 1144 Canadian veterans aged 18-93 years (Mage=56.24, SD=12.92; 77.4% men). We assessed reported telehealth use (ie, for mental healthcare, physical healthcare), healthcare access (ie, difficulty accessing care, avoidance of care) and mental health and stress since the beginning of the COVID-19 pandemic, sociodemographic variables and open-ended responses about telehealth experiences. RESULTS: Findings suggest that sociodemographic factors and previous telehealth use were significantly associated with telehealth use during the COVID-19 pandemic. Qualitative evidence highlighted both the benefits (eg, reducing barriers of access) and drawbacks (eg, not all services can be delivered) of telehealth services. CONCLUSIONS: This paper provided a deeper understanding of Canadian veterans' experiences with accessing telehealth care during the COVID-19 pandemic. While for some, the use of telehealth mitigated perceived barriers (eg, safety concerns of leaving home), others felt that not all health services could be appropriately carried out through telehealth. Altogether, findings support the use of telehealth services in increasing care accessibility for Canadian veterans. Continued use of quality telehealth services may be a valuable form of care that extends the reach of healthcare professionals.

2.
Space Sci Rev ; 218(4): 35, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35664862

RESUMEN

The Voyager spacecraft have left the heliosphere and entered the interstellar medium, making the first observations of the termination shock, heliosheath, and heliopause. New Horizons is observing the solar wind in the outer heliosphere and making the first direct observations of solar wind pickup ions. This paper reviews the observations of the solar wind plasma and magnetic fields throughout the heliosphere and in the interstellar medium.

3.
BMJ Mil Health ; 2022 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-35705259

RESUMEN

Moral injury is a relatively new, but increasingly studied, construct in the field of mental health, particularly in relation to current and ex-serving military personnel. Moral injury refers to the enduring psychosocial, spiritual or ethical harms that can result from exposure to high-stakes events that strongly clash with one's moral beliefs. There is a pressing need for further research to advance understanding of the nature of moral injury; its relationship to mental disorders such as posttraumatic stress disorder and depression; triggering events and underpinning mechanisms; and prevalence, prevention and treatment. In the meantime, military leaders have an immediate need for guidance on how moral injury should be addressed and, where possible, prevented. Such guidance should be theoretically sound, evidence-informed and ethically responsible. Further, the implementation of any practice change based on the guidance should contribute to the advancement of science through robust evaluation. This paper draws together current research on moral injury, best-practice approaches in the adjacent field of psychological resilience, and principles of effective implementation and evaluation. This research is combined with the military and veteran mental health expertise of the authors to provide guidance on the design, implementation and evaluation of moral injury interventions in the military. The paper discusses relevant training in military ethical practice, as well as the key roles leaders have in creating cohesive teams and having frank discussions about the moral and ethical challenges that military personnel face.

4.
Space Sci Rev ; 218(4): 34, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35645425

RESUMEN

Our understanding of the interaction of the large-scale heliosphere with the local interstellar medium (LISM) has undergone a profound change since the very earliest analyses of the problem. In part, the revisions have been a consequence of ever-improving and widening observational results, especially those that identified the entrance of interstellar material and gas into the heliosphere. Accompanying these observations was the identification of the basic underlying physics of how neutral interstellar gas and interstellar charged particles of different energies, up to and including interstellar dust grains, interacted with the temporal flows and electromagnetic fields of the heliosphere. The incorporation of these various basic effects into global models of the interaction, whether focused on neutral interstellar gas and pickup ions, energetic particles such as anomalous and galactic cosmic rays, or magnetic fields and large-scale flows, has profoundly changed our view of how the heliosphere and LISM interact. This article presents a brief history of the conceptual and observation evolution of our understanding of the interaction of the heliosphere with the local interstellar medium, up until approximately 1996.

5.
Space Sci Rev ; 218(4): 27, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35574274

RESUMEN

Large-scale disturbances generated by the Sun's dynamics first propagate through the heliosphere, influence the heliosphere's outer boundaries, and then traverse and modify the very local interstellar medium (VLISM). The existence of shocks in the VLISM was initially suggested by Voyager observations of the 2-3 kHz radio emissions in the heliosphere. A couple of decades later, both Voyagers crossed the definitive edge of our heliosphere and became the first ever spacecraft to sample interstellar space. Since Voyager 1's entrance into the VLISM, it sampled electron plasma oscillation events that indirectly measure the medium's density, increasing as it moves further away from the heliopause. Some of the observed electron oscillation events in the VLISM were associated with the local heliospheric shock waves. The observed VLISM shocks were very different than heliospheric shocks. They were very weak and broad, and the usual dissipation via wave-particle interactions could not explain their structure. Estimates of the dissipation associated with the collisionality show that collisions can determine the VLISM shock structure. According to theory and models, the existence of a bow shock or wave in front of our heliosphere is still an open question as there are no direct observations yet. This paper reviews the outstanding observations recently made by the Voyager 1 and 2 spacecraft, and our current understanding of the properties of shocks/waves in the VLISM. We present some of the most exciting open questions related to the VLISM and shock waves that should be addressed in the future.

6.
Nature ; 576(7786): 228-231, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31802006

RESUMEN

The prediction of a supersonic solar wind1 was first confirmed by spacecraft near Earth2,3 and later by spacecraft at heliocentric distances as small as 62 solar radii4. These missions showed that plasma accelerates as it emerges from the corona, aided by unidentified processes that transport energy outwards from the Sun before depositing it in the wind. Alfvénic fluctuations are a promising candidate for such a process because they are seen in the corona and solar wind and contain considerable energy5-7. Magnetic tension forces the corona to co-rotate with the Sun, but any residual rotation far from the Sun reported until now has been much smaller than the amplitude of waves and deflections from interacting wind streams8. Here we report observations of solar-wind plasma at heliocentric distances of about 35 solar radii9-11, well within the distance at which stream interactions become important. We find that Alfvén waves organize into structured velocity spikes with duration of up to minutes, which are associated with propagating S-like bends in the magnetic-field lines. We detect an increasing rotational component to the flow velocity of the solar wind around the Sun, peaking at 35 to 50 kilometres per second-considerably above the amplitude of the waves. These flows exceed classical velocity predictions of a few kilometres per second, challenging models of circulation in the corona and calling into question our understanding of how stars lose angular momentum and spin down as they age12-14.

7.
BMC Psychiatry ; 17(1): 211, 2017 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-28583100

RESUMEN

BACKGROUND: Past research on the association between insomnia and suicidal ideation (SI) has produced mixed findings. The current study explored the relationship between insomnia, SI, and past-year mental health status among a large Canadian Forces (CF) sample. METHOD: Data was obtained from the 2013 Canadian Forces Mental Health Survey (CFMHS), and included a large representative sample of Canadian Regular Forces personnel (N = 6700). A series of univariate logistic regressions were conducted to test individual associations between past-year mental health status, insomnia, and potential confounds and SI. Mental health status included three groups: 0, 1, or two or more probable diagnoses of posttraumatic stress disorder (PTSD), major depressive disorder (MDD), generalized anxiety disorder (GAD), panic disorder (PD) and alcohol abuse/dependence. Stepwise multivariate logistic regression was used to assess the relationship between insomnia and SI with mental health status as a moderator. RESULTS: 40.8% of respondents reported experiencing insomnia. Both insomnia and number of mental health conditions incrementally increased the risk of SI. However, past-year mental health status was a significant moderator of this relationship, such that for CF personnel with either no (AOR = 1.61, 1.37-1.89) or only one past-year mental health condition (AOR = 1.39, 1.12-1.73), an incremental increase in insomnia was associated with an increased likelihood of SI. However, in personnel with two or more past-year mental health disorders, insomnia was no longer significantly associated with SI (AOR = 1.04, 0.81-1.33). CONCLUSIONS: Insomnia significantly increased the odds of SI, but only among individuals with no or one mental health condition. Findings highlight the importance of assessing insomnia among CF members in order to further suicide prevention efforts.


Asunto(s)
Personal Militar/psicología , Enfermedades Profesionales/psicología , Trastornos del Inicio y del Mantenimiento del Sueño/psicología , Ideación Suicida , Adolescente , Adulto , Alcoholismo/psicología , Trastornos de Ansiedad/psicología , Canadá , Trastorno Depresivo Mayor/psicología , Femenino , Encuestas Epidemiológicas , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Trastorno de Pánico/psicología , Factores de Riesgo , Trastornos por Estrés Postraumático/psicología , Adulto Joven
8.
Eur Heart J Acute Cardiovasc Care ; 5(1): 96-7, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25452560

RESUMEN

A woman with palliative breast cancer presents with dyspnoea and is noted to have an unusual electrocardiogram, with an alternating electrical axis observed. Subsequent echocardiogram demonstrates the classical findings of a large pericardial effusion causing 'electrical alternans' aptly illustrating why this rare phenomenon occurs.


Asunto(s)
Disnea/diagnóstico , Derrame Pericárdico/diagnóstico , Neoplasias de la Mama/fisiopatología , Neoplasias de la Mama/radioterapia , Disnea/etiología , Ecocardiografía/métodos , Electrocardiografía/métodos , Femenino , Humanos , Persona de Mediana Edad , Derrame Pericárdico/cirugía , Pericardiocentesis/métodos
9.
Int J Obes (Lond) ; 40(2): 305-11, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26278005

RESUMEN

BACKGROUND/OBJECTIVES: Breakfast omission is positively associated with obesity and increased risk of disease. However, little is known about the acute effects of extended morning fasting upon subsequent energy intake and associated metabolic/regulatory factors in obese adults. SUBJECTS/METHODS: In a randomised cross-over design, 24 obese men (n=8) and women (n=16) extended their overnight fast by omitting breakfast consumption or ingesting a typical carbohydrate-rich breakfast of 2183±393 kJ (521±94 kcal), before an ad libitum pasta lunch 3 h later. Blood samples were obtained throughout the day until 3 h post lunch and analysed for hormones implicated in appetite regulation, along with metabolic outcomes and subjective appetite measures. RESULTS: Lunch intake was unaffected by extended morning fasting (difference=218 kJ, 95% confidence interval -54 kJ, 490 kJ; P=0.1) resulting in lower total intake in the fasting trial (difference=-1964 kJ, 95% confidence interval -1645 kJ, -2281 kJ; P<0.01). Systemic concentrations of peptide tyrosine-tyrosine and leptin were lower during the afternoon following morning fasting (P⩽0.06). Plasma-acylated ghrelin concentrations were also lower following the ad libitum lunch in the fasting trial (P<0.05) but this effect was not apparent for total ghrelin (P⩾0.1). Serum insulin concentrations were greater throughout the afternoon in the fasting trial (P=0.05), with plasma glucose also greater 1 h after lunch (P<0.01). Extended morning fasting did not result in greater appetite ratings after lunch, with some tendency for lower appetite 3 h post lunch (P=0.09). CONCLUSIONS: We demonstrate for the first time that, in obese adults, extended morning fasting does not cause compensatory intake during an ad libitum lunch nor does it increase appetite during the afternoon. Morning fasting reduced satiety hormone responses to a subsequent lunch meal but counterintuitively also reduced concentrations of the appetite-stimulating hormone-acylated ghrelin during the afternoon relative to lunch consumed after breakfast.


Asunto(s)
Glucemia/metabolismo , Ingestión de Energía , Ghrelina/metabolismo , Leptina/metabolismo , Obesidad/metabolismo , Adulto , Regulación del Apetito , Desayuno , Estudios Cruzados , Carbohidratos de la Dieta , Dipéptidos , Inglaterra/epidemiología , Ayuno , Femenino , Humanos , Almuerzo , Masculino , Persona de Mediana Edad , Obesidad/fisiopatología , Obesidad/prevención & control , Periodo Posprandial , Reproducibilidad de los Resultados , Respuesta de Saciedad , Factores de Tiempo
10.
Am Surg ; 80(9): 910-3, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25197880

RESUMEN

Damage control surgery involves an abbreviated operation followed by resuscitation with planned re-exploration. Damage control techniques can be used in thoracic trauma but has been infrequently reported. Our goal is to describe our experience with the use of damage control techniques in treating thoracic trauma. A retrospective analysis of all patients undergoing damage control thoracic surgery related to trauma from January 1, 2010, to January 1, 2013, at University of Louisville Hospital, a Level I trauma center. Variables studied included injury characteristics, Injury Severity Score, surgery performed, duration of packing, length of stay (LOS), ventilator days, transfusion requirements, complications, and mortality. Twenty-five patients underwent damage control surgery in the chest with packing, temporary closure, and planned re-exploration after stabilization. Seventeen patients underwent anterolateral thoracotomy, and eight patients underwent sternotomy. The mean LOS and duration of temporary packing was 20.6 and 1.4 days in the thoracotomy group, respectively, and 19.5 and 1 day in the sternotomy group, respectively. The overall mortality rate was 40 per cent, 35 per cent in the thoracotomy group and 50 per cent in the sternotomy group. Like in severe abdominal trauma, damage control techniques can be used in the management of severe thoracic injuries with acceptable results.


Asunto(s)
Resucitación/métodos , Traumatismos Torácicos/cirugía , Heridas no Penetrantes/cirugía , Heridas Penetrantes/cirugía , Adulto , Femenino , Humanos , Puntaje de Gravedad del Traumatismo , Tiempo de Internación/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Neumonía Asociada al Ventilador/etiología , Estudios Retrospectivos , Esternotomía , Tasa de Supervivencia , Traumatismos Torácicos/mortalidad , Toracotomía/métodos , Traqueostomía/efectos adversos , Heridas no Penetrantes/mortalidad , Heridas Penetrantes/mortalidad , Adulto Joven
11.
Lab Anim ; 47(4): 291-300, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23836849

RESUMEN

In vivo assessment of ventricular function in rodents has largely been restricted to transthoracic echocardiography (TTE). However 1.5 T cardiac magnetic resonance (CMR) and transoesophageal echocardiography (TOE) have emerged as possible alternatives. Yet, to date, no study has systematically assessed these three imaging modalities in determining ejection fraction (EF) in rats. Twenty rats underwent imaging four weeks after surgically-induced myocardial infarction. CMR was performed on a 1.5 T scanner, TTE was conducted using a 9.2 MHz transducer and TOE was performed with a 10 MHz intracardiac echo catheter. Correlation between the three techniques for EF determination and analysis reproducibility was assessed. Moderate-strong correlation was observed between the three modalities; the greatest between CMR and TOE (intraclass correlation coefficient (ICC) = 0.89), followed by TOE and TTE (ICC = 0.70) and CMR and TTE (ICC = 0.63). Intra- and inter-observer variations were excellent with CMR (ICC = 0.99 and 0.98 respectively), very good with TTE (0.90 and 0.89) and TOE (0.87 and 0.84). Each modality is a viable option for evaluating ventricular function in rats, however the high image quality and excellent reproducibility of CMR offers distinct advantages even at 1.5 T with conventional coils and software.


Asunto(s)
Ecocardiografía Transesofágica/veterinaria , Ecocardiografía/veterinaria , Ventrículos Cardíacos/patología , Imagen por Resonancia Magnética/veterinaria , Función Ventricular , Animales , Ventrículos Cardíacos/diagnóstico por imagen , Masculino , Ratas , Ratas Sprague-Dawley , Reproducibilidad de los Resultados
12.
Am Surg ; 78(4): 398-402, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22472394

RESUMEN

Flail chest represents a severe injury with mortality historically reported at up to 30 per cent. Although management has changed dramatically over the past several decades, there is a paucity of large recent series. With Institutional Review Board approval, a retrospective review of all patients with flail chest admitted from January 2001 through May 2010 was undertaken. Patient demographics, outcomes, and cause of death were specifically analyzed with univariate and multivariate analysis. There were 164 patients at a median age of 51.4 years. Head injury and pulmonary contusion were present in 67 (40.8%) and 125 (77%), respectively. Pneumonia developed in 72 (43.9%). There were 41 deaths (25%), for which flail chest contributed to 15 (9.1%). Of the patients with flail chest-related death, the majority (n = 10 [66.7%]) died within 48 hours of presentation. There were only five deaths (3.0%) related to flail chest after 48 hours. Multivariate analysis of ventilator dependency revealed requirement for laparotomy (P = 0.019) or tracheostomy (P < 0.0001) and pneumonia (P = 0.0002) as significant. Pneumonia was the most significant independent predictor of overall (P < 0.0001) and intensive care unit length of stay (P < 0.0001). The mortality associated with flail chest has greatly improved; however, the rate of pneumonia remains high. Further efforts at pneumonia prevention are thus warranted.


Asunto(s)
Tórax Paradójico/mortalidad , Adulto , Anciano , Femenino , Tórax Paradójico/complicaciones , Tórax Paradójico/terapia , Humanos , Kentucky/epidemiología , Tiempo de Internación/estadística & datos numéricos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Neumonía/etiología , Estudios Retrospectivos , Factores de Riesgo , Resultado del Tratamiento
13.
Heart Lung Circ ; 21(2): 113-6, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21852191

RESUMEN

Coronary spasm is increasingly recognised as an important aetiological mechanism causing myocardial ischaemia. Occasionally cases present with evidence of ST segment elevation myocardial infarction, usually secondary to spasm confined to a solitary coronary artery. We present the rare and life-threatening case of severe coronary spasm afflicting all three major epicardial arteries simultaneously. It describes the difficult emergency scenario and ongoing management dilemmas encountered by physicians confronted with multivessel coronary spasm. Moreover we discuss the malignant prognosis associated with this ailment and describe the potential insights provided by cardiac magnetic resonance imaging that might identify those at greatest risk after the index event.


Asunto(s)
Angiografía Coronaria/métodos , Vasoespasmo Coronario/diagnóstico , Ecocardiografía/métodos , Electrocardiografía/métodos , Imagen por Resonancia Cinemagnética/métodos , Adulto , Diagnóstico Diferencial , Resultado Fatal , Femenino , Humanos
15.
Vaccine ; 29(39): 6728-35, 2011 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-21219978

RESUMEN

We have developed a rapid, reliable, and sensitive quantitative flow cytometric assay to measure the in vitro potency and stability of DNA vaccines to be delivered either by particle-mediated epidermal delivery (PMED) or by electroporation. The method involves transfecting cells with test DNA and comparing the measured antigen expression to that generated with expression from known quantities of reference material DNA. The assay was adapted for performance under Good Laboratory Practice (GLP) guidelines and was successfully utilized to perform potency testing in support of a Phase I study for two hantavirus DNA vaccines delivered by gene gun. The results from the potency assays conducted over a 24-month period using this method proved to be highly reproducible with high signal-to-noise ratios. The assay was also adapted to assess the in vitro potency and stability of a DNA vaccine for Venezuelan equine encephalitis virus that will be delivered by electroporation. Our results indicate that this assay can be readily applied to support potency and stability testing of numerous DNA vaccines delivered by various methods, including multiagent vaccines.


Asunto(s)
Citometría de Flujo/métodos , Orthohantavirus/inmunología , Vacunas de ADN/inmunología , Animales , Antígenos Virales/inmunología , Biolística , Células COS , Chlorocebus aethiops , Sistemas de Liberación de Medicamentos/métodos , Estabilidad de Medicamentos , Electroforesis en Gel de Agar , Electroporación , Virus de la Encefalitis Equina Venezolana/genética , Virus de la Encefalitis Equina Venezolana/inmunología , Citometría de Flujo/instrumentación , Orthohantavirus/genética , Humanos , Plásmidos/genética , Plásmidos/metabolismo , Estándares de Referencia , Reproducibilidad de los Resultados , Transfección , Vacunas de ADN/administración & dosificación , Vacunas Virales/administración & dosificación , Vacunas Virales/inmunología
16.
Nature ; 462(7276): 1036-8, 2009 Dec 24.
Artículo en Inglés | MEDLINE | ID: mdl-20033043

RESUMEN

Magnetic fields play an important (sometimes dominant) role in the evolution of gas clouds in the Galaxy, but the strength and orientation of the field in the interstellar medium near the heliosphere has been poorly constrained. Previous estimates of the field strength range from 1.8-2.5 microG and the field was thought to be parallel to the Galactic plane or inclined by 38-60 degrees (ref. 2) or 60-90 degrees (ref. 3) to this plane. These estimates relied either on indirect observational inferences or modelling in which the interstellar neutral hydrogen was not taken into account. Here we report measurements of the deflection of the solar wind plasma flows in the heliosheath to determine the magnetic field strength and orientation in the interstellar medium. We find that the field strength in the local interstellar medium is 3.7-5.5 microG. The field is tilted approximately 20-30 degrees from the interstellar medium flow direction (resulting from the peculiar motion of the Sun in the Galaxy) and is at an angle of about 30 degrees from the Galactic plane. We conclude that the interstellar medium field is turbulent or has a distortion in the solar vicinity.

17.
Nature ; 454(7200): 75-7, 2008 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-18596803

RESUMEN

A transition between the supersonic solar wind and the subsonic heliosheath was observed by Voyager 1, but the expected termination shock was not seen owing to a gap in the telemetry. Here we report observations of the magnetic field structure and dynamics of the termination shock, made by Voyager 2 on 31 August-1 September 2007 at a distance of 83.7 au from the Sun (1 au is the Earth-Sun distance). A single crossing of the shock was expected, with a boundary that was stable on a timescale of several days. But the data reveal a complex, rippled, quasi-perpendicular supercritical magnetohydrodynamic shock of moderate strength undergoing reformation on a scale of a few hours. The observed structure suggests the importance of ionized interstellar atoms ('pickup protons') at the shock.

18.
Phys Rev Lett ; 97(13): 131801, 2006 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-17026025

RESUMEN

An experimental search for an electric dipole moment (EDM) of the neutron has been carried out at the Institut Laue-Langevin, Grenoble. Spurious signals from magnetic-field fluctuations were reduced to insignificance by the use of a cohabiting atomic-mercury magnetometer. Systematic uncertainties, including geometric-phase-induced false EDMs, have been carefully studied. The results may be interpreted as an upper limit on the neutron EDM of |d(n)|< 2.9 x 10(-26)e cm (90% C.L.).

19.
Fiziol Cheloveka ; 30(2): 86-92, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15150979

RESUMEN

AIMS: Velocity changes in the solar wind, recorded by satellite (IMP8 and Wind) are characterized by a solar cycle dependent approximately 1.3-year component. The presence of any approximately 1.3-year component in human blood pressure (BP) and heart rate (HR) and in mortality from myocardial infarction (MI) is tested and its relative prominence compared to the 1.0-year variation. MATERIALS AND METHODS: Around the clock manual or automatic BP and HR measurements from four subjects recorded over 5 to 35 years and a 29-year record of mortality from MI in Minnesota were analyzed by linear-nonlinear rhythmometry. Point and 95% confidence interval (CI) estimates were obtained for the approximately 1.3-year period and amplitude. The latter is compared with the 1.0-year amplitude for BP and HR records concurrent to the solar data provided by one of us (JDR). RESULTS: An approximately 1.3-year component is resolved nonlinearly for MI, with a period of 1.23 (95% CI: 1.21; 1.26) year. This component was invariably validated with statistical significance for BP and HR by linear rhythmometry. Nonlinearly, the 95% CI for the 1.3-year amplitude did not overlap zero in 11 of the 12 BP and HR series. Given the usually strong synchronizing role of light and temperature, it is surprising that 5 of the 12 cardiovascular series had a numerically larger amplitude of the 1.3-year versus the precise 1.0-year component. The beating of the approximately 1.3-year and 1.0-year components was shown by gliding spectra on actual and simulated data. DISCUSSION AND CONCLUSION: The shortest 5-year record (1998-2003) revealed an approximately 1.3-year component closer to the solar wind speed period characterizing the entire available record (1994-2003) than that for the concurrent 5-year span. Physiological variables may resonate with non-photic environmental cycles that may have entered the genetic code during evolution.


Asunto(s)
Presión Sanguínea/fisiología , Fenómenos Cronobiológicos , Frecuencia Cardíaca/fisiología , Infarto del Miocardio/mortalidad , Actividad Solar , Adulto , Anciano , Humanos , Estudios Longitudinales , Persona de Mediana Edad , Minnesota/epidemiología , Dinámicas no Lineales , Periodicidad , Viento
20.
J Endod ; 27(10): 620-3, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11592491

RESUMEN

Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter that is elevated in inflamed human dental pulp. Because GABA agonists are antihyperalgesic in other tissue, it is possible that GABA agonists have similar effects in dental pulp assuming that this tissue contains GABA receptors. We tested the hypothesis that dental pulp contains functional GABA(B) receptors using a GTPgamma35S binding assay. This is a functional assay because GTPgamma35S will be bound to cell membranes only when activation of metabotropic receptors has lead to binding and activation of their associated G(alpha)-proteins via release of GDP and binding of the GTPgamma35S. Baclofen, a GABA(B) agonist, evoked GTPgamma35S binding in both human and bovine dental pulp. This was mediated by the GABA(B) receptor because it was blocked by the selective antagonist phaclofen in both tissues. The presence of GABA and its receptor, GABA(B), suggests that this system may be relevant in the production or management of endodontic pain.


Asunto(s)
Baclofeno/análogos & derivados , Pulpa Dental/metabolismo , Receptores de GABA-B/metabolismo , Ácido gamma-Aminobutírico/metabolismo , Animales , Baclofeno/farmacología , Biotransformación , Bovinos , Agonistas del GABA/farmacología , Antagonistas del GABA/farmacología , Agonistas de Receptores GABA-B , Antagonistas de Receptores de GABA-B , Proteínas de Unión al GTP/metabolismo , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Humanos , Radiofármacos , Receptores Opioides/metabolismo , Estadísticas no Paramétricas , Radioisótopos de Azufre
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